Review feedback from @copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.github/workflows/reusable-build-test-config.yml

@@ -101,7 +101,7 @@ jobs:
     steps:
       - name: Cleanup workspace (macOS and Windows)
         if: ${{ runner.os == 'macOS' || runner.os == 'Windows' }}
-        uses: XRPLF/actions/cleanup-workspace@c7d9ce5ebb03c752a354889ecd870cadfc2b1cd4
+        uses: XRPLF/actions/cleanup-workspace@cf0433aa74563aead044a1e395610c96d65a37cf
 
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

.github/workflows/upload-conan-deps.yml

@@ -64,7 +64,7 @@ jobs:
     steps:
       - name: Cleanup workspace (macOS and Windows)
         if: ${{ runner.os == 'macOS' || runner.os == 'Windows' }}
-        uses: XRPLF/actions/cleanup-workspace@c7d9ce5ebb03c752a354889ecd870cadfc2b1cd4
+        uses: XRPLF/actions/cleanup-workspace@cf0433aa74563aead044a1e395610c96d65a37cf
 
       - name: Checkout repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

cspell.config.yaml

@@ -71,14 +71,12 @@ words:
   - coldwallet
   - compr
   - conanfile
-  - cppcoro
   - conanrun
   - confs
   - connectability
   - coro
   - coros
   - cowid
-  - cppcoro
   - cryptocondition
   - cryptoconditional
   - cryptoconditions
@@ -101,14 +99,11 @@ words:
   - endmacro
   - exceptioned
   - Falco
-  - fcontext
   - finalizers
   - firewalled
-  - fcontext
   - fmtdur
   - fsanitize
   - funclets
-  - gantt
   - gcov
   - gcovr
   - ghead
@@ -190,7 +185,6 @@ words:
   - ostr
   - pargs
   - partitioner
-  - pratik
   - paychan
   - paychans
   - permdex
@@ -198,7 +192,6 @@ words:
   - permissioned
   - pointee
   - populator
-  - pratik
   - preauth
   - preauthorization
   - preauthorize
@@ -213,7 +206,6 @@ words:
   - queuable
   - Raphson
   - replayer
-  - repost
   - rerere
   - retriable
   - RIPD
@@ -244,7 +236,6 @@ words:
   - soci
   - socidb
   - sslws
-  - stackful
   - statsd
   - STATSDCOLLECTOR
   - stissue

include/xrpl/basics/Number.h

@@ -2,13 +2,19 @@
 
 #include <xrpl/beast/utility/instrumentation.h>
 
+#include <concepts>
 #include <cstdint>
 #include <functional>
 #include <limits>
 #include <optional>
 #include <ostream>
+#include <stdexcept>
 #include <string>
 
+#ifdef _MSC_VER
+#include <boost/multiprecision/cpp_int.hpp>
+#endif  // !defined(_MSC_VER)
+
 namespace xrpl {
 
 class Number;
@@ -16,18 +22,39 @@ class Number;
 std::string
 to_string(Number const& amount);
 
+/** Returns a rough estimate of log10(value).
+ *
+ * The return value is a pair (log, rem), where log is the estimated
+ * base-10 logarithm (roughly floor(log10(value))), and rem is value with
+ * all trailing 0s removed (i.e., divided by the largest power of 10 that
+ * evenly divides value). If rem is 1, then value is an exact power of ten, and
+ * log is the exact log10(value).
+ *
+ * This function only works for positive values.
+ */
+template <std::unsigned_integral T>
+constexpr std::pair<int, T>
+logTenEstimate(T value)
+{
+    int log = 0;
+    T remainder = value;
+    while (value >= 10)
+    {
+        if (value % 10 == 0)
+            remainder = remainder / 10;
+        value /= 10;
+        ++log;
+    }
+    return {log, remainder};
+}
+
 template <typename T>
 constexpr std::optional<int>
 logTen(T value)
 {
-    int log = 0;
-    while (value >= 10 && value % 10 == 0)
-    {
-        value /= 10;
-        ++log;
-    }
-    if (value == 1)
-        return log;
+    auto const est = logTenEstimate(value);
+    if (est.second == 1)
+        return est.first;
     return std::nullopt;
 }
 
@@ -41,12 +68,10 @@ isPowerOfTen(T value)
 /** MantissaRange defines a range for the mantissa of a normalized Number.
  *
  * The mantissa is in the range [min, max], where
- * * min is a power of 10, and
- * * max = min * 10 - 1.
  *
- * The mantissa_scale enum indicates whether the range is "small" or "large".
- * This intentionally restricts the number of MantissaRanges that can be
- * instantiated to two: one for each scale.
+ * The mantissa_scale enum indicates whether the range is "small" or
+ * "large".  This intentionally prevents the creation of any
+ * MantissaRanges representing other values.
  *
  * The "small" scale is based on the behavior of STAmount for IOUs. It has a min
  * value of 10^15, and a max value of 10^16-1. This was sufficient for
@@ -60,8 +85,8 @@ isPowerOfTen(T value)
  * "large" scale.
  *
  * The "large" scale is intended to represent all values that can be represented
- * by an STAmount - IOUs, XRP, and MPTs. It has a min value of 10^18, and a max
- * value of 10^19-1.
+ * by an STAmount - IOUs, XRP, and MPTs. It has a min value of 2^63/10+1
+ * (truncated), and a max value of 2^63-1.
  *
  * Note that if the mentioned amendments are eventually retired, this class
  * should be left in place, but the "small" scale option should be removed. This
@@ -73,25 +98,56 @@ struct MantissaRange
     enum mantissa_scale { small, large };
 
     explicit constexpr MantissaRange(mantissa_scale scale_)
-        : min(getMin(scale_)), max(min * 10 - 1), log(logTen(min).value_or(-1)), scale(scale_)
+        : max(getMax(scale_))
+        , min(computeMin(max))
+        , internalMin(getInternalMin(scale_, min))
+        , log(computeLog(min))
+        , scale(scale_)
     {
+        // Keep the error messages terse. Since this is constexpr, if any of these throw, it won't
+        // compile, so there's no real need to worry about runtime exceptions here.
+        if (min * 10 <= max)
+            throw std::out_of_range("Invalid mantissa range: min * 10 <= max");
+        if (max / 10 >= min)
+            throw std::out_of_range("Invalid mantissa range: max / 10 >= min");
+        if ((min - 1) * 10 > max)
+            throw std::out_of_range("Invalid mantissa range: (min - 1) * 10 > max");
+        // This is a little hacky
+        if ((max + 10) / 10 < min)
+            throw std::out_of_range("Invalid mantissa range: (max + 10) / 10 < min");
+        if (computeLog(internalMin) != log)
+            throw std::out_of_range("Invalid mantissa range: computeLog(internalMin) != log");
     }
 
-    rep min;
+    // Explicitly delete copy and move operations
+    MantissaRange(MantissaRange const&) = delete;
+    MantissaRange(MantissaRange&&) = delete;
+    MantissaRange&
+    operator=(MantissaRange const&) = delete;
+    MantissaRange&
+    operator=(MantissaRange&&) = delete;
+
     rep max;
+    rep min;
+    /* Used to determine if mantissas are in range, but have fewer digits than max.
+     *
+     * Unlike min, internalMin is always an exact power of 10, so a mantissa in the internal
+     * representation will always have a consistent number of digits.
+     */
+    rep internalMin;
     int log;
     mantissa_scale scale;
 
 private:
     static constexpr rep
-    getMin(mantissa_scale scale_)
+    getMax(mantissa_scale scale)
     {
-        switch (scale_)
+        switch (scale)
         {
             case small:
-                return 1'000'000'000'000'000ULL;
+                return 9'999'999'999'999'999ULL;
             case large:
-                return 1'000'000'000'000'000'000ULL;
+                return std::numeric_limits<std::int64_t>::max();
             default:
                 // Since this can never be called outside a non-constexpr
                 // context, this throw assures that the build fails if an
@@ -99,19 +155,59 @@ private:
                 throw std::runtime_error("Unknown mantissa scale");
         }
     }
+
+    static constexpr rep
+    computeMin(rep max)
+    {
+        return max / 10 + 1;
+    }
+
+    static constexpr rep
+    getInternalMin(mantissa_scale scale, rep min)
+    {
+        switch (scale)
+        {
+            case large:
+                return 1'000'000'000'000'000'000ULL;
+            default:
+                if (isPowerOfTen(min))
+                    return min;
+                throw std::runtime_error("Unknown/bad mantissa scale");
+        }
+    }
+
+    static constexpr rep
+    computeLog(rep min)
+    {
+        auto const estimate = logTenEstimate(min);
+        return estimate.first + (estimate.second == 1 ? 0 : 1);
+    }
 };
 
 // Like std::integral, but only 64-bit integral types.
 template <class T>
 concept Integral64 = std::is_same_v<T, std::int64_t> || std::is_same_v<T, std::uint64_t>;
 
+namespace detail {
+#ifdef _MSC_VER
+using uint128_t = boost::multiprecision::uint128_t;
+using int128_t = boost::multiprecision::int128_t;
+#else   // !defined(_MSC_VER)
+using uint128_t = __uint128_t;
+using int128_t = __int128_t;
+#endif  // !defined(_MSC_VER)
+
+template <class T>
+concept UnsignedMantissa = std::is_unsigned_v<T> || std::is_same_v<T, uint128_t>;
+}  // namespace detail
+
 /** Number is a floating point type that can represent a wide range of values.
  *
  * It can represent all values that can be represented by an STAmount -
  * regardless of asset type - XRPAmount, MPTAmount, and IOUAmount, with at least
  * as much precision as those types require.
  *
- * ---- Internal Representation ----
+ * ---- Internal Operational Representation ----
  *
  * Internally, Number is represented with three values:
  *   1. a bool sign flag,
@@ -126,15 +222,21 @@ concept Integral64 = std::is_same_v<T, std::int64_t> || std::is_same_v<T, std::u
  *
  * A non-zero mantissa is (almost) always normalized, meaning it and the
  * exponent are grown or shrunk until the mantissa is in the range
- * [MantissaRange.min, MantissaRange.max].
+ * [MantissaRange.internalMin, MantissaRange.internalMin * 10 - 1].
+ *
+ * This internal representation is only used during some operations to ensure
+ * that the mantissa is a known, predictable size. The class itself stores the
+ * values using the external representation described below.
  *
  * Note:
  *   1. Normalization can be disabled by using the "unchecked" ctor tag. This
  *      should only be used at specific conversion points, some constexpr
  *      values, and in unit tests.
- *   2. The max of the "large" range, 10^19-1, is the largest 10^X-1 value that
- *      fits in an unsigned 64-bit number. (10^19-1 < 2^64-1 and
- *      10^20-1 > 2^64-1). This avoids under- and overflows.
+ *   2. Unlike MantissaRange.min, internalMin is always an exact power of 10,
+ *      so a mantissa in the internal representation will always have a
+ *      consistent number of digits.
+ *   3. The functions toInternal() and fromInternal() are used to convert
+ *      between the two representations.
  *
  * ---- External Interface ----
  *
@@ -147,13 +249,12 @@ concept Integral64 = std::is_same_v<T, std::int64_t> || std::is_same_v<T, std::u
  * represent the full range of valid XRP and MPT integer values accurately.
  *
  * Note:
- *   1. 2^63-1 is between 10^18 and 10^19-1, which are the limits of the "large"
- *      mantissa range.
+ *   1. The "large" mantissa range is (2^63/10+1) to 2^63-1. 2^63-1 is between
+ *      10^18 and 10^19-1, and (2^63/10+1) is between 10^17 and 10^18-1. Thus,
+ *      the mantissa may have 18 or 19 digits. This value will be modified to
+ *      always have 19 digits before some operations to ensure consistency.
  *   2. The functions mantissa() and exponent() return the external view of the
- *      Number value, specifically using a signed 63-bit mantissa. This may
- *      require altering the internal representation to fit into that range
- *      before the value is returned. The interface guarantees consistency of
- *      the two values.
+ *      Number value, specifically using a signed 63-bit mantissa.
  *   3. Number cannot represent -2^63 (std::numeric_limits<std::int64_t>::min())
  *      as an exact integer, but it doesn't need to, because all asset values
  *      on-ledger are non-negative. This is due to implementation details of
@@ -208,8 +309,7 @@ class Number
     using rep = std::int64_t;
     using internalrep = MantissaRange::rep;
 
-    bool negative_{false};
-    internalrep mantissa_{0};
+    rep mantissa_{0};
     int exponent_{std::numeric_limits<int>::lowest()};
 
 public:
@@ -217,10 +317,6 @@ public:
     constexpr static int minExponent = -32768;
     constexpr static int maxExponent = 32768;
 
-    constexpr static internalrep maxRep = std::numeric_limits<rep>::max();
-    static_assert(maxRep == 9'223'372'036'854'775'807);
-    static_assert(-maxRep == std::numeric_limits<rep>::min() + 1);
-
     // May need to make unchecked private
     struct unchecked
     {
@@ -298,8 +394,7 @@ public:
     friend constexpr bool
     operator==(Number const& x, Number const& y) noexcept
     {
-        return x.negative_ == y.negative_ && x.mantissa_ == y.mantissa_ &&
-            x.exponent_ == y.exponent_;
+        return x.mantissa_ == y.mantissa_ && x.exponent_ == y.exponent_;
     }
 
     friend constexpr bool
@@ -313,8 +408,8 @@ public:
     {
         // If the two amounts have different signs (zero is treated as positive)
         // then the comparison is true iff the left is negative.
-        bool const lneg = x.negative_;
-        bool const rneg = y.negative_;
+        bool const lneg = x.mantissa_ < 0;
+        bool const rneg = y.mantissa_ < 0;
 
         if (lneg != rneg)
             return lneg;
@@ -342,7 +437,7 @@ public:
     constexpr int
     signum() const noexcept
     {
-        return negative_ ? -1 : (mantissa_ ? 1 : 0);
+        return mantissa_ < 0 ? -1 : (mantissa_ ? 1 : 0);
     }
 
     Number
@@ -381,6 +476,9 @@ public:
     friend Number
     root2(Number f);
 
+    friend Number
+    power(Number const& f, unsigned n, unsigned d);
+
     // Thread local rounding control.  Default is to_nearest
     enum rounding_mode { to_nearest, towards_zero, downward, upward };
     static rounding_mode
@@ -445,22 +543,39 @@ private:
     static_assert(isPowerOfTen(smallRange.min));
     static_assert(smallRange.min == 1'000'000'000'000'000LL);
     static_assert(smallRange.max == 9'999'999'999'999'999LL);
+    static_assert(smallRange.internalMin == smallRange.min);
     static_assert(smallRange.log == 15);
-    static_assert(smallRange.min < maxRep);
-    static_assert(smallRange.max < maxRep);
     constexpr static MantissaRange largeRange{MantissaRange::large};
-    static_assert(isPowerOfTen(largeRange.min));
-    static_assert(largeRange.min == 1'000'000'000'000'000'000ULL);
-    static_assert(largeRange.max == internalrep(9'999'999'999'999'999'999ULL));
+    static_assert(!isPowerOfTen(largeRange.min));
+    static_assert(largeRange.min == 922'337'203'685'477'581ULL);
+    static_assert(largeRange.max == internalrep(9'223'372'036'854'775'807ULL));
+    static_assert(largeRange.max == std::numeric_limits<rep>::max());
+    static_assert(largeRange.internalMin == 1'000'000'000'000'000'000ULL);
     static_assert(largeRange.log == 18);
-    static_assert(largeRange.min < maxRep);
-    static_assert(largeRange.max > maxRep);
+    // There are 2 values that will not fit in largeRange without some extra
+    // work
+    // * 9223372036854775808
+    // * 9223372036854775809
+    // They both end up < min, but with a leftover. If they round up, everything
+    // will be fine. If they don't, we'll need to bring them up into range.
+    // Guard::bringIntoRange handles this situation.
 
     // The range for the mantissa when normalized.
     // Use reference_wrapper to avoid making copies, and prevent accidentally
     // changing the values inside the range.
     static thread_local std::reference_wrapper<MantissaRange const> range_;
 
+    // And one is needed because it needs to choose between oneSmall and
+    // oneLarge based on the current range
+    static Number
+    one(MantissaRange const& range);
+
+    static Number
+    root(MantissaRange const& range, Number f, unsigned d);
+
+    void
+    normalize(MantissaRange const& range);
+
     void
     normalize();
 
@@ -483,11 +598,14 @@ private:
     friend void
     doNormalize(
         bool& negative,
-        T& mantissa_,
-        int& exponent_,
+        T& mantissa,
+        int& exponent,
         MantissaRange::rep const& minMantissa,
         MantissaRange::rep const& maxMantissa);
 
+    bool
+    isnormal(MantissaRange const& range) const noexcept;
+
     bool
     isnormal() const noexcept;
 
@@ -497,14 +615,60 @@ private:
     Number
     shiftExponent(int exponentDelta) const;
 
-    // Safely convert rep (int64) mantissa to internalrep (uint64). If the rep
-    // is negative, returns the positive value. This takes a little extra work
-    // because converting std::numeric_limits<std::int64_t>::min() flirts with
-    // UB, and can vary across compilers.
+    // Safely return the absolute value of a rep (int64) mantissa as an internalrep (uint64).
     static internalrep
     externalToInternal(rep mantissa);
 
+    /** Breaks down the number into components, potentially de-normalizing it.
+     *
+     * Ensures that the mantissa always has range_.log + 1 digits.
+     *
+     */
+    template <detail::UnsignedMantissa Rep = internalrep>
+    std::tuple<bool, Rep, int>
+    toInternal(MantissaRange const& range) const;
+
+    /** Breaks down the number into components, potentially de-normalizing it.
+     *
+     * Ensures that the mantissa always has range_.log + 1 digits.
+     *
+     */
+    template <detail::UnsignedMantissa Rep = internalrep>
+    std::tuple<bool, Rep, int>
+    toInternal() const;
+
+    /** Rebuilds the number from components.
+     *
+     * If "expectNormal" is true, the values are expected to be normalized - all
+     * in their valid ranges.
+     *
+     * If "expectNormal" is false, the values are expected to be "near
+     * normalized", meaning that the mantissa has to be modified at most once to
+     * bring it back into range.
+     *
+     */
+    template <bool expectNormal = true, detail::UnsignedMantissa Rep = internalrep>
+    void
+    fromInternal(bool negative, Rep mantissa, int exponent, MantissaRange const* pRange);
+
+    /** Rebuilds the number from components.
+     *
+     * If "expectNormal" is true, the values are expected to be normalized - all
+     * in their valid ranges.
+     *
+     * If "expectNormal" is false, the values are expected to be "near
+     * normalized", meaning that the mantissa has to be modified at most once to
+     * bring it back into range.
+     *
+     */
+    template <bool expectNormal = true, detail::UnsignedMantissa Rep = internalrep>
+    void
+    fromInternal(bool negative, Rep mantissa, int exponent);
+
     class Guard;
+
+public:
+    constexpr static internalrep largestMantissa = largeRange.max;
 };
 
 inline constexpr Number::Number(
@@ -512,7 +676,8 @@ inline constexpr Number::Number(
     internalrep mantissa,
     int exponent,
     unchecked) noexcept
-    : negative_(negative), mantissa_{mantissa}, exponent_{exponent}
+    : mantissa_{negative ? -static_cast<rep>(mantissa) : static_cast<rep>(mantissa)}
+    , exponent_{exponent}
 {
 }
 
@@ -523,12 +688,6 @@ inline constexpr Number::Number(internalrep mantissa, int exponent, unchecked) n
 
 constexpr static Number numZero{};
 
-inline Number::Number(bool negative, internalrep mantissa, int exponent, normalized)
-    : Number(negative, mantissa, exponent, unchecked{})
-{
-    normalize();
-}
-
 inline Number::Number(internalrep mantissa, int exponent, normalized)
     : Number(false, mantissa, exponent, normalized{})
 {
@@ -551,17 +710,7 @@ inline Number::Number(rep mantissa) : Number{mantissa, 0}
 inline constexpr Number::rep
 Number::mantissa() const noexcept
 {
-    auto m = mantissa_;
-    if (m > maxRep)
-    {
-        XRPL_ASSERT_PARTS(
-            !isnormal() || (m % 10 == 0 && m / 10 <= maxRep),
-            "xrpl::Number::mantissa",
-            "large normalized mantissa has no remainder");
-        m /= 10;
-    }
-    auto const sign = negative_ ? -1 : 1;
-    return sign * static_cast<Number::rep>(m);
+    return mantissa_;
 }
 
 /** Returns the exponent of the external view of the Number.
@@ -572,16 +721,7 @@ Number::mantissa() const noexcept
 inline constexpr int
 Number::exponent() const noexcept
 {
-    auto e = exponent_;
-    if (mantissa_ > maxRep)
-    {
-        XRPL_ASSERT_PARTS(
-            !isnormal() || (mantissa_ % 10 == 0 && mantissa_ / 10 <= maxRep),
-            "xrpl::Number::exponent",
-            "large normalized mantissa has no remainder");
-        ++e;
-    }
-    return e;
+    return exponent_;
 }
 
 inline constexpr Number
@@ -596,7 +736,7 @@ Number::operator-() const noexcept
     if (mantissa_ == 0)
         return Number{};
     auto x = *this;
-    x.negative_ = !x.negative_;
+    x.mantissa_ = -x.mantissa_;
     return x;
 }
 
@@ -677,42 +817,58 @@ Number::min() noexcept
 inline Number
 Number::max() noexcept
 {
-    return Number{false, std::min(range_.get().max, maxRep), maxExponent, unchecked{}};
+    return Number{false, range_.get().max, maxExponent, unchecked{}};
 }
 
 inline Number
 Number::lowest() noexcept
 {
-    return Number{true, std::min(range_.get().max, maxRep), maxExponent, unchecked{}};
+    return Number{true, range_.get().max, maxExponent, unchecked{}};
+}
+
+inline bool
+Number::isnormal(MantissaRange const& range) const noexcept
+{
+    auto const abs_m = externalToInternal(mantissa_);
+
+    return *this == Number{} ||
+        (range.min <= abs_m && abs_m <= range.max &&  //
+         minExponent <= exponent_ && exponent_ <= maxExponent);
 }
 
 inline bool
 Number::isnormal() const noexcept
 {
-    MantissaRange const& range = range_;
-    auto const abs_m = mantissa_;
-    return *this == Number{} ||
-        (range.min <= abs_m && abs_m <= range.max && (abs_m <= maxRep || abs_m % 10 == 0) &&
-         minExponent <= exponent_ && exponent_ <= maxExponent);
+    return isnormal(range_);
 }
 
 template <Integral64 T>
 std::pair<T, int>
 Number::normalizeToRange(T minMantissa, T maxMantissa) const
 {
-    bool negative = negative_;
-    internalrep mantissa = mantissa_;
+    bool negative = mantissa_ < 0;
+    internalrep mantissa = externalToInternal(mantissa_);
     int exponent = exponent_;
 
     if constexpr (std::is_unsigned_v<T>)
+    {
         XRPL_ASSERT_PARTS(
             !negative,
             "xrpl::Number::normalizeToRange",
             "Number is non-negative for unsigned range.");
+        // To avoid logical errors in release builds, throw if the Number is
+        // negative for an unsigned range.
+        if (negative)
+            throw std::runtime_error(
+                "Number::normalizeToRange: Number is negative for "
+                "unsigned range.");
+    }
     Number::normalize(negative, mantissa, exponent, minMantissa, maxMantissa);
 
-    auto const sign = negative ? -1 : 1;
-    return std::make_pair(static_cast<T>(sign * mantissa), exponent);
+    // Cast mantissa to signed type first (if T is a signed type) to avoid
+    // unsigned integer overflow when multiplying by negative sign
+    T signedMantissa = negative ? -static_cast<T>(mantissa) : static_cast<T>(mantissa);
+    return std::make_pair(signedMantissa, exponent);
 }
 
 inline constexpr Number

include/xrpl/core/CoroTask.h

@@ -1,289 +0,0 @@
-#pragma once
-
-#include <coroutine>
-#include <exception>
-#include <utility>
-#include <variant>
-
-namespace xrpl {
-
-template <typename T = void>
-class CoroTask;
-
-// --------------------------------------------------------------------------
-// CoroTask<void> — coroutine return type for void-returning coroutines
-// --------------------------------------------------------------------------
-
-template <>
-class CoroTask<void>
-{
-public:
-    struct promise_type;
-    using Handle = std::coroutine_handle<promise_type>;
-
-    struct promise_type
-    {
-        std::exception_ptr exception_;
-        std::coroutine_handle<> continuation_;
-
-        CoroTask
-        get_return_object()
-        {
-            return CoroTask{Handle::from_promise(*this)};
-        }
-
-        std::suspend_always
-        initial_suspend() noexcept
-        {
-            return {};
-        }
-
-        struct FinalAwaiter
-        {
-            bool
-            await_ready() noexcept
-            {
-                return false;
-            }
-
-            std::coroutine_handle<>
-            await_suspend(Handle h) noexcept
-            {
-                if (auto cont = h.promise().continuation_)
-                    return cont;
-                return std::noop_coroutine();
-            }
-
-            void
-            await_resume() noexcept
-            {
-            }
-        };
-
-        FinalAwaiter
-        final_suspend() noexcept
-        {
-            return {};
-        }
-
-        void
-        return_void()
-        {
-        }
-
-        void
-        unhandled_exception()
-        {
-            exception_ = std::current_exception();
-        }
-    };
-
-    CoroTask() = default;
-
-    explicit CoroTask(Handle h) : handle_(h)
-    {
-    }
-
-    ~CoroTask()
-    {
-        if (handle_)
-            handle_.destroy();
-    }
-
-    CoroTask(CoroTask&& other) noexcept : handle_(std::exchange(other.handle_, {}))
-    {
-    }
-
-    CoroTask&
-    operator=(CoroTask&& other) noexcept
-    {
-        if (this != &other)
-        {
-            if (handle_)
-                handle_.destroy();
-            handle_ = std::exchange(other.handle_, {});
-        }
-        return *this;
-    }
-
-    CoroTask(CoroTask const&) = delete;
-    CoroTask&
-    operator=(CoroTask const&) = delete;
-
-    Handle
-    handle() const
-    {
-        return handle_;
-    }
-
-    bool
-    done() const
-    {
-        return handle_ && handle_.done();
-    }
-
-    // Awaiter interface — allows co_await on a CoroTask
-    bool
-    await_ready() const noexcept
-    {
-        return false;
-    }
-
-    std::coroutine_handle<>
-    await_suspend(std::coroutine_handle<> caller) noexcept
-    {
-        handle_.promise().continuation_ = caller;
-        return handle_;  // Symmetric transfer
-    }
-
-    void
-    await_resume()
-    {
-        if (auto& ep = handle_.promise().exception_)
-            std::rethrow_exception(ep);
-    }
-
-private:
-    Handle handle_;
-};
-
-// --------------------------------------------------------------------------
-// CoroTask<T> — coroutine return type for value-returning coroutines
-// --------------------------------------------------------------------------
-
-template <typename T>
-class CoroTask
-{
-public:
-    struct promise_type;
-    using Handle = std::coroutine_handle<promise_type>;
-
-    struct promise_type
-    {
-        std::variant<std::monostate, T, std::exception_ptr> result_;
-        std::coroutine_handle<> continuation_;
-
-        CoroTask
-        get_return_object()
-        {
-            return CoroTask{Handle::from_promise(*this)};
-        }
-
-        std::suspend_always
-        initial_suspend() noexcept
-        {
-            return {};
-        }
-
-        struct FinalAwaiter
-        {
-            bool
-            await_ready() noexcept
-            {
-                return false;
-            }
-
-            std::coroutine_handle<>
-            await_suspend(Handle h) noexcept
-            {
-                if (auto cont = h.promise().continuation_)
-                    return cont;
-                return std::noop_coroutine();
-            }
-
-            void
-            await_resume() noexcept
-            {
-            }
-        };
-
-        FinalAwaiter
-        final_suspend() noexcept
-        {
-            return {};
-        }
-
-        void
-        return_value(T value)
-        {
-            result_.template emplace<1>(std::move(value));
-        }
-
-        void
-        unhandled_exception()
-        {
-            result_.template emplace<2>(std::current_exception());
-        }
-    };
-
-    CoroTask() = default;
-
-    explicit CoroTask(Handle h) : handle_(h)
-    {
-    }
-
-    ~CoroTask()
-    {
-        if (handle_)
-            handle_.destroy();
-    }
-
-    CoroTask(CoroTask&& other) noexcept : handle_(std::exchange(other.handle_, {}))
-    {
-    }
-
-    CoroTask&
-    operator=(CoroTask&& other) noexcept
-    {
-        if (this != &other)
-        {
-            if (handle_)
-                handle_.destroy();
-            handle_ = std::exchange(other.handle_, {});
-        }
-        return *this;
-    }
-
-    CoroTask(CoroTask const&) = delete;
-    CoroTask&
-    operator=(CoroTask const&) = delete;
-
-    Handle
-    handle() const
-    {
-        return handle_;
-    }
-
-    bool
-    done() const
-    {
-        return handle_ && handle_.done();
-    }
-
-    bool
-    await_ready() const noexcept
-    {
-        return false;
-    }
-
-    std::coroutine_handle<>
-    await_suspend(std::coroutine_handle<> caller) noexcept
-    {
-        handle_.promise().continuation_ = caller;
-        return handle_;
-    }
-
-    T
-    await_resume()
-    {
-        auto& result = handle_.promise().result_;
-        if (auto* ep = std::get_if<2>(&result))
-            std::rethrow_exception(*ep);
-        return std::get<1>(std::move(result));
-    }
-
-private:
-    Handle handle_;
-};
-
-}  // namespace xrpl

include/xrpl/core/CoroTaskRunner.ipp

@@ -1,158 +0,0 @@
-#pragma once
-
-namespace xrpl {
-
-inline JobQueue::CoroTaskRunner::CoroTaskRunner(
-    create_t,
-    JobQueue& jq,
-    JobType type,
-    std::string const& name)
-    : jq_(jq), type_(type), name_(name), running_(false)
-{
-}
-
-template <class F>
-void
-JobQueue::CoroTaskRunner::init(F&& f)
-{
-    // Store the callable on the heap so it outlives the coroutine frame.
-    // Coroutine frames store a reference to the callable's implicit object
-    // parameter (the lambda). If the callable is a temporary, that reference
-    // dangles after the caller returns. Keeping the callable alive here
-    // ensures the coroutine's captures remain valid.
-    using Fn = std::decay_t<F>;
-    auto store = std::make_unique<FuncStore<Fn>>(std::forward<F>(f));
-    task_ = store->func(shared_from_this());
-    storedFunc_ = std::move(store);
-}
-
-inline JobQueue::CoroTaskRunner::~CoroTaskRunner()
-{
-#ifndef NDEBUG
-    XRPL_ASSERT(finished_, "xrpl::JobQueue::CoroTaskRunner::~CoroTaskRunner : is finished");
-#endif
-}
-
-inline void
-JobQueue::CoroTaskRunner::onSuspend()
-{
-    std::lock_guard lock(jq_.m_mutex);
-    ++jq_.nSuspend_;
-}
-
-inline void
-JobQueue::CoroTaskRunner::onUndoSuspend()
-{
-    std::lock_guard lock(jq_.m_mutex);
-    --jq_.nSuspend_;
-}
-
-inline auto
-JobQueue::CoroTaskRunner::suspend()
-{
-    struct SuspendAwaiter
-    {
-        CoroTaskRunner& runner_;
-
-        bool
-        await_ready() const noexcept
-        {
-            return false;
-        }
-
-        void
-        await_suspend(std::coroutine_handle<>) const
-        {
-            runner_.onSuspend();
-        }
-
-        void
-        await_resume() const noexcept
-        {
-        }
-    };
-    return SuspendAwaiter{*this};
-}
-
-inline bool
-JobQueue::CoroTaskRunner::post()
-{
-    {
-        std::lock_guard lk(mutex_run_);
-        running_ = true;
-    }
-
-    // sp prevents 'this' from being destroyed while the job is pending
-    if (jq_.addJob(type_, name_, [this, sp = shared_from_this()]() { resume(); }))
-    {
-        return true;
-    }
-
-    // The coroutine will not run. Clean up running_.
-    std::lock_guard lk(mutex_run_);
-    running_ = false;
-    cv_.notify_all();
-    return false;
-}
-
-inline void
-JobQueue::CoroTaskRunner::resume()
-{
-    {
-        std::lock_guard lk(mutex_run_);
-        running_ = true;
-    }
-    {
-        std::lock_guard lock(jq_.m_mutex);
-        --jq_.nSuspend_;
-    }
-    auto saved = detail::getLocalValues().release();
-    detail::getLocalValues().reset(&lvs_);
-    std::lock_guard lock(mutex_);
-    XRPL_ASSERT(!task_.done(), "xrpl::JobQueue::CoroTaskRunner::resume : task is not done");
-    task_.handle().resume();
-    detail::getLocalValues().release();
-    detail::getLocalValues().reset(saved);
-#ifndef NDEBUG
-    if (task_.done())
-        finished_ = true;
-#endif
-    std::lock_guard lk(mutex_run_);
-    running_ = false;
-    cv_.notify_all();
-}
-
-inline bool
-JobQueue::CoroTaskRunner::runnable() const
-{
-    return !task_.done();
-}
-
-inline void
-JobQueue::CoroTaskRunner::expectEarlyExit()
-{
-#ifndef NDEBUG
-    if (!finished_)
-#endif
-    {
-        std::lock_guard lock(jq_.m_mutex);
-        --jq_.nSuspend_;
-#ifndef NDEBUG
-        finished_ = true;
-#endif
-    }
-    // Destroy the coroutine frame to break a potential shared_ptr cycle.
-    // The coroutine is at initial_suspend and never ran user code, so
-    // destroying it is safe. Without this, the frame holds a shared_ptr
-    // back to this CoroTaskRunner, creating an unreachable reference cycle.
-    task_ = {};
-}
-
-inline void
-JobQueue::CoroTaskRunner::join()
-{
-    std::unique_lock<std::mutex> lk(mutex_run_);
-    cv_.wait(lk, [this]() { return running_ == false; });
-}
-
-}  // namespace xrpl

include/xrpl/core/JobQueue.h

@@ -2,7 +2,6 @@
 
 #include <xrpl/basics/LocalValue.h>
 #include <xrpl/core/ClosureCounter.h>
-#include <xrpl/core/CoroTask.h>
 #include <xrpl/core/JobTypeData.h>
 #include <xrpl/core/JobTypes.h>
 #include <xrpl/core/detail/Workers.h>
@@ -10,7 +9,6 @@
 
 #include <boost/coroutine/all.hpp>
 
-#include <coroutine>
 #include <set>
 
 namespace xrpl {
@@ -121,112 +119,6 @@ public:
         join();
     };
 
-    /** C++20 coroutine lifecycle manager. Replaces Coro for new code. */
-    class CoroTaskRunner : public std::enable_shared_from_this<CoroTaskRunner>
-    {
-    private:
-        detail::LocalValues lvs_;
-        JobQueue& jq_;
-        JobType type_;
-        std::string name_;
-        bool running_;
-        std::mutex mutex_;
-        std::mutex mutex_run_;
-        std::condition_variable cv_;
-        CoroTask<void> task_;
-
-        // Type-erased storage to keep the coroutine callable alive.
-        // Coroutine frames store a reference to the callable's implicit
-        // object parameter (the lambda). If the callable is a temporary,
-        // that reference dangles after the call returns. Storing the
-        // callable on the heap here ensures it outlives the coroutine.
-        struct FuncBase
-        {
-            virtual ~FuncBase() = default;
-        };
-        template <class F>
-        struct FuncStore : FuncBase
-        {
-            F func;
-            explicit FuncStore(F&& f) : func(std::move(f))
-            {
-            }
-        };
-        std::unique_ptr<FuncBase> storedFunc_;
-
-#ifndef NDEBUG
-        bool finished_ = false;
-#endif
-
-    public:
-        struct create_t
-        {
-            explicit create_t() = default;
-        };
-
-        // Private: Used in the implementation of postCoroTask
-        CoroTaskRunner(create_t, JobQueue&, JobType, std::string const&);
-
-        // Not copy-constructible or assignable
-        CoroTaskRunner(CoroTaskRunner const&) = delete;
-        CoroTaskRunner&
-        operator=(CoroTaskRunner const&) = delete;
-
-        ~CoroTaskRunner();
-
-        /** Initialize with a coroutine function.
-            Must be called exactly once, after the object is managed by
-            shared_ptr. This is handled automatically by postCoroTask().
-        */
-        template <class F>
-        void
-        init(F&& f);
-
-        /** Increment the suspended coroutine count.
-            Called when the coroutine is about to suspend.
-        */
-        void
-        onSuspend();
-
-        /** Decrement the suspended coroutine count without side effects.
-            Used to undo onSuspend() when a suspend is cancelled.
-        */
-        void
-        onUndoSuspend();
-
-        /** Suspend coroutine execution.
-            Returns an awaiter for use with co_await.
-            Effects:
-              Increments nSuspend_ in the JobQueue.
-              The coroutine is suspended.
-            The caller must later call post() or resume() to continue.
-        */
-        auto
-        suspend();
-
-        /** Schedule coroutine execution on the JobQueue.
-            @return true if the job is added to the JobQueue.
-        */
-        bool
-        post();
-
-        /** Resume coroutine on current thread. */
-        void
-        resume();
-
-        /** Returns true if coroutine hasn't completed. */
-        bool
-        runnable() const;
-
-        /** Once called, allows early exit without an assert. */
-        void
-        expectEarlyExit();
-
-        /** Waits until coroutine completes. */
-        void
-        join();
-    };
-
     using JobFunction = std::function<void()>;
 
     JobQueue(
@@ -273,19 +165,6 @@ public:
     std::shared_ptr<Coro>
     postCoro(JobType t, std::string const& name, F&& f);
 
-    /** Creates a C++20 coroutine and adds a job to the queue to run it.
-
-        @param t The type of job.
-        @param name Name of the job.
-        @param f Callable with signature
-            CoroTask<void>(std::shared_ptr<CoroTaskRunner>).
-
-        @return shared_ptr to posted CoroTaskRunner. nullptr if not successful.
-    */
-    template <class F>
-    std::shared_ptr<CoroTaskRunner>
-    postCoroTask(JobType t, std::string const& name, F&& f);
-
     /** Jobs waiting at this priority.
      */
     int
@@ -500,7 +379,6 @@ private:
 }  // namespace xrpl
 
 #include <xrpl/core/Coro.ipp>
-#include <xrpl/core/CoroTaskRunner.ipp>
 
 namespace xrpl {
 
@@ -523,26 +401,4 @@ JobQueue::postCoro(JobType t, std::string const& name, F&& f)
     return coro;
 }
 
-template <class F>
-std::shared_ptr<JobQueue::CoroTaskRunner>
-JobQueue::postCoroTask(JobType t, std::string const& name, F&& f)
-{
-    auto runner = std::make_shared<CoroTaskRunner>(CoroTaskRunner::create_t{}, *this, t, name);
-    runner->init(std::forward<F>(f));
-
-    // Account for the initial suspension (lazy start).
-    // Mirrors the yield() in the Boost Coro constructor.
-    {
-        std::lock_guard lock(m_mutex);
-        ++nSuspend_;
-    }
-
-    if (!runner->post())
-    {
-        runner->expectEarlyExit();
-        runner.reset();
-    }
-    return runner;
-}
-
 }  // namespace xrpl

include/xrpl/core/JobQueueAwaiter.h

@@ -1,56 +0,0 @@
-#pragma once
-
-#include <xrpl/core/JobQueue.h>
-
-#include <coroutine>
-#include <memory>
-
-namespace xrpl {
-
-/** Awaiter that suspends and immediately reschedules on the JobQueue.
-    Equivalent to calling yield() followed by post() in the old Coro API.
-
-    Usage:
-        co_await JobQueueAwaiter{runner};
-
-    What it waits for: The coroutine is re-queued as a job and resumes
-    when a worker thread picks it up.
-
-    Which thread resumes: A JobQueue worker thread.
-
-    What await_resume() returns: void.
-*/
-struct JobQueueAwaiter
-{
-    std::shared_ptr<JobQueue::CoroTaskRunner> runner;
-
-    bool
-    await_ready() const noexcept
-    {
-        return false;
-    }
-
-    bool
-    await_suspend(std::coroutine_handle<>)
-    {
-        // Increment nSuspend (equivalent to yield())
-        runner->onSuspend();
-        // Schedule resume on JobQueue (equivalent to post())
-        if (!runner->post())
-        {
-            // JobQueue is stopping. Undo the suspend count and
-            // don't actually suspend — the coroutine continues
-            // immediately so it can clean up and co_return.
-            runner->onUndoSuspend();
-            return false;
-        }
-        return true;
-    }
-
-    void
-    await_resume() const noexcept
-    {
-    }
-};
-
-}  // namespace xrpl

include/xrpl/protocol/Protocol.h

@@ -232,7 +232,7 @@ std::size_t constexpr maxMPTokenMetadataLength = 1024;
 
 /** The maximum amount of MPTokenIssuance */
 std::uint64_t constexpr maxMPTokenAmount = 0x7FFF'FFFF'FFFF'FFFFull;
-static_assert(Number::maxRep >= maxMPTokenAmount);
+static_assert(Number::largestMantissa >= maxMPTokenAmount);
 
 /** The maximum length of Data payload */
 std::size_t constexpr maxDataPayloadLength = 256;

include/xrpl/protocol/STAmount.h

@@ -539,6 +539,8 @@ STAmount::fromNumber(A const& a, Number const& number)
         return STAmount{asset, intValue, 0, negative};
     }
 
+    XRPL_ASSERT_PARTS(
+        working.signum() >= 0, "xrpl::STAmount::fromNumber", "non-negative Number to normalize");
     auto const [mantissa, exponent] = working.normalizeToRange(cMinValue, cMaxValue);
 
     return STAmount{asset, mantissa, exponent, negative};

include/xrpl/protocol/SystemParameters.h

@@ -23,7 +23,7 @@ systemName()
 /** Number of drops in the genesis account. */
 constexpr XRPAmount INITIAL_XRP{100'000'000'000 * DROPS_PER_XRP};
 static_assert(INITIAL_XRP.drops() == 100'000'000'000'000'000);
-static_assert(Number::maxRep >= INITIAL_XRP.drops());
+static_assert(Number::largestMantissa >= INITIAL_XRP.drops());
 
 /** Returns true if the amount does not exceed the initial XRP in existence. */
 inline bool

src/libxrpl/basics/Number.cpp

@@ -9,20 +9,17 @@
 #include <iterator>
 #include <limits>
 #include <numeric>
-#include <stdexcept>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 
 #ifdef _MSC_VER
 #pragma message("Using boost::multiprecision::uint128_t and int128_t")
-#include <boost/multiprecision/cpp_int.hpp>
-using uint128_t = boost::multiprecision::uint128_t;
-using int128_t = boost::multiprecision::int128_t;
-#else   // !defined(_MSC_VER)
-using uint128_t = __uint128_t;
-using int128_t = __int128_t;
-#endif  // !defined(_MSC_VER)
+#endif
+
+using uint128_t = xrpl::detail::uint128_t;
+using int128_t = xrpl::detail::int128_t;
 
 namespace xrpl {
 
@@ -61,9 +58,6 @@ Number::setMantissaScale(MantissaRange::mantissa_scale scale)
 // precision to an operation.  This enables the final result
 // to be correctly rounded to the internal precision of Number.
 
-template <class T>
-concept UnsignedMantissa = std::is_unsigned_v<T> || std::is_same_v<T, uint128_t>;
-
 class Number::Guard
 {
     std::uint64_t digits_;   // 16 decimal guard digits
@@ -99,7 +93,7 @@ public:
     round() noexcept;
 
     // Modify the result to the correctly rounded value
-    template <UnsignedMantissa T>
+    template <detail::UnsignedMantissa T>
     void
     doRoundUp(
         bool& negative,
@@ -107,22 +101,22 @@ public:
         int& exponent,
         internalrep const& minMantissa,
         internalrep const& maxMantissa,
-        std::string location);
+        std::string_view location);
 
     // Modify the result to the correctly rounded value
-    template <UnsignedMantissa T>
+    template <detail::UnsignedMantissa T>
     void
     doRoundDown(bool& negative, T& mantissa, int& exponent, internalrep const& minMantissa);
 
     // Modify the result to the correctly rounded value
     void
-    doRound(rep& drops, std::string location);
+    doRound(internalrep& drops, std::string_view location);
 
 private:
     void
     doPush(unsigned d) noexcept;
 
-    template <UnsignedMantissa T>
+    template <detail::UnsignedMantissa T>
     void
     bringIntoRange(bool& negative, T& mantissa, int& exponent, internalrep const& minMantissa);
 };
@@ -209,7 +203,7 @@ Number::Guard::round() noexcept
     return 0;
 }
 
-template <UnsignedMantissa T>
+template <detail::UnsignedMantissa T>
 void
 Number::Guard::bringIntoRange(
     bool& negative,
@@ -228,13 +222,11 @@ Number::Guard::bringIntoRange(
     {
         constexpr Number zero = Number{};
 
-        negative = zero.negative_;
-        mantissa = zero.mantissa_;
-        exponent = zero.exponent_;
+        std::tie(negative, mantissa, exponent) = zero.toInternal();
     }
 }
 
-template <UnsignedMantissa T>
+template <detail::UnsignedMantissa T>
 void
 Number::Guard::doRoundUp(
     bool& negative,
@@ -242,7 +234,7 @@ Number::Guard::doRoundUp(
     int& exponent,
     internalrep const& minMantissa,
     internalrep const& maxMantissa,
-    std::string location)
+    std::string_view location)
 {
     auto r = round();
     if (r == 1 || (r == 0 && (mantissa & 1) == 1))
@@ -250,7 +242,7 @@ Number::Guard::doRoundUp(
         ++mantissa;
         // Ensure mantissa after incrementing fits within both the
         // min/maxMantissa range and is a valid "rep".
-        if (mantissa > maxMantissa || mantissa > maxRep)
+        if (mantissa > maxMantissa)
         {
             mantissa /= 10;
             ++exponent;
@@ -258,10 +250,10 @@ Number::Guard::doRoundUp(
     }
     bringIntoRange(negative, mantissa, exponent, minMantissa);
     if (exponent > maxExponent)
-        throw std::overflow_error(location);
+        throw std::overflow_error(std::string{location});
 }
 
-template <UnsignedMantissa T>
+template <detail::UnsignedMantissa T>
 void
 Number::Guard::doRoundDown(
     bool& negative,
@@ -284,26 +276,25 @@ Number::Guard::doRoundDown(
 
 // Modify the result to the correctly rounded value
 void
-Number::Guard::doRound(rep& drops, std::string location)
+Number::Guard::doRound(internalrep& drops, std::string_view location)
 {
     auto r = round();
     if (r == 1 || (r == 0 && (drops & 1) == 1))
     {
-        if (drops >= maxRep)
+        auto const& range = range_.get();
+        if (drops >= range.max)
         {
             static_assert(sizeof(internalrep) == sizeof(rep));
             // This should be impossible, because it's impossible to represent
-            // "maxRep + 0.6" in Number, regardless of the scale. There aren't
-            // enough digits available. You'd either get a mantissa of "maxRep"
-            // or "(maxRep + 1) / 10", neither of which will round up when
+            // "largestMantissa + 0.6" in Number, regardless of the scale. There aren't
+            // enough digits available. You'd either get a mantissa of "largestMantissa"
+            // or "largestMantissa / 10 + 1", neither of which will round up when
             // converting to rep, though the latter might overflow _before_
             // rounding.
-            throw std::overflow_error(location);  // LCOV_EXCL_LINE
+            throw std::overflow_error(std::string{location});  // LCOV_EXCL_LINE
         }
         ++drops;
     }
-    if (is_negative())
-        drops = -drops;
 }
 
 // Number
@@ -318,23 +309,135 @@ Number::externalToInternal(rep mantissa)
     // If the mantissa is already positive, just return it
     if (mantissa >= 0)
         return mantissa;
-    // If the mantissa is negative, but fits within the positive range of rep,
-    // return it negated
-    if (mantissa >= -std::numeric_limits<rep>::max())
-        return -mantissa;
 
-    // If the mantissa doesn't fit within the positive range, convert to
-    // int128_t, negate that, and cast it back down to the internalrep
-    // In practice, this is only going to cover the case of
-    // std::numeric_limits<rep>::min().
-    int128_t temp = mantissa;
-    return static_cast<internalrep>(-temp);
+    // Cast to unsigned before negating to avoid undefined behavior when
+    // mantissa == std::numeric_limits<rep>::min() (INT64_MIN). Negating
+    // INT64_MIN in signed arithmetic is UB, but casting to the unsigned
+    // internalrep first makes the operation well-defined.
+    return -static_cast<internalrep>(mantissa);
+}
+
+/** Breaks down the number into components, potentially de-normalizing it.
+ *
+ * Ensures that the mantissa always has range_.log + 1 digits.
+ *
+ */
+template <detail::UnsignedMantissa Rep>
+std::tuple<bool, Rep, int>
+Number::toInternal(MantissaRange const& range) const
+{
+    auto exponent = exponent_;
+    bool const negative = mantissa_ < 0;
+    // It should be impossible for mantissa_ to be INT64_MIN, but use externalToInternal just in
+    // case.
+    Rep mantissa = static_cast<Rep>(externalToInternal(mantissa_));
+
+    auto const internalMin = range.internalMin;
+    auto const minMantissa = range.min;
+
+    if (mantissa != 0 && mantissa >= minMantissa && mantissa < internalMin)
+    {
+        // Ensure the mantissa has the correct number of digits
+        mantissa *= 10;
+        --exponent;
+        XRPL_ASSERT_PARTS(
+            mantissa >= internalMin && mantissa < internalMin * 10,
+            "xrpl::Number::toInternal()",
+            "Number is within reference range and has 'log' digits");
+    }
+
+    return {negative, mantissa, exponent};
+}
+
+/** Breaks down the number into components, potentially de-normalizing it.
+ *
+ * Ensures that the mantissa always has exactly range_.log + 1 digits.
+ *
+ */
+template <detail::UnsignedMantissa Rep>
+std::tuple<bool, Rep, int>
+Number::toInternal() const
+{
+    return toInternal(range_);
+}
+
+/** Rebuilds the number from components.
+ *
+ * If "expectNormal" is true, the values are expected to be normalized - all
+ * in their valid ranges.
+ *
+ * If "expectNormal" is false, the values are expected to be "near
+ * normalized", meaning that the mantissa has to be modified at most once to
+ * bring it back into range.
+ *
+ */
+template <bool expectNormal, detail::UnsignedMantissa Rep>
+void
+Number::fromInternal(bool negative, Rep mantissa, int exponent, MantissaRange const* pRange)
+{
+    if constexpr (std::is_same_v<std::bool_constant<expectNormal>, std::false_type>)
+    {
+        if (!pRange)
+            throw std::runtime_error("Missing range to Number::fromInternal!");
+        auto const& range = *pRange;
+
+        auto const maxMantissa = range.max;
+        auto const minMantissa = range.min;
+
+        XRPL_ASSERT_PARTS(
+            mantissa >= minMantissa, "xrpl::Number::fromInternal", "mantissa large enough");
+
+        if (mantissa > maxMantissa || mantissa < minMantissa)
+        {
+            normalize(negative, mantissa, exponent, range.min, maxMantissa);
+        }
+
+        XRPL_ASSERT_PARTS(
+            mantissa >= minMantissa && mantissa <= maxMantissa,
+            "xrpl::Number::fromInternal",
+            "mantissa in range");
+    }
+
+    // mantissa is unsigned, but it might not be uint64
+    mantissa_ = static_cast<rep>(static_cast<internalrep>(mantissa));
+    if (negative)
+        mantissa_ = -mantissa_;
+    exponent_ = exponent;
+
+    XRPL_ASSERT_PARTS(
+        (pRange && isnormal(*pRange)) || isnormal(),
+        "xrpl::Number::fromInternal",
+        "Number is normalized");
+}
+
+/** Rebuilds the number from components.
+ *
+ * If "expectNormal" is true, the values are expected to be normalized - all in
+ * their valid ranges.
+ *
+ * If "expectNormal" is false, the values are expected to be "near normalized",
+ * meaning that the mantissa has to be modified at most once to bring it back
+ * into range.
+ *
+ */
+template <bool expectNormal, detail::UnsignedMantissa Rep>
+void
+Number::fromInternal(bool negative, Rep mantissa, int exponent)
+{
+    MantissaRange const* pRange = nullptr;
+    if constexpr (std::is_same_v<std::bool_constant<expectNormal>, std::false_type>)
+    {
+        pRange = &Number::range_.get();
+    }
+
+    fromInternal(negative, mantissa, exponent, pRange);
 }
 
 constexpr Number
 Number::oneSmall()
 {
-    return Number{false, Number::smallRange.min, -Number::smallRange.log, Number::unchecked{}};
+    return Number{
+        false, Number::smallRange.internalMin, -Number::smallRange.log, Number::unchecked{}};
 };
 
 constexpr Number oneSml = Number::oneSmall();
@@ -342,103 +445,86 @@ constexpr Number oneSml = Number::oneSmall();
 constexpr Number
 Number::oneLarge()
 {
-    return Number{false, Number::largeRange.min, -Number::largeRange.log, Number::unchecked{}};
+    return Number{
+        false, Number::largeRange.internalMin, -Number::largeRange.log, Number::unchecked{}};
 };
 
 constexpr Number oneLrg = Number::oneLarge();
 
 Number
-Number::one()
+Number::one(MantissaRange const& range)
 {
-    if (&range_.get() == &smallRange)
+    if (&range == &smallRange)
         return oneSml;
-    XRPL_ASSERT(&range_.get() == &largeRange, "Number::one() : valid range_");
+    XRPL_ASSERT(&range == &largeRange, "Number::one() : valid range");
     return oneLrg;
 }
 
+Number
+Number::one()
+{
+    return one(range_);
+}
+
 // Use the member names in this static function for now so the diff is cleaner
-// TODO: Rename the function parameters to get rid of the "_" suffix
 template <class T>
 void
 doNormalize(
     bool& negative,
-    T& mantissa_,
-    int& exponent_,
+    T& mantissa,
+    int& exponent,
     MantissaRange::rep const& minMantissa,
     MantissaRange::rep const& maxMantissa)
 {
     auto constexpr minExponent = Number::minExponent;
     auto constexpr maxExponent = Number::maxExponent;
-    auto constexpr maxRep = Number::maxRep;
 
     using Guard = Number::Guard;
 
     constexpr Number zero = Number{};
-    if (mantissa_ == 0)
+    auto const& range = Number::range_.get();
+    if (mantissa == 0 || (mantissa < minMantissa && exponent <= minExponent))
     {
-        mantissa_ = zero.mantissa_;
-        exponent_ = zero.exponent_;
-        negative = zero.negative_;
+        std::tie(negative, mantissa, exponent) = zero.toInternal(range);
         return;
     }
-    auto m = mantissa_;
-    while ((m < minMantissa) && (exponent_ > minExponent))
+
+    auto m = mantissa;
+    while ((m < minMantissa) && (exponent > minExponent))
     {
         m *= 10;
-        --exponent_;
+        --exponent;
     }
     Guard g;
     if (negative)
         g.set_negative();
     while (m > maxMantissa)
     {
-        if (exponent_ >= maxExponent)
+        if (exponent >= maxExponent)
             throw std::overflow_error("Number::normalize 1");
         g.push(m % 10);
         m /= 10;
-        ++exponent_;
+        ++exponent;
     }
-    if ((exponent_ < minExponent) || (m < minMantissa))
+    if ((exponent < minExponent) || (m == 0))
     {
-        mantissa_ = zero.mantissa_;
-        exponent_ = zero.exponent_;
-        negative = zero.negative_;
+        std::tie(negative, mantissa, exponent) = zero.toInternal(range);
         return;
     }
 
-    // When using the largeRange, "m" needs fit within an int64, even if
-    // the final mantissa_ is going to end up larger to fit within the
-    // MantissaRange. Cut it down here so that the rounding will be done while
-    // it's smaller.
-    //
-    // Example: 9,900,000,000,000,123,456 > 9,223,372,036,854,775,807,
-    //      so "m" will be modified to 990,000,000,000,012,345. Then that value
-    //      will be rounded to 990,000,000,000,012,345 or
-    //      990,000,000,000,012,346, depending on the rounding mode. Finally,
-    //      mantissa_ will be "m*10" so it fits within the range, and end up as
-    //      9,900,000,000,000,123,450 or 9,900,000,000,000,123,460.
-    // mantissa() will return mantissa_ / 10, and exponent() will return
-    // exponent_ + 1.
-    if (m > maxRep)
-    {
-        if (exponent_ >= maxExponent)
-            throw std::overflow_error("Number::normalize 1.5");
-        g.push(m % 10);
-        m /= 10;
-        ++exponent_;
-    }
-    // Before modification, m should be within the min/max range. After
-    // modification, it must be less than maxRep. In other words, the original
-    // value should have been no more than maxRep * 10.
-    // (maxRep * 10 > maxMantissa)
-    XRPL_ASSERT_PARTS(m <= maxRep, "xrpl::doNormalize", "intermediate mantissa fits in int64");
-    mantissa_ = m;
+    XRPL_ASSERT_PARTS(m <= maxMantissa, "xrpl::doNormalize", "intermediate mantissa fits in int64");
+    mantissa = m;
+
+    g.doRoundUp(negative, mantissa, exponent, minMantissa, maxMantissa, "Number::normalize 2");
 
-    g.doRoundUp(negative, mantissa_, exponent_, minMantissa, maxMantissa, "Number::normalize 2");
     XRPL_ASSERT_PARTS(
-        mantissa_ >= minMantissa && mantissa_ <= maxMantissa,
+        mantissa >= minMantissa && mantissa <= maxMantissa,
         "xrpl::doNormalize",
         "final mantissa fits in range");
+    XRPL_ASSERT_PARTS(
+        exponent >= minExponent && exponent <= maxExponent,
+        "xrpl::doNormalize",
+        "final exponent fits in range");
 }
 
 template <>
@@ -477,11 +563,20 @@ Number::normalize<unsigned long>(
     doNormalize(negative, mantissa, exponent, minMantissa, maxMantissa);
 }
 
+void
+Number::normalize(MantissaRange const& range)
+{
+    auto [negative, mantissa, exponent] = toInternal(range);
+
+    normalize(negative, mantissa, exponent, range.min, range.max);
+
+    fromInternal(negative, mantissa, exponent, &range);
+}
+
 void
 Number::normalize()
 {
-    auto const& range = range_.get();
-    normalize(negative_, mantissa_, exponent_, range.min, range.max);
+    normalize(range_);
 }
 
 // Copy the number, but set a new exponent. Because the mantissa doesn't change,
@@ -491,21 +586,33 @@ Number
 Number::shiftExponent(int exponentDelta) const
 {
     XRPL_ASSERT_PARTS(isnormal(), "xrpl::Number::shiftExponent", "normalized");
-    auto const newExponent = exponent_ + exponentDelta;
-    if (newExponent >= maxExponent)
+
+    Number result = *this;
+
+    result.exponent_ += exponentDelta;
+
+    if (result.exponent_ >= maxExponent)
         throw std::overflow_error("Number::shiftExponent");
-    if (newExponent < minExponent)
+    if (result.exponent_ < minExponent)
     {
         return Number{};
     }
-    Number const result{negative_, mantissa_, newExponent, unchecked{}};
-    XRPL_ASSERT_PARTS(result.isnormal(), "xrpl::Number::shiftExponent", "result is normalized");
+
     return result;
 }
 
+Number::Number(bool negative, internalrep mantissa, int exponent, normalized)
+{
+    auto const& range = range_.get();
+    normalize(negative, mantissa, exponent, range.min, range.max);
+    fromInternal(negative, mantissa, exponent, &range);
+}
+
 Number&
 Number::operator+=(Number const& y)
 {
+    auto const& range = range_.get();
+
     constexpr Number zero = Number{};
     if (y == zero)
         return *this;
@@ -520,7 +627,8 @@ Number::operator+=(Number const& y)
         return *this;
     }
 
-    XRPL_ASSERT(isnormal() && y.isnormal(), "xrpl::Number::operator+=(Number) : is normal");
+    XRPL_ASSERT(
+        isnormal(range) && y.isnormal(range), "xrpl::Number::operator+=(Number) : is normal");
     // *n = negative
     // *s = sign
     // *m = mantissa
@@ -528,13 +636,10 @@ Number::operator+=(Number const& y)
 
     // Need to use uint128_t, because large mantissas can overflow when added
     // together.
-    bool xn = negative_;
-    uint128_t xm = mantissa_;
-    auto xe = exponent_;
+    auto [xn, xm, xe] = toInternal<uint128_t>(range);
+
+    auto [yn, ym, ye] = y.toInternal<uint128_t>(range);
 
-    bool yn = y.negative_;
-    uint128_t ym = y.mantissa_;
-    auto ye = y.exponent_;
     Guard g;
     if (xe < ye)
     {
@@ -559,14 +664,13 @@ Number::operator+=(Number const& y)
         } while (xe > ye);
     }
 
-    auto const& range = range_.get();
     auto const& minMantissa = range.min;
     auto const& maxMantissa = range.max;
 
     if (xn == yn)
     {
         xm += ym;
-        if (xm > maxMantissa || xm > maxRep)
+        if (xm > maxMantissa)
         {
             g.push(xm % 10);
             xm /= 10;
@@ -586,7 +690,7 @@ Number::operator+=(Number const& y)
             xe = ye;
             xn = yn;
         }
-        while (xm < minMantissa && xm * 10 <= maxRep)
+        while (xm < minMantissa)
         {
             xm *= 10;
             xm -= g.pop();
@@ -595,10 +699,8 @@ Number::operator+=(Number const& y)
         g.doRoundDown(xn, xm, xe, minMantissa);
     }
 
-    negative_ = xn;
-    mantissa_ = static_cast<internalrep>(xm);
-    exponent_ = xe;
-    normalize();
+    normalize(xn, xm, xe, minMantissa, maxMantissa);
+    fromInternal(xn, xm, xe, &range);
     return *this;
 }
 
@@ -633,6 +735,8 @@ divu10(uint128_t& u)
 Number&
 Number::operator*=(Number const& y)
 {
+    auto const& range = range_.get();
+
     constexpr Number zero = Number{};
     if (*this == zero)
         return *this;
@@ -646,15 +750,11 @@ Number::operator*=(Number const& y)
     // *m = mantissa
     // *e = exponent
 
-    bool xn = negative_;
+    auto [xn, xm, xe] = toInternal(range);
     int xs = xn ? -1 : 1;
-    internalrep xm = mantissa_;
-    auto xe = exponent_;
 
-    bool yn = y.negative_;
+    auto [yn, ym, ye] = y.toInternal(range);
     int ys = yn ? -1 : 1;
-    internalrep ym = y.mantissa_;
-    auto ye = y.exponent_;
 
     auto zm = uint128_t(xm) * uint128_t(ym);
     auto ze = xe + ye;
@@ -664,11 +764,10 @@ Number::operator*=(Number const& y)
     if (zn)
         g.set_negative();
 
-    auto const& range = range_.get();
     auto const& minMantissa = range.min;
     auto const& maxMantissa = range.max;
 
-    while (zm > maxMantissa || zm > maxRep)
+    while (zm > maxMantissa)
     {
         // The following is optimization for:
         // g.push(static_cast<unsigned>(zm % 10));
@@ -685,17 +784,17 @@ Number::operator*=(Number const& y)
         minMantissa,
         maxMantissa,
         "Number::multiplication overflow : exponent is " + std::to_string(xe));
-    negative_ = zn;
-    mantissa_ = xm;
-    exponent_ = xe;
 
-    normalize();
+    normalize(zn, xm, xe, minMantissa, maxMantissa);
+    fromInternal(zn, xm, xe, &range);
     return *this;
 }
 
 Number&
 Number::operator/=(Number const& y)
 {
+    auto const& range = range_.get();
+
     constexpr Number zero = Number{};
     if (y == zero)
         throw std::overflow_error("Number: divide by 0");
@@ -708,17 +807,12 @@ Number::operator/=(Number const& y)
     // *m = mantissa
     // *e = exponent
 
-    bool np = negative_;
+    auto [np, nm, ne] = toInternal(range);
     int ns = (np ? -1 : 1);
-    auto nm = mantissa_;
-    auto ne = exponent_;
 
-    bool dp = y.negative_;
+    auto [dp, dm, de] = y.toInternal(range);
     int ds = (dp ? -1 : 1);
-    auto dm = y.mantissa_;
-    auto de = y.exponent_;
 
-    auto const& range = range_.get();
     auto const& minMantissa = range.min;
     auto const& maxMantissa = range.max;
 
@@ -730,7 +824,7 @@ Number::operator/=(Number const& y)
     // f can be up to 10^(38-19) = 10^19 safely
     static_assert(smallRange.log == 15);
     static_assert(largeRange.log == 18);
-    bool small = Number::getMantissaScale() == MantissaRange::small;
+    bool small = range.scale == MantissaRange::small;
     uint128_t const f = small ? 100'000'000'000'000'000 : 10'000'000'000'000'000'000ULL;
     XRPL_ASSERT_PARTS(f >= minMantissa * 10, "Number::operator/=", "factor expected size");
 
@@ -780,10 +874,8 @@ Number::operator/=(Number const& y)
         }
     }
     normalize(zn, zm, ze, minMantissa, maxMantissa);
-    negative_ = zn;
-    mantissa_ = static_cast<internalrep>(zm);
-    exponent_ = ze;
-    XRPL_ASSERT_PARTS(isnormal(), "xrpl::Number::operator/=", "result is normalized");
+    fromInternal(zn, zm, ze, &range);
+    XRPL_ASSERT_PARTS(isnormal(range), "xrpl::Number::operator/=", "result is normalized");
 
     return *this;
 }
@@ -791,30 +883,36 @@ Number::operator/=(Number const& y)
 Number::
 operator rep() const
 {
-    rep drops = mantissa();
+    auto const m = mantissa();
+    internalrep drops = externalToInternal(m);
+
+    if (drops == 0)
+        return drops;
+
     int offset = exponent();
     Guard g;
-    if (drops != 0)
+
+    if (m < 0)
     {
-        if (negative_)
-        {
-            g.set_negative();
-            drops = -drops;
-        }
-        for (; offset < 0; ++offset)
-        {
-            g.push(drops % 10);
-            drops /= 10;
-        }
-        for (; offset > 0; --offset)
-        {
-            if (drops > maxRep / 10)
-                throw std::overflow_error("Number::operator rep() overflow");
-            drops *= 10;
-        }
-        g.doRound(drops, "Number::operator rep() rounding overflow");
+        g.set_negative();
     }
-    return drops;
+    for (; offset < 0; ++offset)
+    {
+        g.push(drops % 10);
+        drops /= 10;
+    }
+    for (; offset > 0; --offset)
+    {
+        if (drops >= largeRange.min)
+            throw std::overflow_error("Number::operator rep() overflow");
+        drops *= 10;
+    }
+    g.doRound(drops, "Number::operator rep() rounding overflow");
+
+    if (g.is_negative())
+        return -drops;
+    else
+        return drops;
 }
 
 Number
@@ -838,19 +936,22 @@ Number::truncate() const noexcept
 std::string
 to_string(Number const& amount)
 {
+    auto const& range = Number::range_.get();
+
     // keep full internal accuracy, but make more human friendly if possible
     constexpr Number zero = Number{};
     if (amount == zero)
         return "0";
 
-    auto exponent = amount.exponent_;
-    auto mantissa = amount.mantissa_;
-    bool const negative = amount.negative_;
+    // The mantissa must have a set number of decimal places for this to work
+    auto [negative, mantissa, exponent] = amount.toInternal(range);
 
     // Use scientific notation for exponents that are too small or too large
-    auto const rangeLog = Number::mantissaLog();
-    if (((exponent != 0) && ((exponent < -(rangeLog + 10)) || (exponent > -(rangeLog - 10)))))
+    auto const rangeLog = range.log;
+    if (((exponent != 0 && amount.exponent() != 0) &&
+         ((exponent < -(rangeLog + 10)) || (exponent > -(rangeLog - 10)))))
     {
+        // Remove trailing zeroes from the mantissa.
         while (mantissa != 0 && mantissa % 10 == 0 && exponent < Number::maxExponent)
         {
             mantissa /= 10;
@@ -858,8 +959,11 @@ to_string(Number const& amount)
         }
         std::string ret = negative ? "-" : "";
         ret.append(std::to_string(mantissa));
-        ret.append(1, 'e');
-        ret.append(std::to_string(exponent));
+        if (exponent != 0)
+        {
+            ret.append(1, 'e');
+            ret.append(std::to_string(exponent));
+        }
         return ret;
     }
 
@@ -943,20 +1047,11 @@ power(Number const& f, unsigned n)
     return r;
 }
 
-// Returns f^(1/d)
-// Uses Newton–Raphson iterations until the result stops changing
-// to find the non-negative root of the polynomial g(x) = x^d - f
-
-// This function, and power(Number f, unsigned n, unsigned d)
-// treat corner cases such as 0 roots as advised by Annex F of
-// the C standard, which itself is consistent with the IEEE
-// floating point standards.
-
 Number
-root(Number f, unsigned d)
+Number::root(MantissaRange const& range, Number f, unsigned d)
 {
     constexpr Number zero = Number{};
-    auto const one = Number::one();
+    auto const one = Number::one(range);
 
     if (f == one || d == 1)
         return f;
@@ -973,21 +1068,28 @@ root(Number f, unsigned d)
     if (f == zero)
         return f;
 
-    // Scale f into the range (0, 1) such that f's exponent is a multiple of d
-    auto e = f.exponent_ + Number::mantissaLog() + 1;
-    auto const di = static_cast<int>(d);
-    auto ex = [e = e, di = di]()  // Euclidean remainder of e/d
-    {
-        int k = (e >= 0 ? e : e - (di - 1)) / di;
-        int k2 = e - k * di;
-        if (k2 == 0)
-            return 0;
-        return di - k2;
-    }();
-    e += ex;
-    f = f.shiftExponent(-e);  // f /= 10^e;
+    auto const [e, di] = [&]() {
+        auto const exponent = std::get<2>(f.toInternal(range));
 
-    XRPL_ASSERT_PARTS(f.isnormal(), "xrpl::root(Number, unsigned)", "f is normalized");
+        // Scale f into the range (0, 1) such that the scale change (e) is a
+        // multiple of the root (d)
+        auto e = exponent + range.log + 1;
+        auto const di = static_cast<int>(d);
+        auto ex = [e = e, di = di]()  // Euclidean remainder of e/d
+        {
+            int k = (e >= 0 ? e : e - (di - 1)) / di;
+            int k2 = e - k * di;
+            if (k2 == 0)
+                return 0;
+            return di - k2;
+        }();
+        e += ex;
+        f = f.shiftExponent(-e);  // f /= 10^e;
+        return std::make_tuple(e, di);
+    }();
+
+    XRPL_ASSERT_PARTS(e % di == 0, "xrpl::root(Number, unsigned)", "e is divisible by d");
+    XRPL_ASSERT_PARTS(f.isnormal(range), "xrpl::root(Number, unsigned)", "f is normalized");
     bool neg = false;
     if (f < zero)
     {
@@ -1020,15 +1122,33 @@ root(Number f, unsigned d)
 
     //  return r * 10^(e/d) to reverse scaling
     auto const result = r.shiftExponent(e / di);
-    XRPL_ASSERT_PARTS(result.isnormal(), "xrpl::root(Number, unsigned)", "result is normalized");
+    XRPL_ASSERT_PARTS(
+        result.isnormal(range), "xrpl::root(Number, unsigned)", "result is normalized");
     return result;
 }
 
+// Returns f^(1/d)
+// Uses Newton–Raphson iterations until the result stops changing
+// to find the non-negative root of the polynomial g(x) = x^d - f
+
+// This function, and power(Number f, unsigned n, unsigned d)
+// treat corner cases such as 0 roots as advised by Annex F of
+// the C standard, which itself is consistent with the IEEE
+// floating point standards.
+
+Number
+root(Number f, unsigned d)
+{
+    auto const& range = Number::range_.get();
+    return Number::root(range, f, d);
+}
+
 Number
 root2(Number f)
 {
+    auto const& range = Number::range_.get();
     constexpr Number zero = Number{};
-    auto const one = Number::one();
+    auto const one = Number::one(range);
 
     if (f == one)
         return f;
@@ -1037,12 +1157,18 @@ root2(Number f)
     if (f == zero)
         return f;
 
-    // Scale f into the range (0, 1) such that f's exponent is a multiple of d
-    auto e = f.exponent_ + Number::mantissaLog() + 1;
-    if (e % 2 != 0)
-        ++e;
-    f = f.shiftExponent(-e);  // f /= 10^e;
-    XRPL_ASSERT_PARTS(f.isnormal(), "xrpl::root2(Number)", "f is normalized");
+    auto const e = [&]() {
+        auto const exponent = std::get<2>(f.toInternal(range));
+
+        // Scale f into the range (0, 1) such that f's exponent is a
+        // multiple of d
+        auto e = exponent + range.log + 1;
+        if (e % 2 != 0)
+            ++e;
+        f = f.shiftExponent(-e);  // f /= 10^e;
+        return e;
+    }();
+    XRPL_ASSERT_PARTS(f.isnormal(range), "xrpl::root2(Number)", "f is normalized");
 
     // Quadratic least squares curve fit of f^(1/d) in the range [0, 1]
     auto const D = 105;
@@ -1064,7 +1190,7 @@ root2(Number f)
 
     //  return r * 10^(e/2) to reverse scaling
     auto const result = r.shiftExponent(e / 2);
-    XRPL_ASSERT_PARTS(result.isnormal(), "xrpl::root2(Number)", "result is normalized");
+    XRPL_ASSERT_PARTS(result.isnormal(range), "xrpl::root2(Number)", "result is normalized");
 
     return result;
 }
@@ -1074,8 +1200,10 @@ root2(Number f)
 Number
 power(Number const& f, unsigned n, unsigned d)
 {
+    auto const& range = Number::range_.get();
+
     constexpr Number zero = Number{};
-    auto const one = Number::one();
+    auto const one = Number::one(range);
 
     if (f == one)
         return f;
@@ -1097,7 +1225,7 @@ power(Number const& f, unsigned n, unsigned d)
     d /= g;
     if ((n % 2) == 1 && (d % 2) == 0 && f < zero)
         throw std::overflow_error("Number::power nan");
-    return root(power(f, n), d);
+    return Number::root(range, power(f, n), d);
 }
 
 }  // namespace xrpl

src/test/app/Path_test.cpp

@@ -8,7 +8,6 @@
 #include <xrpld/rpc/detail/Tuning.h>
 
 #include <xrpl/beast/unit_test.h>
-#include <xrpl/core/CoroTask.h>
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/json/json_reader.h>
 #include <xrpl/protocol/ApiVersion.h>
@@ -132,6 +131,7 @@ public:
              c,
              Role::USER,
              {},
+             {},
              RPC::apiVersionIfUnspecified},
             {},
             {}};
@@ -155,11 +155,11 @@ public:
 
         Json::Value result;
         gate g;
-        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
             context.params = std::move(params);
+            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
-            co_return;
         });
 
         using namespace std::chrono_literals;
@@ -240,27 +240,28 @@ public:
              c,
              Role::USER,
              {},
+             {},
              RPC::apiVersionIfUnspecified},
             {},
             {}};
         Json::Value result;
         gate g;
         // Test RPC::Tuning::max_src_cur source currencies.
-        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
             context.params = rpf(Account("alice"), Account("bob"), RPC::Tuning::max_src_cur);
+            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
-            co_return;
         });
         BEAST_EXPECT(g.wait_for(5s));
         BEAST_EXPECT(!result.isMember(jss::error));
 
         // Test more than RPC::Tuning::max_src_cur source currencies.
-        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
             context.params = rpf(Account("alice"), Account("bob"), RPC::Tuning::max_src_cur + 1);
+            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
-            co_return;
         });
         BEAST_EXPECT(g.wait_for(5s));
         BEAST_EXPECT(result.isMember(jss::error));
@@ -268,22 +269,22 @@ public:
         // Test RPC::Tuning::max_auto_src_cur source currencies.
         for (auto i = 0; i < (RPC::Tuning::max_auto_src_cur - 1); ++i)
             env.trust(Account("alice")[std::to_string(i + 100)](100), "bob");
-        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
             context.params = rpf(Account("alice"), Account("bob"), 0);
+            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
-            co_return;
         });
         BEAST_EXPECT(g.wait_for(5s));
         BEAST_EXPECT(!result.isMember(jss::error));
 
         // Test more than RPC::Tuning::max_auto_src_cur source currencies.
         env.trust(Account("alice")["AUD"](100), "bob");
-        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
             context.params = rpf(Account("alice"), Account("bob"), 0);
+            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
-            co_return;
         });
         BEAST_EXPECT(g.wait_for(5s));
         BEAST_EXPECT(result.isMember(jss::error));

src/test/basics/Number_test.cpp

@@ -32,9 +32,10 @@ public:
     test_limits()
     {
         auto const scale = Number::getMantissaScale();
-        testcase << "test_limits " << to_string(scale);
-        bool caught = false;
         auto const minMantissa = Number::minMantissa();
+
+        testcase << "test_limits " << to_string(scale) << ", " << minMantissa;
+        bool caught = false;
         try
         {
             Number x = Number{false, minMantissa * 10, 32768, Number::normalized{}};
@@ -58,8 +59,9 @@ public:
             __LINE__);
         test(Number{false, minMantissa, -32769, Number::normalized{}}, Number{}, __LINE__);
         test(
+            // Use 1501 to force rounding up
             Number{false, minMantissa, 32000, Number::normalized{}} * 1'000 +
-                Number{false, 1'500, 32000, Number::normalized{}},
+                Number{false, 1'501, 32000, Number::normalized{}},
             Number{false, minMantissa + 2, 32003, Number::normalized{}},
             __LINE__);
         // 9,223,372,036,854,775,808
@@ -168,8 +170,12 @@ public:
                 {Number{true, 9'999'999'999'999'999'999ULL, -37, Number::normalized{}},
                  Number{1'000'000'000'000'000'000, -18},
                  Number{false, 9'999'999'999'999'999'990ULL, -19, Number::normalized{}}},
-                {Number{Number::maxRep}, Number{6, -1}, Number{Number::maxRep / 10, 1}},
-                {Number{Number::maxRep - 1}, Number{1, 0}, Number{Number::maxRep}},
+                {Number{Number::largestMantissa},
+                 Number{6, -1},
+                 Number{Number::largestMantissa / 10, 1}},
+                {Number{Number::largestMantissa - 1},
+                 Number{1, 0},
+                 Number{Number::largestMantissa}},
                 // Test extremes
                 {
                     // Each Number operand rounds up, so the actual mantissa is
@@ -179,11 +185,18 @@ public:
                     Number{2, 19},
                 },
                 {
-                    // Does not round. Mantissas are going to be > maxRep, so if
-                    // added together as uint64_t's, the result will overflow.
-                    // With addition using uint128_t, there's no problem. After
-                    // normalizing, the resulting mantissa ends up less than
-                    // maxRep.
+                    // Does not round. Mantissas are going to be >
+                    // largestMantissa, so if added together as uint64_t's, the
+                    // result will overflow. With addition using uint128_t,
+                    // there's no problem. After normalizing, the resulting
+                    // mantissa ends up less than largestMantissa.
+                    Number{false, Number::largestMantissa, 0, Number::normalized{}},
+                    Number{false, Number::largestMantissa, 0, Number::normalized{}},
+                    Number{false, Number::largestMantissa * 2, 0, Number::normalized{}},
+                },
+                {
+                    // These mantissas round down, so adding them together won't
+                    // have any consequences.
                     Number{false, 9'999'999'999'999'999'990ULL, 0, Number::normalized{}},
                     Number{false, 9'999'999'999'999'999'990ULL, 0, Number::normalized{}},
                     Number{false, 1'999'999'999'999'999'998ULL, 1, Number::normalized{}},
@@ -272,14 +285,16 @@ public:
                 {Number{1'000'000'000'000'000'001, -18},
                  Number{1'000'000'000'000'000'000, -18},
                  Number{1'000'000'000'000'000'000, -36}},
-                {Number{Number::maxRep}, Number{6, -1}, Number{Number::maxRep - 1}},
-                {Number{false, Number::maxRep + 1, 0, Number::normalized{}},
+                {Number{Number::largestMantissa},
+                 Number{6, -1},
+                 Number{Number::largestMantissa - 1}},
+                {Number{false, Number::largestMantissa + 1, 0, Number::normalized{}},
                  Number{1, 0},
-                 Number{Number::maxRep / 10 + 1, 1}},
-                {Number{false, Number::maxRep + 1, 0, Number::normalized{}},
+                 Number{Number::largestMantissa / 10 + 1, 1}},
+                {Number{false, Number::largestMantissa + 1, 0, Number::normalized{}},
                  Number{3, 0},
-                 Number{Number::maxRep}},
-                {power(2, 63), Number{3, 0}, Number{Number::maxRep}},
+                 Number{Number::largestMantissa}},
+                {power(2, 63), Number{3, 0}, Number{Number::largestMantissa}},
             });
         auto test = [this](auto const& c) {
             for (auto const& [x, y, z] : c)
@@ -296,20 +311,30 @@ public:
             test(cLarge);
     }
 
+    static std::uint64_t
+    getMaxInternalMantissa()
+    {
+        return static_cast<std::uint64_t>(
+                   static_cast<std::int64_t>(power(10, Number::mantissaLog()))) *
+            10 -
+            1;
+    }
+
     void
     test_mul()
     {
         auto const scale = Number::getMantissaScale();
         testcase << "test_mul " << to_string(scale);
 
-        using Case = std::tuple<Number, Number, Number>;
+        // Case: Factor 1, Factor 2, Expected product, Line number
+        using Case = std::tuple<Number, Number, Number, int>;
         auto test = [this](auto const& c) {
-            for (auto const& [x, y, z] : c)
+            for (auto const& [x, y, z, line] : c)
             {
                 auto const result = x * y;
                 std::stringstream ss;
                 ss << x << " * " << y << " = " << result << ". Expected: " << z;
-                BEAST_EXPECTS(result == z, ss.str());
+                BEAST_EXPECTS(result == z, ss.str() + " line: " + std::to_string(line));
             }
         };
         auto tests = [&](auto const& cSmall, auto const& cLarge) {
@@ -319,70 +344,97 @@ public:
                 test(cLarge);
         };
         auto const maxMantissa = Number::maxMantissa();
+        auto const maxInternalMantissa = getMaxInternalMantissa();
 
         saveNumberRoundMode save{Number::setround(Number::to_nearest)};
         {
             auto const cSmall = std::to_array<Case>({
-                {Number{7}, Number{8}, Number{56}},
+                {Number{7}, Number{8}, Number{56}, __LINE__},
                 {Number{1414213562373095, -15},
                  Number{1414213562373095, -15},
-                 Number{2000000000000000, -15}},
+                 Number{2000000000000000, -15},
+                 __LINE__},
                 {Number{-1414213562373095, -15},
                  Number{1414213562373095, -15},
-                 Number{-2000000000000000, -15}},
+                 Number{-2000000000000000, -15},
+                 __LINE__},
                 {Number{-1414213562373095, -15},
                  Number{-1414213562373095, -15},
-                 Number{2000000000000000, -15}},
+                 Number{2000000000000000, -15},
+                 __LINE__},
                 {Number{3214285714285706, -15},
                  Number{3111111111111119, -15},
-                 Number{1000000000000000, -14}},
-                {Number{1000000000000000, -32768}, Number{1000000000000000, -32768}, Number{0}},
+                 Number{1000000000000000, -14},
+                 __LINE__},
+                {Number{1000000000000000, -32768},
+                 Number{1000000000000000, -32768},
+                 Number{0},
+                 __LINE__},
                 // Maximum mantissa range
                 {Number{9'999'999'999'999'999, 0},
                  Number{9'999'999'999'999'999, 0},
-                 Number{9'999'999'999'999'998, 16}},
+                 Number{9'999'999'999'999'998, 16},
+                 __LINE__},
             });
             auto const cLarge = std::to_array<Case>({
                 // Note that items with extremely large mantissas need to be
                 // calculated, because otherwise they overflow uint64. Items
                 // from C with larger mantissa
-                {Number{7}, Number{8}, Number{56}},
+                {Number{7}, Number{8}, Number{56}, __LINE__},
                 {Number{1414213562373095, -15},
                  Number{1414213562373095, -15},
-                 Number{1999999999999999862, -18}},
+                 Number{1999999999999999862, -18},
+                 __LINE__},
                 {Number{-1414213562373095, -15},
                  Number{1414213562373095, -15},
-                 Number{-1999999999999999862, -18}},
+                 Number{-1999999999999999862, -18},
+                 __LINE__},
                 {Number{-1414213562373095, -15},
                  Number{-1414213562373095, -15},
-                 Number{1999999999999999862, -18}},
+                 Number{1999999999999999862, -18},
+                 __LINE__},
                 {Number{3214285714285706, -15},
                  Number{3111111111111119, -15},
-                 Number{false, 9'999'999'999'999'999'579ULL, -18, Number::normalized{}}},
+                 Number{false, 9'999'999'999'999'999'579ULL, -18, Number::normalized{}},
+                 __LINE__},
                 {Number{1000000000000000000, -32768},
                  Number{1000000000000000000, -32768},
-                 Number{0}},
+                 Number{0},
+                 __LINE__},
                 // Items from cSmall expanded for the larger mantissa,
                 // except duplicates. Sadly, it looks like sqrt(2)^2 != 2
                 // with higher precision
                 {Number{1414213562373095049, -18},
                  Number{1414213562373095049, -18},
-                 Number{2000000000000000001, -18}},
+                 Number{2000000000000000001, -18},
+                 __LINE__},
                 {Number{-1414213562373095048, -18},
                  Number{1414213562373095048, -18},
-                 Number{-1999999999999999998, -18}},
+                 Number{-1999999999999999998, -18},
+                 __LINE__},
                 {Number{-1414213562373095048, -18},
                  Number{-1414213562373095049, -18},
-                 Number{1999999999999999999, -18}},
-                {Number{3214285714285714278, -18}, Number{3111111111111111119, -18}, Number{10, 0}},
-                // Maximum mantissa range - rounds up to 1e19
+                 Number{1999999999999999999, -18},
+                 __LINE__},
+                {Number{3214285714285714278, -18},
+                 Number{3111111111111111119, -18},
+                 Number{10, 0},
+                 __LINE__},
+                // Maximum internal mantissa range - rounds up to 1e19
+                {Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                 Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                 Number{1, 38},
+                 __LINE__},
+                // Maximum actual mantissa range - same as int64 range
                 {Number{false, maxMantissa, 0, Number::normalized{}},
                  Number{false, maxMantissa, 0, Number::normalized{}},
-                 Number{1, 38}},
+                 Number{85'070'591'730'234'615'85, 19},
+                 __LINE__},
                 // Maximum int64 range
-                {Number{Number::maxRep, 0},
-                 Number{Number::maxRep, 0},
-                 Number{85'070'591'730'234'615'85, 19}},
+                {Number{Number::largestMantissa, 0},
+                 Number{Number::largestMantissa, 0},
+                 Number{85'070'591'730'234'615'85, 19},
+                 __LINE__},
             });
             tests(cSmall, cLarge);
         }
@@ -390,66 +442,90 @@ public:
         testcase << "test_mul " << to_string(Number::getMantissaScale()) << " towards_zero";
         {
             auto const cSmall = std::to_array<Case>(
-                {{Number{7}, Number{8}, Number{56}},
+                {{Number{7}, Number{8}, Number{56}, __LINE__},
                  {Number{1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{1999999999999999, -15}},
+                  Number{1999999999999999, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{-1999999999999999, -15}},
+                  Number{-1999999999999999, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{-1414213562373095, -15},
-                  Number{1999999999999999, -15}},
+                  Number{1999999999999999, -15},
+                  __LINE__},
                  {Number{3214285714285706, -15},
                   Number{3111111111111119, -15},
-                  Number{9999999999999999, -15}},
-                 {Number{1000000000000000, -32768}, Number{1000000000000000, -32768}, Number{0}}});
+                  Number{9999999999999999, -15},
+                  __LINE__},
+                 {Number{1000000000000000, -32768},
+                  Number{1000000000000000, -32768},
+                  Number{0},
+                  __LINE__}});
             auto const cLarge = std::to_array<Case>(
                 // Note that items with extremely large mantissas need to be
                 // calculated, because otherwise they overflow uint64. Items
                 // from C with larger mantissa
                 {
-                    {Number{7}, Number{8}, Number{56}},
+                    {Number{7}, Number{8}, Number{56}, __LINE__},
                     {Number{1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{1999999999999999861, -18}},
+                     Number{1999999999999999861, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{-1999999999999999861, -18}},
+                     Number{-1999999999999999861, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{-1414213562373095, -15},
-                     Number{1999999999999999861, -18}},
+                     Number{1999999999999999861, -18},
+                     __LINE__},
                     {Number{3214285714285706, -15},
                      Number{3111111111111119, -15},
-                     Number{false, 9999999999999999579ULL, -18, Number::normalized{}}},
+                     Number{false, 9999999999999999579ULL, -18, Number::normalized{}},
+                     __LINE__},
                     {Number{1000000000000000000, -32768},
                      Number{1000000000000000000, -32768},
-                     Number{0}},
+                     Number{0},
+                     __LINE__},
                     // Items from cSmall expanded for the larger mantissa,
                     // except duplicates. Sadly, it looks like sqrt(2)^2 != 2
                     // with higher precision
                     {Number{1414213562373095049, -18},
                      Number{1414213562373095049, -18},
-                     Number{2, 0}},
+                     Number{2, 0},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{1414213562373095048, -18},
-                     Number{-1999999999999999997, -18}},
+                     Number{-1999999999999999997, -18},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{-1414213562373095049, -18},
-                     Number{1999999999999999999, -18}},
+                     Number{1999999999999999999, -18},
+                     __LINE__},
                     {Number{3214285714285714278, -18},
                      Number{3111111111111111119, -18},
-                     Number{10, 0}},
-                    // Maximum mantissa range - rounds down to maxMantissa/10e1
+                     Number{10, 0},
+                     __LINE__},
+                    // Maximum internal mantissa range - rounds down to
+                    // maxMantissa/10e1
                     // 99'999'999'999'999'999'800'000'000'000'000'000'100
+                    {Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{false, maxInternalMantissa / 10 - 1, 20, Number::normalized{}},
+                     __LINE__},
+                    // Maximum actual mantissa range - same as int64
                     {Number{false, maxMantissa, 0, Number::normalized{}},
                      Number{false, maxMantissa, 0, Number::normalized{}},
-                     Number{false, maxMantissa / 10 - 1, 20, Number::normalized{}}},
+                     Number{85'070'591'730'234'615'84, 19},
+                     __LINE__},
                     // Maximum int64 range
                     // 85'070'591'730'234'615'847'396'907'784'232'501'249
-                    {Number{Number::maxRep, 0},
-                     Number{Number::maxRep, 0},
-                     Number{85'070'591'730'234'615'84, 19}},
+                    {Number{Number::largestMantissa, 0},
+                     Number{Number::largestMantissa, 0},
+                     Number{85'070'591'730'234'615'84, 19},
+                     __LINE__},
                 });
             tests(cSmall, cLarge);
         }
@@ -457,66 +533,90 @@ public:
         testcase << "test_mul " << to_string(Number::getMantissaScale()) << " downward";
         {
             auto const cSmall = std::to_array<Case>(
-                {{Number{7}, Number{8}, Number{56}},
+                {{Number{7}, Number{8}, Number{56}, __LINE__},
                  {Number{1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{1999999999999999, -15}},
+                  Number{1999999999999999, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{-2000000000000000, -15}},
+                  Number{-2000000000000000, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{-1414213562373095, -15},
-                  Number{1999999999999999, -15}},
+                  Number{1999999999999999, -15},
+                  __LINE__},
                  {Number{3214285714285706, -15},
                   Number{3111111111111119, -15},
-                  Number{9999999999999999, -15}},
-                 {Number{1000000000000000, -32768}, Number{1000000000000000, -32768}, Number{0}}});
+                  Number{9999999999999999, -15},
+                  __LINE__},
+                 {Number{1000000000000000, -32768},
+                  Number{1000000000000000, -32768},
+                  Number{0},
+                  __LINE__}});
             auto const cLarge = std::to_array<Case>(
                 // Note that items with extremely large mantissas need to be
                 // calculated, because otherwise they overflow uint64. Items
                 // from C with larger mantissa
                 {
-                    {Number{7}, Number{8}, Number{56}},
+                    {Number{7}, Number{8}, Number{56}, __LINE__},
                     {Number{1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{1999999999999999861, -18}},
+                     Number{1999999999999999861, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{-1999999999999999862, -18}},
+                     Number{-1999999999999999862, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{-1414213562373095, -15},
-                     Number{1999999999999999861, -18}},
+                     Number{1999999999999999861, -18},
+                     __LINE__},
                     {Number{3214285714285706, -15},
                      Number{3111111111111119, -15},
-                     Number{false, 9'999'999'999'999'999'579ULL, -18, Number::normalized{}}},
+                     Number{false, 9'999'999'999'999'999'579ULL, -18, Number::normalized{}},
+                     __LINE__},
                     {Number{1000000000000000000, -32768},
                      Number{1000000000000000000, -32768},
-                     Number{0}},
+                     Number{0},
+                     __LINE__},
                     // Items from cSmall expanded for the larger mantissa,
                     // except duplicates. Sadly, it looks like sqrt(2)^2 != 2
                     // with higher precision
                     {Number{1414213562373095049, -18},
                      Number{1414213562373095049, -18},
-                     Number{2, 0}},
+                     Number{2, 0},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{1414213562373095048, -18},
-                     Number{-1999999999999999998, -18}},
+                     Number{-1999999999999999998, -18},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{-1414213562373095049, -18},
-                     Number{1999999999999999999, -18}},
+                     Number{1999999999999999999, -18},
+                     __LINE__},
                     {Number{3214285714285714278, -18},
                      Number{3111111111111111119, -18},
-                     Number{10, 0}},
-                    // Maximum mantissa range - rounds down to maxMantissa/10e1
+                     Number{10, 0},
+                     __LINE__},
+                    // Maximum internal mantissa range - rounds down to
+                    // maxInternalMantissa/10-1
                     // 99'999'999'999'999'999'800'000'000'000'000'000'100
+                    {Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{false, maxInternalMantissa / 10 - 1, 20, Number::normalized{}},
+                     __LINE__},
+                    // Maximum external mantissa range - same as INT64_MAX (2^63-1)
                     {Number{false, maxMantissa, 0, Number::normalized{}},
                      Number{false, maxMantissa, 0, Number::normalized{}},
-                     Number{false, maxMantissa / 10 - 1, 20, Number::normalized{}}},
+                     Number{85'070'591'730'234'615'84, 19},
+                     __LINE__},
                     // Maximum int64 range
                     // 85'070'591'730'234'615'847'396'907'784'232'501'249
-                    {Number{Number::maxRep, 0},
-                     Number{Number::maxRep, 0},
-                     Number{85'070'591'730'234'615'84, 19}},
+                    {Number{Number::largestMantissa, 0},
+                     Number{Number::largestMantissa, 0},
+                     Number{85'070'591'730'234'615'84, 19},
+                     __LINE__},
                 });
             tests(cSmall, cLarge);
         }
@@ -524,66 +624,89 @@ public:
         testcase << "test_mul " << to_string(Number::getMantissaScale()) << " upward";
         {
             auto const cSmall = std::to_array<Case>(
-                {{Number{7}, Number{8}, Number{56}},
+                {{Number{7}, Number{8}, Number{56}, __LINE__},
                  {Number{1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{2000000000000000, -15}},
+                  Number{2000000000000000, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{1414213562373095, -15},
-                  Number{-1999999999999999, -15}},
+                  Number{-1999999999999999, -15},
+                  __LINE__},
                  {Number{-1414213562373095, -15},
                   Number{-1414213562373095, -15},
-                  Number{2000000000000000, -15}},
+                  Number{2000000000000000, -15},
+                  __LINE__},
                  {Number{3214285714285706, -15},
                   Number{3111111111111119, -15},
-                  Number{1000000000000000, -14}},
-                 {Number{1000000000000000, -32768}, Number{1000000000000000, -32768}, Number{0}}});
+                  Number{1000000000000000, -14},
+                  __LINE__},
+                 {Number{1000000000000000, -32768},
+                  Number{1000000000000000, -32768},
+                  Number{0},
+                  __LINE__}});
             auto const cLarge = std::to_array<Case>(
                 // Note that items with extremely large mantissas need to be
                 // calculated, because otherwise they overflow uint64. Items
                 // from C with larger mantissa
                 {
-                    {Number{7}, Number{8}, Number{56}},
+                    {Number{7}, Number{8}, Number{56}, __LINE__},
                     {Number{1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{1999999999999999862, -18}},
+                     Number{1999999999999999862, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{1414213562373095, -15},
-                     Number{-1999999999999999861, -18}},
+                     Number{-1999999999999999861, -18},
+                     __LINE__},
                     {Number{-1414213562373095, -15},
                      Number{-1414213562373095, -15},
-                     Number{1999999999999999862, -18}},
+                     Number{1999999999999999862, -18},
+                     __LINE__},
                     {Number{3214285714285706, -15},
                      Number{3111111111111119, -15},
-                     Number{999999999999999958, -17}},
+                     Number{999999999999999958, -17},
+                     __LINE__},
                     {Number{1000000000000000000, -32768},
                      Number{1000000000000000000, -32768},
-                     Number{0}},
+                     Number{0},
+                     __LINE__},
                     // Items from cSmall expanded for the larger mantissa,
                     // except duplicates. Sadly, it looks like sqrt(2)^2 != 2
                     // with higher precision
                     {Number{1414213562373095049, -18},
                      Number{1414213562373095049, -18},
-                     Number{2000000000000000001, -18}},
+                     Number{2000000000000000001, -18},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{1414213562373095048, -18},
-                     Number{-1999999999999999997, -18}},
+                     Number{-1999999999999999997, -18},
+                     __LINE__},
                     {Number{-1414213562373095048, -18},
                      Number{-1414213562373095049, -18},
-                     Number{2, 0}},
+                     Number{2, 0},
+                     __LINE__},
                     {Number{3214285714285714278, -18},
                      Number{3111111111111111119, -18},
-                     Number{1000000000000000001, -17}},
-                    // Maximum mantissa range - rounds up to minMantissa*10
-                    // 1e19*1e19=1e38
+                     Number{1000000000000000001, -17},
+                     __LINE__},
+                    // Maximum internal mantissa range - rounds up to
+                    // minMantissa*10 1e19*1e19=1e38
+                    {Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{false, maxInternalMantissa, 0, Number::normalized{}},
+                     Number{1, 38},
+                     __LINE__},
+                    // Maximum mantissa range - same as int64
                     {Number{false, maxMantissa, 0, Number::normalized{}},
                      Number{false, maxMantissa, 0, Number::normalized{}},
-                     Number{1, 38}},
+                     Number{85'070'591'730'234'615'85, 19},
+                     __LINE__},
                     // Maximum int64 range
                     // 85'070'591'730'234'615'847'396'907'784'232'501'249
-                    {Number{Number::maxRep, 0},
-                     Number{Number::maxRep, 0},
-                     Number{85'070'591'730'234'615'85, 19}},
+                    {Number{Number::largestMantissa, 0},
+                     Number{Number::largestMantissa, 0},
+                     Number{85'070'591'730'234'615'85, 19},
+                     __LINE__},
                 });
             tests(cSmall, cLarge);
         }
@@ -814,6 +937,8 @@ public:
         };
         */
 
+        auto const maxInternalMantissa = getMaxInternalMantissa();
+
         auto const cSmall = std::to_array<Case>(
             {{Number{2}, 2, Number{1414213562373095049, -18}},
              {Number{2'000'000}, 2, Number{1414213562373095049, -15}},
@@ -825,16 +950,16 @@ public:
              {Number{0}, 5, Number{0}},
              {Number{5625, -4}, 2, Number{75, -2}}});
         auto const cLarge = std::to_array<Case>({
-            {Number{false, Number::maxMantissa() - 9, -1, Number::normalized{}},
+            {Number{false, maxInternalMantissa - 9, -1, Number::normalized{}},
              2,
              Number{false, 999'999'999'999'999'999, -9, Number::normalized{}}},
-            {Number{false, Number::maxMantissa() - 9, 0, Number::normalized{}},
+            {Number{false, maxInternalMantissa - 9, 0, Number::normalized{}},
              2,
              Number{false, 3'162'277'660'168'379'330, -9, Number::normalized{}}},
-            {Number{Number::maxRep},
+            {Number{Number::largestMantissa},
              2,
              Number{false, 3'037'000'499'976049692, -9, Number::normalized{}}},
-            {Number{Number::maxRep},
+            {Number{Number::largestMantissa},
              4,
              Number{false, 55'108'98747006743627, -14, Number::normalized{}}},
         });
@@ -883,6 +1008,8 @@ public:
             }
         };
 
+        Number const maxInternalMantissa = power(10, Number::mantissaLog()) * 10 - 1;
+
         auto const cSmall = std::to_array<Number>({
             Number{2},
             Number{2'000'000},
@@ -892,7 +1019,10 @@ public:
             Number{5, -1},
             Number{0},
             Number{5625, -4},
-            Number{Number::maxRep},
+            Number{Number::largestMantissa},
+            maxInternalMantissa,
+            Number{Number::minMantissa(), 0, Number::unchecked{}},
+            Number{Number::maxMantissa(), 0, Number::unchecked{}},
         });
         test(cSmall);
         bool caught = false;
@@ -1243,18 +1373,18 @@ public:
             case MantissaRange::large:
                 // Test the edges
                 // ((exponent < -(28)) || (exponent > -(8)))))
-                test(Number::min(), "1e-32750");
+                test(Number::min(), "922337203685477581e-32768");
                 test(Number::max(), "9223372036854775807e32768");
                 test(Number::lowest(), "-9223372036854775807e32768");
                 {
                     NumberRoundModeGuard mg(Number::towards_zero);
 
                     auto const maxMantissa = Number::maxMantissa();
-                    BEAST_EXPECT(maxMantissa == 9'999'999'999'999'999'999ULL);
+                    BEAST_EXPECT(maxMantissa == 9'223'372'036'854'775'807ULL);
                     test(
-                        Number{false, maxMantissa, 0, Number::normalized{}}, "9999999999999999990");
+                        Number{false, maxMantissa, 0, Number::normalized{}}, "9223372036854775807");
                     test(
-                        Number{true, maxMantissa, 0, Number::normalized{}}, "-9999999999999999990");
+                        Number{true, maxMantissa, 0, Number::normalized{}}, "-9223372036854775807");
 
                     test(
                         Number{std::numeric_limits<std::int64_t>::max(), 0}, "9223372036854775807");
@@ -1490,7 +1620,7 @@ public:
             Number const initalXrp{INITIAL_XRP};
             BEAST_EXPECT(initalXrp.exponent() > 0);
 
-            Number const maxInt64{Number::maxRep};
+            Number const maxInt64{Number::largestMantissa};
             BEAST_EXPECT(maxInt64.exponent() > 0);
             // 85'070'591'730'234'615'865'843'651'857'942'052'864 - 38 digits
             BEAST_EXPECT((power(maxInt64, 2) == Number{85'070'591'730'234'62, 22}));
@@ -1507,21 +1637,213 @@ public:
             Number const initalXrp{INITIAL_XRP};
             BEAST_EXPECT(initalXrp.exponent() <= 0);
 
-            Number const maxInt64{Number::maxRep};
+            Number const maxInt64{Number::largestMantissa};
             BEAST_EXPECT(maxInt64.exponent() <= 0);
             // 85'070'591'730'234'615'847'396'907'784'232'501'249 - 38 digits
             BEAST_EXPECT((power(maxInt64, 2) == Number{85'070'591'730'234'615'85, 19}));
 
             NumberRoundModeGuard mg(Number::towards_zero);
 
-            auto const maxMantissa = Number::maxMantissa();
-            Number const max = Number{false, maxMantissa, 0, Number::normalized{}};
-            BEAST_EXPECT(max.mantissa() == maxMantissa / 10);
-            BEAST_EXPECT(max.exponent() == 1);
-            // 99'999'999'999'999'999'800'000'000'000'000'000'100 - also 38
-            // digits
-            BEAST_EXPECT(
-                (power(max, 2) == Number{false, maxMantissa / 10 - 1, 20, Number::normalized{}}));
+            {
+                auto const maxInternalMantissa = getMaxInternalMantissa();
+
+                // Rounds down to fit under 2^63
+                Number const max = Number{false, maxInternalMantissa, 0, Number::normalized{}};
+                // No alterations by the accessors
+                BEAST_EXPECT(max.mantissa() == maxInternalMantissa / 10);
+                BEAST_EXPECT(max.exponent() == 1);
+                // 99'999'999'999'999'999'800'000'000'000'000'000'100 - also 38
+                // digits
+                BEAST_EXPECT(
+                    (power(max, 2) ==
+                     Number{false, maxInternalMantissa / 10 - 1, 20, Number::normalized{}}));
+            }
+
+            {
+                auto const maxMantissa = Number::maxMantissa();
+                Number const max = Number{false, maxMantissa, 0, Number::normalized{}};
+                // No alterations by the accessors
+                BEAST_EXPECT(max.mantissa() == maxMantissa);
+                BEAST_EXPECT(max.exponent() == 0);
+                // 85'070'591'730'234'615'847'396'907'784'232'501'249 - also 38
+                // digits
+                BEAST_EXPECT(
+                    (power(max, 2) ==
+                     Number{false, 85'070'591'730'234'615'84, 19, Number::normalized{}}));
+            }
+        }
+    }
+
+    void
+    testNormalizeToRange()
+    {
+        // Test edge-cases of normalizeToRange
+        auto const scale = Number::getMantissaScale();
+        testcase << "normalizeToRange " << to_string(scale);
+
+        auto test = [this](
+                        Number const& n,
+                        auto const rangeMin,
+                        auto const rangeMax,
+                        auto const expectedMantissa,
+                        auto const expectedExponent,
+                        auto const line) {
+            auto const normalized = n.normalizeToRange(rangeMin, rangeMax);
+            BEAST_EXPECTS(
+                normalized.first == expectedMantissa,
+                "Number " + to_string(n) + " scaled to " + std::to_string(rangeMax) +
+                    ". Expected mantissa:" + std::to_string(expectedMantissa) +
+                    ", got: " + std::to_string(normalized.first) + " @ " + std::to_string(line));
+            BEAST_EXPECTS(
+                normalized.second == expectedExponent,
+                "Number " + to_string(n) + " scaled to " + std::to_string(rangeMax) +
+                    ". Expected exponent:" + std::to_string(expectedExponent) +
+                    ", got: " + std::to_string(normalized.second) + " @ " + std::to_string(line));
+        };
+
+        std::int64_t constexpr iRangeMin = 100;
+        std::int64_t constexpr iRangeMax = 999;
+
+        std::uint64_t constexpr uRangeMin = 100;
+        std::uint64_t constexpr uRangeMax = 999;
+
+        constexpr static MantissaRange largeRange{MantissaRange::large};
+
+        std::int64_t constexpr iBigMin = largeRange.min;
+        std::int64_t constexpr iBigMax = largeRange.max;
+
+        auto const testSuite = [&](Number const& n,
+                                   auto const expectedSmallMantissa,
+                                   auto const expectedSmallExponent,
+                                   auto const expectedLargeMantissa,
+                                   auto const expectedLargeExponent,
+                                   auto const line) {
+            test(n, iRangeMin, iRangeMax, expectedSmallMantissa, expectedSmallExponent, line);
+            test(n, iBigMin, iBigMax, expectedLargeMantissa, expectedLargeExponent, line);
+
+            // Only test non-negative. testing a negative number with an
+            // unsigned range will assert, and asserts can't be tested.
+            if (n.signum() >= 0)
+            {
+                test(n, uRangeMin, uRangeMax, expectedSmallMantissa, expectedSmallExponent, line);
+                test(
+                    n,
+                    largeRange.min,
+                    largeRange.max,
+                    expectedLargeMantissa,
+                    expectedLargeExponent,
+                    line);
+            }
+        };
+
+        {
+            // zero
+            Number const n{0};
+
+            testSuite(
+                n,
+                0,
+                std::numeric_limits<int>::lowest(),
+                0,
+                std::numeric_limits<int>::lowest(),
+                __LINE__);
+        }
+        {
+            // Small positive number
+            Number const n{2};
+
+            testSuite(n, 200, -2, 2'000'000'000'000'000'000, -18, __LINE__);
+        }
+        {
+            // Negative number
+            Number const n{-2};
+
+            testSuite(n, -200, -2, -2'000'000'000'000'000'000, -18, __LINE__);
+        }
+        {
+            // Biggest valid mantissa
+            Number const n{Number::largestMantissa, 0, Number::normalized{}};
+
+            if (scale == MantissaRange::small)
+                // With the small mantissa range, the value rounds up. Because
+                // it rounds up, when scaling up to the full int64 range, it
+                // can't go over the max, so it is one digit smaller than the
+                // full value.
+                testSuite(n, 922, 16, 922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, 922, 16, Number::largestMantissa, 0, __LINE__);
+        }
+        {
+            // Biggest valid mantissa + 1
+            Number const n{Number::largestMantissa + 1, 0, Number::normalized{}};
+
+            if (scale == MantissaRange::small)
+                // With the small mantissa range, the value rounds up. Because
+                // it rounds up, when scaling up to the full int64 range, it
+                // can't go over the max, so it is one digit smaller than the
+                // full value.
+                testSuite(n, 922, 16, 922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, 922, 16, 922'337'203'685'477'581, 1, __LINE__);
+        }
+        {
+            // Biggest valid mantissa + 2
+            Number const n{Number::largestMantissa + 2, 0, Number::normalized{}};
+
+            if (scale == MantissaRange::small)
+                // With the small mantissa range, the value rounds up. Because
+                // it rounds up, when scaling up to the full int64 range, it
+                // can't go over the max, so it is one digit smaller than the
+                // full value.
+                testSuite(n, 922, 16, 922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, 922, 16, 922'337'203'685'477'581, 1, __LINE__);
+        }
+        {
+            // Biggest valid mantissa + 3
+            Number const n{Number::largestMantissa + 3, 0, Number::normalized{}};
+
+            if (scale == MantissaRange::small)
+                // With the small mantissa range, the value rounds up. Because
+                // it rounds up, when scaling up to the full int64 range, it
+                // can't go over the max, so it is one digit smaller than the
+                // full value.
+                testSuite(n, 922, 16, 922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, 922, 16, 922'337'203'685'477'581, 1, __LINE__);
+        }
+        {
+            // int64 min
+            Number const n{std::numeric_limits<std::int64_t>::min(), 0};
+
+            if (scale == MantissaRange::small)
+                testSuite(n, -922, 16, -922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, -922, 16, -922'337'203'685'477'581, 1, __LINE__);
+        }
+        {
+            // int64 min + 1
+            Number const n{std::numeric_limits<std::int64_t>::min() + 1, 0};
+
+            if (scale == MantissaRange::small)
+                testSuite(n, -922, 16, -922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, -922, 16, -9'223'372'036'854'775'807, 0, __LINE__);
+        }
+        {
+            // int64 min - 1
+            // Need to cast to uint, even though we're dealing with a negative
+            // number to avoid overflow and UB
+            Number const n{
+                true,
+                -static_cast<std::uint64_t>(std::numeric_limits<std::int64_t>::min()) + 1,
+                0,
+                Number::normalized{}};
+
+            if (scale == MantissaRange::small)
+                testSuite(n, -922, 16, -922'337'203'685'477'600, 1, __LINE__);
+            else
+                testSuite(n, -922, 16, -922'337'203'685'477'581, 1, __LINE__);
         }
     }
 
@@ -1552,6 +1874,7 @@ public:
             test_truncate();
             testRounding();
             testInt64();
+            testNormalizeToRange();
         }
     }
 };

src/test/core/CoroTask_test.cpp

@@ -1,460 +0,0 @@
-#include <test/jtx.h>
-
-#include <xrpl/core/JobQueue.h>
-#include <xrpl/core/JobQueueAwaiter.h>
-
-#include <chrono>
-#include <mutex>
-
-namespace xrpl {
-namespace test {
-
-class CoroTask_test : public beast::unit_test::suite
-{
-public:
-    class gate
-    {
-    private:
-        std::condition_variable cv_;
-        std::mutex mutex_;
-        bool signaled_ = false;
-
-    public:
-        template <class Rep, class Period>
-        bool
-        wait_for(std::chrono::duration<Rep, Period> const& rel_time)
-        {
-            std::unique_lock<std::mutex> lk(mutex_);
-            auto b = cv_.wait_for(lk, rel_time, [this] { return signaled_; });
-            signaled_ = false;
-            return b;
-        }
-
-        void
-        signal()
-        {
-            std::lock_guard lk(mutex_);
-            signaled_ = true;
-            cv_.notify_all();
-        }
-    };
-
-    // NOTE: All coroutine lambdas passed to postCoroTask use explicit
-    // pointer-by-value captures instead of [&] to work around a GCC 14
-    // bug where reference captures in coroutine lambdas are corrupted
-    // in the coroutine frame.
-
-    // Test: CoroTask<void> runs to completion
-    void
-    testVoidCompletion()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("void completion");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [gp = &g](auto) -> CoroTask<void> {
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g.wait_for(5s));
-        runner->join();
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: correct_order — suspend, join, post, complete
-    // Mirrors existing Coroutine_test::correct_order
-    void
-    testCorrectOrder()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("correct order");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g1, g2;
-        std::shared_ptr<JobQueue::CoroTaskRunner> r;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT,
-            "CoroTaskTest",
-            [rp = &r, g1p = &g1, g2p = &g2](auto runner) -> CoroTask<void> {
-                *rp = runner;
-                g1p->signal();
-                co_await runner->suspend();
-                g2p->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g1.wait_for(5s));
-        runner->join();
-        runner->post();
-        BEAST_EXPECT(g2.wait_for(5s));
-        runner->join();
-    }
-
-    // Test: incorrect_order — post before suspend
-    // Mirrors existing Coroutine_test::incorrect_order
-    void
-    testIncorrectOrder()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("incorrect order");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [gp = &g](auto runner) -> CoroTask<void> {
-                runner->post();
-                co_await runner->suspend();
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(g.wait_for(5s));
-    }
-
-    // Test: JobQueueAwaiter — suspend + auto-repost
-    void
-    testJobQueueAwaiter()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("JobQueueAwaiter");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        int step = 0;
-        env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [sp = &step, gp = &g](auto runner) -> CoroTask<void> {
-                *sp = 1;
-                co_await JobQueueAwaiter{runner};
-                *sp = 2;
-                co_await JobQueueAwaiter{runner};
-                *sp = 3;
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(step == 3);
-    }
-
-    // Test: thread_specific_storage — per-coroutine LocalValue isolation
-    // Mirrors existing Coroutine_test::thread_specific_storage
-    void
-    testThreadSpecificStorage()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("thread specific storage");
-        Env env(*this);
-
-        auto& jq = env.app().getJobQueue();
-
-        static int const N = 4;
-        std::array<std::shared_ptr<JobQueue::CoroTaskRunner>, N> a;
-
-        LocalValue<int> lv(-1);
-        BEAST_EXPECT(*lv == -1);
-
-        gate g;
-        jq.addJob(jtCLIENT, "LocalValTest", [&]() {
-            this->BEAST_EXPECT(*lv == -1);
-            *lv = -2;
-            this->BEAST_EXPECT(*lv == -2);
-            g.signal();
-        });
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(*lv == -1);
-
-        for (int i = 0; i < N; ++i)
-        {
-            jq.postCoroTask(
-                jtCLIENT,
-                "CoroTaskTest",
-                [this, ap = &a, gp = &g, lvp = &lv, id = i](auto runner) -> CoroTask<void> {
-                    (*ap)[id] = runner;
-                    gp->signal();
-                    co_await runner->suspend();
-
-                    this->BEAST_EXPECT(**lvp == -1);
-                    **lvp = id;
-                    this->BEAST_EXPECT(**lvp == id);
-                    gp->signal();
-                    co_await runner->suspend();
-
-                    this->BEAST_EXPECT(**lvp == id);
-                    co_return;
-                });
-            BEAST_EXPECT(g.wait_for(5s));
-            a[i]->join();
-        }
-        for (auto const& r : a)
-        {
-            r->post();
-            BEAST_EXPECT(g.wait_for(5s));
-            r->join();
-        }
-        for (auto const& r : a)
-        {
-            r->post();
-            r->join();
-        }
-
-        jq.addJob(jtCLIENT, "LocalValTest", [&]() {
-            this->BEAST_EXPECT(*lv == -2);
-            g.signal();
-        });
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(*lv == -1);
-    }
-
-    // Test: exception propagation
-    void
-    testExceptionPropagation()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("exception propagation");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [gp = &g](auto) -> CoroTask<void> {
-                gp->signal();
-                throw std::runtime_error("test exception");
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g.wait_for(5s));
-        runner->join();
-        // The exception is caught by promise_type::unhandled_exception()
-        // and the coroutine is considered done
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: multiple sequential co_await points
-    void
-    testMultipleYields()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("multiple yields");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        int counter = 0;
-        std::shared_ptr<JobQueue::CoroTaskRunner> r;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT,
-            "CoroTaskTest",
-            [rp = &r, cp = &counter, gp = &g](auto runner) -> CoroTask<void> {
-                *rp = runner;
-                ++(*cp);
-                gp->signal();
-                co_await runner->suspend();
-                ++(*cp);
-                gp->signal();
-                co_await runner->suspend();
-                ++(*cp);
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(counter == 1);
-        runner->join();
-
-        runner->post();
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(counter == 2);
-        runner->join();
-
-        runner->post();
-        BEAST_EXPECT(g.wait_for(5s));
-        BEAST_EXPECT(counter == 3);
-        runner->join();
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: CoroTask<T> returns a value via co_return
-    void
-    testValueReturn()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("value return");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        int result = 0;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [rp = &result, gp = &g](auto) -> CoroTask<void> {
-                auto inner = []() -> CoroTask<int> { co_return 42; };
-                *rp = co_await inner();
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g.wait_for(5s));
-        runner->join();
-        BEAST_EXPECT(result == 42);
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: CoroTask<T> propagates exceptions from inner coroutines
-    void
-    testValueException()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("value exception");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        bool caught = false;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [cp = &caught, gp = &g](auto) -> CoroTask<void> {
-                auto inner = []() -> CoroTask<int> {
-                    throw std::runtime_error("inner error");
-                    co_return 0;
-                };
-                try
-                {
-                    co_await inner();
-                }
-                catch (std::runtime_error const& e)
-                {
-                    *cp = true;
-                }
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g.wait_for(5s));
-        runner->join();
-        BEAST_EXPECT(caught);
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: CoroTask<T> chaining — nested value-returning coroutines
-    void
-    testValueChaining()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("value chaining");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        gate g;
-        int result = 0;
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [rp = &result, gp = &g](auto) -> CoroTask<void> {
-                auto add = [](int a, int b) -> CoroTask<int> { co_return a + b; };
-                auto mul = [add](int a, int b) -> CoroTask<int> {
-                    int sum = co_await add(a, b);
-                    co_return sum * 2;
-                };
-                *rp = co_await mul(3, 4);
-                gp->signal();
-                co_return;
-            });
-        BEAST_EXPECT(runner);
-        BEAST_EXPECT(g.wait_for(5s));
-        runner->join();
-        BEAST_EXPECT(result == 14);  // (3 + 4) * 2
-        BEAST_EXPECT(!runner->runnable());
-    }
-
-    // Test: postCoroTask returns nullptr when JobQueue is stopping
-    void
-    testShutdownRejection()
-    {
-        using namespace std::chrono_literals;
-        using namespace jtx;
-
-        testcase("shutdown rejection");
-
-        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
-            cfg->FORCE_MULTI_THREAD = true;
-            return cfg;
-        }));
-
-        // Stop the JobQueue
-        env.app().getJobQueue().stop();
-
-        auto runner = env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTaskTest", [](auto) -> CoroTask<void> { co_return; });
-        BEAST_EXPECT(!runner);
-    }
-
-    void
-    run() override
-    {
-        testVoidCompletion();
-        testCorrectOrder();
-        testIncorrectOrder();
-        testJobQueueAwaiter();
-        testThreadSpecificStorage();
-        testExceptionPropagation();
-        testMultipleYields();
-        testValueReturn();
-        testValueException();
-        testValueChaining();
-        testShutdownRejection();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(CoroTask, core, xrpl);
-
-}  // namespace test
-}  // namespace xrpl

src/test/core/Coroutine_test.cpp

@@ -40,11 +40,6 @@ public:
         }
     };
 
-    // NOTE: All coroutine lambdas passed to postCoroTask use explicit
-    // pointer-by-value captures instead of [&] to work around a GCC 14
-    // bug where reference captures in coroutine lambdas are corrupted
-    // in the coroutine frame.
-
     void
     correct_order()
     {
@@ -59,15 +54,13 @@ public:
         }));
 
         gate g1, g2;
-        std::shared_ptr<JobQueue::CoroTaskRunner> c;
-        env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTest", [cp = &c, g1p = &g1, g2p = &g2](auto runner) -> CoroTask<void> {
-                *cp = runner;
-                g1p->signal();
-                co_await runner->suspend();
-                g2p->signal();
-                co_return;
-            });
+        std::shared_ptr<JobQueue::Coro> c;
+        env.app().getJobQueue().postCoro(jtCLIENT, "CoroTest", [&](auto const& cr) {
+            c = cr;
+            g1.signal();
+            c->yield();
+            g2.signal();
+        });
         BEAST_EXPECT(g1.wait_for(5s));
         c->join();
         c->post();
@@ -88,17 +81,11 @@ public:
         }));
 
         gate g;
-        env.app().getJobQueue().postCoroTask(
-            jtCLIENT, "CoroTest", [gp = &g](auto runner) -> CoroTask<void> {
-                // Schedule a resume before suspending.  The posted job
-                // cannot actually call resume() until the current resume()
-                // releases CoroTaskRunner::mutex_, which only happens after
-                // the coroutine suspends at co_await.
-                runner->post();
-                co_await runner->suspend();
-                gp->signal();
-                co_return;
-            });
+        env.app().getJobQueue().postCoro(jtCLIENT, "CoroTest", [&](auto const& c) {
+            c->post();
+            c->yield();
+            g.signal();
+        });
         BEAST_EXPECT(g.wait_for(5s));
     }
 
@@ -114,7 +101,7 @@ public:
         auto& jq = env.app().getJobQueue();
 
         static int const N = 4;
-        std::array<std::shared_ptr<JobQueue::CoroTaskRunner>, N> a;
+        std::array<std::shared_ptr<JobQueue::Coro>, N> a;
 
         LocalValue<int> lv(-1);
         BEAST_EXPECT(*lv == -1);
@@ -131,23 +118,19 @@ public:
 
         for (int i = 0; i < N; ++i)
         {
-            jq.postCoroTask(
-                jtCLIENT,
-                "CoroTest",
-                [this, ap = &a, gp = &g, lvp = &lv, id = i](auto runner) -> CoroTask<void> {
-                    (*ap)[id] = runner;
-                    gp->signal();
-                    co_await runner->suspend();
+            jq.postCoro(jtCLIENT, "CoroTest", [&, id = i](auto const& c) {
+                a[id] = c;
+                g.signal();
+                c->yield();
 
-                    this->BEAST_EXPECT(**lvp == -1);
-                    **lvp = id;
-                    this->BEAST_EXPECT(**lvp == id);
-                    gp->signal();
-                    co_await runner->suspend();
+                this->BEAST_EXPECT(*lv == -1);
+                *lv = id;
+                this->BEAST_EXPECT(*lv == id);
+                g.signal();
+                c->yield();
 
-                    this->BEAST_EXPECT(**lvp == id);
-                    co_return;
-                });
+                this->BEAST_EXPECT(*lv == id);
+            });
             BEAST_EXPECT(g.wait_for(5s));
             a[i]->join();
         }

src/test/core/JobQueue_test.cpp

@@ -43,91 +43,87 @@ class JobQueue_test : public beast::unit_test::suite
         }
     }
 
-    // NOTE: All coroutine lambdas passed to postCoroTask use explicit
-    // pointer-by-value captures instead of [&] to work around a GCC 14
-    // bug where reference captures in coroutine lambdas are corrupted
-    // in the coroutine frame.
-
     void
-    testPostCoroTask()
+    testPostCoro()
     {
         jtx::Env env{*this};
 
         JobQueue& jQueue = env.app().getJobQueue();
         {
-            // Test repeated post()s until the coroutine completes.
+            // Test repeated post()s until the Coro completes.
             std::atomic<int> yieldCount{0};
-            auto const runner = jQueue.postCoroTask(
-                jtCLIENT, "PostCoroTest1", [ycp = &yieldCount](auto runner) -> CoroTask<void> {
-                    while (++(*ycp) < 4)
-                        co_await runner->suspend();
-                    co_return;
+            auto const coro = jQueue.postCoro(
+                jtCLIENT,
+                "PostCoroTest1",
+                [&yieldCount](std::shared_ptr<JobQueue::Coro> const& coroCopy) {
+                    while (++yieldCount < 4)
+                        coroCopy->yield();
                 });
-            BEAST_EXPECT(runner != nullptr);
+            BEAST_EXPECT(coro != nullptr);
 
             // Wait for the Job to run and yield.
             while (yieldCount == 0)
                 ;
 
-            // Now re-post until the CoroTaskRunner says it is done.
+            // Now re-post until the Coro says it is done.
             int old = yieldCount;
-            while (runner->runnable())
+            while (coro->runnable())
             {
-                BEAST_EXPECT(runner->post());
+                BEAST_EXPECT(coro->post());
                 while (old == yieldCount)
                 {
                 }
-                runner->join();
+                coro->join();
                 BEAST_EXPECT(++old == yieldCount);
             }
             BEAST_EXPECT(yieldCount == 4);
         }
         {
-            // Test repeated resume()s until the coroutine completes.
+            // Test repeated resume()s until the Coro completes.
             int yieldCount{0};
-            auto const runner = jQueue.postCoroTask(
-                jtCLIENT, "PostCoroTest2", [ycp = &yieldCount](auto runner) -> CoroTask<void> {
-                    while (++(*ycp) < 4)
-                        co_await runner->suspend();
-                    co_return;
+            auto const coro = jQueue.postCoro(
+                jtCLIENT,
+                "PostCoroTest2",
+                [&yieldCount](std::shared_ptr<JobQueue::Coro> const& coroCopy) {
+                    while (++yieldCount < 4)
+                        coroCopy->yield();
                 });
-            if (!runner)
+            if (!coro)
             {
-                // There's no good reason we should not get a runner, but we
+                // There's no good reason we should not get a Coro, but we
                 // can't continue without one.
                 BEAST_EXPECT(false);
                 return;
             }
 
             // Wait for the Job to run and yield.
-            runner->join();
+            coro->join();
 
-            // Now resume until the CoroTaskRunner says it is done.
+            // Now resume until the Coro says it is done.
             int old = yieldCount;
-            while (runner->runnable())
+            while (coro->runnable())
             {
-                runner->resume();  // Resume runs synchronously on this thread.
+                coro->resume();  // Resume runs synchronously on this thread.
                 BEAST_EXPECT(++old == yieldCount);
             }
             BEAST_EXPECT(yieldCount == 4);
         }
         {
             // If the JobQueue is stopped, we should no
-            // longer be able to post a coroutine (and calling postCoroTask()
-            // should return nullptr).
+            // longer be able to add a Coro (and calling postCoro() should
+            // return false).
             using namespace std::chrono_literals;
             jQueue.stop();
 
-            // The coroutine should never run, so having it access this
+            // The Coro should never run, so having the Coro access this
             // unprotected variable on the stack should be completely safe.
             // Not recommended for the faint of heart...
             bool unprotected;
-            auto const runner = jQueue.postCoroTask(
-                jtCLIENT, "PostCoroTest3", [up = &unprotected](auto) -> CoroTask<void> {
-                    *up = false;
-                    co_return;
+            auto const coro = jQueue.postCoro(
+                jtCLIENT, "PostCoroTest3", [&unprotected](std::shared_ptr<JobQueue::Coro> const&) {
+                    unprotected = false;
                 });
-            BEAST_EXPECT(runner == nullptr);
+            BEAST_EXPECT(coro == nullptr);
         }
     }
 
@@ -136,7 +132,7 @@ public:
     run() override
     {
         testAddJob();
-        testPostCoroTask();
+        testPostCoro();
     }
 };
 

src/test/jtx/impl/AMMTest.cpp

@@ -6,7 +6,6 @@
 
 #include <xrpld/rpc/RPCHandler.h>
 
-#include <xrpl/core/CoroTask.h>
 #include <xrpl/protocol/ApiVersion.h>
 #include <xrpl/protocol/STParsedJSON.h>
 #include <xrpl/resource/Fees.h>
@@ -194,6 +193,7 @@ AMMTest::find_paths_request(
          c,
          Role::USER,
          {},
+         {},
          RPC::apiVersionIfUnspecified},
         {},
         {}};
@@ -215,11 +215,11 @@ AMMTest::find_paths_request(
 
     Json::Value result;
     gate g;
-    app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
+    app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
         context.params = std::move(params);
+        context.coro = coro;
         RPC::doCommand(context, result);
         g.signal();
-        co_return;
     });
 
     using namespace std::chrono_literals;

src/xrpld/app/main/Application.cpp

@@ -1425,6 +1425,7 @@ ApplicationImp::setup(boost::program_options::variables_map const& cmdline)
              c,
              Role::ADMIN,
              {},
+             {},
              RPC::apiMaximumSupportedVersion},
             jvCommand};
 

src/xrpld/app/main/GRPCServer.cpp

@@ -3,7 +3,6 @@
 
 #include <xrpl/beast/core/CurrentThreadName.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
-#include <xrpl/core/CoroTask.h>
 #include <xrpl/resource/Fees.h>
 
 namespace xrpl {
@@ -100,14 +99,13 @@ GRPCServerImpl::CallData<Request, Response>::process()
     // ensures that finished is always true when this CallData object
     // is returned as a tag in handleRpcs(), after sending the response
     finished_ = true;
-    auto runner = app_.getJobQueue().postCoroTask(
-        JobType::jtRPC, "gRPC-Client", [thisShared](auto) -> CoroTask<void> {
-            thisShared->processRequest();
-            co_return;
+    auto coro = app_.getJobQueue().postCoro(
+        JobType::jtRPC, "gRPC-Client", [thisShared](std::shared_ptr<JobQueue::Coro> coro) {
+            thisShared->process(coro);
         });
 
-    // If runner is null, then the JobQueue has already been shutdown
-    if (!runner)
+    // If coro is null, then the JobQueue has already been shutdown
+    if (!coro)
     {
         grpc::Status status{grpc::StatusCode::INTERNAL, "Job Queue is already stopped"};
         responder_.FinishWithError(status, this);
@@ -116,7 +114,7 @@ GRPCServerImpl::CallData<Request, Response>::process()
 
 template <class Request, class Response>
 void
-GRPCServerImpl::CallData<Request, Response>::processRequest()
+GRPCServerImpl::CallData<Request, Response>::process(std::shared_ptr<JobQueue::Coro> coro)
 {
     try
     {
@@ -158,6 +156,7 @@ GRPCServerImpl::CallData<Request, Response>::processRequest()
                  app_.getLedgerMaster(),
                  usage,
                  role,
+                 coro,
                  InfoSub::pointer(),
                  apiVersion},
                 request_};

src/xrpld/app/main/GRPCServer.h

@@ -208,7 +208,7 @@ private:
     private:
         // process the request. Called inside the coroutine passed to JobQueue
         void
-        processRequest();
+        process(std::shared_ptr<JobQueue::Coro> coro);
 
         // return load type of this RPC
         Resource::Charge

src/xrpld/rpc/Context.h

@@ -3,6 +3,7 @@
 #include <xrpld/rpc/Role.h>
 
 #include <xrpl/beast/utility/Journal.h>
+#include <xrpl/core/JobQueue.h>
 #include <xrpl/server/InfoSub.h>
 
 namespace xrpl {
@@ -23,6 +24,7 @@ struct Context
     LedgerMaster& ledgerMaster;
     Resource::Consumer& consumer;
     Role role;
+    std::shared_ptr<JobQueue::Coro> coro{};
     InfoSub::pointer infoSub{};
     unsigned int apiVersion;
 };

src/xrpld/rpc/ServerHandler.h

@@ -169,10 +169,13 @@ public:
 
 private:
     Json::Value
-    processSession(std::shared_ptr<WSSession> const& session, Json::Value const& jv);
+    processSession(
+        std::shared_ptr<WSSession> const& session,
+        std::shared_ptr<JobQueue::Coro> const& coro,
+        Json::Value const& jv);
 
     void
-    processSession(std::shared_ptr<Session> const&);
+    processSession(std::shared_ptr<Session> const&, std::shared_ptr<JobQueue::Coro> coro);
 
     void
     processRequest(
@@ -180,6 +183,7 @@ private:
         std::string const& request,
         beast::IP::Endpoint const& remoteIPAddress,
         Output&&,
+        std::shared_ptr<JobQueue::Coro> coro,
         std::string_view forwardedFor,
         std::string_view user);
 

src/xrpld/rpc/detail/ServerHandler.cpp

@@ -14,7 +14,6 @@
 #include <xrpl/basics/make_SSLContext.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
 #include <xrpl/beast/rfc2616.h>
-#include <xrpl/core/CoroTask.h>
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/json/json_reader.h>
 #include <xrpl/json/to_string.h>
@@ -285,10 +284,9 @@ ServerHandler::onRequest(Session& session)
     }
 
     std::shared_ptr<Session> detachedSession = session.detach();
-    auto const postResult = m_jobQueue.postCoroTask(
-        jtCLIENT_RPC, "RPC-Client", [this, detachedSession](auto) -> CoroTask<void> {
-            processSession(detachedSession);
-            co_return;
+    auto const postResult = m_jobQueue.postCoro(
+        jtCLIENT_RPC, "RPC-Client", [this, detachedSession](std::shared_ptr<JobQueue::Coro> coro) {
+            processSession(detachedSession, coro);
         });
     if (postResult == nullptr)
     {
@@ -324,18 +322,17 @@ ServerHandler::onWSMessage(
 
     JLOG(m_journal.trace()) << "Websocket received '" << jv << "'";
 
-    auto const postResult = m_jobQueue.postCoroTask(
+    auto const postResult = m_jobQueue.postCoro(
         jtCLIENT_WEBSOCKET,
         "WS-Client",
-        [this, session, jv = std::move(jv)](auto) -> CoroTask<void> {
-            auto const jr = this->processSession(session, jv);
+        [this, session, jv = std::move(jv)](std::shared_ptr<JobQueue::Coro> const& coro) {
+            auto const jr = this->processSession(session, coro, jv);
             auto const s = to_string(jr);
             auto const n = s.length();
             boost::beast::multi_buffer sb(n);
             sb.commit(boost::asio::buffer_copy(sb.prepare(n), boost::asio::buffer(s.c_str(), n)));
             session->send(std::make_shared<StreambufWSMsg<decltype(sb)>>(std::move(sb)));
             session->complete();
-            co_return;
         });
     if (postResult == nullptr)
     {
@@ -376,7 +373,10 @@ logDuration(Json::Value const& request, T const& duration, beast::Journal& journ
 }
 
 Json::Value
-ServerHandler::processSession(std::shared_ptr<WSSession> const& session, Json::Value const& jv)
+ServerHandler::processSession(
+    std::shared_ptr<WSSession> const& session,
+    std::shared_ptr<JobQueue::Coro> const& coro,
+    Json::Value const& jv)
 {
     auto is = std::static_pointer_cast<WSInfoSub>(session->appDefined);
     if (is->getConsumer().disconnect(m_journal))
@@ -443,6 +443,7 @@ ServerHandler::processSession(std::shared_ptr<WSSession> const& session, Json::V
                  app_.getLedgerMaster(),
                  is->getConsumer(),
                  role,
+                 coro,
                  is,
                  apiVersion},
                 jv,
@@ -513,14 +514,18 @@ ServerHandler::processSession(std::shared_ptr<WSSession> const& session, Json::V
     return jr;
 }
 
+// Run as a coroutine.
 void
-ServerHandler::processSession(std::shared_ptr<Session> const& session)
+ServerHandler::processSession(
+    std::shared_ptr<Session> const& session,
+    std::shared_ptr<JobQueue::Coro> coro)
 {
     processRequest(
         session->port(),
         buffers_to_string(session->request().body().data()),
         session->remoteAddress().at_port(0),
         makeOutput(*session),
+        coro,
         forwardedFor(session->request()),
         [&] {
             auto const iter = session->request().find("X-User");
@@ -557,6 +562,7 @@ ServerHandler::processRequest(
     std::string const& request,
     beast::IP::Endpoint const& remoteIPAddress,
     Output&& output,
+    std::shared_ptr<JobQueue::Coro> coro,
     std::string_view forwardedFor,
     std::string_view user)
 {
@@ -813,6 +819,7 @@ ServerHandler::processRequest(
              app_.getLedgerMaster(),
              usage,
              role,
+             coro,
              InfoSub::pointer(),
              apiVersion},
             params,

src/xrpld/rpc/handlers/RipplePathFind.cpp

@@ -7,9 +7,6 @@
 #include <xrpl/protocol/RPCErr.h>
 #include <xrpl/resource/Fees.h>
 
-#include <condition_variable>
-#include <mutex>
-
 namespace xrpl {
 
 // This interface is deprecated.
@@ -40,31 +37,98 @@ doRipplePathFind(RPC::JsonContext& context)
         PathRequest::pointer request;
         lpLedger = context.ledgerMaster.getClosedLedger();
 
-        // makeLegacyPathRequest enqueues a path-finding job that runs
-        // asynchronously.  We block this thread with a condition_variable
-        // until the path-finding continuation signals completion.
-        // If makeLegacyPathRequest cannot schedule the job (e.g. during
-        // shutdown), it returns an empty request and we skip the wait.
-        std::mutex mtx;
-        std::condition_variable cv;
-        bool pathDone = false;
-
+        // It doesn't look like there's much odd happening here, but you should
+        // be aware this code runs in a JobQueue::Coro, which is a coroutine.
+        // And we may be flipping around between threads.  Here's an overview:
+        //
+        // 1. We're running doRipplePathFind() due to a call to
+        //    ripple_path_find.  doRipplePathFind() is currently running
+        //    inside of a JobQueue::Coro using a JobQueue thread.
+        //
+        // 2. doRipplePathFind's call to makeLegacyPathRequest() enqueues the
+        //    path-finding request.  That request will (probably) run at some
+        //    indeterminate future time on a (probably different) JobQueue
+        //    thread.
+        //
+        // 3. As a continuation from that path-finding JobQueue thread, the
+        //    coroutine we're currently running in (!) is posted to the
+        //    JobQueue.  Because it is a continuation, that post won't
+        //    happen until the path-finding request completes.
+        //
+        // 4. Once the continuation is enqueued, and we have reason to think
+        //    the path-finding job is likely to run, then the coroutine we're
+        //    running in yield()s.  That means it surrenders its thread in
+        //    the JobQueue.  The coroutine is suspended, but ready to run,
+        //    because it is kept resident by a shared_ptr in the
+        //    path-finding continuation.
+        //
+        // 5. If all goes well then path-finding runs on a JobQueue thread
+        //    and executes its continuation.  The continuation posts this
+        //    same coroutine (!) to the JobQueue.
+        //
+        // 6. When the JobQueue calls this coroutine, this coroutine resumes
+        //    from the line below the coro->yield() and returns the
+        //    path-finding result.
+        //
+        // With so many moving parts, what could go wrong?
+        //
+        // Just in terms of the JobQueue refusing to add jobs at shutdown
+        // there are two specific things that can go wrong.
+        //
+        // 1. The path-finding Job queued by makeLegacyPathRequest() might be
+        //    rejected (because we're shutting down).
+        //
+        //    Fortunately this problem can be addressed by looking at the
+        //    return value of makeLegacyPathRequest().  If
+        //    makeLegacyPathRequest() cannot get a thread to run the path-find
+        //    on, then it returns an empty request.
+        //
+        // 2. The path-finding job might run, but the Coro::post() might be
+        //    rejected by the JobQueue (because we're shutting down).
+        //
+        //    We handle this case by resuming (not posting) the Coro.
+        //    By resuming the Coro, we allow the Coro to run to completion
+        //    on the current thread instead of requiring that it run on a
+        //    new thread from the JobQueue.
+        //
+        // Both of these failure modes are hard to recreate in a unit test
+        // because they are so dependent on inter-thread timing.  However
+        // the failure modes can be observed by synchronously (inside the
+        // rippled source code) shutting down the application.  The code to
+        // do so looks like this:
+        //
+        //   context.app.signalStop();
+        //   while (! context.app.getJobQueue().jobCounter().joined()) { }
+        //
+        // The first line starts the process of shutting down the app.
+        // The second line waits until no more jobs can be added to the
+        // JobQueue before letting the thread continue.
+        //
+        // May 2017
         jvResult = context.app.getPathRequests().makeLegacyPathRequest(
             request,
-            [&]() {
+            [&context]() {
+                // Copying the shared_ptr keeps the coroutine alive up
+                // through the return.  Otherwise the storage under the
+                // captured reference could evaporate when we return from
+                // coroCopy->resume().  This is not strictly necessary, but
+                // will make maintenance easier.
+                std::shared_ptr<JobQueue::Coro> coroCopy{context.coro};
+                if (!coroCopy->post())
                 {
-                    std::lock_guard lk(mtx);
-                    pathDone = true;
+                    // The post() failed, so we won't get a thread to let
+                    // the Coro finish.  We'll call Coro::resume() so the
+                    // Coro can finish on our thread.  Otherwise the
+                    // application will hang on shutdown.
+                    coroCopy->resume();
                 }
-                cv.notify_one();
             },
             context.consumer,
             lpLedger,
             context.params);
         if (request)
         {
-            std::unique_lock lk(mtx);
-            cv.wait(lk, [&] { return pathDone; });
+            context.coro->yield();
             jvResult = request->doStatus(context.params);
         }