feat: Add parallel apply access-set scheduler

.github/workflows/conflicting-pr.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check if PRs are dirty
-        uses: eps1lon/actions-label-merge-conflict@0273be72a0bbd58fcd71d0d6c02c209b50d1e5e1 # v3.1.0
+        uses: eps1lon/actions-label-merge-conflict@1df065ebe6e3310545d4f4c4e862e43bdca146f0 # v3.0.3
         with:
           dirtyLabel: "PR: has conflicts"
           repoToken: "${{ secrets.GITHUB_TOKEN }}"

.gitignore

@@ -86,3 +86,5 @@ __pycache__
 
 # clangd cache
 /.cache
+labrun/
+build-release/

cfg/xrpld-example.cfg

@@ -953,21 +953,6 @@
 #
 #   Optional keys for NuDB and RocksDB:
 #
-#       cache_size          Size of cache for database records. Default is 16384.
-#                           Setting this value to 0 will use the default value.
-#
-#       cache_age           Length of time in minutes to keep database records
-#                           cached. Default is 5 minutes. Setting this value to
-#                           0 will use the default value.
-#
-#                           Note: if cache_size or cache_age is not specified,
-#                           default values will be used for the unspecified
-#                           parameter.
-#
-#                           Note: the cache will not be created if online_delete
-#                           is specified, because the rotating NodeStore does
-#                           not use this cache).
-#
 #       fast_load           Boolean. If set, load the last persisted ledger
 #                           from disk upon process start before syncing to
 #                           the network. This is likely to improve performance

cmake/scripts/codegen/templates/LedgerEntry.h.mako

@@ -33,7 +33,7 @@ public:
      * @brief Construct a ${name} ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit ${name}(SLE::const_pointer sle)
+    explicit ${name}(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -168,7 +168,7 @@ ${field['typeData']['setter_type']} ${field['paramName']}${',' if i < len(requir
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    ${name}Builder(SLE::const_pointer sle)
+    ${name}Builder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ${tag})
         {

docker/check-sanitizers.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# Sanity-check that the sanitizer runtimes shipped with g++/clang++ work
+# end-to-end against the system loader: compile each example with both
+# compilers, run it, and confirm the expected diagnostic is emitted.
+
+set -eo pipefail
+
+cpp_files_dir="${1:?usage: $0 <cpp_files_dir>}"
+
+case "$(uname -m)" in
+    x86_64) loader=/lib64/ld-linux-x86-64.so.2 ;;
+    aarch64) loader=/lib/ld-linux-aarch64.so.1 ;;
+    *)
+        echo "Unsupported arch: $(uname -m)" >&2
+        exit 1
+        ;;
+esac
+
+declare -A sanitize=(
+    [asan]="-fsanitize=address"
+    [tsan]="-fsanitize=thread"
+    [ubsan]="-fsanitize=undefined"
+)
+declare -A expect=(
+    [asan]="heap-use-after-free"
+    [tsan]="data race"
+    [ubsan]="signed integer overflow"
+)
+
+for compiler in g++ clang++; do
+    for name in asan tsan ubsan; do
+        bin="/tmp/${name}-${compiler}"
+        echo "=== Build ${name} with ${compiler} ==="
+        "$compiler" -std=c++20 -O1 -g ${sanitize[$name]} \
+            -Wl,--dynamic-linker=$loader \
+            "${cpp_files_dir}/${name}.cpp" -o "$bin"
+        echo "=== Run ${name}-${compiler} ==="
+        output=$("$bin" 2>&1) || true
+        echo "$output"
+        echo "$output" | grep -q "${expect[$name]}" ||
+            {
+                echo "expected '${expect[$name]}' from $bin"
+                exit 1
+            }
+        rm -f "$bin"
+    done
+done

docker/loader-path.sh

@@ -1,12 +0,0 @@
-#!/bin/bash
-
-case "$(uname -m)" in
-    x86_64) LOADER=/lib64/ld-linux-x86-64.so.2 ;;
-    aarch64) LOADER=/lib/ld-linux-aarch64.so.1 ;;
-    *)
-        echo "Unsupported arch: $(uname -m)" >&2
-        exit 1
-        ;;
-esac
-
-echo "${LOADER}"

docker/nix.Dockerfile

@@ -27,9 +27,7 @@ RUN mkdir /tmp/nix-store-closure && \
     cp -R $(nix-store -qR result/) /tmp/nix-store-closure
 
 # Final image
-FROM ${BASE_IMAGE} AS final
-
-ARG BASE_IMAGE
+FROM ${BASE_IMAGE}
 
 # bash is not located at /bin/bash in nixos/nix, so we need to create a symlink to it.
 RUN if [ -d /nix ]; then \
@@ -45,23 +43,25 @@ ENTRYPOINT ["/bin/bash"]
 COPY --from=builder /tmp/nix-store-closure /nix/store
 COPY --from=builder /tmp/build/result /nix/ci-env
 
-ENV PATH="/nix/ci-env/bin:${PATH}"
+ENV PATH="/nix/ci-env/bin:$PATH"
 
 # Externally-built dynamically-linked ELF binaries hard-code the loader path
-# (e.g. /lib64/ld-linux-x86-64.so.2) in their PT_INTERP header. Install it
-# from the Nix store when the base image doesn't already provide one.
-COPY docker/loader-path.sh /tmp/loader-path.sh
-
+# (e.g. /lib64/ld-linux-x86-64.so.2) in their PT_INTERP header. Copy the
+# loader from the Nix store to that path when the base image doesn't already
+# provide one (i.e. on nixos/nix).
 RUN <<EOF
-target="$(/tmp/loader-path.sh)"
-
-if [ ! -e "${target}" ]; then
+case "$(uname -m)" in
+    x86_64)  target=/lib64/ld-linux-x86-64.so.2 ;;
+    aarch64) target=/lib/ld-linux-aarch64.so.1 ;;
+    *) echo "Unsupported arch: $(uname -m)" >&2; exit 1 ;;
+esac
+if [ ! -e "$target" ]; then
     # Use the loader from the same glibc that gcc links libc against, so
     # ld-linux and libc/libpthread share GLIBC_PRIVATE symbols at runtime.
-    src="$(dirname "$(gcc -print-file-name=libc.so.6)")/$(basename "${target}")"
-    [ -e "${src}" ] || { echo "ld-linux not found at ${src}" >&2; exit 1; }
-    mkdir -p "$(dirname "${target}")"
-    cp "${src}" "${target}"
+    src="$(dirname "$(gcc -print-file-name=libc.so.6)")/$(basename "$target")"
+    [ -e "$src" ] || { echo "ld-linux not found at $src" >&2; exit 1; }
+    mkdir -p "$(dirname "$target")"
+    cp "$src" "$target"
 fi
 EOF
 
@@ -87,16 +87,9 @@ run-clang-tidy --help
 vim --version
 EOF
 
-# Sanity-check that the sanitizer runtimes shipped with g++/clang++ are able to build binaries
-COPY docker/test_files/cpp_sources/ /tmp/cpp_sources/
-COPY docker/test_files/compile-cpp-sources.sh /tmp/compile-cpp-sources.sh
-RUN /tmp/compile-cpp-sources.sh /tmp/cpp_sources /tmp/bins
+# Sanity-check that the sanitizer runtimes shipped with g++/clang++ work
+# end-to-end against the system loader.
+COPY docker/cpp_files/ /tmp/cpp_files/
+COPY docker/check-sanitizers.sh /tmp/check-sanitizers.sh
 
-# Sanity-check that the built binaries are able to run.
-# We only support running the test binaries on Ubuntu and NixOS right now (will be fixed in the future)
-#
-# When build and test images will be separate, we will be to run on vanilla images.
-COPY docker/test_files/run-test-binaries.sh /tmp/run-test-binaries.sh
-RUN if echo "${BASE_IMAGE}" | grep -qiE '(ubuntu|nixos)'; then \
-        /tmp/run-test-binaries.sh /tmp/bins; \
-    fi
+RUN grep -qi ubuntu /etc/os-release 2>/dev/null && /tmp/check-sanitizers.sh /tmp/cpp_files || true

docker/test_files/compile-cpp-sources.sh

@@ -1,50 +0,0 @@
-#!/bin/bash
-# Compile all C++ test binaries during the Docker image build.
-# Each binary has the target system's ELF PT_INTERP (dynamic-linker path)
-# baked in so it can run on the (potentially minimal) final BASE_IMAGE.
-
-set -eo pipefail
-
-src_dir="${1:?usage: $0 <src_dir> <dst_dir>}"
-dst_dir="${2:?usage: $0 <src_dir> <dst_dir>}"
-
-loader="$(/tmp/loader-path.sh)"
-
-mkdir -p "${dst_dir}"
-
-function compile() {
-    local compiler="${1}"
-    local name="${2}"
-    local san_flag="${3:-}"
-
-    local src="${src_dir}/${name}.cpp"
-    local binary="${dst_dir}/${name}-${compiler}"
-
-    echo "=== Compile ${name} with ${compiler} ==="
-    cmd="${compiler} -std=c++23 -O1 -g \
-        -pthread \
-        -Wl,--dynamic-linker=${loader} \
-        ${san_flag} \
-        ${src} -o ${binary}"
-    echo "Command: ${cmd}"
-    eval "${cmd}"
-}
-
-declare -A sanitize=(
-    [regular]=""
-
-    [asan]="-fsanitize=address"
-    [tsan]="-fsanitize=thread"
-    [ubsan]="-fsanitize=undefined -fno-sanitize-recover=all"
-)
-
-for name in regular asan tsan ubsan; do
-    san_flag="${sanitize[${name}]}"
-    for compiler in g++ clang++; do
-        compile "${compiler}" "${name}" "${san_flag}"
-    done
-done
-
-echo "=== All binaries compiled ==="
-
-ls -la "${dst_dir}"

docker/test_files/cpp_sources/regular.cpp

@@ -1,28 +0,0 @@
-#include <iostream>
-#include <mutex>
-#include <thread>
-#include <vector>
-
-static std::mutex gMutex;
-
-void
-worker(int id)
-{
-    std::lock_guard<std::mutex> lock(gMutex);
-    std::cout << "Hello from thread " << id << "\n";
-}
-
-int
-main()
-{
-    constexpr int kNumThreads = 10;
-    std::vector<std::thread> threads;
-    threads.reserve(kNumThreads);
-    for (int i = 0; i < kNumThreads; ++i)
-        threads.emplace_back(worker, i);
-    for (auto& t : threads)
-        t.join();
-
-    std::cout << "Hello from main thread\n";
-    return 0;
-}

docker/test_files/run-test-binaries.sh

@@ -1,62 +0,0 @@
-#!/bin/bash
-# Run pre-compiled sanitizer binaries and confirm each emits its expected diagnostic.
-# Binaries must already exist in <bins_dir> with the layout:
-# <name>-g++ and <name>-clang++ for name in {regular,asan,tsan,ubsan}
-
-set -eo pipefail
-
-bins_dir="${1:?usage: $0 <bins_dir>}"
-
-# Run a binary and verify its exit code and output.
-# Usage: run <binary> <expected_output> <expected_rc>
-function run() {
-    local binary="${1}"
-    local expected_output="${2}"
-    local expected_rc="${3}"
-
-    local out_file
-    out_file="$(mktemp)"
-
-    echo "=== Run ${binary} ==="
-    local rc=0
-    "${binary}" >"${out_file}" 2>&1 || rc=$?
-
-    cat "${out_file}"
-
-    if [ "${expected_rc}" = "nonzero" ]; then
-        if [ "${rc}" -eq 0 ]; then
-            echo "ERROR: expected non-zero exit code from ${binary}, got ${rc}" >&2
-            exit 1
-        fi
-    elif [ "${rc}" -ne "${expected_rc}" ]; then
-        echo "ERROR: expected exit code ${expected_rc} from ${binary}, got ${rc}" >&2
-        exit 1
-    fi
-
-    grep -q "${expected_output}" "${out_file}" ||
-        {
-            echo "ERROR: expected '${expected_output}' from ${binary}" >&2
-            exit 1
-        }
-    echo "OK: '${expected_output}' detected"
-}
-
-declare -A expect=(
-    [regular]="Hello from main thread"
-
-    [asan]="heap-use-after-free"
-    [tsan]="data race"
-    [ubsan]="signed integer overflow"
-)
-
-for compiler in g++ clang++; do
-    for name in regular asan tsan ubsan; do
-        binary="${bins_dir}/${name}-${compiler}"
-        if [ "${name}" = "regular" ]; then
-            expected_rc=0
-        else
-            expected_rc=nonzero
-        fi
-        run "${binary}" "${expect[$name]}" "${expected_rc}"
-    done
-done

include/xrpl/basics/Number.h

@@ -2,14 +2,12 @@
 
 #include <xrpl/beast/utility/instrumentation.h>
 
-#include <array>
 #include <cstdint>
 #include <functional>
 #include <limits>
 #include <optional>
 #include <ostream>
 #include <set>
-#include <stdexcept>
 #include <string>
 #include <unordered_map>
 
@@ -42,47 +40,6 @@ isPowerOfTen(T value)
     return logTen(value).has_value();
 }
 
-namespace detail {
-
-/** Builds a table of the powers of 10
- *
- * This function is marked consteval, so it can only be run in
- * a constexpr context. This assures that it is and can only be run at
- * compile time. Doing it at runtime would be pretty wasteful and
- * inefficient.
- */
-constexpr std::size_t kInt64Digits = 20;
-consteval std::array<std::uint64_t, kInt64Digits>
-buildPowersOfTen()
-{
-    std::array<std::uint64_t, kInt64Digits> result{};
-
-    std::uint64_t power = 1;
-    std::size_t exponent = 0;
-    // end the loop early so it doesn't overflow;
-    for (; exponent < result.size() - 1; ++exponent, power *= 10)
-    {
-        result[exponent] = power;
-        if (power > std::numeric_limits<std::uint64_t>::max() / 10)
-            throw std::logic_error("Power of 10 table is too big");
-    }
-    result[exponent] = power;
-    if (power < std::numeric_limits<std::uint64_t>::max() / 10)
-        throw std::logic_error("Power of 10 table is not big enough for the uint64_t type");
-
-    return result;
-}
-
-}  // namespace detail
-
-constexpr std::array<std::uint64_t, detail::kInt64Digits> kPowerOfTen = detail::buildPowersOfTen();
-
-static_assert(kPowerOfTen[0] == 1);
-static_assert(kPowerOfTen[1] == 10);
-static_assert(kPowerOfTen[10] == 10'000'000'000);
-static_assert(
-    isPowerOfTen(kPowerOfTen.back()) && *logTen(kPowerOfTen.back()) == detail::kInt64Digits - 1);
-
 /** MantissaRange defines a range for the mantissa of a normalized Number.
  *
  * The mantissa is in the range [min, max], where
@@ -119,7 +76,6 @@ static_assert(
 struct MantissaRange final
 {
     using rep = std::uint64_t;
-
     enum class MantissaScale {
         Small,
         // LargeLegacy can be removed when fixCleanup3_2_0 is retired
@@ -133,15 +89,19 @@ struct MantissaRange final
         Enabled = true,
     };
 
-    explicit constexpr MantissaRange(MantissaScale sc) : scale(sc)
+    explicit constexpr MantissaRange(MantissaScale scale)
+        : min(getMin(scale))
+        , cuspRoundingFixEnabled(isCuspFixEnabled(scale))
+        , log(logTen(min).value_or(-1))
+        , scale(scale)
     {
     }
 
-    MantissaScale const scale;
-    int const log{getExponent(scale)};
-    rep const min{getMin(scale, log)};
-    rep const max{(min * 10) - 1};
-    CuspRoundingFix const cuspRoundingFixEnabled{isCuspFixEnabled(scale)};
+    rep min;
+    rep max{(min * 10) - 1};
+    CuspRoundingFix cuspRoundingFixEnabled;
+    int log;
+    MantissaScale scale;
 
     static MantissaRange const&
     getMantissaRange(MantissaScale scale);
@@ -150,35 +110,23 @@ struct MantissaRange final
     getAllScales();
 
 private:
-    static constexpr int
-    getExponent(MantissaScale scale)
+    static constexpr rep
+    getMin(MantissaScale scale)
     {
         switch (scale)
         {
             case MantissaScale::Small:
-                return 15;
+                return 1'000'000'000'000'000ULL;
             case MantissaScale::LargeLegacy:
             case MantissaScale::Large:
-                return 18;
-            // LCOV_EXCL_START
+                return 1'000'000'000'000'000'000ULL;
             default:
                 // If called in a constexpr context, this throw assures that the build fails if an
                 // invalid scale is used.
-                throw std::runtime_error("Unknown mantissa scale");
-                // LCOV_EXCL_STOP
+                throw std::runtime_error("Unknown mantissa scale");  // LCOV_EXCL_LINE
         }
     }
 
-    // Keep this function for future use with different ways to compute
-    // the ranges.
-    static constexpr rep
-    getMin(MantissaScale scale, int exponent)
-    {
-        if (exponent < 0 || exponent >= kPowerOfTen.size())
-            throw std::runtime_error("Invalid exponent");  // LCOV_EXCL_LINE
-        return kPowerOfTen[exponent];
-    }
-
     static constexpr CuspRoundingFix
     isCuspFixEnabled(MantissaScale scale)
     {
@@ -529,7 +477,8 @@ public:
     template <
         auto MinMantissa,
         auto MaxMantissa,
-        Integral64 T = std::decay_t<decltype(MinMantissa)>>
+        Integral64 T = std::decay_t<decltype(MinMantissa)>,
+        Integral64 TMax = std::decay_t<decltype(MaxMantissa)>>
     [[nodiscard]]
     std::pair<T, int>
     normalizeToRange() const;
@@ -570,8 +519,7 @@ private:
         int& exponent,
         MantissaRange::rep const& minMantissa,
         MantissaRange::rep const& maxMantissa,
-        MantissaRange::CuspRoundingFix cuspRoundingFixEnabled,
-        bool dropped);
+        MantissaRange::CuspRoundingFix cuspRoundingFixEnabled);
 
     [[nodiscard]] bool
     isnormal() const noexcept;
@@ -777,18 +725,16 @@ Number::isnormal() const noexcept
          kMinExponent <= exponent_ && exponent_ <= kMaxExponent);
 }
 
-template <auto MinMantissa, auto MaxMantissa, Integral64 T>
+template <auto MinMantissa, auto MaxMantissa, Integral64 T, Integral64 TMax>
 std::pair<T, int>
 Number::normalizeToRange() const
 {
     static_assert(std::is_same_v<T, std::uint64_t> || std::is_same_v<T, std::int64_t>);
-    static_assert(std::is_same_v<T, std::decay_t<decltype(MinMantissa)>>);
-    static_assert(std::is_same_v<T, std::decay_t<decltype(MaxMantissa)>>);
+    static_assert(std::is_same_v<T, TMax>);
     auto constexpr kMIN = static_cast<T>(MinMantissa);
     auto constexpr kMAX = static_cast<T>(MaxMantissa);
     static_assert(kMIN > 0);
     static_assert(kMIN % 10 == 0);
-    static_assert(isPowerOfTen(kMIN));
     static_assert(kMAX % 10 == 9);
     static_assert((kMAX + 1) / 10 == kMIN);
 

include/xrpl/basics/TaggedCache.h

@@ -157,7 +157,7 @@ public:
     /** Fetch an item from the cache.
         If the digest was not found, Handler
         will be called with this signature:
-            SLE::const_pointer(void)
+            std::shared_ptr<SLE const>(void)
     */
     template <class Handler>
     SharedPointerType

include/xrpl/ledger/ApplyView.h

@@ -123,7 +123,7 @@ private:
         bool preserveOrder,
         Keylet const& directory,
         uint256 const& key,
-        std::function<void(SLE::ref)> const& describe);
+        std::function<void(std::shared_ptr<SLE> const&)> const& describe);
 
 public:
     ApplyView() = default;
@@ -153,7 +153,7 @@ public:
 
         @return `nullptr` if the key is not present
     */
-    virtual SLE::pointer
+    virtual std::shared_ptr<SLE>
     peek(Keylet const& k) = 0;
 
     /** Remove a peeked SLE.
@@ -168,7 +168,7 @@ public:
             The key is no longer associated with the SLE.
     */
     virtual void
-    erase(SLE::ref sle) = 0;
+    erase(std::shared_ptr<SLE> const& sle) = 0;
 
     /** Insert a new state SLE
 
@@ -189,7 +189,7 @@ public:
         @note The key is taken from the SLE
     */
     virtual void
-    insert(SLE::ref sle) = 0;
+    insert(std::shared_ptr<SLE> const& sle) = 0;
 
     /** Indicate changes to a peeked SLE
 
@@ -208,7 +208,7 @@ public:
     */
     /** @{ */
     virtual void
-    update(SLE::ref sle) = 0;
+    update(std::shared_ptr<SLE> const& sle) = 0;
 
     //--------------------------------------------------------------------------
 
@@ -301,7 +301,7 @@ public:
     dirAppend(
         Keylet const& directory,
         Keylet const& key,
-        std::function<void(SLE::ref)> const& describe)
+        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
     {
         if (key.type != ltOFFER)
         {
@@ -340,7 +340,7 @@ public:
     dirInsert(
         Keylet const& directory,
         uint256 const& key,
-        std::function<void(SLE::ref)> const& describe)
+        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
     {
         return dirAdd(false, directory, key, describe);
     }
@@ -349,7 +349,7 @@ public:
     dirInsert(
         Keylet const& directory,
         Keylet const& key,
-        std::function<void(SLE::ref)> const& describe)
+        std::function<void(std::shared_ptr<SLE> const&)> const& describe)
     {
         return dirAdd(false, directory, key.key, describe);
     }
@@ -411,7 +411,7 @@ createRoot(
     ApplyView& view,
     Keylet const& directory,
     uint256 const& key,
-    std::function<void(SLE::ref)> const& describe);
+    std::function<void(std::shared_ptr<SLE> const&)> const& describe);
 
 auto
 findPreviousPage(ApplyView& view, Keylet const& directory, SLE::ref start);
@@ -434,7 +434,7 @@ insertPage(
     SLE::ref next,
     uint256 const& key,
     Keylet const& directory,
-    std::function<void(SLE::ref)> const& describe);
+    std::function<void(std::shared_ptr<SLE> const&)> const& describe);
 
 }  // namespace directory
 }  // namespace xrpl

include/xrpl/ledger/ApplyViewImpl.h

@@ -67,8 +67,8 @@ public:
         std::function<void(
             uint256 const& key,
             bool isDelete,
-            SLE::const_ref before,
-            SLE::const_ref after)> const& func);
+            std::shared_ptr<SLE const> const& before,
+            std::shared_ptr<SLE const> const& after)> const& func);
 
 private:
     std::optional<STAmount> deliver_;

include/xrpl/ledger/BookDirs.h

@@ -11,13 +11,13 @@ private:
     uint256 const root_;
     uint256 const nextQuality_;
     uint256 const key_;
-    SLE::const_pointer sle_ = nullptr;
+    std::shared_ptr<SLE const> sle_ = nullptr;
     unsigned int entry_ = 0;
     uint256 index_;
 
 public:
     class const_iterator;  // NOLINT(readability-identifier-naming)
-    using value_type = SLE::const_pointer;
+    using value_type = std::shared_ptr<SLE const>;
 
     BookDirs(ReadView const&, Book const&);
 
@@ -76,7 +76,7 @@ private:
     uint256 nextQuality_;
     uint256 key_;
     uint256 curKey_;
-    SLE::const_pointer sle_;
+    std::shared_ptr<SLE const> sle_;
     unsigned int entry_ = 0;
     uint256 index_;
     std::optional<value_type> mutable cache_;

include/xrpl/ledger/CachedView.h

@@ -36,7 +36,7 @@ public:
     bool
     exists(Keylet const& k) const override;
 
-    SLE::const_pointer
+    std::shared_ptr<SLE const>
     read(Keylet const& k) const override;
 
     bool

include/xrpl/ledger/Dir.h

@@ -22,12 +22,12 @@ class Dir
 private:
     ReadView const* view_ = nullptr;
     Keylet root_;
-    SLE::const_pointer sle_;
+    std::shared_ptr<SLE const> sle_;
     STVector256 const* indexes_ = nullptr;
 
 public:
     class ConstIterator;
-    using value_type = SLE::const_pointer;
+    using value_type = std::shared_ptr<SLE const>;
 
     Dir(ReadView const&, Keylet const&);
 
@@ -102,7 +102,7 @@ private:
     Keylet page_;
     uint256 index_;
     std::optional<value_type> mutable cache_;
-    SLE::const_pointer sle_;
+    std::shared_ptr<SLE const> sle_;
     STVector256 const* indexes_ = nullptr;
     std::vector<uint256>::const_iterator it_;
 };

include/xrpl/ledger/Ledger.h

@@ -166,7 +166,7 @@ public:
     std::optional<uint256>
     succ(uint256 const& key, std::optional<uint256> const& last = std::nullopt) const override;
 
-    SLE::const_pointer
+    std::shared_ptr<SLE const>
     read(Keylet const& k) const override;
 
     std::unique_ptr<SlesType::iter_base>
@@ -202,16 +202,16 @@ public:
     //
 
     void
-    rawErase(SLE::ref sle) override;
+    rawErase(std::shared_ptr<SLE> const& sle) override;
 
     void
-    rawInsert(SLE::ref sle) override;
+    rawInsert(std::shared_ptr<SLE> const& sle) override;
 
     void
     rawErase(uint256 const& key);
 
     void
-    rawReplace(SLE::ref sle) override;
+    rawReplace(std::shared_ptr<SLE> const& sle) override;
 
     void
     rawDestroyXRP(XRPAmount const& fee) override
@@ -361,7 +361,7 @@ public:
     bool
     isVotingLedger() const;
 
-    SLE::pointer
+    std::shared_ptr<SLE>
     peek(Keylet const& k) const;
 
 private:

include/xrpl/ledger/OpenView.h

@@ -197,7 +197,7 @@ public:
     std::optional<key_type>
     succ(key_type const& key, std::optional<key_type> const& last = std::nullopt) const override;
 
-    SLE::const_pointer
+    std::shared_ptr<SLE const>
     read(Keylet const& k) const override;
 
     std::unique_ptr<SlesType::iter_base>
@@ -224,13 +224,13 @@ public:
     // RawView
 
     void
-    rawErase(SLE::ref sle) override;
+    rawErase(std::shared_ptr<SLE> const& sle) override;
 
     void
-    rawInsert(SLE::ref sle) override;
+    rawInsert(std::shared_ptr<SLE> const& sle) override;
 
     void
-    rawReplace(SLE::ref sle) override;
+    rawReplace(std::shared_ptr<SLE> const& sle) override;
 
     void
     rawDestroyXRP(XRPAmount const& fee) override;

include/xrpl/ledger/RawView.h

@@ -25,7 +25,7 @@ public:
         can calculate metadata.
     */
     virtual void
-    rawErase(SLE::ref sle) = 0;
+    rawErase(std::shared_ptr<SLE> const& sle) = 0;
 
     /** Unconditionally insert a state item.
 
@@ -39,7 +39,7 @@ public:
         @note The key is taken from the SLE
     */
     virtual void
-    rawInsert(SLE::ref sle) = 0;
+    rawInsert(std::shared_ptr<SLE> const& sle) = 0;
 
     /** Unconditionally replace a state item.
 
@@ -54,7 +54,7 @@ public:
         @note The key is taken from the SLE
     */
     virtual void
-    rawReplace(SLE::ref sle) = 0;
+    rawReplace(std::shared_ptr<SLE> const& sle) = 0;
 
     /** Destroy XRP.
 

include/xrpl/ledger/ReadView.h

@@ -34,9 +34,9 @@ public:
 
     using key_type = uint256;
 
-    using mapped_type = SLE::const_pointer;
+    using mapped_type = std::shared_ptr<SLE const>;
 
-    struct SlesType : detail::ReadViewFwdRange<SLE::const_pointer>
+    struct SlesType : detail::ReadViewFwdRange<std::shared_ptr<SLE const>>
     {
         explicit SlesType(ReadView const& view);
         [[nodiscard]] Iterator
@@ -143,7 +143,7 @@ public:
         @return `nullptr` if the key is not present or
                 if the type does not match.
     */
-    [[nodiscard]] virtual SLE::const_pointer
+    [[nodiscard]] virtual std::shared_ptr<SLE const>
     read(Keylet const& k) const = 0;
 
     // Accounts in a payment are not allowed to use assets acquired during that

include/xrpl/ledger/View.h

@@ -12,6 +12,7 @@
 #include <cstdint>
 #include <functional>
 #include <map>
+#include <memory>
 #include <optional>
 #include <set>
 #include <utility>
@@ -134,7 +135,7 @@ areCompatible(
 dirLink(
     ApplyView& view,
     AccountID const& owner,
-    SLE::pointer& object,
+    std::shared_ptr<SLE>& object,
     SF_UINT64 const& node = sfOwnerNode);
 
 /** Checks that can withdraw funds from an object to itself or a destination.
@@ -214,8 +215,8 @@ doWithdraw(
  * (if should not be skipped) and if the entry should be skipped. The status
  * is always tesSUCCESS if the entry should be skipped.
  */
-using EntryDeleter =
-    std::function<std::pair<TER, SkipEntry>(LedgerEntryType, uint256 const&, SLE::pointer&)>;
+using EntryDeleter = std::function<
+    std::pair<TER, SkipEntry>(LedgerEntryType, uint256 const&, std::shared_ptr<SLE>&)>;
 /** Cleanup owner directory entries on account delete.
  * Used for a regular and AMM accounts deletion. The caller
  * has to provide the deleter function, which handles details of

include/xrpl/ledger/detail/ApplyStateTable.h

@@ -4,10 +4,16 @@
 #include <xrpl/ledger/OpenView.h>
 #include <xrpl/ledger/RawView.h>
 #include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/LedgerFormats.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxMeta.h>
 #include <xrpl/protocol/XRPAmount.h>
 
+#include <memory>
+#ifndef NDEBUG
+#include <map>
+#endif
+
 namespace xrpl::detail {
 
 // Helper class that buffers modifications
@@ -24,7 +30,7 @@ private:
         Modify,
     };
 
-    using items_t = std::map<key_type, std::pair<Action, SLE::pointer>>;
+    using items_t = std::map<key_type, std::pair<Action, std::shared_ptr<SLE>>>;
 
     items_t items_;
     XRPAmount dropsDestroyed_{0};
@@ -58,10 +64,10 @@ public:
     [[nodiscard]] std::optional<key_type>
     succ(ReadView const& base, key_type const& key, std::optional<key_type> const& last) const;
 
-    [[nodiscard]] SLE::const_pointer
+    [[nodiscard]] std::shared_ptr<SLE const>
     read(ReadView const& base, Keylet const& k) const;
 
-    SLE::pointer
+    std::shared_ptr<SLE>
     peek(ReadView const& base, Keylet const& k);
 
     [[nodiscard]] std::size_t
@@ -73,23 +79,23 @@ public:
         std::function<void(
             uint256 const& key,
             bool isDelete,
-            SLE::const_ref before,
-            SLE::const_ref after)> const& func) const;
+            std::shared_ptr<SLE const> const& before,
+            std::shared_ptr<SLE const> const& after)> const& func) const;
 
     void
-    erase(ReadView const& base, SLE::ref sle);
+    erase(ReadView const& base, std::shared_ptr<SLE> const& sle);
 
     void
-    rawErase(ReadView const& base, SLE::ref sle);
+    rawErase(ReadView const& base, std::shared_ptr<SLE> const& sle);
 
     void
-    insert(ReadView const& base, SLE::ref sle);
+    insert(ReadView const& base, std::shared_ptr<SLE> const& sle);
 
     void
-    update(ReadView const& base, SLE::ref sle);
+    update(ReadView const& base, std::shared_ptr<SLE> const& sle);
 
     void
-    replace(ReadView const& base, SLE::ref sle);
+    replace(ReadView const& base, std::shared_ptr<SLE> const& sle);
 
     void
     destroyXRP(XRPAmount const& fee);
@@ -101,13 +107,45 @@ public:
         return dropsDestroyed_;
     }
 
+#ifndef NDEBUG
+    /** Every ledger entry this table has read or written, mapped to its type.
+
+        Populated in DEBUG builds by the access methods below (reads via
+        read/exists/peek and writes via insert/update/replace/erase). Directory
+        iteration via succ() is deliberately NOT recorded — see AccessSet for
+        why directory entries are out of scope for conflict tracking. Used by
+        the parallel-apply access-set assertion to verify a transactor's
+        declared footprint is a superset of what it actually touched.
+    */
+    [[nodiscard]] std::map<key_type, LedgerEntryType> const&
+    touchedEntries() const
+    {
+        return touched_;
+    }
+#endif
+
 private:
-    using Mods = hash_map<key_type, SLE::pointer>;
+#ifndef NDEBUG
+    void
+    recordTouch(key_type const& key, LedgerEntryType type) const
+    {
+        // Prefer ltDIR_NODE on collision so directory pages stay identifiable
+        // regardless of access order; non-dir objects are never accessed via a
+        // directory keylet, so this never mislabels a real object.
+        auto const [it, inserted] = touched_.try_emplace(key, type);
+        if (!inserted && type == ltDIR_NODE)
+            it->second = ltDIR_NODE;
+    }
+
+    mutable std::map<key_type, LedgerEntryType> touched_;
+#endif
+
+    using Mods = hash_map<key_type, std::shared_ptr<SLE>>;
 
     static void
-    threadItem(TxMeta& meta, SLE::ref to);
+    threadItem(TxMeta& meta, std::shared_ptr<SLE> const& to);
 
-    SLE::pointer
+    std::shared_ptr<SLE>
     getForMod(ReadView const& base, key_type const& key, Mods& mods, beast::Journal j);
 
     void
@@ -117,7 +155,7 @@ private:
     threadOwners(
         ReadView const& base,
         TxMeta& meta,
-        SLE::const_ref sle,
+        std::shared_ptr<SLE const> const& sle,
         Mods& mods,
         beast::Journal j);
 };

include/xrpl/ledger/detail/ApplyViewBase.h

@@ -40,7 +40,7 @@ public:
     [[nodiscard]] std::optional<key_type>
     succ(key_type const& key, std::optional<key_type> const& last = std::nullopt) const override;
 
-    [[nodiscard]] SLE::const_pointer
+    [[nodiscard]] std::shared_ptr<SLE const>
     read(Keylet const& k) const override;
 
     [[nodiscard]] std::unique_ptr<SlesType::iter_base>
@@ -69,32 +69,42 @@ public:
     [[nodiscard]] ApplyFlags
     flags() const override;
 
-    SLE::pointer
+    std::shared_ptr<SLE>
     peek(Keylet const& k) override;
 
     void
-    erase(SLE::ref sle) override;
+    erase(std::shared_ptr<SLE> const& sle) override;
 
     void
-    insert(SLE::ref sle) override;
+    insert(std::shared_ptr<SLE> const& sle) override;
 
     void
-    update(SLE::ref sle) override;
+    update(std::shared_ptr<SLE> const& sle) override;
 
     // RawView
 
     void
-    rawErase(SLE::ref sle) override;
+    rawErase(std::shared_ptr<SLE> const& sle) override;
 
     void
-    rawInsert(SLE::ref sle) override;
+    rawInsert(std::shared_ptr<SLE> const& sle) override;
 
     void
-    rawReplace(SLE::ref sle) override;
+    rawReplace(std::shared_ptr<SLE> const& sle) override;
 
     void
     rawDestroyXRP(XRPAmount const& feeDrops) override;
 
+#ifndef NDEBUG
+    /** Every ledger entry touched (read or written) by this view, with type.
+        DEBUG-only; backs the parallel-apply access-set assertion. */
+    [[nodiscard]] std::map<uint256, LedgerEntryType> const&
+    touchedEntries() const
+    {
+        return items_.touchedEntries();
+    }
+#endif
+
 protected:
     ApplyFlags flags_;
     ReadView const* base_;

include/xrpl/ledger/detail/RawStateTable.h

@@ -49,15 +49,15 @@ public:
     succ(ReadView const& base, key_type const& key, std::optional<key_type> const& last) const;
 
     void
-    erase(SLE::ref sle);
+    erase(std::shared_ptr<SLE> const& sle);
 
     void
-    insert(SLE::ref sle);
+    insert(std::shared_ptr<SLE> const& sle);
 
     void
-    replace(SLE::ref sle);
+    replace(std::shared_ptr<SLE> const& sle);
 
-    [[nodiscard]] SLE::const_pointer
+    [[nodiscard]] std::shared_ptr<SLE const>
     read(ReadView const& base, Keylet const& k) const;
 
     void
@@ -84,10 +84,10 @@ private:
     struct SleAction
     {
         Action action;
-        SLE::pointer sle;
+        std::shared_ptr<SLE> sle;
 
         // Constructor needed for emplacement in std::map
-        SleAction(Action action, SLE::pointer sle) : action(action), sle(std::move(sle))
+        SleAction(Action action, std::shared_ptr<SLE> const& sle) : action(action), sle(sle)
         {
         }
     };

include/xrpl/ledger/helpers/AMMHelpers.h

@@ -200,7 +200,7 @@ getAMMOfferStartWithTakerGets(
 
     auto getAmounts = [&pool, &tfee](Number const& nTakerGetsProposed) {
         // Round downward to minimize the offer and to maximize the quality.
-        // This has the most impact when takerGets is integral.
+        // This has the most impact when takerGets is XRP.
         auto const takerGets =
             toAmount<TOut>(getAsset(pool.out), nTakerGetsProposed, Number::RoundingMode::Downward);
         return TAmounts<TIn, TOut>{swapAssetOut(pool, takerGets, tfee), takerGets};
@@ -215,7 +215,7 @@ getAMMOfferStartWithTakerGets(
 }
 
 /** Generate AMM offer starting with takerPays when AMM pool
- * from the payment perspective has a fractional output asset.
+ * from the payment perspective is XRP(in)/IOU(out) or IOU(in)/IOU(out).
  * Equations:
  * Spot Price Quality after the offer is consumed:
  *     Qsp = (O - o) / (I + i)       -- equation (1)
@@ -267,7 +267,7 @@ getAMMOfferStartWithTakerPays(
 
     auto getAmounts = [&pool, &tfee](Number const& nTakerPaysProposed) {
         // Round downward to minimize the offer and to maximize the quality.
-        // This has the most impact when takerPays is integral.
+        // This has the most impact when takerPays is XRP.
         auto const takerPays =
             toAmount<TIn>(getAsset(pool.in), nTakerPaysProposed, Number::RoundingMode::Downward);
         return TAmounts<TIn, TOut>{takerPays, swapAssetIn(pool, takerPays, tfee)};
@@ -285,11 +285,11 @@ getAMMOfferStartWithTakerPays(
  * is equal to LOB quality (in this case AMM offer quality is
  * better than LOB quality) or AMM offer is equal to LOB quality
  * (in this case SPQ is better than LOB quality).
- * Pre-amendment code calculates takerPays first. If takerGets is the
- * economically coarser integral side, it is rounded down, which results in
- * worse offer quality than LOB quality, and the offer might fail to generate.
- * Post-amendment code calculates the economically coarser integral offer side
- * first. The result is rounded down, which makes the offer quality better.
+ * Pre-amendment code calculates takerPays first. If takerGets is XRP,
+ * it is rounded down, which results in worse offer quality than
+ * LOB quality, and the offer might fail to generate.
+ * Post-amendment code calculates the XRP offer side first. The result
+ * is rounded down, which makes the offer quality better.
  *   It might not be possible to match either SPQ or AMM offer to LOB
  * quality. This generally happens at higher fees.
  * @param pool AMM pool balances
@@ -368,18 +368,10 @@ changeSpotPriceQuality(
         return std::nullopt;
     }
 
+    // Generate the offer starting with XRP side. Return seated offer amounts
+    // if the offer can be generated, otherwise nullopt.
     auto amounts = [&]() {
-        bool const inIntegral = getAsset(pool.in).integral();
-        bool const outIntegral = getAsset(pool.out).integral();
-
-        // Preserve historical behavior for fractional pairs and XRP/IOU-style
-        // one-integral-side pairs. For two integral assets, pick the side whose
-        // minimum unit is economically coarser at this quality.
-        //
-        // Quality::rate() is input units per output unit, so one output unit is
-        // coarser when it costs at least one input unit. Ties use takerGets,
-        // matching the historical XRP-output behavior.
-        if (outIntegral && (!inIntegral || Number(quality.rate()) >= 1))
+        if (isXRP(getAsset(pool.out)))
             return getAMMOfferStartWithTakerGets(pool, quality, tfee);
         return getAMMOfferStartWithTakerPays(pool, quality, tfee);
     }();
@@ -800,7 +792,7 @@ deleteAMMAccount(Sandbox& view, Asset const& asset, Asset const& asset2, beast::
 void
 initializeFeeAuctionVote(
     ApplyView& view,
-    SLE::pointer& ammSle,
+    std::shared_ptr<SLE>& ammSle,
     AccountID const& account,
     Asset const& lptAsset,
     std::uint16_t tfee);
@@ -820,7 +812,7 @@ Expected<bool, TER>
 verifyAndAdjustLPTokenBalance(
     Sandbox& sb,
     STAmount const& lpTokens,
-    SLE::pointer& ammSle,
+    std::shared_ptr<SLE>& ammSle,
     AccountID const& account);
 
 }  // namespace xrpl

include/xrpl/ledger/helpers/AccountRootHelpers.h

@@ -9,6 +9,7 @@
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/TER.h>
 
+#include <memory>
 #include <set>
 #include <vector>
 
@@ -35,7 +36,11 @@ xrpLiquid(ReadView const& view, AccountID const& id, std::int32_t ownerCountAdj,
 
 /** Adjust the owner count up or down. */
 void
-adjustOwnerCount(ApplyView& view, SLE::ref sle, std::int32_t amount, beast::Journal j);
+adjustOwnerCount(
+    ApplyView& view,
+    std::shared_ptr<SLE> const& sle,
+    std::int32_t amount,
+    beast::Journal j);
 
 /** Returns IOU issuer transfer fee as Rate. Rate specifies
  * the fee as fractions of 1 billion. For example, 1% transfer rate
@@ -71,7 +76,9 @@ getPseudoAccountFields();
     - null pointer
 */
 [[nodiscard]] bool
-isPseudoAccount(SLE::const_pointer sleAcct, std::set<SField const*> const& pseudoFieldFilter = {});
+isPseudoAccount(
+    std::shared_ptr<SLE const> sleAcct,
+    std::set<SField const*> const& pseudoFieldFilter = {});
 
 /** Convenience overload that reads the account from the view. */
 [[nodiscard]] inline bool
@@ -91,7 +98,7 @@ isPseudoAccount(
  * before using a field. The amendment check is **not** performed in
  * createPseudoAccount.
  */
-[[nodiscard]] Expected<SLE::pointer, TER>
+[[nodiscard]] Expected<std::shared_ptr<SLE>, TER>
 createPseudoAccount(ApplyView& view, uint256 const& pseudoOwnerKey, SField const& ownerField);
 
 /** Checks the destination and tag.

include/xrpl/ledger/helpers/CredentialHelpers.h

@@ -23,7 +23,7 @@ checkExpired(SLE const& sleCredential, NetClock::time_point const& closed);
 
 // Actually remove a credentials object from the ledger
 [[nodiscard]] TER
-deleteSLE(ApplyView& view, SLE::ref sleCredential, beast::Journal j);
+deleteSLE(ApplyView& view, std::shared_ptr<SLE> const& sleCredential, beast::Journal j);
 
 // Amendment and parameters checks for sfCredentialIDs field
 NotTEC
@@ -70,7 +70,7 @@ verifyDepositPreauth(
     ApplyView& view,
     AccountID const& src,
     AccountID const& dst,
-    SLE::const_ref sleDst,
+    std::shared_ptr<SLE const> const& sleDst,
     beast::Journal j);
 
 }  // namespace xrpl

include/xrpl/ledger/helpers/DelegateHelpers.h

@@ -15,7 +15,7 @@ namespace xrpl {
  * if not.
  */
 NotTEC
-checkTxPermission(SLE::const_ref delegate, STTx const& tx);
+checkTxPermission(std::shared_ptr<SLE const> const& delegate, STTx const& tx);
 
 /**
  * Load the granular permissions granted to the delegate account for the
@@ -28,7 +28,7 @@ checkTxPermission(SLE::const_ref delegate, STTx const& tx);
  */
 void
 loadGranularPermission(
-    SLE::const_ref delegate,
+    std::shared_ptr<SLE const> const& delegate,
     TxType const& type,
     std::unordered_set<GranularPermissionType>& granularPermissions);
 

include/xrpl/ledger/helpers/DirectoryHelpers.h

@@ -115,7 +115,7 @@ bool
 cdirFirst(
     ReadView const& view,
     uint256 const& root,
-    SLE::const_pointer& page,
+    std::shared_ptr<SLE const>& page,
     unsigned int& index,
     uint256& entry);
 
@@ -123,7 +123,7 @@ bool
 dirFirst(
     ApplyView& view,
     uint256 const& root,
-    SLE::pointer& page,
+    std::shared_ptr<SLE>& page,
     unsigned int& index,
     uint256& entry);
 /** @} */
@@ -147,7 +147,7 @@ bool
 cdirNext(
     ReadView const& view,
     uint256 const& root,
-    SLE::const_pointer& page,
+    std::shared_ptr<SLE const>& page,
     unsigned int& index,
     uint256& entry);
 
@@ -155,14 +155,17 @@ bool
 dirNext(
     ApplyView& view,
     uint256 const& root,
-    SLE::pointer& page,
+    std::shared_ptr<SLE>& page,
     unsigned int& index,
     uint256& entry);
 /** @} */
 
 /** Iterate all items in the given directory. */
 void
-forEachItem(ReadView const& view, Keylet const& root, std::function<void(SLE::const_ref)> const& f);
+forEachItem(
+    ReadView const& view,
+    Keylet const& root,
+    std::function<void(std::shared_ptr<SLE const> const&)> const& f);
 
 /** Iterate all items after an item in the given directory.
     @param after The key of the item to start after
@@ -177,11 +180,14 @@ forEachItemAfter(
     uint256 const& after,
     std::uint64_t const hint,
     unsigned int limit,
-    std::function<bool(SLE::const_ref)> const& f);
+    std::function<bool(std::shared_ptr<SLE const> const&)> const& f);
 
 /** Iterate all items in an account's owner directory. */
 inline void
-forEachItem(ReadView const& view, AccountID const& id, std::function<void(SLE::const_ref)> const& f)
+forEachItem(
+    ReadView const& view,
+    AccountID const& id,
+    std::function<void(std::shared_ptr<SLE const> const&)> const& f)
 {
     forEachItem(view, keylet::ownerDir(id), f);
 }
@@ -199,7 +205,7 @@ forEachItemAfter(
     uint256 const& after,
     std::uint64_t const hint,
     unsigned int limit,
-    std::function<bool(SLE::const_ref)> const& f)
+    std::function<bool(std::shared_ptr<SLE const> const&)> const& f)
 {
     return forEachItemAfter(view, keylet::ownerDir(id), after, hint, limit, f);
 }

include/xrpl/ledger/helpers/EscrowHelpers.h

@@ -18,7 +18,7 @@ TER
 escrowUnlockApplyHelper(
     ApplyView& view,
     Rate lockedRate,
-    SLE::ref sleDest,
+    std::shared_ptr<SLE> const& sleDest,
     STAmount const& xrpBalance,
     STAmount const& amount,
     AccountID const& issuer,
@@ -32,7 +32,7 @@ inline TER
 escrowUnlockApplyHelper<Issue>(
     ApplyView& view,
     Rate lockedRate,
-    SLE::ref sleDest,
+    std::shared_ptr<SLE> const& sleDest,
     STAmount const& xrpBalance,
     STAmount const& amount,
     AccountID const& issuer,
@@ -162,7 +162,7 @@ inline TER
 escrowUnlockApplyHelper<MPTIssue>(
     ApplyView& view,
     Rate lockedRate,
-    SLE::ref sleDest,
+    std::shared_ptr<SLE> const& sleDest,
     STAmount const& xrpBalance,
     STAmount const& amount,
     AccountID const& issuer,

include/xrpl/ledger/helpers/LendingHelpers.h

@@ -461,7 +461,6 @@ loanAccruedInterest(
 
 ExtendedPaymentComponents
 computeOverpaymentComponents(
-    Rules const& rules,
     Asset const& asset,
     int32_t const loanScale,
     Number const& overpayment,

include/xrpl/ledger/helpers/MPTokenHelpers.h

@@ -230,14 +230,6 @@ createMPToken(
     AccountID const& account,
     std::uint32_t const flags);
 
-TER
-checkCreateMPT(
-    xrpl::ApplyView& view,
-    xrpl::MPTIssue const& mptIssue,
-    xrpl::AccountID const& holder,
-    std::uint32_t flags,
-    beast::Journal j);
-
 TER
 checkCreateMPT(
     xrpl::ApplyView& view,

include/xrpl/ledger/helpers/NFTokenHelpers.h

@@ -28,9 +28,10 @@ findToken(ReadView const& view, AccountID const& owner, uint256 const& nftokenID
 struct TokenAndPage
 {
     STObject token;
-    SLE::pointer page;
+    std::shared_ptr<SLE> page;
 
-    TokenAndPage(STObject token, SLE::pointer page) : token(std::move(token)), page(std::move(page))
+    TokenAndPage(STObject token, std::shared_ptr<SLE> page)
+        : token(std::move(token)), page(std::move(page))
     {
     }
 };
@@ -46,7 +47,11 @@ TER
 removeToken(ApplyView& view, AccountID const& owner, uint256 const& nftokenID);
 
 TER
-removeToken(ApplyView& view, AccountID const& owner, uint256 const& nftokenID, SLE::ref page);
+removeToken(
+    ApplyView& view,
+    AccountID const& owner,
+    uint256 const& nftokenID,
+    std::shared_ptr<SLE> const& page);
 
 /** Deletes the given token offer.
 
@@ -58,7 +63,7 @@ removeToken(ApplyView& view, AccountID const& owner, uint256 const& nftokenID, S
     The offer also consumes one incremental reserve.
  */
 bool
-deleteTokenOffer(ApplyView& view, SLE::ref offer);
+deleteTokenOffer(ApplyView& view, std::shared_ptr<SLE> const& offer);
 
 /** Repairs the links in an NFTokenPage directory.
 

include/xrpl/ledger/helpers/OfferHelpers.h

@@ -5,6 +5,8 @@
 #include <xrpl/protocol/STLedgerEntry.h>
 #include <xrpl/protocol/TER.h>
 
+#include <memory>
+
 namespace xrpl {
 
 /** Delete an offer.
@@ -21,6 +23,6 @@ namespace xrpl {
 */
 // [[nodiscard]] // nodiscard commented out so Flow, BookTip and others compile.
 TER
-offerDelete(ApplyView& view, SLE::ref sle, beast::Journal j);
+offerDelete(ApplyView& view, std::shared_ptr<SLE> const& sle, beast::Journal j);
 
 }  // namespace xrpl

include/xrpl/ledger/helpers/PaymentChannelHelpers.h

@@ -8,6 +8,10 @@
 namespace xrpl {
 
 TER
-closeChannel(SLE::ref slep, ApplyView& view, uint256 const& key, beast::Journal j);
+closeChannel(
+    std::shared_ptr<SLE> const& slep,
+    ApplyView& view,
+    uint256 const& key,
+    beast::Journal j);
 
 }  // namespace xrpl

include/xrpl/ledger/helpers/RippleStateHelpers.h

@@ -154,7 +154,7 @@ trustCreate(
 [[nodiscard]] TER
 trustDelete(
     ApplyView& view,
-    SLE::ref sleRippleState,
+    std::shared_ptr<SLE> const& sleRippleState,
     AccountID const& uLowAccountID,
     AccountID const& uHighAccountID,
     beast::Journal j);
@@ -248,7 +248,7 @@ removeEmptyHolding(
 [[nodiscard]] TER
 deleteAMMTrustLine(
     ApplyView& view,
-    SLE::pointer sleState,
+    std::shared_ptr<SLE> sleState,
     std::optional<AccountID> const& ammAccountID,
     beast::Journal j);
 
@@ -258,7 +258,7 @@ deleteAMMTrustLine(
 [[nodiscard]] TER
 deleteAMMMPToken(
     ApplyView& view,
-    SLE::pointer sleMPT,
+    std::shared_ptr<SLE> sleMPT,
     AccountID const& ammAccountID,
     beast::Journal j);
 

include/xrpl/ledger/helpers/VaultHelpers.h

@@ -5,6 +5,7 @@
 #include <xrpl/protocol/STAmount.h>
 #include <xrpl/protocol/STLedgerEntry.h>
 
+#include <memory>
 #include <optional>
 
 namespace xrpl {
@@ -20,7 +21,10 @@ namespace xrpl {
     @return The number of shares, or nullopt on error.
 */
 [[nodiscard]] std::optional<STAmount>
-assetsToSharesDeposit(SLE::const_ref vault, SLE::const_ref issuance, STAmount const& assets);
+assetsToSharesDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& assets);
 
 /** From the perspective of a vault, return the number of assets to take from
     depositor when they receive a fixed amount of shares. Note, since shares are
@@ -33,7 +37,10 @@ assetsToSharesDeposit(SLE::const_ref vault, SLE::const_ref issuance, STAmount co
     @return The number of assets, or nullopt on error.
 */
 [[nodiscard]] std::optional<STAmount>
-sharesToAssetsDeposit(SLE::const_ref vault, SLE::const_ref issuance, STAmount const& shares);
+sharesToAssetsDeposit(
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
+    STAmount const& shares);
 
 /** Controls whether to truncate shares instead of rounding. */
 enum class TruncateShares : bool { No = false, Yes = true };
@@ -62,8 +69,8 @@ enum class WaiveUnrealizedLoss : bool { No = false, Yes = true };
 */
 [[nodiscard]] std::optional<STAmount>
 assetsToSharesWithdraw(
-    SLE::const_ref vault,
-    SLE::const_ref issuance,
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
     STAmount const& assets,
     TruncateShares truncate = TruncateShares::No,
     WaiveUnrealizedLoss waive = WaiveUnrealizedLoss::No);
@@ -82,8 +89,8 @@ assetsToSharesWithdraw(
 */
 [[nodiscard]] std::optional<STAmount>
 sharesToAssetsWithdraw(
-    SLE::const_ref vault,
-    SLE::const_ref issuance,
+    std::shared_ptr<SLE const> const& vault,
+    std::shared_ptr<SLE const> const& issuance,
     STAmount const& shares,
     WaiveUnrealizedLoss waive = WaiveUnrealizedLoss::No);
 
@@ -97,6 +104,9 @@ sharesToAssetsWithdraw(
                     both the share MPTID and the outstanding-amount total.
 */
 [[nodiscard]] bool
-isSoleShareholder(ReadView const& view, AccountID const& account, SLE::const_ref issuance);
+isSoleShareholder(
+    ReadView const& view,
+    AccountID const& account,
+    std::shared_ptr<SLE const> const& issuance);
 
 }  // namespace xrpl

include/xrpl/nodestore/Database.h

@@ -131,10 +131,6 @@ public:
         std::uint32_t ledgerSeq,
         std::function<void(std::shared_ptr<NodeObject> const&)>&& callback);
 
-    /** Remove expired entries from the positive and negative caches. */
-    virtual void
-    sweep() = 0;
-
     /** Gather statistics pertaining to read and write activities.
      *
      * @param obj Json object reference into which to place counters.

include/xrpl/nodestore/detail/DatabaseNodeImp.h

@@ -22,32 +22,6 @@ public:
         beast::Journal j)
         : Database(scheduler, readThreads, config, j), backend_(std::move(backend))
     {
-        std::optional<int> cacheSize, cacheAge;
-
-        if (config.exists("cache_size"))
-        {
-            cacheSize = get<int>(config, "cache_size");
-            if (cacheSize.value() < 0)
-                Throw<std::runtime_error>("Specified negative value for cache_size");
-        }
-
-        if (config.exists("cache_age"))
-        {
-            cacheAge = get<int>(config, "cache_age");
-            if (cacheAge.value() < 0)
-                Throw<std::runtime_error>("Specified negative value for cache_age");
-        }
-
-        if (cacheSize.has_value() || cacheAge.has_value())
-        {
-            cache_ = std::make_shared<TaggedCache<uint256, NodeObject>>(
-                "DatabaseNodeImp",
-                cacheSize.value_or(0),
-                std::chrono::minutes(cacheAge.value_or(0)),
-                stopwatch(),
-                j);
-        }
-
         XRPL_ASSERT(
             backend_,
             "xrpl::NodeStore::DatabaseNodeImp::DatabaseNodeImp : non-null "
@@ -99,13 +73,7 @@ public:
         std::uint32_t ledgerSeq,
         std::function<void(std::shared_ptr<NodeObject> const&)>&& callback) override;
 
-    void
-    sweep() override;
-
 private:
-    // Cache for database objects. This cache is not always initialized. Check
-    // for null before using.
-    std::shared_ptr<TaggedCache<uint256, NodeObject>> cache_;
     // Persistent key/value storage
     std::shared_ptr<Backend> backend_;
 

include/xrpl/nodestore/detail/DatabaseRotatingImp.h

@@ -55,9 +55,6 @@ public:
     void
     sync() override;
 
-    void
-    sweep() override;
-
 private:
     std::shared_ptr<Backend> writableBackend_;
     std::shared_ptr<Backend> archiveBackend_;

include/xrpl/protocol/AmountConversions.h

@@ -144,7 +144,7 @@ T
 toAmount(Asset const& asset, Number const& n, Number::RoundingMode mode = Number::getround())
 {
     SaveNumberRoundMode const rm(Number::getround());
-    if (asset.integral())
+    if (isXRP(asset))
         Number::setround(mode);
 
     if constexpr (std::is_same_v<IOUAmount, T>)

include/xrpl/protocol/QualityFunction.h

@@ -51,14 +51,6 @@ public:
     std::optional<Number>
     outFromAvgQ(Quality const& quality);
 
-    /** Return whether `out` produces at least the requested
-     * average quality.
-     * @param quality requested average quality (quality limit)
-     * @param out output amount to test
-     */
-    [[nodiscard]] bool
-    satisfiesAvgQ(Quality const& quality, Number const& out) const;
-
     /** Return true if the quality function is constant
      */
     [[nodiscard]] bool

include/xrpl/protocol_autogen/LedgerEntryBase.h

@@ -27,7 +27,7 @@ public:
      * @brief Construct a ledger entry wrapper from an existing SLE object.
      * @param sle The underlying serialized ledger entry to wrap
      */
-    explicit LedgerEntryBase(SLE::const_pointer sle) : sle_(std::move(sle))
+    explicit LedgerEntryBase(std::shared_ptr<SLE const> sle) : sle_(std::move(sle))
     {
     }
 
@@ -151,7 +151,7 @@ public:
      * @return A constant reference to the underlying SLE object
      */
     [[nodiscard]]
-    SLE::const_pointer
+    std::shared_ptr<SLE const>
     getSle() const
     {
         return sle_;
@@ -159,7 +159,7 @@ public:
 
 protected:
     /** @brief The underlying serialized ledger entry being wrapped. */
-    SLE::const_pointer sle_;
+    std::shared_ptr<SLE const> sle_;
 };
 
 }  // namespace xrpl::ledger_entries

include/xrpl/protocol_autogen/ledger_entries/AMM.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a AMM ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit AMM(SLE::const_pointer sle)
+    explicit AMM(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -256,7 +256,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    AMMBuilder(SLE::const_pointer sle)
+    AMMBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltAMM)
         {

include/xrpl/protocol_autogen/ledger_entries/AccountRoot.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a AccountRoot ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit AccountRoot(SLE::const_pointer sle)
+    explicit AccountRoot(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -555,7 +555,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    AccountRootBuilder(SLE::const_pointer sle)
+    AccountRootBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltACCOUNT_ROOT)
         {

include/xrpl/protocol_autogen/ledger_entries/Amendments.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Amendments ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Amendments(SLE::const_pointer sle)
+    explicit Amendments(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -166,7 +166,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    AmendmentsBuilder(SLE::const_pointer sle)
+    AmendmentsBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltAMENDMENTS)
         {

include/xrpl/protocol_autogen/ledger_entries/Bridge.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Bridge ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Bridge(SLE::const_pointer sle)
+    explicit Bridge(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -210,7 +210,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    BridgeBuilder(SLE::const_pointer sle)
+    BridgeBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltBRIDGE)
         {

include/xrpl/protocol_autogen/ledger_entries/Check.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Check ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Check(SLE::const_pointer sle)
+    explicit Check(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -269,7 +269,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    CheckBuilder(SLE::const_pointer sle)
+    CheckBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltCHECK)
         {

include/xrpl/protocol_autogen/ledger_entries/Credential.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Credential ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Credential(SLE::const_pointer sle)
+    explicit Credential(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -219,7 +219,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    CredentialBuilder(SLE::const_pointer sle)
+    CredentialBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltCREDENTIAL)
         {

include/xrpl/protocol_autogen/ledger_entries/DID.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a DID ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit DID(SLE::const_pointer sle)
+    explicit DID(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -193,7 +193,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    DIDBuilder(SLE::const_pointer sle)
+    DIDBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltDID)
         {

include/xrpl/protocol_autogen/ledger_entries/Delegate.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Delegate ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Delegate(SLE::const_pointer sle)
+    explicit Delegate(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -172,7 +172,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    DelegateBuilder(SLE::const_pointer sle)
+    DelegateBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltDELEGATE)
         {

include/xrpl/protocol_autogen/ledger_entries/DepositPreauth.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a DepositPreauth ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit DepositPreauth(SLE::const_pointer sle)
+    explicit DepositPreauth(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -170,7 +170,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    DepositPreauthBuilder(SLE::const_pointer sle)
+    DepositPreauthBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltDEPOSIT_PREAUTH)
         {

include/xrpl/protocol_autogen/ledger_entries/DirectoryNode.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a DirectoryNode ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit DirectoryNode(SLE::const_pointer sle)
+    explicit DirectoryNode(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -431,7 +431,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    DirectoryNodeBuilder(SLE::const_pointer sle)
+    DirectoryNodeBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltDIR_NODE)
         {

include/xrpl/protocol_autogen/ledger_entries/Escrow.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Escrow ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Escrow(SLE::const_pointer sle)
+    explicit Escrow(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -363,7 +363,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    EscrowBuilder(SLE::const_pointer sle)
+    EscrowBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltESCROW)
         {

include/xrpl/protocol_autogen/ledger_entries/FeeSettings.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a FeeSettings ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit FeeSettings(SLE::const_pointer sle)
+    explicit FeeSettings(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -285,7 +285,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    FeeSettingsBuilder(SLE::const_pointer sle)
+    FeeSettingsBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltFEE_SETTINGS)
         {

include/xrpl/protocol_autogen/ledger_entries/LedgerHashes.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a LedgerHashes ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit LedgerHashes(SLE::const_pointer sle)
+    explicit LedgerHashes(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -130,7 +130,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    LedgerHashesBuilder(SLE::const_pointer sle)
+    LedgerHashesBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltLEDGER_HASHES)
         {

include/xrpl/protocol_autogen/ledger_entries/Loan.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Loan ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Loan(SLE::const_pointer sle)
+    explicit Loan(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -607,7 +607,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    LoanBuilder(SLE::const_pointer sle)
+    LoanBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltLOAN)
         {

include/xrpl/protocol_autogen/ledger_entries/LoanBroker.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a LoanBroker ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit LoanBroker(SLE::const_pointer sle)
+    explicit LoanBroker(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -378,7 +378,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    LoanBrokerBuilder(SLE::const_pointer sle)
+    LoanBrokerBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltLOAN_BROKER)
         {

include/xrpl/protocol_autogen/ledger_entries/MPToken.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a MPToken ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit MPToken(SLE::const_pointer sle)
+    explicit MPToken(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -182,7 +182,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    MPTokenBuilder(SLE::const_pointer sle)
+    MPTokenBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltMPTOKEN)
         {

include/xrpl/protocol_autogen/ledger_entries/MPTokenIssuance.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a MPTokenIssuance ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit MPTokenIssuance(SLE::const_pointer sle)
+    explicit MPTokenIssuance(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -339,7 +339,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    MPTokenIssuanceBuilder(SLE::const_pointer sle)
+    MPTokenIssuanceBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltMPTOKEN_ISSUANCE)
         {

include/xrpl/protocol_autogen/ledger_entries/NFTokenOffer.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a NFTokenOffer ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit NFTokenOffer(SLE::const_pointer sle)
+    explicit NFTokenOffer(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -208,7 +208,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    NFTokenOfferBuilder(SLE::const_pointer sle)
+    NFTokenOfferBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltNFTOKEN_OFFER)
         {

include/xrpl/protocol_autogen/ledger_entries/NFTokenPage.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a NFTokenPage ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit NFTokenPage(SLE::const_pointer sle)
+    explicit NFTokenPage(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -157,7 +157,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    NFTokenPageBuilder(SLE::const_pointer sle)
+    NFTokenPageBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltNFTOKEN_PAGE)
         {

include/xrpl/protocol_autogen/ledger_entries/NegativeUNL.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a NegativeUNL ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit NegativeUNL(SLE::const_pointer sle)
+    explicit NegativeUNL(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -190,7 +190,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    NegativeUNLBuilder(SLE::const_pointer sle)
+    NegativeUNLBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltNEGATIVE_UNL)
         {

include/xrpl/protocol_autogen/ledger_entries/Offer.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Offer ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Offer(SLE::const_pointer sle)
+    explicit Offer(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -259,7 +259,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    OfferBuilder(SLE::const_pointer sle)
+    OfferBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltOFFER)
         {

include/xrpl/protocol_autogen/ledger_entries/Oracle.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Oracle ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Oracle(SLE::const_pointer sle)
+    explicit Oracle(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -222,7 +222,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    OracleBuilder(SLE::const_pointer sle)
+    OracleBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltORACLE)
         {

include/xrpl/protocol_autogen/ledger_entries/PayChannel.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a PayChannel ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit PayChannel(SLE::const_pointer sle)
+    explicit PayChannel(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -330,7 +330,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    PayChannelBuilder(SLE::const_pointer sle)
+    PayChannelBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltPAYCHAN)
         {

include/xrpl/protocol_autogen/ledger_entries/PermissionedDomain.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a PermissionedDomain ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit PermissionedDomain(SLE::const_pointer sle)
+    explicit PermissionedDomain(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -148,7 +148,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    PermissionedDomainBuilder(SLE::const_pointer sle)
+    PermissionedDomainBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltPERMISSIONED_DOMAIN)
         {

include/xrpl/protocol_autogen/ledger_entries/RippleState.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a RippleState ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit RippleState(SLE::const_pointer sle)
+    explicit RippleState(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -278,7 +278,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    RippleStateBuilder(SLE::const_pointer sle)
+    RippleStateBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltRIPPLE_STATE)
         {

include/xrpl/protocol_autogen/ledger_entries/SignerList.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a SignerList ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit SignerList(SLE::const_pointer sle)
+    explicit SignerList(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -172,7 +172,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    SignerListBuilder(SLE::const_pointer sle)
+    SignerListBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltSIGNER_LIST)
         {

include/xrpl/protocol_autogen/ledger_entries/Ticket.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Ticket ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Ticket(SLE::const_pointer sle)
+    explicit Ticket(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -134,7 +134,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    TicketBuilder(SLE::const_pointer sle)
+    TicketBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltTICKET)
         {

include/xrpl/protocol_autogen/ledger_entries/Vault.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a Vault ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit Vault(SLE::const_pointer sle)
+    explicit Vault(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -330,7 +330,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    VaultBuilder(SLE::const_pointer sle)
+    VaultBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltVAULT)
         {

include/xrpl/protocol_autogen/ledger_entries/XChainOwnedClaimID.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a XChainOwnedClaimID ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit XChainOwnedClaimID(SLE::const_pointer sle)
+    explicit XChainOwnedClaimID(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -187,7 +187,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    XChainOwnedClaimIDBuilder(SLE::const_pointer sle)
+    XChainOwnedClaimIDBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltXCHAIN_OWNED_CLAIM_ID)
         {

include/xrpl/protocol_autogen/ledger_entries/XChainOwnedCreateAccountClaimID.h

@@ -33,7 +33,7 @@ public:
      * @brief Construct a XChainOwnedCreateAccountClaimID ledger entry wrapper from an existing SLE object.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    explicit XChainOwnedCreateAccountClaimID(SLE::const_pointer sle)
+    explicit XChainOwnedCreateAccountClaimID(std::shared_ptr<SLE const> sle)
         : LedgerEntryBase(std::move(sle))
     {
         // Verify ledger entry type
@@ -161,7 +161,7 @@ public:
      * @param sle The existing ledger entry to copy from.
      * @throws std::runtime_error if the ledger entry type doesn't match.
      */
-    XChainOwnedCreateAccountClaimIDBuilder(SLE::const_pointer sle)
+    XChainOwnedCreateAccountClaimIDBuilder(std::shared_ptr<SLE const> sle)
     {
         if (sle->at(sfLedgerEntryType) != ltXCHAIN_OWNED_CREATE_ACCOUNT_CLAIM_ID)
         {

include/xrpl/tx/AccessSet.h

@@ -0,0 +1,92 @@
+#pragma once
+
+#include <xrpl/basics/base_uint.h>
+
+#include <boost/container/flat_set.hpp>
+
+#include <set>
+
+namespace xrpl {
+
+/** The statically-declared ledger footprint of a single transaction.
+
+    An AccessSet enumerates the ledger entries a transaction may read or write,
+    grouped by category for readability. It is produced by `accessSetOf()` from
+    the signed transaction body (and, where required, a read-only snapshot of
+    the closed ledger) — never from another transaction's in-flight writes.
+
+    Two transactions are independent (safe to apply concurrently) iff their
+    AccessSets do not conflict; see `conflictsWith()`. A transaction whose
+    footprint cannot be enumerated statically sets `touchesGlobal` and is
+    serialized against everything.
+
+    Directory-node (ltDIR_NODE) entries are intentionally NOT represented here.
+    Owner-directory bookkeeping is a consequence of mutating the owning account,
+    whose AccountRoot is already declared; shared (book) directories belong only
+    to transactors that are `touchesGlobal` in this version. Conflict detection
+    on directories is therefore subsumed by the account/object entries.
+
+    The category split is for human readability and future scheduler heuristics;
+    conflict detection itself operates on the flat union, `keys()`.
+*/
+struct AccessSet
+{
+    boost::container::flat_set<uint256> accounts;     // AccountRoot entries
+    boost::container::flat_set<uint256> trustlines;   // RippleState entries
+    boost::container::flat_set<uint256> offerBooks;   // book directory roots
+    boost::container::flat_set<uint256> ammPools;     // AMM root entries
+    boost::container::flat_set<uint256> nftPages;     // NFToken page roots
+    boost::container::flat_set<uint256> miscObjects;  // escrow/check/ticket/etc.
+
+    /** When true, the footprint is not statically known; serialize this tx. */
+    bool touchesGlobal = false;
+
+    /** The conservative "I touch everything" footprint. */
+    [[nodiscard]] static AccessSet
+    global()
+    {
+        AccessSet a;
+        a.touchesGlobal = true;
+        return a;
+    }
+
+    /** The flat union of every declared entry key, across all categories. */
+    [[nodiscard]] std::set<uint256>
+    keys() const
+    {
+        std::set<uint256> out;
+        for (auto const* s :
+             {&accounts, &trustlines, &offerBooks, &ammPools, &nftPages, &miscObjects})
+            out.insert(s->begin(), s->end());
+        return out;
+    }
+
+    /** True if these two transactions cannot safely apply concurrently.
+
+        Either side touching global state forces a conflict; otherwise the two
+        conflict iff their declared key sets intersect.
+    */
+    [[nodiscard]] bool
+    conflictsWith(AccessSet const& other) const
+    {
+        if (touchesGlobal || other.touchesGlobal)
+            return true;
+
+        auto const a = keys();
+        auto const b = other.keys();
+        auto i = a.begin();
+        auto j = b.begin();
+        while (i != a.end() && j != b.end())
+        {
+            if (*i < *j)
+                ++i;
+            else if (*j < *i)
+                ++j;
+            else
+                return true;
+        }
+        return false;
+    }
+};
+
+}  // namespace xrpl

include/xrpl/tx/ApplyContext.h

@@ -93,8 +93,8 @@ public:
         std::function<void(
             uint256 const& key,
             bool isDelete,
-            SLE::const_ref before,
-            SLE::const_ref after)> const& func);
+            std::shared_ptr<SLE const> const& before,
+            std::shared_ptr<SLE const> const& after)> const& func);
 
     void
     destroyXRP(XRPAmount const& fee)
@@ -112,6 +112,24 @@ public:
     TER
     checkInvariants(TER const result, XRPAmount const fee);
 
+#ifndef NDEBUG
+    /** The read-only base (closed-ledger) snapshot this tx applies against. */
+    [[nodiscard]] ReadView const&
+    baseView() const
+    {
+        return base_;
+    }
+
+    /** Every ledger entry touched during apply, with type. Backs the
+        access-set assertion in Transactor::operator(). */
+    [[nodiscard]] std::map<uint256, LedgerEntryType> const&
+    touchedEntries() const
+    {
+        // NOLINTNEXTLINE(bugprone-unchecked-optional-access) view_ emplaced in ctor
+        return view_->touchedEntries();
+    }
+#endif
+
 private:
     static TER
     failInvariantCheck(TER const result);

include/xrpl/tx/Schedule.h

@@ -0,0 +1,128 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/RawView.h>
+#include <xrpl/ledger/ReadView.h>
+#include <xrpl/protocol/STTx.h>
+#include <xrpl/tx/AccessSet.h>
+
+#include <cstddef>
+#include <memory>
+#include <vector>
+
+namespace xrpl {
+
+class ServiceRegistry;
+
+/** A maximal set of transactions that conflict (transitively) with each other.
+
+    The transactions are held in canonical (input) order, which is significant:
+    within a group they must be applied serially in this order. Two distinct
+    groups are independent by construction — their declared access sets are
+    disjoint — so groups may be applied concurrently, and the order in which
+    groups are applied does not affect the resulting state.
+*/
+struct ConflictGroup
+{
+    std::vector<std::shared_ptr<STTx const>> txns;
+};
+
+/** The partitioning of a canonically-ordered transaction set for parallel
+    application.
+
+    Either the set was partitioned into independent `groups` (the parallel
+    case), or scheduling fell back to a single serial ordering in `serial`
+    (the conservative case — see `scheduleApply`). Exactly one of the two is
+    populated; `fullySerial` says which.
+*/
+struct Schedule
+{
+    std::vector<ConflictGroup> groups;
+    std::vector<std::shared_ptr<STTx const>> serial;
+    bool fullySerial = false;
+
+    /** Total transactions scheduled, across groups or the serial list. */
+    [[nodiscard]] std::size_t
+    size() const
+    {
+        if (fullySerial)
+            return serial.size();
+        std::size_t n = 0;
+        for (auto const& g : groups)
+            n += g.txns.size();
+        return n;
+    }
+};
+
+/** Partition a canonically-ordered transaction set into independent groups by
+    static access-set conflict, for parallel application.
+
+    For each transaction, `accessSetOf` is consulted against `base` (the closed
+    -ledger snapshot the round applies to). Transactions are unioned into the
+    same group iff their access sets conflict — i.e. they share any declared
+    ledger entry, or (implicitly, via the access set) act on the same account.
+
+    If ANY transaction declares `touchesGlobal` (a pseudo-transaction such as
+    SetFee/EnableAmendment/UNLModify, or any not-yet-migrated transactor), the
+    schedule falls back to fully serial in canonical order. This is the
+    conservative flag-ledger handling: correctness over throughput, at a cost of
+    ~1/256 of ledgers. A later version may apply the global transactions first
+    and parallelize the remainder.
+
+    Deterministic: identical input yields an identical schedule (groups are
+    ordered by their lowest canonical index, transactions within a group keep
+    canonical order). Applies nothing and reads only `base`.
+*/
+Schedule
+scheduleApply(std::vector<std::shared_ptr<STTx const>> const& txns, ReadView const& base);
+
+/** Outcome of applyScheduled. */
+struct ScheduledApplyResult
+{
+    std::size_t groupCount = 0;  // independent groups (1 if fully serial)
+    std::size_t applied = 0;     // transactions that applied successfully
+    bool fullySerial = false;
+};
+
+/** Apply a canonically-ordered transaction set via its schedule.
+
+    Schedules `txns` (see `scheduleApply`), then applies each independent group
+    in its own `OpenView` layered over the immutable `closed` snapshot, and
+    merges the per-group write-sets into `to`. Because distinct groups have
+    disjoint access sets, their write-sets are disjoint and the merge is
+    order-independent — so the resulting state in `to` is byte-identical to a
+    serial canonical apply. (That equivalence is what the differential test
+    asserts, and it is the correctness contract a parallel executor relies on.)
+
+    `workers` controls concurrency of the per-group apply phase:
+      - `workers <= 1`: groups applied sequentially (deterministic baseline).
+      - `workers > 1`: up to `workers` groups apply concurrently, each in its own
+        view over the immutable `closed` snapshot; the write-sets are then merged
+        into `to` sequentially in deterministic group order.
+    The result is identical for any `workers` value (the merge is order-
+    independent because groups are disjoint, and is performed in a fixed order).
+
+    NOTE on the threaded path: it is correct by construction here, but it is NOT
+    certified for production consensus use. A non-deterministic apply forks the
+    network, so before the threaded path may be trusted it needs ThreadSanitizer
+    clean runs, adversarial scheduling (Antithesis), and a mainnet-history replay
+    differential — none of which a unit test establishes. The concurrent reads
+    of `closed` and the shared `registry` are the surfaces that must be cleared.
+
+    @param registry service registry used by the apply pipeline.
+    @param closed   the immutable closed-ledger snapshot to read and schedule against.
+    @param to       the target ledger receiving the merged writes.
+    @param txns     transactions in canonical order.
+    @param j        journal.
+    @param workers  max concurrent group-apply threads (default 1 = sequential).
+*/
+ScheduledApplyResult
+applyScheduled(
+    ServiceRegistry& registry,
+    ReadView const& closed,
+    TxsRawView& to,
+    std::vector<std::shared_ptr<STTx const>> const& txns,
+    beast::Journal j,
+    unsigned workers = 1);
+
+}  // namespace xrpl

include/xrpl/tx/Transactor.h

@@ -4,6 +4,7 @@
 #include <xrpl/beast/utility/WrappedSink.h>
 #include <xrpl/protocol/Permissions.h>
 #include <xrpl/protocol/XRPAmount.h>
+#include <xrpl/tx/AccessSet.h>
 #include <xrpl/tx/ApplyContext.h>
 #include <xrpl/tx/applySteps.h>
 
@@ -222,10 +223,39 @@ public:
         return tesSUCCESS;
     }
 
+    /** The static ledger footprint this transaction may read or write.
+
+        Consumed by the parallel-apply scheduler to decide which transactions
+        can apply concurrently. The base implementation is fail-safe: it
+        declares `touchesGlobal`, so an un-migrated transactor is serialized
+        against everything. A transactor opts into concurrency by hiding this
+        with its own static `accessSetOf` that enumerates exactly what it
+        touches. Like preclaim/calculateBaseFee, this is dispatched by
+        compile-time name hiding, not virtual dispatch.
+
+        @param tx   the signed transaction.
+        @param base a read-only snapshot of the ledger the tx applies to, for
+                    the few transactors whose footprint needs a state lookup
+                    (e.g. resolving an AMM pseudo-account). Most ignore it.
+    */
+    static AccessSet
+    accessSetOf(STTx const& tx, ReadView const& base)
+    {
+        return AccessSet::global();
+    }
+
     static NotTEC
     checkPermission(ReadView const& view, STTx const& tx);
     /////////////////////////////////////////////////////
 
+    /** The ledger footprint every transaction incurs, regardless of type: the
+        actor's AccountRoot, the fee-payer's AccountRoot (when delegated), and
+        the consumed Ticket object (when ticket-sequenced). Directory pages are
+        excluded by design — see AccessSet. A migrated `accessSetOf` seeds its
+        result with this and adds its type-specific entries. */
+    static AccessSet
+    commonAccountFootprint(STTx const& tx);
+
     // Interface used by AccountDelete
     static TER
     ticketDelete(
@@ -263,7 +293,10 @@ protected:
      *                   to detect deletions.
      */
     virtual void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) = 0;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) = 0;
 
     /** Check transaction-specific post-conditions after all entries have
      *  been visited.
@@ -365,7 +398,7 @@ private:
         ReadView const& view,
         AccountID const& idSigner,
         AccountID const& idAccount,
-        SLE::const_pointer sleAccount,
+        std::shared_ptr<SLE const> sleAccount,
         beast::Journal const j);
     static NotTEC
     checkMultiSign(
@@ -377,6 +410,15 @@ private:
 
     void trapTransaction(uint256) const;
 
+#ifndef NDEBUG
+    /** DEBUG: assert the transaction's actual ledger footprint is a subset of
+        the access set declared by `accessSetOf`, or — for `touchesGlobal`
+        transactors — optionally record the measured footprint for the
+        hard-transactor audit. Called only on a clean tesSUCCESS apply. */
+    void
+    verifyAccessSet() const;
+#endif
+
     /** Performs early sanity checks on the account and fee fields.
 
         (And passes flagMask to preflight0)

include/xrpl/tx/applySteps.h

@@ -2,6 +2,7 @@
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ApplyViewImpl.h>
+#include <xrpl/tx/AccessSet.h>
 
 namespace xrpl {
 
@@ -308,6 +309,19 @@ preclaim(PreflightResult const& preflightResult, ServiceRegistry& registry, Open
 XRPAmount
 calculateBaseFee(ReadView const& view, STTx const& tx);
 
+/** Compute the static ledger footprint of a transaction.
+
+    Dispatches to the concrete transactor's `accessSetOf`. Un-migrated
+    transactors return `touchesGlobal`. Used by the parallel-apply scheduler
+    (and the DEBUG access-set assertion) to reason about which transactions can
+    apply concurrently. No validation is implied.
+
+    @param tx   the transaction.
+    @param base a read-only snapshot of the ledger the tx applies to.
+*/
+AccessSet
+accessSetOf(STTx const& tx, ReadView const& base);
+
 /** Return the minimum fee that an "ordinary" transaction would pay.
 
     When computing the FeeLevel for a transaction the TxQ sometimes needs

include/xrpl/tx/invariants/AMMInvariant.h

@@ -22,7 +22,7 @@ public:
 
     ValidAMM() = default;
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/FreezeInvariant.h

@@ -22,7 +22,7 @@ class TransfersNotFrozen
 {
     struct BalanceChange
     {
-        SLE::const_pointer const line;
+        std::shared_ptr<SLE const> const line;
         int const balanceChangeSign;
     };
 
@@ -35,34 +35,37 @@ class TransfersNotFrozen
     using ByIssuer = std::map<Issue, IssuerChanges>;
     ByIssuer balanceChanges_;
 
-    std::map<AccountID, SLE::const_pointer const> possibleIssuers_;
+    std::map<AccountID, std::shared_ptr<SLE const> const> possibleIssuers_;
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
 
 private:
     bool
-    isValidEntry(SLE::const_ref before, SLE::const_ref after);
+    isValidEntry(std::shared_ptr<SLE const> const& before, std::shared_ptr<SLE const> const& after);
 
     static STAmount
-    calculateBalanceChange(SLE::const_ref before, SLE::const_ref after, bool isDelete);
+    calculateBalanceChange(
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after,
+        bool isDelete);
 
     void
     recordBalance(Issue const& issue, BalanceChange change);
 
     void
-    recordBalanceChanges(SLE::const_ref after, STAmount const& balanceChange);
+    recordBalanceChanges(std::shared_ptr<SLE const> const& after, STAmount const& balanceChange);
 
-    SLE::const_pointer
+    std::shared_ptr<SLE const>
     findIssuer(AccountID const& issuerID, ReadView const& view);
 
     static bool
     validateIssuerChanges(
-        SLE::const_ref issuer,
+        std::shared_ptr<SLE const> const& issuer,
         IssuerChanges const& changes,
         STTx const& tx,
         beast::Journal const& j,

include/xrpl/tx/invariants/InvariantCheck.h

@@ -70,7 +70,10 @@ public:
      * @param after ledger entry after modification by the transaction
      */
     void
-    visitEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after);
+    visitEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after);
 
     /**
      * @brief called after all ledger entries have been visited to determine
@@ -108,7 +111,7 @@ class TransactionFeeCheck
 {
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     static bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
@@ -128,7 +131,7 @@ class XRPNotCreated
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -148,7 +151,7 @@ class AccountRootsNotDeleted
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -171,11 +174,11 @@ class AccountRootsDeletedClean
     // deleted, it can still be found. After is used specifically for any checks
     // that are expected as part of the deletion, such as zeroing out the
     // balance.
-    std::vector<std::pair<SLE::const_pointer, SLE::const_pointer>> accountsDeleted_;
+    std::vector<std::pair<std::shared_ptr<SLE const>, std::shared_ptr<SLE const>>> accountsDeleted_;
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
@@ -194,7 +197,7 @@ class XRPBalanceChecks
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -211,7 +214,7 @@ class LedgerEntryTypesMatch
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -229,7 +232,7 @@ class NoXRPTrustLines
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -248,7 +251,7 @@ class NoDeepFreezeTrustLinesWithoutFreeze
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -267,7 +270,7 @@ class NoBadOffers
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -283,7 +286,7 @@ class NoZeroEscrow
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -303,7 +306,7 @@ class ValidNewAccountRoot
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -324,7 +327,7 @@ class ValidClawback
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -344,7 +347,7 @@ class ValidPseudoAccounts
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);
@@ -364,7 +367,7 @@ class NoModifiedUnmodifiableFields
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/LoanBrokerInvariant.h

@@ -46,7 +46,7 @@ class ValidLoanBroker
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/LoanInvariant.h

@@ -23,7 +23,7 @@ class ValidLoan
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/MPTInvariant.h

@@ -37,7 +37,7 @@ class ValidMPTIssuance
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -65,7 +65,7 @@ class ValidMPTPayment
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/NFTInvariant.h

@@ -33,7 +33,7 @@ class ValidNFTokenPage
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;
@@ -61,7 +61,7 @@ class NFTokenCountTracking
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     [[nodiscard]] bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&) const;

include/xrpl/tx/invariants/PermissionedDEXInvariant.h

@@ -18,7 +18,7 @@ class ValidPermissionedDEX
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/PermissionedDomainInvariant.h

@@ -32,7 +32,7 @@ class ValidPermissionedDomain
 
 public:
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/invariants/VaultInvariant.h

@@ -154,7 +154,7 @@ public:
     computeCoarsestScale(std::vector<DeltaInfo> const& numbers);
 
     void
-    visitEntry(bool, SLE::const_ref, SLE::const_ref);
+    visitEntry(bool, std::shared_ptr<SLE const> const&, std::shared_ptr<SLE const> const&);
 
     bool
     finalize(STTx const&, TER const, XRPAmount const, ReadView const&, beast::Journal const&);

include/xrpl/tx/paths/BookTip.h

@@ -21,7 +21,7 @@ private:
     uint256 end_;
     uint256 dir_;
     uint256 index_;
-    SLE::pointer entry_;
+    std::shared_ptr<SLE> entry_;
     Quality quality_{};
 
 public:

include/xrpl/tx/paths/detail/StrandFlow.h

@@ -352,7 +352,7 @@ qualityUpperBound(ReadView const& v, Strand const& strand)
  * increases quality of AMM steps, increasing the strand's composite
  * quality as the result.
  */
-template <StepAmount TOutAmt>
+template <typename TOutAmt>
 inline TOutAmt
 limitOut(
     ReadView const& v,
@@ -390,29 +390,21 @@ limitOut(
         auto const out = qf->outFromAvgQ(limitQuality);
         if (!out)
             return remainingOut;
-        if constexpr (std::is_same_v<TOutAmt, XRPAmount> || std::is_same_v<TOutAmt, MPTAmount>)
+        if constexpr (std::is_same_v<TOutAmt, XRPAmount>)
         {
-            auto const roundedOut = TOutAmt{*out};
-            // Integral outputs that round above the continuous target can
-            // realize worse average quality than the requested limit. Keep the
-            // default rounded value when it still satisfies the limit, since it
-            // is the largest matching offer; otherwise round down.
-            if (v.rules().enabled(featureMPTokensV2) && roundedOut > *out &&
-                !qf->satisfiesAvgQ(limitQuality, roundedOut))
-            {
-                NumberRoundModeGuard const g(Number::RoundingMode::Downward);
-                return TOutAmt{*out};
-            }
-            return roundedOut;
+            return XRPAmount{*out};
         }
         else if constexpr (std::is_same_v<TOutAmt, IOUAmount>)
         {
             return IOUAmount{*out};
         }
+        else if constexpr (std::is_same_v<TOutAmt, MPTAmount>)
+        {
+            return MPTAmount{*out};
+        }
         else
         {
-            static constexpr bool kAlwaysFalse = !std::is_same_v<TOutAmt, TOutAmt>;
-            static_assert(kAlwaysFalse, "Unhandled StepAmount type");
+            return STAmount{remainingOut.asset(), out->mantissa(), out->exponent()};
         }
     }();
     // A tiny difference could be due to the round off

include/xrpl/tx/transactors/account/AccountDelete.h

@@ -29,7 +29,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(

include/xrpl/tx/transactors/account/AccountSet.h

@@ -29,11 +29,17 @@ public:
     static TER
     preclaim(PreclaimContext const& ctx);
 
+    static AccessSet
+    accessSetOf(STTx const& tx, ReadView const& base);
+
     TER
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(

include/xrpl/tx/transactors/account/SetRegularKey.h

@@ -19,11 +19,17 @@ public:
     static XRPAmount
     calculateBaseFee(ReadView const& view, STTx const& tx);
 
+    static AccessSet
+    accessSetOf(STTx const& tx, ReadView const& base);
+
     TER
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(

include/xrpl/tx/transactors/account/SignerListSet.h

@@ -36,13 +36,19 @@ public:
     static NotTEC
     preflight(PreflightContext const& ctx);
 
+    static AccessSet
+    accessSetOf(STTx const& tx, ReadView const& base);
+
     TER
     doApply() override;
     void
     preCompute() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(

include/xrpl/tx/transactors/bridge/XChainBridge.h

@@ -28,7 +28,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -61,7 +64,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -105,7 +111,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -143,7 +152,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -183,7 +195,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -223,7 +238,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -254,7 +272,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(
@@ -309,7 +330,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(

include/xrpl/tx/transactors/check/CheckCancel.h

@@ -23,7 +23,10 @@ public:
     doApply() override;
 
     void
-    visitInvariantEntry(bool isDelete, SLE::const_ref before, SLE::const_ref after) override;
+    visitInvariantEntry(
+        bool isDelete,
+        std::shared_ptr<SLE const> const& before,
+        std::shared_ptr<SLE const> const& after) override;
 
     [[nodiscard]] bool
     finalizeInvariants(