Merge branch 'develop' into ximinez/lending-sendmulti

* XRPLF/develop:
  ci: [DEPENDABOT] bump actions/upload-artifact from 4.6.2 to 6.0.0 (6396)
  ci: [DEPENDABOT] bump actions/checkout from 4.3.0 to 6.0.2 (6397)
  ci: [DEPENDABOT] bump actions/setup-python from 5.6.0 to 6.2.0 (6395)
  ci: [DEPENDABOT] bump tj-actions/changed-files from 46.0.5 to 47.0.4 (6394)
  ci: [DEPENDABOT] bump codecov/codecov-action from 5.4.3 to 5.5.2 (6398)
  ci: Build docs in PRs and in private repos (6400)
  ci: Add dependabot config (6379)
  Fix tautological assertion (6393)

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

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

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

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

cspell.config.yaml

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

include/xrpl/core/CoroTask.h

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

include/xrpl/core/CoroTaskRunner.ipp

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

include/xrpl/core/JobQueue.h

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

include/xrpl/core/JobQueueAwaiter.h

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

src/libxrpl/ledger/View.cpp

@@ -2020,6 +2020,99 @@ rippleSendIOU(
     return terResult;
 }
 
+template <class TAsset>
+static TER
+doSendMulti(
+    std::string const& name,
+    ApplyView& view,
+    AccountID const& senderID,
+    TAsset const& issue,
+    MultiplePaymentDestinations const& receivers,
+    STAmount& actual,
+    beast::Journal j,
+    WaiveTransferFee waiveFee,
+    // Don't pass back parameters that the caller already has
+    std::function<
+        TER(AccountID const& senderID,
+            AccountID const& receiverID,
+            STAmount const& amount,
+            bool checkIssuer)> doCredit,
+    std::function<
+        TER(AccountID const& issuer, STAmount const& takeFromSender, STAmount const& amount)>
+        preMint = {})
+{
+    // Use the same pattern for all the SendMulti functions to help avoid
+    // divergence and copy/paste errors.
+    auto const& issuer = issue.getIssuer();
+
+    // These values may not stay in sync
+    STAmount takeFromSender{issue};
+    actual = takeFromSender;
+
+    // Failures return immediately.
+    for (auto const& r : receivers)
+    {
+        auto const& receiverID = r.first;
+        STAmount amount{issue, r.second};
+
+        if (amount < beast::zero)
+        {
+            return tecINTERNAL;  // LCOV_EXCL_LINE
+        }
+
+        /* If we aren't sending anything or if the sender is the same as the
+         * receiver then we don't need to do anything.
+         */
+        if (!amount || (senderID == receiverID))
+            continue;
+
+        using namespace std::string_literals;
+        XRPL_ASSERT(!isXRP(receiverID), ("xrpl::"s + name + " : receiver is not XRP").c_str());
+
+        if (senderID == issuer || receiverID == issuer || issuer == noAccount())
+        {
+            if (preMint)
+            {
+                if (auto const ter = preMint(issuer, takeFromSender, amount))
+                    return ter;
+            }
+            // Direct send: redeeming IOUs and/or sending own IOUs.
+            if (auto const ter = doCredit(senderID, receiverID, amount, false))
+                return ter;
+            actual += amount;
+            // Do not add amount to takeFromSender, because doCredit took
+            // it.
+
+            continue;
+        }
+
+        // Sending 3rd party: transit.
+
+        // Calculate the amount to transfer accounting
+        // for any transfer fees if the fee is not waived:
+        STAmount actualSend = (waiveFee == WaiveTransferFee::Yes || issue.native())
+            ? amount
+            : multiply(amount, transferRate(view, amount));
+        actual += actualSend;
+        takeFromSender += actualSend;
+
+        JLOG(j.debug()) << name << "> " << to_string(senderID) << " - > " << to_string(receiverID)
+                        << " : deliver=" << amount.getFullText()
+                        << " cost=" << actualSend.getFullText();
+
+        if (TER const terResult = doCredit(issuer, receiverID, amount, true))
+            return terResult;
+    }
+
+    if (senderID != issuer && takeFromSender)
+    {
+        if (TER const terResult = doCredit(senderID, issuer, takeFromSender, true))
+            return terResult;
+    }
+
+    return tesSUCCESS;
+}
+
 // Send regardless of limits.
 // --> receivers: Amount/currency/issuer to deliver to receivers.
 // <-- saActual: Amount actually cost to sender.  Sender pays fees.
@@ -2033,65 +2126,18 @@ rippleSendMultiIOU(
     beast::Journal j,
     WaiveTransferFee waiveFee)
 {
-    auto const& issuer = issue.getIssuer();
-
     XRPL_ASSERT(!isXRP(senderID), "xrpl::rippleSendMultiIOU : sender is not XRP");
 
-    // These may diverge
-    STAmount takeFromSender{issue};
-    actual = takeFromSender;
+    auto doCredit = [&view, j](
+                        AccountID const& senderID,
+                        AccountID const& receiverID,
+                        STAmount const& amount,
+                        bool checkIssuer) {
+        return rippleCreditIOU(view, senderID, receiverID, amount, checkIssuer, j);
+    };
 
-    // Failures return immediately.
-    for (auto const& r : receivers)
-    {
-        auto const& receiverID = r.first;
-        STAmount amount{issue, r.second};
-
-        /* If we aren't sending anything or if the sender is the same as the
-         * receiver then we don't need to do anything.
-         */
-        if (!amount || (senderID == receiverID))
-            continue;
-
-        XRPL_ASSERT(!isXRP(receiverID), "xrpl::rippleSendMultiIOU : receiver is not XRP");
-
-        if (senderID == issuer || receiverID == issuer || issuer == noAccount())
-        {
-            // Direct send: redeeming IOUs and/or sending own IOUs.
-            if (auto const ter = rippleCreditIOU(view, senderID, receiverID, amount, false, j))
-                return ter;
-            actual += amount;
-            // Do not add amount to takeFromSender, because rippleCreditIOU took
-            // it.
-
-            continue;
-        }
-
-        // Sending 3rd party IOUs: transit.
-
-        // Calculate the amount to transfer accounting
-        // for any transfer fees if the fee is not waived:
-        STAmount actualSend = (waiveFee == WaiveTransferFee::Yes)
-            ? amount
-            : multiply(amount, transferRate(view, issuer));
-        actual += actualSend;
-        takeFromSender += actualSend;
-
-        JLOG(j.debug()) << "rippleSendMultiIOU> " << to_string(senderID) << " - > "
-                        << to_string(receiverID) << " : deliver=" << amount.getFullText()
-                        << " cost=" << actual.getFullText();
-
-        if (TER const terResult = rippleCreditIOU(view, issuer, receiverID, amount, true, j))
-            return terResult;
-    }
-
-    if (senderID != issuer && takeFromSender)
-    {
-        if (TER const terResult = rippleCreditIOU(view, senderID, issuer, takeFromSender, true, j))
-            return terResult;
-    }
-
-    return tesSUCCESS;
+    return doSendMulti(
+        "rippleSendMultiIOU", view, senderID, issue, receivers, actual, j, waiveFee, doCredit);
 }
 
 static TER
@@ -2225,9 +2271,9 @@ accountSendMultiIOU(
     XRPL_ASSERT_PARTS(
         receivers.size() > 1, "xrpl::accountSendMultiIOU", "multiple recipients provided");
 
+    STAmount actual;
     if (!issue.native())
     {
-        STAmount actual;
         JLOG(j.trace()) << "accountSendMultiIOU: " << to_string(senderID) << " sending "
                         << receivers.size() << " IOUs";
 
@@ -2254,6 +2300,85 @@ accountSendMultiIOU(
                << receivers.size() << " receivers.";
     }
 
+    auto doCredit = [&view, &sender, &receivers, j](
+                        AccountID const& senderID,
+                        AccountID const& receiverID,
+                        STAmount const& amount,
+                        bool /*checkIssuer*/) -> TER {
+        if (!senderID)
+        {
+            SLE::pointer receiver =
+                receiverID != beast::zero ? view.peek(keylet::account(receiverID)) : SLE::pointer();
+
+            if (auto stream = j.trace())
+            {
+                std::string receiver_bal("-");
+
+                if (receiver)
+                    receiver_bal = receiver->getFieldAmount(sfBalance).getFullText();
+
+                stream << "accountSendMultiIOU> " << to_string(senderID) << " -> "
+                       << to_string(receiverID) << " (" << receiver_bal
+                       << ") : " << amount.getFullText();
+            }
+
+            if (receiver)
+            {
+                // Increment XRP balance.
+                auto const rcvBal = receiver->getFieldAmount(sfBalance);
+                receiver->setFieldAmount(sfBalance, rcvBal + amount);
+                view.creditHook(xrpAccount(), receiverID, amount, -rcvBal);
+
+                view.update(receiver);
+            }
+
+            if (auto stream = j.trace())
+            {
+                std::string receiver_bal("-");
+
+                if (receiver)
+                    receiver_bal = receiver->getFieldAmount(sfBalance).getFullText();
+
+                stream << "accountSendMultiIOU< " << to_string(senderID) << " -> "
+                       << to_string(receiverID) << " (" << receiver_bal
+                       << ") : " << amount.getFullText();
+            }
+            return tesSUCCESS;
+        }
+        // Sender
+        if (sender)
+        {
+            if (sender->getFieldAmount(sfBalance) < amount)
+            {
+                return TER{tecFAILED_PROCESSING};
+            }
+            else
+            {
+                auto const sndBal = sender->getFieldAmount(sfBalance);
+                view.creditHook(senderID, xrpAccount(), amount, sndBal);
+
+                // Decrement XRP balance.
+                sender->setFieldAmount(sfBalance, sndBal - amount);
+                view.update(sender);
+            }
+        }
+
+        if (auto stream = j.trace())
+        {
+            std::string sender_bal("-");
+
+            if (sender)
+                sender_bal = sender->getFieldAmount(sfBalance).getFullText();
+
+            stream << "accountSendMultiIOU< " << to_string(senderID) << " (" << sender_bal
+                   << ") -> " << receivers.size() << " receivers.";
+        }
+
+        return tesSUCCESS;
+    };
+    return doSendMulti(
+        "accountSendMultiIOU", view, senderID, issue, receivers, actual, j, waiveFee, doCredit);
+
     // Failures return immediately.
     STAmount takeFromSender{issue};
     for (auto const& r : receivers)
@@ -2472,82 +2597,47 @@ rippleSendMultiMPT(
     beast::Journal j,
     WaiveTransferFee waiveFee)
 {
-    // Safe to get MPT since rippleSendMultiMPT is only called by
-    // accountSendMultiMPT
-    auto const& issuer = mptIssue.getIssuer();
-
     auto const sle = view.read(keylet::mptIssuance(mptIssue.getMptID()));
     if (!sle)
         return tecOBJECT_NOT_FOUND;
 
-    // These may diverge
-    STAmount takeFromSender{mptIssue};
-    actual = takeFromSender;
-
-    for (auto const& r : receivers)
-    {
-        auto const& receiverID = r.first;
-        STAmount amount{mptIssue, r.second};
-
-        if (amount < beast::zero)
+    auto preMint = [&](AccountID const& issuer,
+                       STAmount const& takeFromSender,
+                       STAmount const& amount) -> TER {
+        // if sender is issuer, check that the new OutstandingAmount will
+        // not exceed MaximumAmount
+        if (senderID == issuer)
         {
-            return tecINTERNAL;  // LCOV_EXCL_LINE
+            XRPL_ASSERT_PARTS(
+                takeFromSender == beast::zero,
+                "rippler::rippleSendMultiMPT",
+                "sender == issuer, takeFromSender == zero");
+            auto const sendAmount = amount.mpt().value();
+            auto const maximumAmount = sle->at(~sfMaximumAmount).value_or(maxMPTokenAmount);
+            if (sendAmount > maximumAmount ||
+                sle->getFieldU64(sfOutstandingAmount) > maximumAmount - sendAmount)
+                return tecPATH_DRY;
         }
 
-        /* If we aren't sending anything or if the sender is the same as the
-         * receiver then we don't need to do anything.
-         */
-        if (!amount || (senderID == receiverID))
-            continue;
+        return tesSUCCESS;
+    };
+    auto doCredit =
+        [&view, j](
+            AccountID const& senderID, AccountID const& receiverID, STAmount const& amount, bool) {
+            return rippleCreditMPT(view, senderID, receiverID, amount, j);
+        };
 
-        if (senderID == issuer || receiverID == issuer)
-        {
-            // if sender is issuer, check that the new OutstandingAmount will
-            // not exceed MaximumAmount
-            if (senderID == issuer)
-            {
-                XRPL_ASSERT_PARTS(
-                    takeFromSender == beast::zero,
-                    "rippler::rippleSendMultiMPT",
-                    "sender == issuer, takeFromSender == zero");
-                auto const sendAmount = amount.mpt().value();
-                auto const maximumAmount = sle->at(~sfMaximumAmount).value_or(maxMPTokenAmount);
-                if (sendAmount > maximumAmount ||
-                    sle->getFieldU64(sfOutstandingAmount) > maximumAmount - sendAmount)
-                    return tecPATH_DRY;
-            }
-
-            // Direct send: redeeming MPTs and/or sending own MPTs.
-            if (auto const ter = rippleCreditMPT(view, senderID, receiverID, amount, j))
-                return ter;
-            actual += amount;
-            // Do not add amount to takeFromSender, because rippleCreditMPT took
-            // it
-
-            continue;
-        }
-
-        // Sending 3rd party MPTs: transit.
-        STAmount actualSend = (waiveFee == WaiveTransferFee::Yes)
-            ? amount
-            : multiply(amount, transferRate(view, amount.get<MPTIssue>().getMptID()));
-        actual += actualSend;
-        takeFromSender += actualSend;
-
-        JLOG(j.debug()) << "rippleSendMultiMPT> " << to_string(senderID) << " - > "
-                        << to_string(receiverID) << " : deliver=" << amount.getFullText()
-                        << " cost=" << actualSend.getFullText();
-
-        if (auto const terResult = rippleCreditMPT(view, issuer, receiverID, amount, j))
-            return terResult;
-    }
-    if (senderID != issuer && takeFromSender)
-    {
-        if (TER const terResult = rippleCreditMPT(view, senderID, issuer, takeFromSender, j))
-            return terResult;
-    }
-
-    return tesSUCCESS;
+    return doSendMulti(
+        "rippleSendMultiMPT",
+        view,
+        senderID,
+        mptIssue,
+        receivers,
+        actual,
+        j,
+        waiveFee,
+        doCredit,
+        preMint);
 }
 
 static TER

src/test/app/Path_test.cpp

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

src/test/core/CoroTask_test.cpp

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

src/test/jtx/impl/AMMTest.cpp

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

src/xrpld/app/main/Application.cpp

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

src/xrpld/app/main/GRPCServer.cpp

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

src/xrpld/app/main/GRPCServer.h

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

src/xrpld/rpc/Context.h

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

src/xrpld/rpc/ServerHandler.h

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

src/xrpld/rpc/detail/ServerHandler.cpp

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

src/xrpld/rpc/handlers/RipplePathFind.cpp

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