Remove redundant CoroTask.h includes from test files

CoroTask.h is already transitively included via JobQueue.h.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/on-pr.yml

@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Determine changed files
         # This step checks whether any files have changed that should
         # cause the next jobs to run. We do it this way rather than
@@ -46,7 +46,7 @@ jobs:
         # that Github considers any skipped jobs to have passed, and in
         # turn the required checks as well.
         id: changes
-        uses: tj-actions/changed-files@ed68ef82c095e0d48ec87eccea555d944a631a4c # v46.0.5
+        uses: tj-actions/changed-files@7dee1b0c1557f278e5c7dc244927139d78c0e22a # v47.0.4
         with:
           files: |
             # These paths are unique to `on-pr.yml`.

.github/workflows/pre-commit.yml

@@ -14,4 +14,4 @@ jobs:
     uses: XRPLF/actions/.github/workflows/pre-commit.yml@320be44621ca2a080f05aeb15817c44b84518108
     with:
       runs_on: ubuntu-latest
-      container: '{ "image": "ghcr.io/xrplf/ci/tools-rippled-pre-commit:sha-ab4d1f0" }'
+      container: '{ "image": "ghcr.io/xrplf/ci/tools-rippled-pre-commit:sha-41ec7c1" }'

.github/workflows/publish-docs.yml

@@ -4,6 +4,18 @@ name: Build and publish documentation
 
 on:
   push:
+    branches:
+      - "develop"
+      - "release*"
+    paths:
+      - ".github/workflows/publish-docs.yml"
+      - "*.md"
+      - "**/*.md"
+      - "docs/**"
+      - "include/**"
+      - "src/libxrpl/**"
+      - "src/xrpld/**"
+  pull_request:
     paths:
       - ".github/workflows/publish-docs.yml"
       - "*.md"
@@ -23,7 +35,9 @@ defaults:
 
 env:
   BUILD_DIR: build
-  NPROC_SUBTRACT: 2
+  # ubuntu-latest has only 2 CPUs for private repositories
+  # https://docs.github.com/en/actions/reference/runners/github-hosted-runners#standard-github-hosted-runners-for--private-repositories
+  NPROC_SUBTRACT: ${{ github.event.repository.private && '1' || '2' }}
 
 jobs:
   publish:
@@ -33,7 +47,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Get number of processors
         uses: XRPLF/actions/get-nproc@cf0433aa74563aead044a1e395610c96d65a37cf
@@ -65,7 +79,7 @@ jobs:
           cmake --build . --target docs --parallel ${BUILD_NPROC}
 
       - name: Publish documentation
-        if: ${{ github.ref_type == 'branch' && github.ref_name == github.event.repository.default_branch }}
+        if: ${{ github.event_name == 'push' }}
         uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4.0.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}

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

@@ -101,10 +101,10 @@ jobs:
     steps:
       - name: Cleanup workspace (macOS and Windows)
         if: ${{ runner.os == 'macOS' || runner.os == 'Windows' }}
-        uses: XRPLF/actions/cleanup-workspace@cf0433aa74563aead044a1e395610c96d65a37cf
+        uses: XRPLF/actions/cleanup-workspace@c7d9ce5ebb03c752a354889ecd870cadfc2b1cd4
 
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Prepare runner
         uses: XRPLF/actions/prepare-runner@2cbf481018d930656e9276fcc20dc0e3a0be5b6d
@@ -177,7 +177,7 @@ jobs:
 
       - name: Upload the binary (Linux)
         if: ${{ github.repository_owner == 'XRPLF' && runner.os == 'Linux' }}
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         with:
           name: xrpld-${{ inputs.config_name }}
           path: ${{ env.BUILD_DIR }}/xrpld
@@ -254,7 +254,7 @@ jobs:
 
       - name: Upload coverage report
         if: ${{ github.repository_owner == 'XRPLF' && !inputs.build_only && env.COVERAGE_ENABLED == 'true' }}
-        uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3
+        uses: codecov/codecov-action@671740ac38dd9b0130fbe1cec585b89eea48d3de # v5.5.2
         with:
           disable_search: true
           disable_telem: true

.github/workflows/reusable-check-levelization.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Check levelization
         run: .github/scripts/levelization/generate.sh
       - name: Check for differences

.github/workflows/reusable-check-rename.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Check definitions
         run: .github/scripts/rename/definitions.sh .
       - name: Check copyright notices

.github/workflows/reusable-clang-tidy-files.yml

@@ -32,7 +32,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Prepare runner
         uses: XRPLF/actions/prepare-runner@2cbf481018d930656e9276fcc20dc0e3a0be5b6d
@@ -84,7 +84,7 @@ jobs:
 
       - name: Upload clang-tidy output
         if: steps.run_clang_tidy.outcome != 'success'
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         with:
           name: clang-tidy-results
           path: clang-tidy-output.txt

.github/workflows/reusable-clang-tidy.yml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Get changed C++ files
         id: changed_files
-        uses: tj-actions/changed-files@ed68ef82c095e0d48ec87eccea555d944a631a4c # v46.0.5
+        uses: tj-actions/changed-files@7dee1b0c1557f278e5c7dc244927139d78c0e22a # v47.0.4
         with:
           files: |
             **/*.cpp

.github/workflows/reusable-strategy-matrix.yml

@@ -29,10 +29,10 @@ jobs:
       matrix: ${{ steps.generate.outputs.matrix }}
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Set up Python
-        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: 3.13
 

.github/workflows/reusable-upload-recipe.yml

@@ -43,7 +43,7 @@ jobs:
     container: ghcr.io/xrplf/ci/ubuntu-noble:gcc-13-sha-5dd7158
     steps:
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Generate build version number
         id: version

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

@@ -64,10 +64,10 @@ jobs:
     steps:
       - name: Cleanup workspace (macOS and Windows)
         if: ${{ runner.os == 'macOS' || runner.os == 'Windows' }}
-        uses: XRPLF/actions/cleanup-workspace@cf0433aa74563aead044a1e395610c96d65a37cf
+        uses: XRPLF/actions/cleanup-workspace@c7d9ce5ebb03c752a354889ecd870cadfc2b1cd4
 
       - name: Checkout repository
-        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Prepare runner
         uses: XRPLF/actions/prepare-runner@2cbf481018d930656e9276fcc20dc0e3a0be5b6d

.gitignore

@@ -42,6 +42,9 @@ gmon.out
 # Locally patched Conan recipes
 external/conan-center-index/
 
+# Local conan directory
+.conan
+
 # XCode IDE.
 *.pbxuser
 !default.pbxuser
@@ -72,5 +75,8 @@ DerivedData
 /.claude
 /CLAUDE.md
 
+# Direnv's directory
+/.direnv
+
 # clangd cache
 /.cache

.pre-commit-config.yaml

@@ -57,6 +57,16 @@ repos:
           - .git/COMMIT_EDITMSG
         stages: [commit-msg]
 
+  - repo: local
+    hooks:
+      - id: nix-fmt
+        name: Format Nix files
+        entry: nix --extra-experimental-features 'nix-command flakes' fmt
+        language: system
+        types:
+          - nix
+        pass_filenames: true
+
 exclude: |
   (?x)^(
       external/.*|

cspell.config.yaml

@@ -77,6 +77,7 @@ words:
   - coro
   - coros
   - cowid
+  - cppcoro
   - cryptocondition
   - cryptoconditional
   - cryptoconditions
@@ -99,11 +100,13 @@ words:
   - endmacro
   - exceptioned
   - Falco
+  - fcontext
   - finalizers
   - firewalled
   - fmtdur
   - fsanitize
   - funclets
+  - gantt
   - gcov
   - gcovr
   - ghead
@@ -173,6 +176,9 @@ words:
   - nftokens
   - nftpage
   - nikb
+  - nixfmt
+  - nixos
+  - nixpkgs
   - nonxrp
   - noripple
   - nudb
@@ -189,6 +195,7 @@ words:
   - permissioned
   - pointee
   - populator
+  - pratik
   - preauth
   - preauthorization
   - preauthorize
@@ -203,6 +210,7 @@ words:
   - queuable
   - Raphson
   - replayer
+  - repost
   - rerere
   - retriable
   - RIPD
@@ -233,6 +241,7 @@ words:
   - soci
   - socidb
   - sslws
+  - stackful
   - statsd
   - STATSDCOLLECTOR
   - stissue

docs/build/environment.md

@@ -3,6 +3,8 @@ environment complete with Git, Python, Conan, CMake, and a C++ compiler.
 This document exists to help readers set one up on any of the Big Three
 platforms: Linux, macOS, or Windows.
 
+As an alternative to system packages, the Nix development shell can be used to provide a development environment. See [using nix development shell](./nix.md) for more details.
+
 [BUILD.md]: ../../BUILD.md
 
 ## Linux

docs/build/nix.md

@@ -0,0 +1,95 @@
+# Using Nix Development Shell for xrpld Development
+
+This guide explains how to use Nix to set up a reproducible development environment for xrpld. Using Nix eliminates the need to manually install utilities and ensures consistent tooling across different machines.
+
+## Benefits of Using Nix
+
+- **Reproducible environment**: Everyone gets the same versions of tools and compilers
+- **No system pollution**: Dependencies are isolated and don't affect your system packages
+- **Multiple compiler versions**: Easily switch between different GCC and Clang versions
+- **Quick setup**: Get started with a single command
+- **Works on Linux and macOS**: Consistent experience across platforms
+
+## Install Nix
+
+Please follow [the official installation instructions of nix package manager](https://nixos.org/download/) for your system.
+
+## Entering the Development Shell
+
+### Basic Usage
+
+From the root of the xrpld repository, enter the default development shell:
+
+```bash
+nix --experimental-features 'nix-command flakes' develop
+```
+
+This will:
+
+- Download and set up all required development tools (CMake, Ninja, Conan, etc.)
+- Configure the appropriate compiler for your platform:
+  - **macOS**: Apple Clang (default system compiler)
+  - **Linux**: GCC 15
+
+The first time you run this command, it will take a few minutes to download and build the environment. Subsequent runs will be much faster.
+
+> [!TIP]
+> To avoid typing `--experimental-features 'nix-command flakes'` every time, you can permanently enable flakes by creating `~/.config/nix/nix.conf`:
+>
+> ```bash
+> mkdir -p ~/.config/nix
+> echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf
+> ```
+>
+> After this, you can simply use `nix develop` instead.
+
+> [!NOTE]
+> The examples below assume you've enabled flakes in your config. If you haven't, add `--experimental-features 'nix-command flakes'` after each `nix` command.
+
+### Choosing a different compiler
+
+A compiler can be chosen by providing its name with the `.#` prefix, e.g. `nix develop .#gcc15`.
+Use `nix flake show` to see all the available development shells.
+
+Use `nix develop .#no_compiler` to use the compiler from your system.
+
+### Example Usage
+
+```bash
+# Use GCC 14
+nix develop .#gcc14
+
+# Use Clang 19
+nix develop .#clang19
+
+# Use default for your platform
+nix develop
+```
+
+### Using a different shell
+
+`nix develop` opens bash by default. If you want to use another shell this could be done by adding `-c` flag. For example:
+
+```bash
+nix develop -c zsh
+```
+
+## Building xrpld with Nix
+
+Once inside the Nix development shell, follow the standard [build instructions](../../BUILD.md#steps). The Nix shell provides all necessary tools (CMake, Ninja, Conan, etc.).
+
+## Automatic Activation with direnv
+
+[direnv](https://direnv.net/) or [nix-direnv](https://github.com/nix-community/nix-direnv) can automatically activate the Nix development shell when you enter the repository directory.
+
+## Conan and Prebuilt Packages
+
+Please note that there is no guarantee that binaries from conan cache will work when using nix. If you encounter any errors, please use `--build '*'` to force conan to compile everything from source:
+
+```bash
+conan install .. --output-folder . --build '*' --settings build_type=Release
+```
+
+## Updating `flake.lock` file
+
+To update `flake.lock` to the latest revision use `nix flake update` command.

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1769461804,
+        "narHash": "sha256-6h5sROT/3CTHvzPy9koKBmoCa2eJKh4fzQK8eYFEgl8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b579d443b37c9c5373044201ea77604e37e748c8",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,16 @@
+{
+  description = "Nix related things for xrpld";
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      forEachSystem = (import ./nix/utils.nix { inherit nixpkgs; }).forEachSystem;
+    in
+    {
+      devShells = forEachSystem (import ./nix/devshell.nix);
+      formatter = forEachSystem ({ pkgs, ... }: pkgs.nixfmt);
+    };
+}

include/xrpl/basics/MallocTrim.h

@@ -0,0 +1,73 @@
+#pragma once
+
+#include <xrpl/beast/utility/Journal.h>
+
+#include <chrono>
+#include <cstdint>
+#include <string_view>
+
+namespace xrpl {
+
+// cSpell:ignore ptmalloc
+
+// -----------------------------------------------------------------------------
+// Allocator interaction note:
+// - This facility invokes glibc's malloc_trim(0) on Linux/glibc to request that
+//   ptmalloc return free heap pages to the OS.
+// - If an alternative allocator (e.g. jemalloc or tcmalloc) is linked or
+//   preloaded (LD_PRELOAD), calling glibc's malloc_trim typically has no effect
+//   on the *active* heap. The call is harmless but may not reclaim memory
+//   because those allocators manage their own arenas.
+// - Only glibc sbrk/arena space is eligible for trimming; large mmap-backed
+//   allocations are usually returned to the OS on free regardless of trimming.
+// - Call at known reclamation points (e.g., after cache sweeps / online delete)
+//   and consider rate limiting to avoid churn.
+// -----------------------------------------------------------------------------
+
+struct MallocTrimReport
+{
+    bool supported{false};
+    int trimResult{-1};
+    std::int64_t rssBeforeKB{-1};
+    std::int64_t rssAfterKB{-1};
+    std::chrono::microseconds durationUs{-1};
+    std::int64_t minfltDelta{-1};
+    std::int64_t majfltDelta{-1};
+
+    [[nodiscard]] std::int64_t
+    deltaKB() const noexcept
+    {
+        if (rssBeforeKB < 0 || rssAfterKB < 0)
+            return 0;
+        return rssAfterKB - rssBeforeKB;
+    }
+};
+
+/**
+ * @brief Attempt to return freed memory to the operating system.
+ *
+ * On Linux with glibc malloc, this issues ::malloc_trim(0), which may release
+ * free space from ptmalloc arenas back to the kernel. On other platforms, or if
+ * a different allocator is in use, this function is a no-op and the report will
+ * indicate that trimming is unsupported or had no effect.
+ *
+ * @param tag     Identifier for logging/debugging purposes.
+ * @param journal Journal for diagnostic logging.
+ * @return Report containing before/after metrics and the trim result.
+ *
+ * @note If an alternative allocator (jemalloc/tcmalloc) is linked or preloaded,
+ *       calling glibc's malloc_trim may have no effect on the active heap. The
+ *       call is harmless but typically does not reclaim memory under those
+ *       allocators.
+ *
+ * @note Only memory served from glibc's sbrk/arena heaps is eligible for trim.
+ *       Large allocations satisfied via mmap are usually returned on free
+ *       independently of trimming.
+ *
+ * @note Intended for use after operations that free significant memory (e.g.,
+ *       cache sweeps, ledger cleanup, online delete). Consider rate limiting.
+ */
+MallocTrimReport
+mallocTrim(std::string_view tag, beast::Journal journal);
+
+}  // namespace xrpl

include/xrpl/core/CoroTask.h

@@ -0,0 +1,289 @@
+#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

@@ -0,0 +1,152 @@
+#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)
+{
+    task_ = std::forward<F>(f)(shared_from_this());
+}
+
+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

@@ -2,6 +2,7 @@
 
 #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>
@@ -9,6 +10,7 @@
 
 #include <boost/coroutine/all.hpp>
 
+#include <coroutine>
 #include <set>
 
 namespace xrpl {
@@ -119,6 +121,92 @@ 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_;
+#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(
@@ -165,6 +253,19 @@ 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
@@ -379,6 +480,7 @@ private:
 }  // namespace xrpl
 
 #include <xrpl/core/Coro.ipp>
+#include <xrpl/core/CoroTaskRunner.ipp>
 
 namespace xrpl {
 
@@ -401,4 +503,26 @@ 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

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

include/xrpl/protocol/detail/features.macro

@@ -15,9 +15,10 @@
 
 // Add new amendments to the top of this list.
 // Keep it sorted in reverse chronological order.
+
 XRPL_FIX   (PermissionedDomainInvariant, Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (ExpiredNFTokenOfferRemoval, Supported::yes, VoteBehavior::DefaultNo)
-XRPL_FIX    (BatchInnerSigs,             Supported::yes, VoteBehavior::DefaultNo)
+XRPL_FIX    (BatchInnerSigs,             Supported::no, VoteBehavior::DefaultNo)
 XRPL_FEATURE(LendingProtocol,            Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(PermissionDelegationV1_1,   Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FIX    (DirectoryLimit,             Supported::yes, VoteBehavior::DefaultNo)
@@ -31,7 +32,7 @@ XRPL_FEATURE(TokenEscrow,                Supported::yes, VoteBehavior::DefaultNo
 XRPL_FIX    (EnforceNFTokenTrustlineV2,  Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (AMMv1_3,                    Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(PermissionedDEX,            Supported::yes, VoteBehavior::DefaultNo)
-XRPL_FEATURE(Batch,                      Supported::yes, VoteBehavior::DefaultNo)
+XRPL_FEATURE(Batch,                      Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(SingleAssetVault,           Supported::yes,  VoteBehavior::DefaultNo)
 XRPL_FIX    (PayChanCancelAfter,         Supported::yes, VoteBehavior::DefaultNo)
 // Check flags in Credential transactions

nix/devshell.nix

@@ -0,0 +1,140 @@
+{ pkgs, ... }:
+let
+  commonPackages = with pkgs; [
+    ccache
+    cmake
+    conan
+    gcovr
+    git
+    gnumake
+    llvmPackages_21.clang-tools
+    ninja
+    perl # needed for openssl
+    pkg-config
+    pre-commit
+    python314
+  ];
+
+  # Supported compiler versions
+  gccVersion = pkgs.lib.range 13 15;
+  clangVersions = pkgs.lib.range 18 21;
+
+  defaultCompiler = if pkgs.stdenv.isDarwin then "apple-clang" else "gcc";
+  defaultGccVersion = pkgs.lib.last gccVersion;
+  defaultClangVersion = pkgs.lib.last clangVersions;
+
+  strToCompilerEnv =
+    compiler: version:
+    (
+      if compiler == "gcc" then
+        let
+          gccPkg = pkgs."gcc${toString version}Stdenv" or null;
+        in
+        if gccPkg != null && builtins.elem version gccVersion then
+          gccPkg
+        else
+          throw "Invalid GCC version: ${toString version}. Must be one of: ${toString gccVersion}"
+      else if compiler == "clang" then
+        let
+          clangPkg = pkgs."llvmPackages_${toString version}".stdenv or null;
+        in
+        if clangPkg != null && builtins.elem version clangVersions then
+          clangPkg
+        else
+          throw "Invalid Clang version: ${toString version}. Must be one of: ${toString clangVersions}"
+      else if compiler == "apple-clang" || compiler == "none" then
+        pkgs.stdenvNoCC
+      else
+        throw "Invalid compiler: ${compiler}. Must be one of: gcc, clang, apple-clang, none"
+    );
+
+  # Helper function to create a shell with a specific compiler
+  makeShell =
+    {
+      compiler ? defaultCompiler,
+      version ? (
+        if compiler == "gcc" then
+          defaultGccVersion
+        else if compiler == "clang" then
+          defaultClangVersion
+        else
+          null
+      ),
+    }:
+    let
+      compilerStdEnv = strToCompilerEnv compiler version;
+
+      compilerName =
+        if compiler == "apple-clang" then
+          "clang"
+        else if compiler == "none" then
+          null
+        else
+          compiler;
+
+      gccOnMacWarning =
+        if pkgs.stdenv.isDarwin && compiler == "gcc" then
+          ''
+            echo "WARNING: Using GCC on macOS with Conan may not work."
+            echo "         Consider using 'nix develop .#clang' or the default shell instead."
+            echo ""
+          ''
+        else
+          "";
+
+      compilerVersion =
+        if compilerName != null then
+          ''
+            echo "Compiler: "
+            ${compilerName} --version
+          ''
+        else
+          ''
+            echo "No compiler specified - using system compiler"
+          '';
+
+      shellAttrs = {
+        packages = commonPackages;
+
+        shellHook = ''
+          echo "Welcome to xrpld development shell";
+          ${gccOnMacWarning}${compilerVersion}
+        '';
+      };
+    in
+    pkgs.mkShell.override { stdenv = compilerStdEnv; } shellAttrs;
+
+  # Generate shells for each compiler version
+  gccShells = builtins.listToAttrs (
+    map (version: {
+      name = "gcc${toString version}";
+      value = makeShell {
+        compiler = "gcc";
+        version = version;
+      };
+    }) gccVersion
+  );
+
+  clangShells = builtins.listToAttrs (
+    map (version: {
+      name = "clang${toString version}";
+      value = makeShell {
+        compiler = "clang";
+        version = version;
+      };
+    }) clangVersions
+  );
+
+in
+gccShells
+// clangShells
+// {
+  # Default shells
+  default = makeShell { };
+  gcc = makeShell { compiler = "gcc"; };
+  clang = makeShell { compiler = "clang"; };
+
+  # No compiler
+  no-compiler = makeShell { compiler = "none"; };
+  apple-clang = makeShell { compiler = "apple-clang"; };
+}

nix/utils.nix

@@ -0,0 +1,19 @@
+{ nixpkgs }:
+{
+  forEachSystem =
+    function:
+    nixpkgs.lib.genAttrs
+      [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ]
+      (
+        system:
+        function {
+          inherit system;
+          pkgs = import nixpkgs { inherit system; };
+        }
+      );
+}

src/libxrpl/basics/MallocTrim.cpp

@@ -0,0 +1,157 @@
+#include <xrpl/basics/Log.h>
+#include <xrpl/basics/MallocTrim.h>
+
+#include <boost/predef.h>
+
+#include <chrono>
+#include <cstdint>
+#include <cstdio>
+#include <fstream>
+#include <sstream>
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+#include <sys/resource.h>
+
+#include <malloc.h>
+#include <unistd.h>
+
+// Require RUSAGE_THREAD for thread-scoped page fault tracking
+#ifndef RUSAGE_THREAD
+#error "MallocTrim rusage instrumentation requires RUSAGE_THREAD on Linux/glibc"
+#endif
+
+namespace {
+
+bool
+getRusageThread(struct rusage& ru)
+{
+    return ::getrusage(RUSAGE_THREAD, &ru) == 0;  // LCOV_EXCL_LINE
+}
+
+}  // namespace
+#endif
+
+namespace xrpl {
+
+namespace detail {
+
+// cSpell:ignore statm
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+
+inline int
+mallocTrimWithPad(std::size_t padBytes)
+{
+    return ::malloc_trim(padBytes);
+}
+
+long
+parseStatmRSSkB(std::string const& statm)
+{
+    // /proc/self/statm format: size resident shared text lib data dt
+    // We want the second field (resident) which is in pages
+    std::istringstream iss(statm);
+    long size, resident;
+    if (!(iss >> size >> resident))
+        return -1;
+
+    // Convert pages to KB
+    long const pageSize = ::sysconf(_SC_PAGESIZE);
+    if (pageSize <= 0)
+        return -1;
+
+    return (resident * pageSize) / 1024;
+}
+
+#endif  // __GLIBC__ && BOOST_OS_LINUX
+
+}  // namespace detail
+
+MallocTrimReport
+mallocTrim(std::string_view tag, beast::Journal journal)
+{
+    // LCOV_EXCL_START
+
+    MallocTrimReport report;
+
+#if !(defined(__GLIBC__) && BOOST_OS_LINUX)
+    JLOG(journal.debug()) << "malloc_trim not supported on this platform (tag=" << tag << ")";
+#else
+    // Keep glibc malloc_trim padding at 0 (default): 12h Mainnet tests across 0/256KB/1MB/16MB
+    // showed no clear, consistent benefit from custom padding—0 provided the best overall balance
+    // of RSS reduction and trim-latency stability without adding a tuning surface.
+    constexpr std::size_t TRIM_PAD = 0;
+
+    report.supported = true;
+
+    if (journal.debug())
+    {
+        auto readFile = [](std::string const& path) -> std::string {
+            std::ifstream ifs(path, std::ios::in | std::ios::binary);
+            if (!ifs.is_open())
+                return {};
+
+            // /proc files are often not seekable; read as a stream.
+            std::ostringstream oss;
+            oss << ifs.rdbuf();
+            return oss.str();
+        };
+
+        std::string const tagStr{tag};
+        std::string const statmPath = "/proc/self/statm";
+
+        auto const statmBefore = readFile(statmPath);
+        long const rssBeforeKB = detail::parseStatmRSSkB(statmBefore);
+
+        struct rusage ru0{};
+        bool const have_ru0 = getRusageThread(ru0);
+
+        auto const t0 = std::chrono::steady_clock::now();
+
+        report.trimResult = detail::mallocTrimWithPad(TRIM_PAD);
+
+        auto const t1 = std::chrono::steady_clock::now();
+
+        struct rusage ru1{};
+        bool const have_ru1 = getRusageThread(ru1);
+
+        auto const statmAfter = readFile(statmPath);
+        long const rssAfterKB = detail::parseStatmRSSkB(statmAfter);
+
+        // Populate report fields
+        report.rssBeforeKB = rssBeforeKB;
+        report.rssAfterKB = rssAfterKB;
+        report.durationUs = std::chrono::duration_cast<std::chrono::microseconds>(t1 - t0);
+
+        if (have_ru0 && have_ru1)
+        {
+            report.minfltDelta = ru1.ru_minflt - ru0.ru_minflt;
+            report.majfltDelta = ru1.ru_majflt - ru0.ru_majflt;
+        }
+
+        std::int64_t const deltaKB = (rssBeforeKB < 0 || rssAfterKB < 0)
+            ? 0
+            : (static_cast<std::int64_t>(rssAfterKB) - static_cast<std::int64_t>(rssBeforeKB));
+
+        JLOG(journal.debug()) << "malloc_trim tag=" << tagStr << " result=" << report.trimResult
+                              << " pad=" << TRIM_PAD << " bytes"
+                              << " rss_before=" << rssBeforeKB << "kB"
+                              << " rss_after=" << rssAfterKB << "kB"
+                              << " delta=" << deltaKB << "kB"
+                              << " duration_us=" << report.durationUs.count()
+                              << " minflt_delta=" << report.minfltDelta
+                              << " majflt_delta=" << report.majfltDelta;
+    }
+    else
+    {
+        report.trimResult = detail::mallocTrimWithPad(TRIM_PAD);
+    }
+
+#endif
+
+    return report;
+
+    // LCOV_EXCL_STOP
+}
+
+}  // namespace xrpl

src/test/app/Path_test.cpp

@@ -8,6 +8,7 @@
 #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>
@@ -131,7 +132,6 @@ public:
              c,
              Role::USER,
              {},
-             {},
              RPC::apiVersionIfUnspecified},
             {},
             {}};
@@ -155,11 +155,11 @@ public:
 
         Json::Value result;
         gate g;
-        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
+        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
             context.params = std::move(params);
-            context.coro = coro;
             RPC::doCommand(context, result);
             g.signal();
+            co_return;
         });
 
         using namespace std::chrono_literals;
@@ -240,28 +240,27 @@ public:
              c,
              Role::USER,
              {},
-             {},
              RPC::apiVersionIfUnspecified},
             {},
             {}};
         Json::Value result;
         gate g;
         // Test RPC::Tuning::max_src_cur source currencies.
-        app.getJobQueue().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
+        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
             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().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
+        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
             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));
@@ -269,22 +268,22 @@ 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().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
+        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
             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().postCoro(jtCLIENT, "RPC-Client", [&](auto const& coro) {
+        app.getJobQueue().postCoroTask(jtCLIENT, "RPC-Client", [&](auto) -> CoroTask<void> {
             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

@@ -0,0 +1,448 @@
+#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();
+        }
+    };
+
+    // 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", [&](auto) -> CoroTask<void> {
+                g.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", [&](auto runner) -> CoroTask<void> {
+                r = runner;
+                g1.signal();
+                co_await runner->suspend();
+                g2.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", [&](auto runner) -> CoroTask<void> {
+                runner->post();
+                co_await runner->suspend();
+                g.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", [&](auto runner) -> CoroTask<void> {
+                step = 1;
+                co_await JobQueueAwaiter{runner};
+                step = 2;
+                co_await JobQueueAwaiter{runner};
+                step = 3;
+                g.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", [&, id = i](auto runner) -> CoroTask<void> {
+                a[id] = runner;
+                g.signal();
+                co_await runner->suspend();
+
+                this->BEAST_EXPECT(*lv == -1);
+                *lv = id;
+                this->BEAST_EXPECT(*lv == id);
+                g.signal();
+                co_await runner->suspend();
+
+                this->BEAST_EXPECT(*lv == 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", [&](auto) -> CoroTask<void> {
+                g.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", [&](auto runner) -> CoroTask<void> {
+                r = runner;
+                ++counter;
+                g.signal();
+                co_await runner->suspend();
+                ++counter;
+                g.signal();
+                co_await runner->suspend();
+                ++counter;
+                g.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", [&](auto) -> CoroTask<void> {
+                auto inner = []() -> CoroTask<int> { co_return 42; };
+                result = co_await inner();
+                g.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", [&](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)
+                {
+                    caught = true;
+                }
+                g.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", [&](auto) -> CoroTask<void> {
+                auto add = [](int a, int b) -> CoroTask<int> { co_return a + b; };
+                auto mul = [&](int a, int b) -> CoroTask<int> {
+                    int sum = co_await add(a, b);
+                    co_return sum * 2;
+                };
+                result = co_await mul(3, 4);
+                g.signal();
+                co_return;
+            });
+        BEAST_EXPECT(runner);
+        BEAST_EXPECT(g.wait_for(5s));
+        runner->join();
+        BEAST_EXPECT(result == 14);  // (3 + 4) * 2
+        BEAST_EXPECT(!runner->runnable());
+    }
+
+    // Test: postCoroTask returns nullptr when JobQueue is stopping
+    void
+    testShutdownRejection()
+    {
+        using namespace std::chrono_literals;
+        using namespace jtx;
+
+        testcase("shutdown rejection");
+
+        Env env(*this, envconfig([](std::unique_ptr<Config> cfg) {
+            cfg->FORCE_MULTI_THREAD = true;
+            return cfg;
+        }));
+
+        // Stop the JobQueue
+        env.app().getJobQueue().stop();
+
+        auto runner = env.app().getJobQueue().postCoroTask(
+            jtCLIENT, "CoroTaskTest", [&](auto) -> CoroTask<void> { co_return; });
+        BEAST_EXPECT(!runner);
+    }
+
+    void
+    run() override
+    {
+        testVoidCompletion();
+        testCorrectOrder();
+        testIncorrectOrder();
+        testJobQueueAwaiter();
+        testThreadSpecificStorage();
+        testExceptionPropagation();
+        testMultipleYields();
+        testValueReturn();
+        testValueException();
+        testValueChaining();
+        testShutdownRejection();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(CoroTask, core, xrpl);
+
+}  // namespace test
+}  // namespace xrpl

src/test/core/Coroutine_test.cpp

@@ -54,13 +54,15 @@ public:
         }));
 
         gate g1, g2;
-        std::shared_ptr<JobQueue::Coro> c;
-        env.app().getJobQueue().postCoro(jtCLIENT, "CoroTest", [&](auto const& cr) {
-            c = cr;
-            g1.signal();
-            c->yield();
-            g2.signal();
-        });
+        std::shared_ptr<JobQueue::CoroTaskRunner> c;
+        env.app().getJobQueue().postCoroTask(
+            jtCLIENT, "CoroTest", [&](auto runner) -> CoroTask<void> {
+                c = runner;
+                g1.signal();
+                co_await runner->suspend();
+                g2.signal();
+                co_return;
+            });
         BEAST_EXPECT(g1.wait_for(5s));
         c->join();
         c->post();
@@ -81,11 +83,17 @@ public:
         }));
 
         gate g;
-        env.app().getJobQueue().postCoro(jtCLIENT, "CoroTest", [&](auto const& c) {
-            c->post();
-            c->yield();
-            g.signal();
-        });
+        env.app().getJobQueue().postCoroTask(
+            jtCLIENT, "CoroTest", [&](auto runner) -> CoroTask<void> {
+                // Schedule a resume before suspending.  The posted job
+                // cannot actually call resume() until the current resume()
+                // releases CoroTaskRunner::mutex_, which only happens after
+                // the coroutine suspends at co_await.
+                runner->post();
+                co_await runner->suspend();
+                g.signal();
+                co_return;
+            });
         BEAST_EXPECT(g.wait_for(5s));
     }
 
@@ -101,7 +109,7 @@ public:
         auto& jq = env.app().getJobQueue();
 
         static int const N = 4;
-        std::array<std::shared_ptr<JobQueue::Coro>, N> a;
+        std::array<std::shared_ptr<JobQueue::CoroTaskRunner>, N> a;
 
         LocalValue<int> lv(-1);
         BEAST_EXPECT(*lv == -1);
@@ -118,18 +126,19 @@ public:
 
         for (int i = 0; i < N; ++i)
         {
-            jq.postCoro(jtCLIENT, "CoroTest", [&, id = i](auto const& c) {
-                a[id] = c;
+            jq.postCoroTask(jtCLIENT, "CoroTest", [&, id = i](auto runner) -> CoroTask<void> {
+                a[id] = runner;
                 g.signal();
-                c->yield();
+                co_await runner->suspend();
 
                 this->BEAST_EXPECT(*lv == -1);
                 *lv = id;
                 this->BEAST_EXPECT(*lv == id);
                 g.signal();
-                c->yield();
+                co_await runner->suspend();
 
                 this->BEAST_EXPECT(*lv == id);
+                co_return;
             });
             BEAST_EXPECT(g.wait_for(5s));
             a[i]->join();

src/test/core/JobQueue_test.cpp

@@ -44,86 +44,85 @@ class JobQueue_test : public beast::unit_test::suite
     }
 
     void
-    testPostCoro()
+    testPostCoroTask()
     {
         jtx::Env env{*this};
 
         JobQueue& jQueue = env.app().getJobQueue();
         {
-            // Test repeated post()s until the Coro completes.
+            // Test repeated post()s until the coroutine completes.
             std::atomic<int> yieldCount{0};
-            auto const coro = jQueue.postCoro(
-                jtCLIENT,
-                "PostCoroTest1",
-                [&yieldCount](std::shared_ptr<JobQueue::Coro> const& coroCopy) {
+            auto const runner = jQueue.postCoroTask(
+                jtCLIENT, "PostCoroTest1", [&yieldCount](auto runner) -> CoroTask<void> {
                     while (++yieldCount < 4)
-                        coroCopy->yield();
+                        co_await runner->suspend();
+                    co_return;
                 });
-            BEAST_EXPECT(coro != nullptr);
+            BEAST_EXPECT(runner != nullptr);
 
             // Wait for the Job to run and yield.
             while (yieldCount == 0)
                 ;
 
-            // Now re-post until the Coro says it is done.
+            // Now re-post until the CoroTaskRunner says it is done.
             int old = yieldCount;
-            while (coro->runnable())
+            while (runner->runnable())
             {
-                BEAST_EXPECT(coro->post());
+                BEAST_EXPECT(runner->post());
                 while (old == yieldCount)
                 {
                 }
-                coro->join();
+                runner->join();
                 BEAST_EXPECT(++old == yieldCount);
             }
             BEAST_EXPECT(yieldCount == 4);
         }
         {
-            // Test repeated resume()s until the Coro completes.
+            // Test repeated resume()s until the coroutine completes.
             int yieldCount{0};
-            auto const coro = jQueue.postCoro(
-                jtCLIENT,
-                "PostCoroTest2",
-                [&yieldCount](std::shared_ptr<JobQueue::Coro> const& coroCopy) {
+            auto const runner = jQueue.postCoroTask(
+                jtCLIENT, "PostCoroTest2", [&yieldCount](auto runner) -> CoroTask<void> {
                     while (++yieldCount < 4)
-                        coroCopy->yield();
+                        co_await runner->suspend();
+                    co_return;
                 });
-            if (!coro)
+            if (!runner)
             {
-                // There's no good reason we should not get a Coro, but we
+                // There's no good reason we should not get a runner, but we
                 // can't continue without one.
                 BEAST_EXPECT(false);
                 return;
             }
 
             // Wait for the Job to run and yield.
-            coro->join();
+            runner->join();
 
-            // Now resume until the Coro says it is done.
+            // Now resume until the CoroTaskRunner says it is done.
             int old = yieldCount;
-            while (coro->runnable())
+            while (runner->runnable())
             {
-                coro->resume();  // Resume runs synchronously on this thread.
+                runner->resume();  // Resume runs synchronously on this thread.
                 BEAST_EXPECT(++old == yieldCount);
             }
             BEAST_EXPECT(yieldCount == 4);
         }
         {
             // If the JobQueue is stopped, we should no
-            // longer be able to add a Coro (and calling postCoro() should
-            // return false).
+            // longer be able to post a coroutine (and calling postCoroTask()
+            // should return nullptr).
             using namespace std::chrono_literals;
             jQueue.stop();
 
-            // The Coro should never run, so having the Coro access this
+            // The coroutine should never run, so having it access this
             // unprotected variable on the stack should be completely safe.
             // Not recommended for the faint of heart...
             bool unprotected;
-            auto const coro = jQueue.postCoro(
-                jtCLIENT, "PostCoroTest3", [&unprotected](std::shared_ptr<JobQueue::Coro> const&) {
+            auto const runner = jQueue.postCoroTask(
+                jtCLIENT, "PostCoroTest3", [&unprotected](auto) -> CoroTask<void> {
                     unprotected = false;
+                    co_return;
                 });
-            BEAST_EXPECT(coro == nullptr);
+            BEAST_EXPECT(runner == nullptr);
         }
     }
 
@@ -132,7 +131,7 @@ public:
     run() override
     {
         testAddJob();
-        testPostCoro();
+        testPostCoroTask();
     }
 };
 

src/test/jtx/impl/AMMTest.cpp

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

src/tests/libxrpl/basics/MallocTrim.cpp

@@ -0,0 +1,209 @@
+#include <xrpl/basics/MallocTrim.h>
+
+#include <boost/predef.h>
+
+#include <gtest/gtest.h>
+
+using namespace xrpl;
+
+// cSpell:ignore statm
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+namespace xrpl::detail {
+long
+parseStatmRSSkB(std::string const& statm);
+}  // namespace xrpl::detail
+#endif
+
+TEST(MallocTrimReport, structure)
+{
+    // Test default construction
+    MallocTrimReport report;
+    EXPECT_EQ(report.supported, false);
+    EXPECT_EQ(report.trimResult, -1);
+    EXPECT_EQ(report.rssBeforeKB, -1);
+    EXPECT_EQ(report.rssAfterKB, -1);
+    EXPECT_EQ(report.durationUs, std::chrono::microseconds{-1});
+    EXPECT_EQ(report.minfltDelta, -1);
+    EXPECT_EQ(report.majfltDelta, -1);
+    EXPECT_EQ(report.deltaKB(), 0);
+
+    // Test deltaKB calculation - memory freed
+    report.rssBeforeKB = 1000;
+    report.rssAfterKB = 800;
+    EXPECT_EQ(report.deltaKB(), -200);
+
+    // Test deltaKB calculation - memory increased
+    report.rssBeforeKB = 500;
+    report.rssAfterKB = 600;
+    EXPECT_EQ(report.deltaKB(), 100);
+
+    // Test deltaKB calculation - no change
+    report.rssBeforeKB = 1234;
+    report.rssAfterKB = 1234;
+    EXPECT_EQ(report.deltaKB(), 0);
+}
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+TEST(parseStatmRSSkB, standard_format)
+{
+    using xrpl::detail::parseStatmRSSkB;
+
+    // Test standard format: size resident shared text lib data dt
+    // Assuming 4KB page size: resident=1000 pages = 4000 KB
+    {
+        std::string statm = "25365 1000 2377 0 0 5623 0";
+        long result = parseStatmRSSkB(statm);
+        // Note: actual result depends on system page size
+        // On most systems it's 4KB, so 1000 pages = 4000 KB
+        EXPECT_GT(result, 0);
+    }
+
+    // Test with newline
+    {
+        std::string statm = "12345 2000 1234 0 0 3456 0\n";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_GT(result, 0);
+    }
+
+    // Test with tabs
+    {
+        std::string statm = "12345\t2000\t1234\t0\t0\t3456\t0";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_GT(result, 0);
+    }
+
+    // Test zero resident pages
+    {
+        std::string statm = "25365 0 2377 0 0 5623 0";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_EQ(result, 0);
+    }
+
+    // Test with extra whitespace
+    {
+        std::string statm = "  25365   1000   2377  ";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_GT(result, 0);
+    }
+
+    // Test empty string
+    {
+        std::string statm = "";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_EQ(result, -1);
+    }
+
+    // Test malformed data (only one field)
+    {
+        std::string statm = "25365";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_EQ(result, -1);
+    }
+
+    // Test malformed data (non-numeric)
+    {
+        std::string statm = "abc def ghi";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_EQ(result, -1);
+    }
+
+    // Test malformed data (second field non-numeric)
+    {
+        std::string statm = "25365 abc 2377";
+        long result = parseStatmRSSkB(statm);
+        EXPECT_EQ(result, -1);
+    }
+}
+#endif
+
+TEST(mallocTrim, without_debug_logging)
+{
+    beast::Journal journal{beast::Journal::getNullSink()};
+
+    MallocTrimReport report = mallocTrim("without_debug", journal);
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+    EXPECT_EQ(report.supported, true);
+    EXPECT_GE(report.trimResult, 0);
+    EXPECT_EQ(report.durationUs, std::chrono::microseconds{-1});
+    EXPECT_EQ(report.minfltDelta, -1);
+    EXPECT_EQ(report.majfltDelta, -1);
+#else
+    EXPECT_EQ(report.supported, false);
+    EXPECT_EQ(report.trimResult, -1);
+    EXPECT_EQ(report.rssBeforeKB, -1);
+    EXPECT_EQ(report.rssAfterKB, -1);
+    EXPECT_EQ(report.durationUs, std::chrono::microseconds{-1});
+    EXPECT_EQ(report.minfltDelta, -1);
+    EXPECT_EQ(report.majfltDelta, -1);
+#endif
+}
+
+TEST(mallocTrim, empty_tag)
+{
+    beast::Journal journal{beast::Journal::getNullSink()};
+    MallocTrimReport report = mallocTrim("", journal);
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+    EXPECT_EQ(report.supported, true);
+    EXPECT_GE(report.trimResult, 0);
+#else
+    EXPECT_EQ(report.supported, false);
+#endif
+}
+
+TEST(mallocTrim, with_debug_logging)
+{
+    struct DebugSink : public beast::Journal::Sink
+    {
+        DebugSink() : Sink(beast::severities::kDebug, false)
+        {
+        }
+        void
+        write(beast::severities::Severity, std::string const&) override
+        {
+        }
+        void
+        writeAlways(beast::severities::Severity, std::string const&) override
+        {
+        }
+    };
+
+    DebugSink sink;
+    beast::Journal journal{sink};
+
+    MallocTrimReport report = mallocTrim("debug_test", journal);
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+    EXPECT_EQ(report.supported, true);
+    EXPECT_GE(report.trimResult, 0);
+    EXPECT_GE(report.durationUs.count(), 0);
+    EXPECT_GE(report.minfltDelta, 0);
+    EXPECT_GE(report.majfltDelta, 0);
+#else
+    EXPECT_EQ(report.supported, false);
+    EXPECT_EQ(report.trimResult, -1);
+    EXPECT_EQ(report.durationUs, std::chrono::microseconds{-1});
+    EXPECT_EQ(report.minfltDelta, -1);
+    EXPECT_EQ(report.majfltDelta, -1);
+#endif
+}
+
+TEST(mallocTrim, repeated_calls)
+{
+    beast::Journal journal{beast::Journal::getNullSink()};
+
+    // Call malloc_trim multiple times to ensure it's safe
+    for (int i = 0; i < 5; ++i)
+    {
+        MallocTrimReport report = mallocTrim("iteration_" + std::to_string(i), journal);
+
+#if defined(__GLIBC__) && BOOST_OS_LINUX
+        EXPECT_EQ(report.supported, true);
+        EXPECT_GE(report.trimResult, 0);
+#else
+        EXPECT_EQ(report.supported, false);
+#endif
+    }
+}

src/xrpld/app/main/Application.cpp

@@ -31,6 +31,7 @@
 #include <xrpld/shamap/NodeFamily.h>
 
 #include <xrpl/basics/ByteUtilities.h>
+#include <xrpl/basics/MallocTrim.h>
 #include <xrpl/basics/ResolverAsio.h>
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/asio/io_latency_probe.h>
@@ -1053,6 +1054,8 @@ public:
                                     << "; size after: " << cachedSLEs_.size();
         }
 
+        mallocTrim("doSweep", m_journal);
+
         // Set timer to do another sweep later.
         setSweepTimer();
     }
@@ -1422,7 +1425,6 @@ ApplicationImp::setup(boost::program_options::variables_map const& cmdline)
              c,
              Role::ADMIN,
              {},
-             {},
              RPC::apiMaximumSupportedVersion},
             jvCommand};
 

src/xrpld/app/main/GRPCServer.cpp

@@ -3,6 +3,7 @@
 
 #include <xrpl/beast/core/CurrentThreadName.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
+#include <xrpl/core/CoroTask.h>
 #include <xrpl/resource/Fees.h>
 
 namespace xrpl {
@@ -99,13 +100,14 @@ 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 coro = app_.getJobQueue().postCoro(
-        JobType::jtRPC, "gRPC-Client", [thisShared](std::shared_ptr<JobQueue::Coro> coro) {
-            thisShared->process(coro);
+    auto runner = app_.getJobQueue().postCoroTask(
+        JobType::jtRPC, "gRPC-Client", [thisShared](auto) -> CoroTask<void> {
+            thisShared->processRequest();
+            co_return;
         });
 
-    // If coro is null, then the JobQueue has already been shutdown
-    if (!coro)
+    // If runner is null, then the JobQueue has already been shutdown
+    if (!runner)
     {
         grpc::Status status{grpc::StatusCode::INTERNAL, "Job Queue is already stopped"};
         responder_.FinishWithError(status, this);
@@ -114,7 +116,7 @@ GRPCServerImpl::CallData<Request, Response>::process()
 
 template <class Request, class Response>
 void
-GRPCServerImpl::CallData<Request, Response>::process(std::shared_ptr<JobQueue::Coro> coro)
+GRPCServerImpl::CallData<Request, Response>::processRequest()
 {
     try
     {
@@ -156,7 +158,6 @@ GRPCServerImpl::CallData<Request, Response>::process(std::shared_ptr<JobQueue::C
                  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
-        process(std::shared_ptr<JobQueue::Coro> coro);
+        processRequest();
 
         // return load type of this RPC
         Resource::Charge

src/xrpld/rpc/Context.h

@@ -3,7 +3,6 @@
 #include <xrpld/rpc/Role.h>
 
 #include <xrpl/beast/utility/Journal.h>
-#include <xrpl/core/JobQueue.h>
 #include <xrpl/server/InfoSub.h>
 
 namespace xrpl {
@@ -24,7 +23,6 @@ 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

@@ -169,13 +169,10 @@ public:
 
 private:
     Json::Value
-    processSession(
-        std::shared_ptr<WSSession> const& session,
-        std::shared_ptr<JobQueue::Coro> const& coro,
-        Json::Value const& jv);
+    processSession(std::shared_ptr<WSSession> const& session, Json::Value const& jv);
 
     void
-    processSession(std::shared_ptr<Session> const&, std::shared_ptr<JobQueue::Coro> coro);
+    processSession(std::shared_ptr<Session> const&);
 
     void
     processRequest(
@@ -183,7 +180,6 @@ 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

@@ -14,6 +14,7 @@
 #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>
@@ -284,9 +285,10 @@ ServerHandler::onRequest(Session& session)
     }
 
     std::shared_ptr<Session> detachedSession = session.detach();
-    auto const postResult = m_jobQueue.postCoro(
-        jtCLIENT_RPC, "RPC-Client", [this, detachedSession](std::shared_ptr<JobQueue::Coro> coro) {
-            processSession(detachedSession, coro);
+    auto const postResult = m_jobQueue.postCoroTask(
+        jtCLIENT_RPC, "RPC-Client", [this, detachedSession](auto) -> CoroTask<void> {
+            processSession(detachedSession);
+            co_return;
         });
     if (postResult == nullptr)
     {
@@ -322,17 +324,18 @@ ServerHandler::onWSMessage(
 
     JLOG(m_journal.trace()) << "Websocket received '" << jv << "'";
 
-    auto const postResult = m_jobQueue.postCoro(
+    auto const postResult = m_jobQueue.postCoroTask(
         jtCLIENT_WEBSOCKET,
         "WS-Client",
-        [this, session, jv = std::move(jv)](std::shared_ptr<JobQueue::Coro> const& coro) {
-            auto const jr = this->processSession(session, coro, jv);
+        [this, session, jv = std::move(jv)](auto) -> CoroTask<void> {
+            auto const jr = this->processSession(session, 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)
     {
@@ -373,10 +376,7 @@ logDuration(Json::Value const& request, T const& duration, beast::Journal& journ
 }
 
 Json::Value
-ServerHandler::processSession(
-    std::shared_ptr<WSSession> const& session,
-    std::shared_ptr<JobQueue::Coro> const& coro,
-    Json::Value const& jv)
+ServerHandler::processSession(std::shared_ptr<WSSession> const& session, Json::Value const& jv)
 {
     auto is = std::static_pointer_cast<WSInfoSub>(session->appDefined);
     if (is->getConsumer().disconnect(m_journal))
@@ -443,7 +443,6 @@ ServerHandler::processSession(
                  app_.getLedgerMaster(),
                  is->getConsumer(),
                  role,
-                 coro,
                  is,
                  apiVersion},
                 jv,
@@ -514,18 +513,14 @@ ServerHandler::processSession(
     return jr;
 }
 
-// Run as a coroutine.
 void
-ServerHandler::processSession(
-    std::shared_ptr<Session> const& session,
-    std::shared_ptr<JobQueue::Coro> coro)
+ServerHandler::processSession(std::shared_ptr<Session> const& session)
 {
     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");
@@ -562,7 +557,6 @@ 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)
 {
@@ -819,7 +813,6 @@ ServerHandler::processRequest(
              app_.getLedgerMaster(),
              usage,
              role,
-             coro,
              InfoSub::pointer(),
              apiVersion},
             params,

src/xrpld/rpc/handlers/RipplePathFind.cpp

@@ -7,6 +7,9 @@
 #include <xrpl/protocol/RPCErr.h>
 #include <xrpl/resource/Fees.h>
 
+#include <condition_variable>
+#include <mutex>
+
 namespace xrpl {
 
 // This interface is deprecated.
@@ -37,98 +40,31 @@ doRipplePathFind(RPC::JsonContext& context)
         PathRequest::pointer request;
         lpLedger = context.ledgerMaster.getClosedLedger();
 
-        // 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
+        // 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;
+
         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())
+            [&]() {
                 {
-                    // 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();
+                    std::lock_guard lk(mtx);
+                    pathDone = true;
                 }
+                cv.notify_one();
             },
             context.consumer,
             lpLedger,
             context.params);
         if (request)
         {
-            context.coro->yield();
+            std::unique_lock lk(mtx);
+            cv.wait(lk, [&] { return pathDone; });
             jvResult = request->doStatus(context.params);
         }