Replace detail/work_guard.hpp with net::executor_work_guard

In newer versions of Asio, `executor_work_guard<>` can be used even when
`ASIO_NO_TS_EXECUTORS` is defined.

.drone.star

@@ -19,6 +19,7 @@ def main(ctx):
   linux_cxx("GCC Valgrind", "g++", packages="g++-14 libssl-dev valgrind", image="cppalliance/droneubuntu2404:1", buildtype="boost_v1", buildscript="drone", environment={ "VARIANT": "beast_valgrind", "TOOLSET": "gcc", "COMPILER": "g++", "CXXSTD": "11" }, globalenv=globalenv),
   linux_cxx("Default g++", "g++", packages="mlocate", image="cppalliance/droneubuntu1604:1", buildtype="boost_v1", buildscript="drone", environment={ "VARIANT": "release", "TOOLSET": "gcc", "COMPILER": "g++", "CXXSTD": "11" }, globalenv=globalenv),
   linux_cxx("GCC 8, C++17, libstdc++, release", "g++-8", packages="g++-8 mlocate", image="cppalliance/droneubuntu1604:1", buildtype="boost_v1", buildscript="drone", environment={  "VARIANT": "release", "TOOLSET": "gcc", "COMPILER": "g++-8", "CXXSTD" : "17" }, globalenv=globalenv),
+  linux_cxx("GCC 14, -DBOOST_ASIO_NO_TS_EXECUTORS", "g++-14", packages="g++-14", image="cppalliance/droneubuntu2404:1", buildtype="boost_v1", buildscript="drone", environment={  "VARIANT": "release", "TOOLSET": "gcc", "COMPILER": "g++-14", "CXXSTD" : "20" , "CXX_FLAGS": "<cxxflags>-DBOOST_ASIO_NO_TS_EXECUTORS"}, globalenv=globalenv),
   linux_cxx("Clang 18, UBasan", "clang++-18", packages="clang-18 libssl-dev", image="cppalliance/droneubuntu2404:1", buildtype="boost_v1", buildscript="drone", environment={"VARIANT": "beast_ubasan", "TOOLSET": "clang", "COMPILER": "clang++-18", "CXXSTD": "17", "UBSAN_OPTIONS": 'print_stacktrace=1', "DRONE_BEFORE_INSTALL": "UBasan" }, globalenv=globalenv, privileged=True),
   linux_cxx("docs", "", packages="docbook docbook-xml docbook-xsl xsltproc libsaxonhe-java default-jre-headless flex libfl-dev bison unzip rsync mlocate", image="cppalliance/droneubuntu1804:1", buildtype="docs", buildscript="drone", environment={"COMMENT": "docs"}, globalenv=globalenv),
   linux_cxx("GCC 14, UBasan", "g++-14", packages="g++-14", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu2404:1", environment={'COMMENT': 'ubsan', 'B2_VARIANT': 'debug', 'B2_TOOLSET': 'gcc-14', 'B2_CXXSTD': '14,17,20,23', 'B2_UBSAN': '1', 'B2_DEFINES': 'BOOST_NO_STRESS_TEST=1', 'B2_LINKFLAGS': '-fuse-ld=gold'}, globalenv=globalenv, privileged=True),

cmake/toolchains/gcc.cmake

@@ -2,4 +2,4 @@
 include(${CMAKE_CURRENT_LIST_DIR}/common.cmake)
 
 # Compiler options.
-add_compile_options(-Wall -Wextra -Wpedantic -Wno-unused-parameter)
+add_compile_options(-Wall -Wextra -Wpedantic)

example/advanced/server-flex-awaitable/advanced_server_flex_awaitable.cpp

@@ -362,8 +362,7 @@ net::awaitable<void, executor_type>
 run_websocket_session(
     Stream& stream,
     beast::flat_buffer& buffer,
-    http::request<http::string_body> req,
+    http::request<http::string_body> req)
-    beast::string_view doc_root)
 {
     auto cs = co_await net::this_coro::cancellation_state;
     auto ws = websocket::stream<Stream&>{ stream };
@@ -438,7 +437,7 @@ run_session(
             beast::get_lowest_layer(stream).expires_never();
 
             co_await run_websocket_session(
-                stream, buffer, parser.release(), doc_root);
+                stream, buffer, parser.release());
 
             co_return;
         }
@@ -581,7 +580,9 @@ handle_signals(task_group& task_group)
     }
     else // SIGTERM
     {
-        executor.get_inner_executor().context().stop();
+        net::query(
+            executor.get_inner_executor(),
+            net::execution::context).stop();
     }
 }
 

include/boost/beast/_experimental/test/impl/stream.hpp

@@ -17,6 +17,7 @@
 #include <boost/asio/append.hpp>
 #include <boost/asio/associated_cancellation_slot.hpp>
 #include <boost/asio/dispatch.hpp>
+#include <boost/asio/executor_work_guard.hpp>
 #include <boost/asio/post.hpp>
 #include <mutex>
 #include <stdexcept>
@@ -57,13 +58,8 @@ class basic_stream<Executor>::read_op : public detail::stream_read_op_base
         Handler h_;
         boost::weak_ptr<detail::stream_state> wp_;
         Buffers b_;
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
-        net::any_io_executor wg2_;
-#else // defined(BOOST_ASIO_NO_TS_EXECUTORS)
         net::executor_work_guard<
             net::associated_executor_t<Handler, net::any_io_executor>> wg2_;
-#endif // defined(BOOST_ASIO_NO_TS_EXECUTORS)
-
         lambda(lambda&&) = default;
         lambda(lambda const&) = default;
 
@@ -75,15 +71,7 @@ class basic_stream<Executor>::read_op : public detail::stream_read_op_base
             : h_(std::forward<Handler_>(h))
             , wp_(s)
             , b_(b)
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
+            , wg2_(net::get_associated_executor(h_, s->exec))
-            , wg2_(net::prefer(
-                net::get_associated_executor(
-                  h_, s->exec),
-                net::execution::outstanding_work.tracked))
-#else // defined(BOOST_ASIO_NO_TS_EXECUTORS)
-            , wg2_(net::get_associated_executor(
-                h_, s->exec))
-#endif // defined(BOOST_ASIO_NO_TS_EXECUTORS)
         {
         }
 
@@ -131,24 +119,14 @@ class basic_stream<Executor>::read_op : public detail::stream_read_op_base
                 }
             }
 
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
-            net::dispatch(wg2_,
-                net::append(std::move(h_), ec, bytes_transferred));
-            wg2_ = net::any_io_executor(); // probably unnecessary
-#else // defined(BOOST_ASIO_NO_TS_EXECUTORS)
             net::dispatch(wg2_.get_executor(),
                 net::append(std::move(h_), ec, bytes_transferred));
             wg2_.reset();
-#endif // defined(BOOST_ASIO_NO_TS_EXECUTORS)
         }
     };
 
     lambda fn_;
-#if defined(BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
     net::executor_work_guard<net::any_io_executor> wg1_;
-#else
-    net::any_io_executor wg1_;
-#endif
 
 public:
     template<class Handler_>
@@ -157,25 +135,15 @@ public:
         boost::shared_ptr<detail::stream_state> const& s,
         Buffers const& b)
         : fn_(std::forward<Handler_>(h), s, b)
-#if defined(BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
         , wg1_(s->exec)
-#else
-        , wg1_(net::prefer(s->exec,
-            net::execution::outstanding_work.tracked))
-#endif
     {
     }
 
     void
     operator()(error_code ec) override
     {
-#if defined(BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
         net::post(wg1_.get_executor(), net::append(std::move(fn_), ec));
         wg1_.reset();
-#else
-        net::post(wg1_, net::append(std::move(fn_), ec));
-        wg1_ = net::any_io_executor(); // probably unnecessary
-#endif
     }
 };
 

include/boost/beast/_experimental/test/stream.hpp

@@ -19,7 +19,6 @@
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/buffer.hpp>
 #include <boost/asio/error.hpp>
-#include <boost/asio/executor_work_guard.hpp>
 #include <boost/asio/any_io_executor.hpp>
 #include <boost/asio/io_context.hpp>
 #include <boost/assert.hpp>

include/boost/beast/core/async_base.hpp

@@ -14,7 +14,6 @@
 #include <boost/beast/core/detail/allocator.hpp>
 #include <boost/beast/core/detail/async_base.hpp>
 #include <boost/beast/core/detail/filtering_cancellation_slot.hpp>
-#include <boost/beast/core/detail/work_guard.hpp>
 #include <boost/asio/append.hpp>
 #include <boost/asio/associated_allocator.hpp>
 #include <boost/asio/associated_cancellation_slot.hpp>
@@ -22,6 +21,7 @@
 #include <boost/asio/associated_immediate_executor.hpp>
 #include <boost/asio/bind_executor.hpp>
 #include <boost/asio/dispatch.hpp>
+#include <boost/asio/executor_work_guard.hpp>
 #include <boost/asio/handler_continuation_hook.hpp>
 #include <boost/asio/post.hpp>
 #include <boost/core/exchange.hpp>
@@ -186,7 +186,7 @@ class async_base
         "Executor type requirements not met");
 
     Handler h_;
-    detail::select_work_guard_t<Executor1> wg1_;
+    net::executor_work_guard<Executor1> wg1_;
     net::cancellation_type act_{net::cancellation_type::terminal};
 public:
     /** The type of executor associated with this object.
@@ -202,7 +202,7 @@ public:
         typename
         net::associated_executor<
             Handler,
-            typename detail::select_work_guard_t<Executor1>::executor_type
+            typename net::executor_work_guard<Executor1>::executor_type
                 >::type;
 #endif
 
@@ -260,7 +260,7 @@ public:
         Handler_&& handler,
         Executor1 const& ex1)
         : h_(std::forward<Handler_>(handler))
-        , wg1_(detail::make_work_guard(ex1))
+        , wg1_(ex1)
     {
     }
 
@@ -327,10 +327,10 @@ public:
         handler, then the object returned from this function will be used
         as the associated immediate executor of the derived class.
     */
-    auto
+    net::associated_immediate_executor_t<
+        Handler,
+        typename net::executor_work_guard<Executor1>::executor_type>
     get_immediate_executor() const noexcept
-        -> decltype(net::get_associated_immediate_executor(
-            h_, wg1_.get_executor()))
     {
         return net::get_associated_immediate_executor(
             h_, wg1_.get_executor());

include/boost/beast/core/detail/work_guard.hpp

@@ -1,102 +0,0 @@
-//
-// Copyright (c) 2020 Richard Hodges (hodges.r@gmail.com)
-//
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//
-// Official repository: https://github.com/boostorg/beast
-//
-
-#ifndef BOOST_BEAST_CORE_DETAIL_WORK_GUARD_HPP
-#define BOOST_BEAST_CORE_DETAIL_WORK_GUARD_HPP
-
-#include <boost/asio/executor_work_guard.hpp>
-#include <boost/asio/execution.hpp>
-#include <boost/optional.hpp>
-
-namespace boost {
-namespace beast {
-namespace detail {
-
-template<class Executor, class Enable = void>
-struct select_work_guard;
-
-template<class Executor>
-using select_work_guard_t = typename
-    select_work_guard<Executor>::type;
-
-#if !defined(BOOST_ASIO_NO_TS_EXECUTORS)
-template<class Executor>
-struct select_work_guard
-<
-    Executor,
-    typename std::enable_if
-    <
-        net::is_executor<Executor>::value
-    >::type
->
-{
-    using type = net::executor_work_guard<Executor>;
-};
-#endif
-
-template<class Executor>
-struct execution_work_guard
-{
-    using executor_type = typename std::decay<decltype(
-         net::prefer(std::declval<Executor const&>(),
-            net::execution::outstanding_work.tracked))>::type;
-
-    execution_work_guard(Executor const& exec)
-    : ex_(net::prefer(exec, net::execution::outstanding_work.tracked))
-    {
-
-    }
-
-    executor_type
-    get_executor() const noexcept
-    {
-        BOOST_ASSERT(ex_.has_value());
-        return *ex_;
-    }
-
-    void reset() noexcept
-    {
-        ex_.reset();
-    }
-
-private:
-
-    boost::optional<executor_type> ex_;
-};
-
-template<class Executor>
-struct select_work_guard
-<
-    Executor,
-    typename std::enable_if
-    <
-        net::execution::is_executor<Executor>::value
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
-        || net::is_executor<Executor>::value
-#else
-        && !net::is_executor<Executor>::value
-#endif
-    >::type
->
-{
-    using type = execution_work_guard<Executor>;
-};
-
-template<class Executor>
-select_work_guard_t<Executor>
-make_work_guard(Executor const& exec) noexcept
-{
-    return select_work_guard_t<Executor>(exec);
-}
-
-}
-}
-}
-
-#endif // BOOST_BEAST_CORE_DETAIL_WORK_GUARD_HPP

include/boost/beast/core/impl/saved_handler.hpp

@@ -66,28 +66,15 @@ class saved_handler::impl final : public base
     };
 
     ebo_pair v_;
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
-    typename std::decay<decltype(net::prefer(std::declval<
-        net::associated_executor_t<Handler>>(),
-        net::execution::outstanding_work.tracked))>::type
-          wg2_;
-#else // defined(BOOST_ASIO_NO_TS_EXECUTORS)
     net::executor_work_guard<
         net::associated_executor_t<Handler>> wg2_;
-#endif // defined(BOOST_ASIO_NO_TS_EXECUTORS)
     net::cancellation_slot slot_{net::get_associated_cancellation_slot(v_.h)};
 public:
     template<class Handler_>
     impl(alloc_type const& a, Handler_&& h, 
          saved_handler * owner)
         : base(owner), v_(a, std::forward<Handler_>(h))
-#if defined(BOOST_ASIO_NO_TS_EXECUTORS)
-        , wg2_(net::prefer(
-            net::get_associated_executor(v_.h),
-            net::execution::outstanding_work.tracked))
-#else // defined(BOOST_ASIO_NO_TS_EXECUTORS)
         , wg2_(net::get_associated_executor(v_.h))
-#endif // defined(BOOST_ASIO_NO_TS_EXECUTORS)
     {
     }
 

test/beast/core/async_base.cpp

@@ -44,7 +44,7 @@ struct ex1_type
 {
 
     net::execution_context &
-    query(net::execution::context_t c) const noexcept
+    query(net::execution::context_t) const noexcept
     { return *reinterpret_cast<net::execution_context *>(&ex1ctx); }
 
     net::execution::blocking_t
@@ -52,23 +52,23 @@ struct ex1_type
     { return net::execution::blocking; };
 
     net::execution::outstanding_work_t
-    query(net::execution::outstanding_work_t w) const noexcept
+    query(net::execution::outstanding_work_t) const noexcept
     { return net::execution::outstanding_work; }
 
     ex1_type
-    require(net::execution::blocking_t::possibly_t b) const
+    require(net::execution::blocking_t::possibly_t) const
     { return *this; }
 
     ex1_type
-    require(net::execution::blocking_t::never_t b) const
+    require(net::execution::blocking_t::never_t) const
     { return *this; };
 
     ex1_type
-    prefer(net::execution::outstanding_work_t::untracked_t w) const
+    prefer(net::execution::outstanding_work_t::untracked_t) const
     { return *this; };
 
     ex1_type
-    prefer(net::execution::outstanding_work_t::tracked_t w) const
+    prefer(net::execution::outstanding_work_t::tracked_t) const
     { return *this; };
 
     template<class F>

test/beast/core/test_handler.hpp

@@ -69,6 +69,7 @@ public:
     template<class F>
     void execute(F&&) const {}
     simple_executor prefer(net::execution::outstanding_work_t::tracked_t) const { return *this; }
+    simple_executor require(net::execution::blocking_t::never_t) const { return *this; };
 #else
     void* context() { return nullptr; }
     void on_work_started() {}

test/extras/include/boost/beast/test/yield_to.hpp

@@ -41,9 +41,7 @@ protected:
     net::io_context ioc_;
 
 private:
-    beast::detail::select_work_guard_t<
+    net::executor_work_guard<net::io_context::executor_type> work_;
-        net::io_context::executor_type>
-            work_;
     std::vector<std::thread> threads_;
     std::mutex m_;
     std::condition_variable cv_;
@@ -56,8 +54,7 @@ public:
 
     explicit
     enable_yield_to(std::size_t concurrency = 1)
-        : work_(beast::detail::make_work_guard(
+        : work_(ioc_.get_executor())
-            ioc_.get_executor()))
     {
         threads_.reserve(concurrency);
         while(concurrency--)