Thomas Rodgers writes:
Let's try this again.
From 23e1c9402cc15666d099fd61b58a0019181a9115 Mon Sep 17 00:00:00 2001
From: Thomas Rodgers <trodgers@trodgers.remote.f30>
Date: Tue, 22 Oct 2019 17:53:00 -0700
Subject: [PATCH] Add support for C++2a stop_token
* include/Makefile.am: Add <stop_token> header.
* include/Makefile.in: Regenerate.
* include/std/stop_token: New file.
* include/std/version (__cpp_lib_jthread): New value.
* testsuite/30_threads/stop_token/1.cc: New test.
* testsuite/30_threads/stop_token/2.cc: New test.
* testsuite/30_threads/stop_token/stop_token.cc: New test.
---
libstdc++-v3/ChangeLog | 10 +
libstdc++-v3/include/Makefile.am | 1 +
libstdc++-v3/include/Makefile.in | 1 +
libstdc++-v3/include/std/stop_token | 338 ++++++++++++++++++
libstdc++-v3/include/std/version | 1 +
.../testsuite/30_threads/stop_token/1.cc | 27 ++
.../testsuite/30_threads/stop_token/2.cc | 27 ++
.../30_threads/stop_token/stop_token.cc | 93 +++++
8 files changed, 498 insertions(+)
create mode 100644 libstdc++-v3/include/std/stop_token
create mode 100644 libstdc++-v3/testsuite/30_threads/stop_token/1.cc
create mode 100644 libstdc++-v3/testsuite/30_threads/stop_token/2.cc
create mode 100644 libstdc++-v3/testsuite/30_threads/stop_token/stop_token.cc
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 2ea0fe4ec40..970c5c2a018 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2019-10-22 Thomas Rodgers <trodg...@redhat.com>
+
+ * include/Makefile.am: Add <stop_token> header.
+ * include/Makefile.in: Regenerate.
+ * include/std/stop_token: New file.
+ * include/std/version (__cpp_lib_jthread): New value.
+ * testsuite/30_threads/stop_token/1.cc: New test.
+ * testsuite/30_threads/stop_token/2.cc: New test.
+ * testsuite/30_threads/stop_token/stop_token.cc: New test.
+
2019-09-05 Jonathan Wakely <jwak...@redhat.com>
* doc/xml/manual/status_cxx2020.xml: Update status for P0122R7 and
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index b8b786d9260..fb6777366bd 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -72,6 +72,7 @@ std_headers = \
${std_srcdir}/sstream \
${std_srcdir}/stack \
${std_srcdir}/stdexcept \
+ ${std_srcdir}/stop_token \
${std_srcdir}/streambuf \
${std_srcdir}/string \
${std_srcdir}/string_view \
diff --git a/libstdc++-v3/include/Makefile.in b/libstdc++-v3/include/Makefile.in
index cd1e9df5482..9b4ab670315 100644
--- a/libstdc++-v3/include/Makefile.in
+++ b/libstdc++-v3/include/Makefile.in
@@ -416,6 +416,7 @@ std_headers = \
${std_srcdir}/sstream \
${std_srcdir}/stack \
${std_srcdir}/stdexcept \
+ ${std_srcdir}/stop_token \
${std_srcdir}/streambuf \
${std_srcdir}/string \
${std_srcdir}/string_view \
diff --git a/libstdc++-v3/include/std/stop_token b/libstdc++-v3/include/std/stop_token
new file mode 100644
index 00000000000..b3655b85eae
--- /dev/null
+++ b/libstdc++-v3/include/std/stop_token
@@ -0,0 +1,338 @@
+// <stop_token> -*- C++ -*-
+
+// Copyright (C) 2008-2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file include/stop_token
+ * This is a Standard C++ Library header.
+ */
+
+#ifndef _GLIBCXX_STOP_TOKEN
+#define _GLIBCXX_STOP_TOKEN
+
+#include <type_traits>
+#include <memory>
+#include <mutex>
+#include <atomic>
+
+#define __cpp_lib_jthread 201907L
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+ _GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ class stop_source;
+ template<class _Callback>
+ class stop_callback;
+
+ struct nostopstate_t { explicit nostopstate_t() = default; };
+ inline constexpr nostopstate_t nostopstate();
+
+ class stop_token {
+ public:
+ stop_token() noexcept = default;
+
+ stop_token(const stop_token& __other) noexcept
+ : _M_state(__other._M_state)
+ { }
+
+ stop_token(stop_token&& __other) noexcept
+ : _M_state(std::move(__other._M_state))
+ { }
+
+ ~stop_token() = default;
+
+ stop_token&
+ operator=(const stop_token& __rhs) noexcept {
+ _M_state = __rhs._M_state;
+ return *this;
+ }
+
+ stop_token&
+ operator=(stop_token&& __rhs) noexcept {
+ std::swap(_M_state, __rhs._M_state);
+ return *this;
+ }
+
+ [[nodiscard]]
+ bool
+ stop_possible() const noexcept
+ {
+ return static_cast<bool>(_M_state);
+ }
+
+ [[nodiscard]]
+ bool
+ stop_requested() const noexcept
+ {
+ return stop_possible() && _M_state->_M_stop_requested();
+ }
+
+ private:
+ friend stop_source;
+ template<typename _Callback>
+ friend class stop_callback;
+
+ struct _Stop_cb {
+ void(*_M_callback)(_Stop_cb*);
+ _Stop_cb* _M_prev = nullptr;
+ _Stop_cb* _M_next = nullptr;
+
+ template<typename _CB>
+ _Stop_cb(_CB&& __cb)
+ : _M_callback(std::move(__cb))
+ { }
+
+ static void
+ _S_execute(_Stop_cb* __cb) noexcept
+ {
+ __cb->_M_callback(__cb);
+ }
+ };
+
+ struct _Stop_state_t {
+ std::atomic<bool> _M_stopped;
+ std::mutex _M_mtx;
+ _Stop_cb* _M_head = nullptr;
+
+ _Stop_state_t()
+ : _M_stopped{false}
+ { }
+
+ bool
+ _M_stop_requested()
+ {
+ return _M_stopped;
+ }
+
+ bool
+ _M_request_stop()
+ {
+ bool __stopped = false;
+ if (_M_stopped.compare_exchange_strong(__stopped, true))
+ {
+ std::unique_lock<std::mutex> __lck{_M_mtx};
+ while (auto __p = _M_head)
+ {
+ _M_head = __p->_M_next;
+ _Stop_cb::_S_execute(__p);
+ }
+ return true;
+ }
+ return false;
+ }
+
+ bool
+ _M_register_callback(_Stop_cb* __cb)
+ {
+ std::unique_lock<std::mutex> __lck{_M_mtx};
+ if (_M_stopped)
+ return false;
+
+ __cb->_M_next = _M_head;
+ _M_head->_M_prev = __cb;
+ _M_head = __cb;
+ return true;
+ }
+
+ void
+ _M_remove_callback(_Stop_cb* __cb)
+ {
+ std::unique_lock<std::mutex> __lck{_M_mtx};
+ if (__cb == _M_head)
+ {
+ _M_head = _M_head->_M_next;
+ _M_head->_M_prev = nullptr;
+ }
+ else
+ {
+ __cb->_M_prev->_M_next = __cb->_M_next;
+ if (__cb->_M_next)
+ {
+ __cb->_M_next->_M_prev = __cb->_M_prev;
+ }
+ }
+ }
+ };
+
+ using _Stop_state = std::shared_ptr<_Stop_state_t>;
+ _Stop_state _M_state;
+
+ explicit stop_token(_Stop_state __state)
+ : _M_state{std::move(__state)}
+ { }
+ };
+
+ class stop_source {
+ using _Stop_state_t = stop_token::_Stop_state_t;
+ using _Stop_state = stop_token::_Stop_state;
+
+ public:
+ stop_source()
+ : _M_state(std::make_shared<_Stop_state_t>())
+ { }
+
+ explicit stop_source(std::nostopstate_t) noexcept
+ { }
+
+ stop_source(const stop_source& __other) noexcept
+ : _M_state(__other._M_state)
+ { }
+
+ stop_source(stop_source&& __other) noexcept
+ : _M_state(std::move(__other._M_state))
+ { }
+
+ stop_source&
+ operator=(const stop_source& __rhs) noexcept
+ {
+ if (_M_state != __rhs._M_state)
+ _M_state = __rhs._M_state;
+ return *this;
+ }
+
+ stop_source&
+ operator=(stop_source&& __rhs) noexcept
+ {
+ std::swap(_M_state, __rhs._M_state);
+ return *this;
+ }
+
+ [[nodiscard]]
+ bool
+ stop_possible() const noexcept
+ {
+ return static_cast<bool>(_M_state);
+ }
+
+ [[nodiscard]]
+ bool
+ stop_requested() const noexcept
+ {
+ return stop_possible() && _M_state->_M_stop_requested();
+ }
+
+ bool
+ request_stop() const noexcept
+ {
+ if (stop_possible())
+ return _M_state->_M_request_stop();
+ return false;
+ }
+
+ [[nodiscard]]
+ stop_token
+ get_token() const noexcept
+ {
+ return stop_token{_M_state};
+ }
+
+ void
+ swap(stop_source& __other) noexcept
+ {
+ std::swap(_M_state, __other._M_state);
+ }
+
+ [[nodiscard]]
+ friend bool
+ operator==(const stop_source& __a, const stop_source& __b) noexcept
+ {
+ return __a._M_state == __b._M_state;
+ }
+
+ [[nodiscard]]
+ friend bool
+ operator!=(const stop_source& __a, const stop_source& __b) noexcept
+ {
+ return __a._M_state != __b._M_state;
+ }
+
+ private:
+ _Stop_state _M_state;
+ };
+
+ template<typename _Callback>
+ class [[nodiscard]] stop_callback
+ : private stop_token::_Stop_cb {
+ using _Stop_cb = stop_token::_Stop_cb;
+ using _Stop_state = stop_token::_Stop_state;
+ public:
+ using callback_type = _Callback;
+
+ template<typename _CB,
+ std::enable_if_t<std::is_constructible_v<_Callback, _CB>, int> = 0>
+ explicit stop_callback(const stop_token& __token, _CB&& __cb)
+ noexcept(std::is_nothrow_constructible_v<_Callback, _CB>)
+ : _Stop_cb([](_Stop_cb* __that) noexcept
+ {
+ static_cast<stop_callback*>(__that)->_M_execute();
+ }),
+ _M_cb(std::move(__cb))
+ {
+ if (__token._M_state && __token._M_state->_M_register_callback(this))
+ {
+ _M_state = __token._M_state;
+ }
+ }
+
+ template<typename _CB,
+ std::enable_if_t<std::is_constructible_v<_Callback, _CB>, int> = 0>
+ explicit stop_callback(stop_token&& __token, _CB&& __cb)
+ noexcept(std::is_nothrow_constructible_v<_Callback, _CB>)
+ : _Stop_cb([](_Stop_cb* __that) noexcept
+ {
+ static_cast<stop_callback*>(__that)->_M_execute();
+ }),
+ _M_cb(std::move(__cb))
+ {
+ if (__token._M_state && __token._M_state->_M_register_callback(this))
+ {
+ std::swap(_M_state, __token._M_state);
+ }
+ }
+
+ ~stop_callback()
+ {
+ if (_M_state)
+ _M_state->_M_remove_callback(this);
+ }
+
+ stop_callback(const stop_callback&) = delete;
+ stop_callback& operator=(const stop_callback&) = delete;
+ stop_callback(stop_callback&&) = delete;
+ stop_callback& operator=(stop_callback&&) = delete;
+
+ private:
+ _Callback _M_cb;
+ _Stop_state _M_state = nullptr;
+
+ void
+ _M_execute() noexcept
+ {
+ _M_cb();
+ }
+ };
+ _GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
+;
+#endif // _GLIBCXX_STOP_TOKEN
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 7625d397a0d..9fb190537f8 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -168,6 +168,7 @@
#define __cpp_lib_math_constants 201907L
#define __cpp_lib_span 201902L
#define __cpp_lib_to_array 201907L
+#define __cpp_lib_jthread 201907L
#endif // C++2a
#endif // C++17
#endif // C++14
diff --git a/libstdc++-v3/testsuite/30_threads/stop_token/1.cc b/libstdc++-v3/testsuite/30_threads/stop_token/1.cc
new file mode 100644
index 00000000000..4c0e7a33d25
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/stop_token/1.cc
@@ -0,0 +1,27 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <stop_token>
+
+#ifndef __cpp_lib_jthread
+# error "Feature-test macro for jthread missing in <stop_token>"
+#elif __cpp_lib_jthread != 201907L
+# error "Feature-test macro for jthread has wrong value in <stop_token>"
+#endif
diff --git a/libstdc++-v3/testsuite/30_threads/stop_token/2.cc b/libstdc++-v3/testsuite/30_threads/stop_token/2.cc
new file mode 100644
index 00000000000..621965c8910
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/stop_token/2.cc
@@ -0,0 +1,27 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <version>
+
+#ifndef __cpp_lib_jthread
+# error "Feature-test macro for jthread missing in <version>"
+#elif __cpp_lib_jthread != 201907L
+# error "Feature-test macro for jthread has wrong value in <version>"
+#endif
diff --git a/libstdc++-v3/testsuite/30_threads/stop_token/stop_token.cc b/libstdc++-v3/testsuite/30_threads/stop_token/stop_token.cc
new file mode 100644
index 00000000000..96390918c84
--- /dev/null
+++ b/libstdc++-v3/testsuite/30_threads/stop_token/stop_token.cc
@@ -0,0 +1,93 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <stop_token>
+#include <cassert>
+
+int main()
+{
+ // create stop_source
+ std::stop_source ssrc;
+ assert(ssrc.stop_possible());
+ assert(!ssrc.stop_requested());
+
+ // create stop_token from stop_source
+ std::stop_token stok{ssrc.get_token()};
+ assert(ssrc.stop_possible());
+ assert(!ssrc.stop_requested());
+ assert(stok.stop_possible());
+ assert(!stok.stop_requested());
+
+ // register callback
+ bool cb1called{false};
+ auto cb1 = [&]{
+ cb1called = true;
+ };
+ {
+ std::stop_callback<decltype(cb1)> scb1{stok, cb1}; // copies cb1
+ assert(ssrc.stop_possible());
+ assert(!ssrc.stop_requested());
+ assert(stok.stop_possible());
+ assert(!stok.stop_requested());
+ assert(!cb1called);
+ } // unregister callback
+
+ // register another callback
+ bool cb2called{false};
+ auto cb2 = [&]{
+ assert(stok.stop_requested());
+ cb2called = true;
+ };
+ std::stop_callback<decltype(cb2)> scb2a{stok, cb2}; // copies cb2
+ std::stop_callback<decltype(cb2)> scb2b{stok, std::move(cb2)};
+ assert(ssrc.stop_possible());
+ assert(!ssrc.stop_requested());
+ assert(stok.stop_possible());
+ assert(!stok.stop_requested());
+ assert(!cb1called);
+ assert(!cb2called);
+
+ // request stop
+ auto b = ssrc.request_stop();
+ assert(b);
+ assert(ssrc.stop_possible());
+ assert(ssrc.stop_requested());
+ assert(stok.stop_possible());
+ assert(stok.stop_requested());
+ assert(!cb1called);
+ assert(cb2called);
+
+ b = ssrc.request_stop();
+ assert(!b);
+
+ // register another callback
+ bool cb3called{false};
+ auto cb3 = [&]{
+ cb3called = true;
+ };
+ std::stop_callback<decltype(cb3)> scb3{stok, cb3};
+ assert(ssrc.stop_possible());
+ assert(ssrc.stop_requested());
+ assert(stok.stop_possible());
+ assert(stok.stop_requested());
+ assert(!cb1called);
+ assert(cb2called);
+ assert(cb3called);
+}
--
2.21.0
