On 23/10/19 12:50 -0700, Thomas Rodgers wrote:
Thomas Rodgers writes:
Let's try this again.
That's better, thanks :-)
+ * 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.
ChangeLog entries should be provided separately from the patch (e.g.
inline in the makefile, or as a separte attachment) because they never
apply cleanly.
Also it looks like you have a mixture of tabs and space there, it
should be only tabs.
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 \
Generated files like Makefile.in don't need to be in the patch. I use
a git alias called 'filter' to filter them out:
!f(){ git $@ | filterdiff -x '*/ChangeLog' -x '*/Makefile.in' -x '*/configure'
-x '*/config.h.in' -x '*/doc/html/*' | sed -e '/^diff.*ChangeLog/{N;d}' ; }; f
And then I create a patch with this alias:
!f(){ git filter show --diff-algorithm=histogram ${*:-HEAD} >
/dev/shm/patch.txt; }; f
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.
The copyright date should be just 2019.
+//
+// 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
+
Please add:
#if __cplusplus > 201703L
here (and the corresponding #endif before the final #endif) so that
this file is empty when included pre-C++20.
+#include <type_traits>
+#include <memory>
+#include <mutex>
+#include <atomic>
+
+#define __cpp_lib_jthread 201907L
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+ _GLIBCXX_BEGIN_NAMESPACE_VERSION
These BEGIN/END macros should not be indented (which has to be done
manually as editors always want to indent the content following the
opening brace of the namespace).
+
+ class stop_source;
+ template<class _Callback>
s/class/typename/
+ class stop_callback;
+
+ struct nostopstate_t { explicit nostopstate_t() = default; };
+ inline constexpr nostopstate_t nostopstate();
+
+ class stop_token {
The opening brace should be on the next line please, in the same
column as "class".
(Same comment for all classes and structs in the patch).
+ 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;
+ }
This doesn't leave the RHS empty as required.
I think the copy/move constructors and copy/move assignment operators
can all be defined as = default and that will do the right thing.
+
+ [[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>
Please Use _Cb so it's not all uppercase (which is more likely to
conflict with libc macros).
+ _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;
+ }
These can all be defaulted too.
+ [[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 {
Opening brace on the next line, in the same column as "class".
+ using _Stop_cb = stop_token::_Stop_cb;
And then everything in the class body should be indented by another
two columns.
+ using _Stop_state = stop_token::_Stop_state;
+ public:
+ using callback_type = _Callback;
+
+ template<typename _CB,
Change to _Cb here too.
