diff options
Diffstat (limited to 'libstdc++-v3')
-rw-r--r-- | libstdc++-v3/ChangeLog | 10 | ||||
-rw-r--r-- | libstdc++-v3/include/std/future | 29 | ||||
-rw-r--r-- | libstdc++-v3/testsuite/30_threads/promise/60966.cc | 67 |
3 files changed, 96 insertions, 10 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index b78daca58ca..3ade6310e4e 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,13 @@ +2014-05-16 Jonathan Wakely <jwakely@redhat.com> + + PR libstdc++/60966 + * include/std/future (__future_base::_State_baseV2::_M_set_result): + Signal condition variable after call_once returns. + (__future_base::_State_baseV2::_M_do_set): Do not signal here. + (promise::set_value, promise::set_exception): Increment the reference + count on the shared state until the function returns. + * testsuite/30_threads/promise/60966.cc: New. + 2014-05-08 Joshua Gay <jgay@gnu.org> PR libstdc++/61117 diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future index 717ce7105df..998e90a9856 100644 --- a/libstdc++-v3/include/std/future +++ b/libstdc++-v3/include/std/future @@ -365,12 +365,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void _M_set_result(function<_Ptr_type()> __res, bool __ignore_failure = false) { - bool __set = __ignore_failure; + bool __set = false; // all calls to this function are serialized, // side-effects of invoking __res only happen once call_once(_M_once, &_State_baseV2::_M_do_set, this, ref(__res), ref(__set)); - if (!__set) + if (__set) + _M_cond.notify_all(); + else if (!__ignore_failure) __throw_future_error(int(future_errc::promise_already_satisfied)); } @@ -485,7 +487,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION lock_guard<mutex> __lock(_M_mutex); _M_result.swap(__res); } - _M_cond.notify_all(); __set = true; } @@ -495,6 +496,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION virtual void _M_complete_async() { } // Return true if state contains a deferred function. + // Caller must own _M_mutex. virtual bool _M_has_deferred() const { return false; } }; @@ -1007,22 +1009,25 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void set_value(const _Res& __r) { + auto __future = _M_future; auto __setter = _State::__setter(this, __r); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } void set_value(_Res&& __r) { + auto __future = _M_future; auto __setter = _State::__setter(this, std::move(__r)); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } void set_exception(exception_ptr __p) { + auto __future = _M_future; auto __setter = _State::__setter(__p, this); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } }; @@ -1105,15 +1110,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void set_value(_Res& __r) { + auto __future = _M_future; auto __setter = _State::__setter(this, __r); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } void set_exception(exception_ptr __p) { + auto __future = _M_future; auto __setter = _State::__setter(__p, this); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } }; @@ -1190,8 +1197,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void set_exception(exception_ptr __p) { + auto __future = _M_future; auto __setter = _State::__setter(__p, this); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } }; @@ -1217,8 +1225,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION inline void promise<void>::set_value() { + auto __future = _M_future; auto __setter = _State::__setter(this); - _M_future->_M_set_result(std::move(__setter)); + __future->_M_set_result(std::move(__setter)); } diff --git a/libstdc++-v3/testsuite/30_threads/promise/60966.cc b/libstdc++-v3/testsuite/30_threads/promise/60966.cc new file mode 100644 index 00000000000..269268b989b --- /dev/null +++ b/libstdc++-v3/testsuite/30_threads/promise/60966.cc @@ -0,0 +1,67 @@ +// { dg-do run { target *-*-freebsd* *-*-netbsd* *-*-linux* *-*-gnu* *-*-solaris* *-*-cygwin *-*-darwin* powerpc-ibm-aix* } } +// { dg-options " -std=gnu++11 -pthread" { target *-*-freebsd* *-*-netbsd* *-*-linux* *-*-gnu* powerpc-ibm-aix* } } +// { dg-options " -std=gnu++11 -pthreads" { target *-*-solaris* } } +// { dg-options " -std=gnu++11 " { target *-*-cygwin *-*-darwin* } } +// { dg-require-cstdint "" } +// { dg-require-gthreads "" } +// { dg-require-atomic-builtins "" } + +// Copyright (C) 2014 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/>. + +// libstdc++/60966 +// This test hangs if std::promise::~promise() destroys the +// shared state before std::promise::set_value() finishes using it. + +#include <future> +#include <thread> +#include <vector> + +const int THREADS = 10; + +void run_task(std::promise<void>* pr) +{ + std::this_thread::sleep_for(std::chrono::milliseconds(100)); + pr->set_value(); +} + +int main() +{ + std::vector<std::promise<void>*> tasks(THREADS); + std::vector<std::thread> threads(THREADS); + std::vector<std::future<void>> futures(THREADS); + + for (int i = 0; i < THREADS; ++i) + { + std::promise<void>* task = new std::promise<void>; + tasks[i] = task; + futures[i] = task->get_future(); + threads[i] = std::thread(run_task, task); + } + + for (int i = 0; i < THREADS; ++i) + { + // the temporary future releases the state as soon as wait() returns + std::future<void>(std::move(futures[i])).wait(); + // state is ready, should now be safe to delete promise, so it + // releases the shared state too + delete tasks[i]; + } + + for (auto& t : threads) + t.join(); +} |