[gcc r17-2856] libstdc++: Implement LWG 4301 changes to condition_variable{_any}
Patrick Palka via Gcc-cvs <[email protected]> Fri, 31 Jul 2026 18:13:51 +0000 (GMT)
| Newsgroups | gmane.comp.gcc.cvs |
|---|---|
| Message-ID | <20260731181351.A2CE24BBC0C7__20188.6029027932$1785521645$gmane$org@sourceware.org> |
https://gcc.gnu.org/g:0a4e2861d9ed69eac1e1c69b84fd61d9e1925ff2 commit r17-2856-g0a4e2861d9ed69eac1e1c69b84fd61d9e1925ff2 Author: Patrick Palka <[email protected]> Date: Fri Jul 31 14:11:38 2026 -0400 libstdc++: Implement LWG 4301 changes to condition_variable{_any} * include/std/condition_variable (condition_variable::wait_until): Take timeout parameter by value as per LWG 4301. (condition_variable::wait_for): Likewise. (condition_variable::__wait_until_impl): Likewise. (condition_variable_any::wait_until): Likewise. (condition_variable_any::wait_for): Likewise. Reviewed-by: Tomasz Kamiński <[email protected]> Reviewed-by: Jonathan Wakely <[email protected]> Diff: --- libstdc++-v3/include/std/condition_variable | 34 +++++++++++++++++------------ 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/libstdc++-v3/include/std/condition_variable b/libstdc++-v3/include/std/condition_variable index ce995ed57779..b5831cdd8714 100644 --- a/libstdc++-v3/include/std/condition_variable +++ b/libstdc++-v3/include/std/condition_variable @@ -107,24 +107,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION wait(__lock); } + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 4301. condition_variable{_any}::wait_{for, until} should take timeout by value + #ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT template<typename _Duration> cv_status wait_until(unique_lock<mutex>& __lock, - const chrono::time_point<steady_clock, _Duration>& __atime) + chrono::time_point<steady_clock, _Duration> __atime) { return __wait_until_impl(__lock, __atime); } #endif template<typename _Duration> cv_status wait_until(unique_lock<mutex>& __lock, - const chrono::time_point<system_clock, _Duration>& __atime) + chrono::time_point<system_clock, _Duration> __atime) { return __wait_until_impl(__lock, __atime); } template<typename _Clock, typename _Duration> cv_status wait_until(unique_lock<mutex>& __lock, - const chrono::time_point<_Clock, _Duration>& __atime) + chrono::time_point<_Clock, _Duration> __atime) { #if __cplusplus > 201703L static_assert(chrono::is_clock_v<_Clock>); @@ -149,7 +152,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Clock, typename _Duration, typename _Predicate> bool wait_until(unique_lock<mutex>& __lock, - const chrono::time_point<_Clock, _Duration>& __atime, + chrono::time_point<_Clock, _Duration> __atime, _Predicate __p) { while (!__p()) @@ -161,7 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Rep, typename _Period> cv_status wait_for(unique_lock<mutex>& __lock, - const chrono::duration<_Rep, _Period>& __rtime) + chrono::duration<_Rep, _Period> __rtime) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // 3504. condition_variable::wait_for is overspecified @@ -174,7 +177,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Rep, typename _Period, typename _Predicate> bool wait_for(unique_lock<mutex>& __lock, - const chrono::duration<_Rep, _Period>& __rtime, + chrono::duration<_Rep, _Period> __rtime, _Predicate __p) { using __dur = typename steady_clock::duration; @@ -193,7 +196,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Dur> cv_status __wait_until_impl(unique_lock<mutex>& __lock, - const chrono::time_point<steady_clock, _Dur>& __atime) + chrono::time_point<steady_clock, _Dur> __atime) { __gthread_time_t __ts = chrono::__to_timeout_gthread_time_t(__atime); _M_cond.wait_until(*__lock.mutex(), CLOCK_MONOTONIC, __ts); @@ -206,7 +209,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Dur> cv_status __wait_until_impl(unique_lock<mutex>& __lock, - const chrono::time_point<system_clock, _Dur>& __atime) + chrono::time_point<system_clock, _Dur> __atime) { __gthread_time_t __ts = chrono::__to_timeout_gthread_time_t(__atime); _M_cond.wait_until(*__lock.mutex(), __ts); @@ -312,10 +315,13 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2) wait(__lock); } + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 4301. condition_variable{_any}::wait_{for, until} should take timeout by value + template<typename _Lock, typename _Clock, typename _Duration> cv_status wait_until(_Lock& __lock, - const chrono::time_point<_Clock, _Duration>& __atime) + chrono::time_point<_Clock, _Duration> __atime) { shared_ptr<mutex> __mutex = _M_mutex; unique_lock<mutex> __my_lock(*__mutex); @@ -330,7 +336,7 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2) typename _Duration, typename _Predicate> bool wait_until(_Lock& __lock, - const chrono::time_point<_Clock, _Duration>& __atime, + chrono::time_point<_Clock, _Duration> __atime, _Predicate __p) { while (!__p()) @@ -341,14 +347,14 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2) template<typename _Lock, typename _Rep, typename _Period> cv_status - wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime) + wait_for(_Lock& __lock, chrono::duration<_Rep, _Period> __rtime) { return wait_until(__lock, __clock_t::now() + __rtime); } template<typename _Lock, typename _Rep, typename _Period, typename _Predicate> bool wait_for(_Lock& __lock, - const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p) + chrono::duration<_Rep, _Period> __rtime, _Predicate __p) { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); } #ifdef __glibcxx_jthread @@ -383,7 +389,7 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2) template <class _Lock, class _Clock, class _Duration, class _Predicate> bool wait_until(_Lock& __lock, stop_token __stoken, - const chrono::time_point<_Clock, _Duration>& __abs_time, + chrono::time_point<_Clock, _Duration> __abs_time, _Predicate __p) { if (__stoken.stop_requested()) @@ -418,7 +424,7 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2) template <class _Lock, class _Rep, class _Period, class _Predicate> bool wait_for(_Lock& __lock, stop_token __stoken, - const chrono::duration<_Rep, _Period>& __rel_time, + chrono::duration<_Rep, _Period> __rel_time, _Predicate __p) { auto __abst = std::chrono::steady_clock::now() + __rel_time;