diff options
| author | Thomas Rodgers <rodgert@twrodgers.com> | 2021-04-21 10:01:06 -0700 |
|---|---|---|
| committer | Thomas Rodgers <rodgert@twrodgers.com> | 2021-04-21 18:32:26 -0700 |
| commit | c0ffafb343ac80654e87b459492c575b7916d60c (patch) | |
| tree | ed8b0c9a7f4bd67c9f06ef26e0e4a271db0ae104 | |
| parent | 3a8437df2918114dae03f5614a250ff8a150050d (diff) | |
| download | gcc-c0ffafb343ac80654e87b459492c575b7916d60c.zip gcc-c0ffafb343ac80654e87b459492c575b7916d60c.tar.gz gcc-c0ffafb343ac80654e87b459492c575b7916d60c.tar.bz2 | |
[libstdc++] Fix test timeout in stop_calback/destroy.cc
A change was made to __atomic_semaphore::_S_do_try_acquire() to
(ideally) let the compare_exchange reload the value of __old rather than
always reloading it twice. This causes _M_acquire to spin indefinitely
if the value of __old is already 0.
libstdc++-v3/ChangeLog:
* include/bits/semaphore_base.h: Always reload __old in
__atomic_semaphore::_S_do_try_acquire().
* testsuite/30_threads/stop_token/stop_callback/destroy.cc:
re-enable testcase.
(cherry picked from commit 7eeb8c04e53fa880ee559efb727517ce778d17a0)
| -rw-r--r-- | libstdc++-v3/include/bits/semaphore_base.h | 16 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/30_threads/stop_token/stop_callback/destroy.cc | 2 |
2 files changed, 6 insertions, 12 deletions
diff --git a/libstdc++-v3/include/bits/semaphore_base.h b/libstdc++-v3/include/bits/semaphore_base.h index 35469e4..84b3342 100644 --- a/libstdc++-v3/include/bits/semaphore_base.h +++ b/libstdc++-v3/include/bits/semaphore_base.h @@ -196,9 +196,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __atomic_semaphore& operator=(const __atomic_semaphore&) = delete; static _GLIBCXX_ALWAYS_INLINE bool - _S_do_try_acquire(__detail::__platform_wait_t* __counter, - __detail::__platform_wait_t& __old) noexcept + _S_do_try_acquire(__detail::__platform_wait_t* __counter) noexcept { + auto __old = __atomic_impl::load(__counter, memory_order::acquire); if (__old == 0) return false; @@ -211,18 +211,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _GLIBCXX_ALWAYS_INLINE void _M_acquire() noexcept { - auto __old = __atomic_impl::load(&_M_counter, memory_order::acquire); auto const __pred = - [this, &__old] { return _S_do_try_acquire(&this->_M_counter, __old); }; + [this] { return _S_do_try_acquire(&this->_M_counter); }; std::__atomic_wait_address_bare(&_M_counter, __pred); } bool _M_try_acquire() noexcept { - auto __old = __atomic_impl::load(&_M_counter, memory_order::acquire); auto const __pred = - [this, &__old] { return _S_do_try_acquire(&this->_M_counter, __old); }; + [this] { return _S_do_try_acquire(&this->_M_counter); }; return std::__detail::__atomic_spin(__pred); } @@ -231,9 +229,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_try_acquire_until(const chrono::time_point<_Clock, _Duration>& __atime) noexcept { - auto __old = __atomic_impl::load(&_M_counter, memory_order_relaxed); auto const __pred = - [this, &__old] { return _S_do_try_acquire(&this->_M_counter, __old); }; + [this] { return _S_do_try_acquire(&this->_M_counter); }; return __atomic_wait_address_until_bare(&_M_counter, __pred, __atime); } @@ -243,9 +240,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _M_try_acquire_for(const chrono::duration<_Rep, _Period>& __rtime) noexcept { - auto __old = __atomic_impl::load(&_M_counter, memory_order_relaxed); auto const __pred = - [this, &__old] { return _S_do_try_acquire(&this->_M_counter, __old); }; + [this] { return _S_do_try_acquire(&this->_M_counter); }; return __atomic_wait_address_for_bare(&_M_counter, __pred, __rtime); } diff --git a/libstdc++-v3/testsuite/30_threads/stop_token/stop_callback/destroy.cc b/libstdc++-v3/testsuite/30_threads/stop_token/stop_callback/destroy.cc index c2cfba0..061ed44 100644 --- a/libstdc++-v3/testsuite/30_threads/stop_token/stop_callback/destroy.cc +++ b/libstdc++-v3/testsuite/30_threads/stop_token/stop_callback/destroy.cc @@ -21,8 +21,6 @@ // { dg-require-effective-target pthread } // { dg-require-gthreads "" } -// { dg-skip-if "FIXME: times out" { *-*-* } } - #include <stop_token> #include <atomic> #include <thread> |