Merge pull request #6868 from yzct12345/safe-threads-no-deadlocks

threadsafe_queue: Fix deadlock
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bunnei 2021-08-14 02:28:59 -07:00 committed by GitHub
commit bdd617da03
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@ -46,15 +46,13 @@ public:
ElementPtr* new_ptr = new ElementPtr(); ElementPtr* new_ptr = new ElementPtr();
write_ptr->next.store(new_ptr, std::memory_order_release); write_ptr->next.store(new_ptr, std::memory_order_release);
write_ptr = new_ptr; write_ptr = new_ptr;
++size;
const size_t previous_size{size++}; // cv_mutex must be held or else there will be a missed wakeup if the other thread is in the
// line before cv.wait
// Acquire the mutex and then immediately release it as a fence.
// TODO(bunnei): This can be replaced with C++20 waitable atomics when properly supported. // TODO(bunnei): This can be replaced with C++20 waitable atomics when properly supported.
// See discussion on https://github.com/yuzu-emu/yuzu/pull/3173 for details. // See discussion on https://github.com/yuzu-emu/yuzu/pull/3173 for details.
if (previous_size == 0) { std::lock_guard lock{cv_mutex};
std::lock_guard lock{cv_mutex};
}
cv.notify_one(); cv.notify_one();
} }