f4d76853b9
This fixes a rare but possible deadlock, maybe due to undefined behavior. The new implementation is safer, at the cost of some added boilerplate.
90 lines
3.9 KiB
C++
90 lines
3.9 KiB
C++
/**************************************************************************/
|
|
/* condition_variable.h */
|
|
/**************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* https://godotengine.org */
|
|
/**************************************************************************/
|
|
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
|
|
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
|
|
/* */
|
|
/* Permission is hereby granted, free of charge, to any person obtaining */
|
|
/* a copy of this software and associated documentation files (the */
|
|
/* "Software"), to deal in the Software without restriction, including */
|
|
/* without limitation the rights to use, copy, modify, merge, publish, */
|
|
/* distribute, sublicense, and/or sell copies of the Software, and to */
|
|
/* permit persons to whom the Software is furnished to do so, subject to */
|
|
/* the following conditions: */
|
|
/* */
|
|
/* The above copyright notice and this permission notice shall be */
|
|
/* included in all copies or substantial portions of the Software. */
|
|
/* */
|
|
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
|
|
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
|
|
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
|
|
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
|
|
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
|
|
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
|
|
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
|
/**************************************************************************/
|
|
|
|
#ifndef CONDITION_VARIABLE_H
|
|
#define CONDITION_VARIABLE_H
|
|
|
|
#include "core/os/mutex.h"
|
|
#include "core/os/safe_binary_mutex.h"
|
|
|
|
#ifdef THREADS_ENABLED
|
|
|
|
#ifdef MINGW_ENABLED
|
|
#define MINGW_STDTHREAD_REDUNDANCY_WARNING
|
|
#include "thirdparty/mingw-std-threads/mingw.condition_variable.h"
|
|
#define THREADING_NAMESPACE mingw_stdthread
|
|
#else
|
|
#include <condition_variable>
|
|
#define THREADING_NAMESPACE std
|
|
#endif
|
|
|
|
// An object one or multiple threads can wait on a be notified by some other.
|
|
// Normally, you want to use a semaphore for such scenarios, but when the
|
|
// condition is something different than a count being greater than zero
|
|
// (which is the built-in logic in a semaphore) or you want to provide your
|
|
// own mutex to tie the wait-notify to some other behavior, you need to use this.
|
|
|
|
class ConditionVariable {
|
|
mutable THREADING_NAMESPACE::condition_variable condition;
|
|
|
|
public:
|
|
template <typename BinaryMutexT>
|
|
_ALWAYS_INLINE_ void wait(const MutexLock<BinaryMutexT> &p_lock) const {
|
|
condition.wait(const_cast<THREADING_NAMESPACE::unique_lock<THREADING_NAMESPACE::mutex> &>(p_lock._get_lock()));
|
|
}
|
|
|
|
template <int Tag>
|
|
_ALWAYS_INLINE_ void wait(const MutexLock<SafeBinaryMutex<Tag>> &p_lock) const {
|
|
condition.wait(const_cast<THREADING_NAMESPACE::unique_lock<THREADING_NAMESPACE::mutex> &>(p_lock.mutex._get_lock()));
|
|
}
|
|
|
|
_ALWAYS_INLINE_ void notify_one() const {
|
|
condition.notify_one();
|
|
}
|
|
|
|
_ALWAYS_INLINE_ void notify_all() const {
|
|
condition.notify_all();
|
|
}
|
|
};
|
|
|
|
#else // No threads.
|
|
|
|
class ConditionVariable {
|
|
public:
|
|
template <typename BinaryMutexT>
|
|
void wait(const MutexLock<BinaryMutexT> &p_lock) const {}
|
|
void notify_one() const {}
|
|
void notify_all() const {}
|
|
};
|
|
|
|
#endif // THREADS_ENABLED
|
|
|
|
#endif // CONDITION_VARIABLE_H
|