godot/core/os/rw_lock.h

118 lines
3.8 KiB
C++

/**************************************************************************/
/* rw_lock.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 RW_LOCK_H
#define RW_LOCK_H
#include "core/error_list.h"
#if !defined(NO_THREADS)
#include "core/typedefs.h"
#include <shared_mutex>
class RWLock {
mutable std::shared_timed_mutex mutex;
public:
// Lock the RWLock, block if locked by someone else.
_ALWAYS_INLINE_ void read_lock() const {
mutex.lock_shared();
}
// Unlock the RWLock, let other threads continue.
_ALWAYS_INLINE_ void read_unlock() const {
mutex.unlock_shared();
}
// Attempt to lock the RWLock for reading. True on success, false means it can't lock.
_ALWAYS_INLINE_ Error read_try_lock() const {
return mutex.try_lock_shared() ? OK : ERR_BUSY;
}
// Lock the RWLock, block if locked by someone else.
_ALWAYS_INLINE_ void write_lock() {
mutex.lock();
}
// Unlock the RWLock, let other threads continue.
_ALWAYS_INLINE_ void write_unlock() {
mutex.unlock();
}
// Attempt to lock the RWLock for writing. True on success, false means it can't lock.
_ALWAYS_INLINE_ Error write_try_lock() {
return mutex.try_lock() ? OK : ERR_BUSY;
}
};
#else
class RWLock {
public:
void read_lock() const {}
void read_unlock() const {}
Error read_try_lock() const { return OK; }
void write_lock() {}
void write_unlock() {}
Error write_try_lock() { return OK; }
};
#endif
class RWLockRead {
const RWLock &lock;
public:
_ALWAYS_INLINE_ RWLockRead(const RWLock &p_lock) :
lock(p_lock) {
lock.read_lock();
}
_ALWAYS_INLINE_ ~RWLockRead() {
lock.read_unlock();
}
};
class RWLockWrite {
RWLock &lock;
public:
_ALWAYS_INLINE_ RWLockWrite(RWLock &p_lock) :
lock(p_lock) {
lock.write_lock();
}
_ALWAYS_INLINE_ ~RWLockWrite() {
lock.write_unlock();
}
};
#endif // RW_LOCK_H