8ed259b792
- Based on C++14's `shared_time_mutex` - No more need to allocate-deallocate or check for null - No pointer anymore, just a member variable - Platform-specific implementations no longer needed - Simpler for `NO_THREADS`
117 lines
3.6 KiB
C++
117 lines
3.6 KiB
C++
/*************************************************************************/
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/* rw_lock.h */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* https://godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
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/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#ifndef RW_LOCK_H
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#define RW_LOCK_H
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#include "core/error/error_list.h"
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#if !defined(NO_THREADS)
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#include <shared_mutex>
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class RWLock {
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mutable std::shared_timed_mutex mutex;
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public:
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// Lock the rwlock, block if locked by someone else
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void read_lock() const {
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mutex.lock_shared();
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}
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// Unlock the rwlock, let other threads continue
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void read_unlock() const {
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mutex.unlock_shared();
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}
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// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
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Error read_try_lock() const {
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return mutex.try_lock_shared() ? OK : ERR_BUSY;
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}
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// Lock the rwlock, block if locked by someone else
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void write_lock() {
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mutex.lock();
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}
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// Unlock the rwlock, let other thwrites continue
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void write_unlock() {
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mutex.unlock();
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}
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// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
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Error write_try_lock() {
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return mutex.try_lock() ? OK : ERR_BUSY;
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}
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};
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#else
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class RWLock {
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public:
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void read_lock() const {}
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void read_unlock() const {}
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Error read_try_lock() const { return OK; }
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void write_lock() {}
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void write_unlock() {}
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Error write_try_lock() { return OK; }
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};
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#endif
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class RWLockRead {
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const RWLock &lock;
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public:
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RWLockRead(const RWLock &p_lock) :
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lock(p_lock) {
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lock.read_lock();
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}
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~RWLockRead() {
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lock.read_unlock();
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}
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};
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class RWLockWrite {
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RWLock &lock;
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public:
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RWLockWrite(RWLock &p_lock) :
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lock(p_lock) {
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lock.write_lock();
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}
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~RWLockWrite() {
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lock.write_unlock();
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}
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};
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#endif // RW_LOCK_H
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