mirror of
https://github.com/TextureGroup/Texture.git
synced 2026-04-07 19:17:39 +00:00
Adlai Holler
d688ce3d20
- Use relaxed memory since we don't need acquire/release. This'll make it faster. - Add a couple assertions and organize the code better. - In contested case, just lock instead of tryLock-fail-lock. - In recursive case, do not tryLock. Just notice it's recursive and be done. - In uncontested case, just lock instead of tryLock. PRESUBMIT=passed BUG=137413265 R=maicki CC=maxwang,rexhu,wiseoldduck,yt-elements-eng+cl REQUIRED_REVIEW=1 DELTA=50 (14 added, 13 deleted, 23 changed) DELTA_BY_EXTENSION=h=1,mm=36 OCL=278419008 P4 change: 278454084
48 lines
1.3 KiB
Objective-C
48 lines
1.3 KiB
Objective-C
//
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// ASRecursiveUnfairLock.h
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// Texture
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//
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// Copyright (c) Pinterest, Inc. All rights reserved.
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// Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
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//
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#import <Foundation/Foundation.h>
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#import <AsyncDisplayKit/ASBaseDefines.h>
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#import <pthread/pthread.h>
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#import <os/lock.h>
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// Note: We don't use ATOMIC_VAR_INIT here because C++ compilers don't like it,
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// and it literally does absolutely nothing.
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#define AS_RECURSIVE_UNFAIR_LOCK_INIT ((ASRecursiveUnfairLock){ OS_UNFAIR_LOCK_INIT, NULL, 0})
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NS_ASSUME_NONNULL_BEGIN
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OS_UNFAIR_LOCK_AVAILABILITY
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typedef struct {
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os_unfair_lock _lock OS_UNFAIR_LOCK_AVAILABILITY;
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_Atomic(pthread_t) _thread;
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int _count; // Protected by lock
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} ASRecursiveUnfairLock;
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/**
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* Lock, blocking if needed.
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*/
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AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
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void ASRecursiveUnfairLockLock(ASRecursiveUnfairLock *l);
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/**
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* Try to lock without blocking. Returns whether we took the lock.
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*/
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AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
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BOOL ASRecursiveUnfairLockTryLock(ASRecursiveUnfairLock *l);
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/**
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* Unlock. Calling this on a thread that does not own
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* the lock will result in an assertion failure, and undefined
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* behavior if foundation assertions are disabled.
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*/
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AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
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void ASRecursiveUnfairLockUnlock(ASRecursiveUnfairLock *l);
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NS_ASSUME_NONNULL_END
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