Swiftgram/submodules/AsyncDisplayKit/Source/ASRecursiveUnfairLock.h
2019-11-11 16:39:27 +04:00

48 lines
1.4 KiB
Objective-C

//
// ASRecursiveUnfairLock.h
// Texture
//
// Copyright (c) Pinterest, Inc. All rights reserved.
// Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
//
#import <Foundation/Foundation.h>
#import <AsyncDisplayKit/ASBaseDefines.h>
#import <pthread/pthread.h>
#import <os/lock.h>
// Note: We don't use ATOMIC_VAR_INIT here because C++ compilers don't like it,
// and it literally does absolutely nothing.
#define AS_RECURSIVE_UNFAIR_LOCK_INIT ((ASRecursiveUnfairLock){ OS_UNFAIR_LOCK_INIT, NULL, 0})
NS_ASSUME_NONNULL_BEGIN
OS_UNFAIR_LOCK_AVAILABILITY
typedef struct {
os_unfair_lock _lock OS_UNFAIR_LOCK_AVAILABILITY;
_Atomic(pthread_t) _thread; // Write-protected by lock
int _count; // Protected by lock
} ASRecursiveUnfairLock;
/**
* Lock, blocking if needed.
*/
AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
void ASRecursiveUnfairLockLock(ASRecursiveUnfairLock *l);
/**
* Try to lock without blocking. Returns whether we took the lock.
*/
AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
BOOL ASRecursiveUnfairLockTryLock(ASRecursiveUnfairLock *l);
/**
* Unlock. Calling this on a thread that does not own
* the lock will result in an assertion failure, and undefined
* behavior if foundation assertions are disabled.
*/
AS_EXTERN OS_UNFAIR_LOCK_AVAILABILITY
void ASRecursiveUnfairLockUnlock(ASRecursiveUnfairLock *l);
NS_ASSUME_NONNULL_END