CKKSCondition.m   [plain text]

/*
* Copyright (c) 2017 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/

#import "keychain/ckks/CKKSCondition.h"

@interface CKKSCondition ()
@property dispatch_semaphore_t semaphore;
@property CKKSCondition* chain;
@end

@implementation CKKSCondition

-(instancetype)init {
return [self initToChain:nil];
}

-(instancetype)initToChain:(CKKSCondition*)chain
{
if((self = [super init])) {
_semaphore = dispatch_semaphore_create(0);
_chain = chain;
}
return self;
}

-(void)fulfill {
dispatch_semaphore_signal(self.semaphore);
[self.chain fulfill];
self.chain = nil; // break the retain, since that condition is filled
}

-(long)wait:(uint64_t)timeout {
long result = dispatch_semaphore_wait(self.semaphore, dispatch_time(DISPATCH_TIME_NOW, timeout));

// If we received a go-ahead from the semaphore, replace the signal
if(0 == result) {
dispatch_semaphore_signal(self.semaphore);
}

return result;
}

@end