keychain/ckks/CKKSCondition.h

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #import <Foundation/Foundation.h>
  25 #import <dispatch/dispatch.h>
  26
  27 NS_ASSUME_NONNULL_BEGIN
  28
  29 /*
  30  * CKKSCondition is for implementing one-shot condition variables,
  31  * based on libdispatch semaphores (which might use condition variables underneath).
  32  */
  33
  34 @interface CKKSCondition : NSObject
  35
  36 - (instancetype)init;
  37
  38 // Fulfilling this condition will also fulfill the chained condition.
  39 // Fulfilling the chained condition will do nothing to this condition.
  40 - (instancetype)initToChain:(CKKSCondition* _Nullable)chain;
  41
  42 /* Fulfills the condition. Can only be called once per CKKSCondition. */
  43 - (void)fulfill;
  44
  45 /* Wait for the the condition to be fulfilled. The returned result behaves exactly like
  46    libdispatch's dispatch_semaphore_wait. */
  47 - (long)wait:(uint64_t)timeout;
  48
  49 @end
  50
  51 NS_ASSUME_NONNULL_END