bolts_performance_tests.m

- (void)testContinueWithBlockOnSerialQueue {
  // Arrange.
  XCTestExpectation *expectation = [self expectationWithDescription:@""];
  expectation.expectedFulfillmentCount = FBLPromisePerformanceTestIterationCount;
  dispatch_queue_t queue = dispatch_queue_create(
      __FUNCTION__,
      dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_USER_INITIATED, 0));
  dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
  BFExecutor *executor = [BFExecutor executorWithDispatchQueue:queue];

  // Act.
  dispatch_async(dispatch_get_main_queue(), ^{
    uint64_t time = dispatch_benchmark(FBLPromisePerformanceTestIterationCount, ^{
      [[BFTask taskWithResult:@YES] continueWithExecutor:executor withBlock:^id(BFTask *task) {
        dispatch_semaphore_signal(semaphore);
        [expectation fulfill];
        return task.result;
      }];
      dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    });
    FBLLogAverageTime(time);
  });

  // Assert.
  [self waitForExpectationsWithTimeout:10 handler:nil];
}

- (void)testDoubleContinueWithBlockOnSerialQueue {
  // Arrange.
  XCTestExpectation *expectation = [self expectationWithDescription:@""];
  expectation.expectedFulfillmentCount = FBLPromisePerformanceTestIterationCount;
  dispatch_queue_t queue = dispatch_queue_create(
      __FUNCTION__,
      dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_USER_INITIATED, 0));
  dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
  BFExecutor *executor = [BFExecutor executorWithDispatchQueue:queue];

  // Act.
  dispatch_async(dispatch_get_main_queue(), ^{
    uint64_t time = dispatch_benchmark(FBLPromisePerformanceTestIterationCount, ^{
      [[[BFTask taskWithResult:@YES] continueWithExecutor:executor
                                                withBlock:^id(BFTask *task) {
                                                  return task.result;
                                                }]
          continueWithExecutor:executor
                     withBlock:^id(BFTask *task) {
                       dispatch_semaphore_signal(semaphore);
                       [expectation fulfill];
                       return task.result;
                     }];
      dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    });
    FBLLogAverageTime(time);
  });

  // Assert.
  [self waitForExpectationsWithTimeout:10 handler:nil];
}

- (void)testTripleContinueWithBlockOnSerialQueue {
  // Arrange.
  XCTestExpectation *expectation = [self expectationWithDescription:@""];
  expectation.expectedFulfillmentCount = FBLPromisePerformanceTestIterationCount;
  dispatch_queue_t queue = dispatch_queue_create(
      __FUNCTION__,
      dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_USER_INITIATED, 0));
  dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
  BFExecutor *executor = [BFExecutor executorWithDispatchQueue:queue];

  // Act.
  dispatch_async(dispatch_get_main_queue(), ^{
    uint64_t time = dispatch_benchmark(FBLPromisePerformanceTestIterationCount, ^{
      [[[[BFTask taskWithResult:@YES] continueWithExecutor:executor
                                                 withBlock:^id(BFTask *task) {
                                                   return task.result;
                                                 }] continueWithExecutor:executor
                                                               withBlock:^id(BFTask *task) {
                                                                 return task.result;
                                                               }]
          continueWithExecutor:executor
                     withBlock:^id(BFTask *task) {
                       dispatch_semaphore_signal(semaphore);
                       [expectation fulfill];
                       return task.result;
                     }];
      dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    });
    FBLLogAverageTime(time);
  });

  // Assert.
  [self waitForExpectationsWithTimeout:10 handler:nil];
}

- (void)testContinueWithBlockOnConcurrentQueue {
  // Arrange.
  dispatch_queue_t queue = dispatch_queue_create(
      __FUNCTION__, dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_CONCURRENT,
                                                            QOS_CLASS_USER_INITIATED, 0));
  dispatch_group_t group = dispatch_group_create();
  NSMutableArray<BFTaskCompletionSource *> *sources =
      [NSMutableArray arrayWithCapacity:FBLPromisePerformanceTestIterationCount];
  BFExecutor *executor = [BFExecutor executorWithDispatchQueue:queue];
  for (NSUInteger i = 0; i < FBLPromisePerformanceTestIterationCount; ++i) {
    dispatch_group_enter(group);
    BFTaskCompletionSource *source = [BFTaskCompletionSource taskCompletionSource];
    [source.task continueWithExecutor:executor
                            withBlock:^id(BFTask *task) {
                              dispatch_group_leave(group);
                              return task.result;
                            }];
    [sources addObject:source];
  }
  NSDate *startDate = [NSDate date];

  // Act.
  [sources makeObjectsPerformSelector:@selector(setResult:) withObject:@YES];

  // Assert.
  XCTAssert(dispatch_group_wait(group, dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC)) == 0,
            @"Asynchronous wait failed: Exceeded timeout of 1 second.");
  NSDate *endDate = [NSDate date];
  FBLLogTotalTime([endDate timeIntervalSinceDate:startDate]);
}