The result of simulator running is different from that of real machine running

- (void)blockOperation

{

NSBlockOperation *op = [NSBlockOperation blockOperationWithBlock:^{

// mainThread

NSLog(@"task1------%@", [NSThread currentThread]);

}];

[op addExecutionBlock:^{

NSLog(@"task2------%@", [NSThread currentThread]);

}];

[op addExecutionBlock:^{

NSLog(@"task3------%@", [NSThread currentThread]);

}];

[op addExecutionBlock:^{

NSLog(@"task4------%@", [NSThread currentThread]);

}];

[op start];

}