标签：style blog class code java tar
1.NSOperation
对于NSOperation，In OS X v10.6 and later, operation queues ignore the value returned by this method and always start operations on a separate thread.就是一个operation就新建一个thread。但是，这个说法是针对 NSOperationQueue *testQueue = [[NSOperationQueue alloc] init]; 这种queue来说的，如果向mainQueue中加入operation，那么这些operation一定会执行在main thread中，而且由于都在main thread中执行，在operation一次runloop action 完成前，不会去理会其他的operation，也就是说，如果向mainqueue加入多个operation，那么他们会串行执行。
下面看一段例子
NSOperationQueue *mainQueue = [NSOperationQueue mainQueue]; [mainQueue addOperationWithBlock:^{ for(int i=0;i<200;i++) { NSLog(@"i is %d",i); } }]; [mainQueue addOperationWithBlock:^{ for(int m=0;m<200;m++) { NSLog(@"m is %d",m); } }];
以下是它的部分输出
2014-05-05 10:21:55.000 OperationQueueTest[9876:60b] i is 194 2014-05-05 10:21:55.001 OperationQueueTest[9876:60b] i is 195 2014-05-05 10:21:55.001 OperationQueueTest[9876:60b] i is 196 2014-05-05 10:21:55.002 OperationQueueTest[9876:60b] i is 197 2014-05-05 10:21:55.002 OperationQueueTest[9876:60b] i is 198 2014-05-05 10:21:55.003 OperationQueueTest[9876:60b] i is 199 2014-05-05 10:21:55.004 OperationQueueTest[9876:60b] m is 0 2014-05-05 10:21:55.004 OperationQueueTest[9876:60b] m is 1 2014-05-05 10:21:55.004 OperationQueueTest[9876:60b] m is 2 2014-05-05 10:21:55.005 OperationQueueTest[9876:60b] m is 3 2014-05-05 10:21:55.005 OperationQueueTest[9876:60b] m is 4 2014-05-05 10:21:55.006 OperationQueueTest[9876:60b] m is 5 2014-05-05 10:21:55.006 OperationQueueTest[9876:60b] m is 6 2014-05-05 10:21:55.007 OperationQueueTest[9876:60b] m is 7 2014-05-05 10:21:55.017 OperationQueueTest[9876:60b] m is 8 2014-05-05 10:21:55.017 OperationQueueTest[9876:60b] m is 9 2014-05-05 10:21:55.018 OperationQueueTest[9876:60b] m is 10 2014-05-05 10:21:55.018 OperationQueueTest[9876:60b] m is 11 2014-05-05 10:21:55.019 OperationQueueTest[9876:60b] m is 12
可以看出，加入mainQueue后，两个operation是顺序执行的。
再看下面一段代码
NSOperationQueue *testQueue = [[NSOperationQueue alloc] init]; [testQueue addOperationWithBlock:^{ NSLog(@"111111 thread is %@",[NSThread currentThread]); for(int i=0;i<200;i++) { NSLog(@"i is %d",i); } }]; [testQueue addOperationWithBlock:^{ NSLog(@"222222 thread is %@",[NSThread currentThread]); for(int m=0;m<200;m++) { NSLog(@"m is %d",m); } }];
下面是它的部分输出
2014-05-05 10:27:59.566 OperationQueueTest[9898:1303] i is 186 2014-05-05 10:27:59.566 OperationQueueTest[9898:1303] i is 187 2014-05-05 10:27:59.564 OperationQueueTest[9898:3507] m is 183 2014-05-05 10:27:59.566 OperationQueueTest[9898:1303] i is 188 2014-05-05 10:27:59.566 OperationQueueTest[9898:1303] i is 189 2014-05-05 10:27:59.567 OperationQueueTest[9898:1303] i is 190 2014-05-05 10:27:59.567 OperationQueueTest[9898:1303] i is 191 2014-05-05 10:27:59.568 OperationQueueTest[9898:1303] i is 192 2014-05-05 10:27:59.568 OperationQueueTest[9898:1303] i is 193 2014-05-05 10:27:59.568 OperationQueueTest[9898:1303] i is 194 2014-05-05 10:27:59.569 OperationQueueTest[9898:1303] i is 195 2014-05-05 10:27:59.569 OperationQueueTest[9898:1303] i is 196 2014-05-05 10:27:59.567 OperationQueueTest[9898:3507] m is 184 2014-05-05 10:27:59.570 OperationQueueTest[9898:3507] m is 185 2014-05-05 10:27:59.569 OperationQueueTest[9898:1303] i is 197 2014-05-05 10:27:59.571 OperationQueueTest[9898:1303] i is 198 2014-05-05 10:27:59.572 OperationQueueTest[9898:1303] i is 199 2014-05-05 10:27:59.571 OperationQueueTest[9898:3507] m is 186 2014-05-05 10:27:59.573 OperationQueueTest[9898:3507] m is 187 2014-05-05 10:27:59.573 OperationQueueTest[9898:3507] m is 188 2014-05-05 10:27:59.574 OperationQueueTest[9898:3507] m is 189 2014-05-05 10:27:59.575 OperationQueueTest[9898:3507] m is 190 2014-05-05 10:27:59.575 OperationQueueTest[9898:3507] m is 191 2014-05-05 10:27:59.576 OperationQueueTest[9898:3507] m is 192 2014-05-05 10:27:59.577 OperationQueueTest[9898:3507] m is 193
可以看出Operation是同时在运行的，它们运行在2个不同的thread中！
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标签：style blog class code java tar
原文地址：http://www.cnblogs.com/breezemist/p/3708638.html
