线程、同步异步、队列

dispatch_queue_t _serialQueue = dispatch_queue_create("gao mao a", DISPATCH_QUEUE_SERIAL);
//(两个队列，都是同步的时候，就没什么卵用了，一个队列就够了)
dispatch_queue_t _gaomaoa  = dispatch_queue_create("gao maoss a", DISPATCH_QUEUE_SERIAL);

NSLog(@"wo ca lei ge da ye =======  1  /n");
//同步
dispatch_async(_gaomaoa, ^{
NSLog(@"wo ca lei ge da ye =======  2  /n");
NSLog(@"wo ca lei ge da ye =======  2  /n");
NSLog(@"wo ca lei ge da ye =======  2  /n");
NSLog(@"wo ca lei ge da ye =======  2  /n");
NSLog(@"wo ca lei ge da ye =======  2  /n");
});
//异步
dispatch_sync(_serialQueue, ^{
NSLog(@"wo ca lei ge da ye =======  3  /n");
NSLog(@"wo ca lei ge da ye =======  3  /n");
NSLog(@"wo ca lei ge da ye =======  3  /n");
NSLog(@"wo ca lei ge da ye =======  3  /n");
NSLog(@"wo ca lei ge da ye =======  3  /n");
});

dispatch_sync(_serialQueue, ^{
NSLog(@"wo ca lei ge da ye =======  4  /n");
NSLog(@"wo ca lei ge da ye =======  4  /n");
NSLog(@"wo ca lei ge da ye =======  4  /n");
NSLog(@"wo ca lei ge da ye =======  4  /n");
NSLog(@"wo ca lei ge da ye =======  4  /n");
});

NSLog(@"wo ca lei ge da ye =======  5  /n");

NSLog(@"wo ca lei ge da ye =======  6  /n");