Dispatch Queue即 执行处理的等待队列。
存在两种Dispatch Queue,即
Serial Dispatch Queue 等待现在的处理
Concurrent Dispatch Queue 不等待现在的处理
1.dispatch_queue_create("com.gcd.test",Null)
创建Dispatch queue,
DISPATCH_QUEUE_SERIAL
DISPATCH_QUEUE_CONCURRENT
- (void)tsGCD
{
dispatch_queue_t queue = dispatch_queue_create("com.gcd.test", DISPATCH_QUEUE_CONCURRENT);
NSMutableArray *array = [[NSMutableArray alloc]init];
for (int i = 0; i < 100000; i++) {
dispatch_async(queue, ^{
[array addObject:[NSNumber numberWithInt:i]];
});
}
NSLog(@"done");
}
当为DISPATCH_QUEUE_CONCURRENT,数组AddObject非线程安全，同时访问容易引起问题，
gcdTest(2484,0x11395b000) malloc: *** error for object 0x7f9c8b802e00: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
当为DISPATCH_QUEUE_SERIAL时，线程有序进行，不会引起并发问题。