- NSTimer依赖于RunLoop，如果RunLoop的任务过于繁重，可能会导致NSTimer不准时；
- GCD的定时器是直接跟系统内核挂钩的。
- (void)test {
// 队列
// dispatch_queue_t queue = dispatch_get_main_queue();
dispatch_queue_t queue = dispatch_queue_create("timer", DISPATCH_QUEUE_SERIAL);
// 创建定时器
dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
// 设置时间
uint64_t start = 2.0; // 2秒后开始执行
uint64_t interval = 1.0; // 每隔1秒执行
dispatch_source_set_timer(timer,
dispatch_time(DISPATCH_TIME_NOW, start * NSEC_PER_SEC),
interval * NSEC_PER_SEC, 0);
dispatch_source_set_event_handler_f(timer, timerFire);
// 启动定时器
dispatch_resume(timer);
self.timer = timer;
}
void timerFire(void *param) {
NSLog(@"timer");
}
