GCDTimer

 #import <Foundation/Foundation.h>

 @interface JKTimerManager : NSObject

 + (instancetype)sharedTimerManager;

 /**
  *  启动一个timer，默认精度为0.1秒
  *
  *  @param name          timer的名称，作为唯一标识
  *  @param timerInterval 执行的时间间隔
  *  @param queue         timer将被放入的队列，也就是最终action执行的队列。传入nil将自动放到一个子线程队列中
  *  @param repeats       timer是否循环调用
  *  @param action        时间间隔到点时执行的block
  */
 - (void)scheduledDispatchTimerWithName:(NSString *)name timeInterval:(NSTimeInterval)timerInterval queue:(dispatch_queue_t)queue repeats:(BOOL)repeats action:(dispatch_block_t)action;

 /**
  *  撤销某个timer
  *
  *  @param name timer的名称，唯一标识
  */
 - (void)cancelTimerWithName:(NSString *)name;

 /**
  *  撤销所有timer
  */
 - (void)cancelAllTimer;

 @end

 #import "JKTimerManager.h"

 @interface JKTimerManager ()

 @property (nonatomic,strong) NSMutableDictionary *timerContainer;

 @end

 @implementation JKTimerManager

 + (instancetype)sharedTimerManager {
     static JKTimerManager *manager = nil;
     static dispatch_once_t token;
     dispatch_once(&token, ^{
         manager = [[JKTimerManager alloc] init];
     });

     return manager;
 }

 - (NSMutableDictionary *)timerContainer {
     if (!_timerContainer) {
         _timerContainer = [NSMutableDictionary dictionary];
     }
     return _timerContainer;
 }

 - (void)scheduledDispatchTimerWithName:(NSString *)name
                           timeInterval:(NSTimeInterval)timerInterval
                                  queue:(dispatch_queue_t)queue
                                repeats:(BOOL)repeats
                                 action:(dispatch_block_t)action {
     if (name == nil)
         return;
     if (queue == nil)
         queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, );

     dispatch_source_t timer = [self.timerContainer objectForKey:name];
     if (!timer) {
         timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, , , queue);
         dispatch_resume(timer);
         [self.timerContainer setObject:timer forKey:name];
     }

     dispatch_source_set_timer(timer, dispatch_time(DISPATCH_TIME_NOW, timerInterval * NSEC_PER_SEC), timerInterval * NSEC_PER_SEC, 0.1 * NSEC_PER_SEC);
     __weak typeof(self) weakSelf = self;
     dispatch_source_set_event_handler(timer, ^{
         if (action) {
             action();
             if (!repeats) {
                 [weakSelf cancelTimerWithName:name];
             }
         }
     });

 }

 - (void)cancelTimerWithName:(NSString *)name {
     dispatch_source_t timer = [self.timerContainer objectForKey:name];
     if (!timer) {
         return;
     }

     [self.timerContainer removeObjectForKey:name];
     dispatch_source_cancel(timer);
 }

 - (void)cancelAllTimer {
     for (NSString *name in self.timerContainer.allKeys) {
         [self cancelTimerWithName:name];
     }
 }

 @end