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, 0);
    
    dispatch_source_t timer = [self.timerContainer objectForKey:name];
    if (!timer) {
        timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, 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