【iOS】【ReactiveCocoa】[RACSignal interval]定时器

//Reactive cocoa: Stop a RACSignal after UIViewController is dealloc
    //启用一个RAC定时器 
    RACSignal *rac_viewWillDisappear = [self rac_signalForSelector:@selector(viewWillDisappear:)];
    [[[RACSignal interval:10 onScheduler:[RACScheduler mainThreadScheduler]] takeUntil:rac_viewWillDisappear] subscribeNext:^(id x) {
        //Do what you need
        NSLog(@"--rac_willDeallocSignal");
    }];

Q：【保留作业】有没有像oc一样的 [_timer fire];//立即执行的方法

【解题过程】【错误代码示范】
/*无效，viewdidiappear时不执行*/
/*无效，completed时也没回调*/
/*没用到，信号dispose*/
/*http://www.cnblogs.com/guoxiaoqian/p/4691035.html
  RAC的坑 [6.rac_willDeallocSignal不会sendNext，只会sendComplete]
  //错误
*/
    //这里要加takeUntil条件限制一下否则当控制器pop后依旧会执行
    [[[RACSignal interval:2 onScheduler:[RACScheduler mainThreadScheduler]] takeUntil:self.rac_willDeallocSignal ] subscribeNext:^(id x) {
        
        NSLog(@"每两秒执行一次");
        
    } completed:^{
        NSLog(@"每两秒执行一次:completed");
    }];
/*
 持保留意见
 https://github.com/SkyHarute/StudyForRAC
*/
    //这里这样写只是为了给大家开拓一种思路,selector的方法可以应需求更改,即当这个方法执行后,产生一个信号告知控制器释放掉这个订阅的信号
    RACSignal * deallocSignal = [self rac_signalForSelector:@selector(viewWillDisappear:)];
    
    [[[[NSNotificationCenter defaultCenter] rac_addObserverForName:@"haha" object:nil] takeUntil:deallocSignal] subscribeNext:^(id x) {
        
        NSLog(@"haha");
        
    }];

                            ^_^ ^.^ ^=^ ^&^ ^!^  

http://stackoverflow.com/questions/27561582/reactive-cocoa-stop-a-racsignal-after-uiviewcontroller-is-dealloc