停止计时器时释放计时器块中使用但已分配的内存

发布于 2024-12-28 11:28:34 字数 1139 浏览 1 评论 0原文

我声明一个计时器，用一个块指定其代码（以便每 x 秒执行此代码）。

我希望计时器在用户点击按钮时启动，因此我在 IBAction 函数内创建并恢复计时器。

最后，这就是问题所在，因为块中管理的数据始终具有相同的大小，为了避免每次计时器触发时分配和释放内存，我将内存分配为块外的 __block 指针，但在块内函数（不能在本地范围之外声明它们）。

一切正常，但我想用另一个按钮停止并重新启动计时器几次，那么如何释放函数中分配的内存呢？我想在每次点击“开始按钮”时分配它，而不是每次计时器触发时分配它，并在点击“停止按钮”时释放它。这个代码结构可以吗？ ¿做我想做的事的最好方法是什么？

这是代码：

 dispatch_source_t creaTimer(uint64_t interval,uint64_t leeway, dispatch_queue_t queue,                                                          dispatch_block_t block){

 dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,0,0,queue);    

 if (timer)
  {
     dispatch_source_set_timer(timer, dispatch_walltime(NULL, 0), interval, leeway);
     dispatch_source_set_event_handler(timer, block);
  }
  return timer;
}


-(IBAction) begin{

   __block double *array;
   array = (double*) malloc (512);

   timer = creaTimer(5ull * NSEC_PER_SEC, 0, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH,0)
                  ,^{ 
                      //it uses the space allocated in *array;
                    });    

   dispatch_resume(timer); 

}

原文

I am declaring a timer specifying its code with a block (in order to executing this code every x seconds).

I want the timer to start when the user taps a button, so I create and resume the timer inside a function which is an IBAction.

Finally, and this is the problem, as the data managed in the block have always the same size, in order to avoiding allocating and freeing memory each time the timer fires, I allocate the memory as __block pointers out of the block, but inside the function (they can't be declared out of this local scope).

Everything works fine, but I want, with another button, to stop and restart the timer several times, so ¿how could I free the memory allocated in the function?
I want to allocate it each time the "Begin Button" is tapped, not each time the timer fires, and free it when the "Stop Button" is tapped.
¿Is it possible with this code structure? ¿What is the best way to do what I want?

This is the code:

 dispatch_source_t creaTimer(uint64_t interval,uint64_t leeway, dispatch_queue_t queue,                                                          dispatch_block_t block){

 dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER,0,0,queue);    

 if (timer)
  {
     dispatch_source_set_timer(timer, dispatch_walltime(NULL, 0), interval, leeway);
     dispatch_source_set_event_handler(timer, block);
  }
  return timer;
}


-(IBAction) begin{

   __block double *array;
   array = (double*) malloc (512);

   timer = creaTimer(5ull * NSEC_PER_SEC, 0, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH,0)
                  ,^{ 
                      //it uses the space allocated in *array;
                    });    

   dispatch_resume(timer); 

}

分享到QQ

分享到微博