how to use thread

最新推荐文章于 2024-07-04 17:43:56 发布

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#thread #c

本文探讨了在程序中使用线程显示工作进度时遇到的同步问题。原本期望线程能够与主程序并行运行，但实际上线程仅短暂运行便被主程序抢占资源。为解决该问题，作者将工作负载拆分为独立线程，实现了真正的并行执行。

Just got a problem which wasted me some time. The problem is just:

Regarding a procedure A, which mainly implements a work B, I want to use a progress bar to show the progress of the work of B, because A need to run a lot of sub functions and take a lot of time. So inside A, right before executing the code directly related to B's work, I insert a few code to create a thread C to display the progress of B, and after the code of creating the thread C, I continue to put A's original code.

I thought C will work with A's code at the same time(sychronization), since it is thread. However the result is, although thread C starts to work, but just for one second, then A's code takes over CPU until A gets finished, and then B continues. This makes using thread C no sense.

Then I found the reason: because thread C is created inside the code of A, then CPU have more priority for A. It always tries to finish more work of A.

Solution:

I put the code in A related to work B out and make it a separate thread D to do the work. Then in procedure A, I create the thread C at first, and then create thread D (which does the work B). Now these two threads have the same prority, and then their run are sychoronized.