如何从主线程唤醒睡眠线程? [英] How to wake up a sleeping thread from the main Thread?

问题描述

我有一个捕获程序，该程序除了捕获数据并将其写入文件外，还会打印一些统计信息.该功能可打印统计信息

I have a capture program which in addition do capturing data and writing it into a file also prints some statistics.The function that prints the statistics

static void report(void)
{
         /*Print statistics*/
}

大约每秒钟都会使用一个警报来每秒调用一次，因此该程序就像

is called roughly every second using an ALARM that expires every second.So The program is like

void capture_program()
{
       pthread_t report_thread

            while()
            {
                     if(pthread_create(&report_thread,NULL,report,NULL)){
                            fprintf(stderr,"Error creating reporting thread! \n");
                     }

                     /*
                        Capturing code
                        --------------
                        --------------
                      */
                      if(doreport)
                             /*wakeup the sleeping thread.*/

            }
}

void *report(void *param)
{
       //access some register from hardware
       //sleep for a second 

}

计时器到期将设置doreport标志.如果设置了此标志，则会调用report()清除该标志.

The expiry of the timer sets the doreport flag.If this flag is set report() is called which clears the flag.

当计时器在主线程中关闭时，如何唤醒睡眠线程(运行report())?

How do I wake up the sleeping thread (that runs the report()) when the timer goes off in the main thread?

推荐答案

当 计时器在主线程中关闭?

How do I wake up the sleeping thread (that runs the report()) when the timer goes off in the main thread?

我认为条件变量是您要寻找的机制.在条件变量上具有report-thread块，并且每当您要唤醒报告线程时，主线程就会向条件变量发出信号(请参阅链接以获取更多详细说明).

I think a condition variable is the mechanism you are looking for. Have the report-thread block on the condition variable, and the main thread signal the condition variable whenever you want the report-thread to wake up (see the link for more detailed instructions).

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