Linux中，C：终止multple线程在几秒钟后（计时器？） [英] Linux, C: terminate multple threads after some seconds (timer?)

问题描述

的Linux，C。
我创建多个线程运行的工作负载，我想这些信号线程停止/指定秒/次出来后终止。
我如何用C实现这一点？

Linux, C. I created multiple threads to run workloads, and I want to signal those threads to stop/terminate after a specified seconds/time out. How do I implement this by C?

void *do_function(void *ptr)
{
    //calculating, dothe workload here;
}

int run(struct calculate_node *node)
{
    pthread_t threads[MAX_NUM_THREADS];
    for (t = 0; t < node->max_threads; t++) {
        rc = pthread_create(&threads[t], NULL, do_function, (void*)node);
        if(rc) return -1;
    }

    //how do I create timer here to fire to signal those threads to exit after specified seconds?


    for (t = 0; t < node->max_threads; t++) {
        pthread_join(threads[t], NULL);
    }
    free(threads);
}

谢谢！

推荐答案

不知道是否有创建一个定时事件可移植的方法，但如果主没有还有别的事做，它可以简单地调用睡眠浪费时间。

Not sure if there's a portable way to create a timer event, but if main doesn't have anything else to do, it could simply call sleep to waste time.

至于信号线程，你有两个选择：合作或者终止非合作终止。随着合作终止后，线程必须定期检查标志，看它是否应该终止。随着非合作终止后，你叫 pthread_cancel可以来结束线程。 （有关可用于优雅地结束线程附加功能信息，请参阅 pthread_cancel可以的手册页。）

As for signaling the threads, you have two choices: cooperative termination or non-cooperative termination. With cooperative termination, the thread must periodically check a flag to see if it's supposed to terminate. With non-cooperative termination, you call pthread_cancel to end the thread. (See the man page for pthread_cancel for information about additional functions that can be used to gracefully end the thread.)

我觉得合作的终止更容易实现。这里有一个例子：

I find cooperative termination easier to implement. Here's an example:

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>

static int QuitFlag = 0;
static pthread_mutex_t QuitMutex = PTHREAD_MUTEX_INITIALIZER;

void setQuitFlag( void )
{
    pthread_mutex_lock( &QuitMutex );
    QuitFlag = 1;
    pthread_mutex_unlock( &QuitMutex );
}

int shouldQuit( void )
{
    int temp;

    pthread_mutex_lock( &QuitMutex );
    temp = QuitFlag;
    pthread_mutex_unlock( &QuitMutex );

    return temp;
}

void *somefunc( void *arg )
{
    while ( !shouldQuit() )
    {
        fprintf( stderr, "still running...\n");
        sleep( 2 );
    }

    fprintf( stderr, "quitting now...\n" );
    return( NULL );
}

int main( void )
{
    pthread_t threadID;

    if ( pthread_create( &threadID, NULL, somefunc, NULL) != 0 )
    {
        perror( "create" );
        return 1;
    }

    sleep( 5 );
    setQuitFlag();
    pthread_join( threadID, NULL );
    fprintf( stderr, "end of main\n" );
}

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