pthread

pkill 可以单独向某一个线程发信号：

两个线程都注册了SIGUSR1信号，但只有线程tid1收到该信号

#include "apue.h"
#include <pthread.h>

#define LOGI(format,...) printf("function: %s",format,__FUNCTION__, __VA_ARGS__)

void sig_handle(int signo)
{
    printf("%s:tid: (0x%lx) signo:%d
",__FUNCTION__, (unsigned long)pthread_self(),signo);
    pthread_exit((void*)3);
}
void *
thr_fn1(void *arg)
{
        signal(SIGUSR1,sig_handle);
        pid_t        pid;
    pthread_t    tid;

    pid = getpid();
    tid = pthread_self();
                
    printf("thread 1 start
");
        printf("pid %lu tid %lu (0x%lx)
", (unsigned long)pid,
      (unsigned long)tid, (unsigned long)tid);
        while(1);
        printf("thread 1 end
");
    return((void *)1);
}

void sig_handle2(int signo)
{
    printf("%s: tid: (0x%lx) signo:%d
", __FUNCTION__, (unsigned long)pthread_self(),signo);
    pthread_exit((void*)20);
}

void *
thr_fn2(void *arg)
{
        signal(SIGUSR1,sig_handle2);  
     pid_t        pid;
    pthread_t    tid;

    pid = getpid();
    tid = pthread_self();
    printf("thread 2 start
");
    printf("pid %lu tid %lu (0x%lx)
", (unsigned long)pid,
      (unsigned long)tid, (unsigned long)tid);
        sleep(12);
    printf("thread 2 end
");
    pthread_exit((void *)2);
}

int
main(void)
{
    int            err;
    pthread_t    tid1, tid2;
    void        *tret;

    err = pthread_create(&tid1, NULL, thr_fn1, NULL);
    if (err != 0)
        err_exit(err, "can't create thread 1");
    err = pthread_create(&tid2, NULL, thr_fn2, NULL);
    if (err != 0)
        err_exit(err, "can't create thread 2");
    
        sleep(2);

        pthread_kill(tid1,SIGUSR1);

        err = pthread_join(tid1, &tret);
    if (err != 0)
        err_exit(err, "can't join with thread 2");
    printf("thread 1 exit code %ld
", (long)tret);
 
        err = pthread_join(tid2, &tret);
    if (err != 0)
        err_exit(err, "can't join with thread 1");
    printf("thread 2 exit code %ld
", (long)tret);
    
    
    exit(0);
}

运行结果：

w00367381@ubuntu:~/apue.3e/threads$ ./exitstatus 
thread 2 start
pid 3651 tid 140564637652736 (0x7fd7c14b9700)
thread 1 start
pid 3651 tid 140564646045440 (0x7fd7c1cba700)
sig_handle:tid: (0x7fd7c1cba700) signo:10
thread 1 exit code 3
thread 2 end
thread 2 exit code 2