线程

代码

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

void *thr_fn1(void *arg)
{
    printf("thread 1 returning\n");
    return ((void*)1);
}

void *thr_fn2(void *arg)
{
    printf("thread 2 returning\n");
    return ((void *)2);
}

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

    err=pthread_create(&tid1,NULL,thr_fn1,NULL);
    err=pthread_create(&tid2,NULL,thr_fn2,NULL);
    err=pthread_join(tid1,&tret);
    printf("thread 1 exti code %d\n",(int)tret);
    err=pthread_join(tid2,&tret);
    printf("thread 2 exit code %d\n",(int)tret);
    return 0;
}

代码

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

int quitflag;
sigset_t mask;
pthread_mutex_t lock=PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t wait=PTHREAD_COND_INITIALIZER;

void *thr_fn(void *arg)
{
    int err,signo;
    while(1)
    {
        err=sigwait(&mask,&signo);
        switch(signo)
        {
            case SIGINT:
                printf("\nSIGINT\n");
                break;
            case SIGQUIT:
                pthread_mutex_lock(&lock);
                quitflag=1;
                pthread_mutex_unlock(&lock);
                pthread_cond_signal(&wait);
                exit(0);
            default:
                printf("unexpected signal %d\n",signo);
                exit(1);
        }
    }
}

int main(void)
{
    int err;
    sigset_t oldmask;
    pthread_t tid;
    sigemptyset(&mask);
    sigaddset(&mask,SIGINT);
    sigaddset(&mask,SIGQUIT);
    if((err=pthread_sigmask(SIG_BLOCK,&mask,&oldmask)) != 0)
    {
        printf("SIG_BLOCK error\n");
        return 1;
    }

    err=pthread_create(&tid,NULL,thr_fn,0);
    pthread_mutex_lock(&lock);
    while(quitflag==0)
        pthread_cond_wait(&wait,&lock);
    pthread_mutex_unlock(&lock);
    quitflag=0;
    if(sigprocmask(SIG_SETMASK,&oldmask,NULL)<0)
    {
        printf("SIG_SETMASK error\n");
    }
}

代码

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

void cleanup(void *arg)
{
    printf("cleanup:%s\n",(char *)arg);
}

void *thr_fn1(void *arg)
{
    printf("thread 1 start\n");
    pthread_cleanup_push(cleanup,(void*)"thread 1 first handler");
    pthread_cleanup_push(cleanup,(void*)"thread 1 second handler");
    printf("thread 1 push complete\n");
    if(arg)
        return ((void *)1);
    pthread_cleanup_pop(0);
    pthread_cleanup_pop(0);
    return ((void *)1);
}

void *thr_fn2(void *arg)
{
    printf("thread 2 start\n");
    pthread_cleanup_push(cleanup,(void*)"thread 2 first handler");
    pthread_cleanup_push(cleanup,(void*)"thread 2 second handler");
    printf("thread 2 push complete\n");
    if(arg)
        pthread_exit((void*)2);
    pthread_cleanup_pop(0);
    pthread_cleanup_pop(0);
    pthread_exit((void *)2);
}

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

    err=pthread_create(&tid1,NULL,thr_fn1,(void*)1);
    err=pthread_create(&tid2,NULL,thr_fn2,(void*)2);
    err=pthread_join(tid1,&tret);
    printf("thread 1 exit code %d\n",(int)tret);
    err=pthread_join(tid2,&tret);
    printf("thread 2 exit code %d\n",(int)tret);
    return 0;
}

代码

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

pthread_mutex_t lock1=PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t lock2=PTHREAD_MUTEX_INITIALIZER;

void prepare(void)
{
    printf("preparing locks...\n");
    pthread_mutex_lock(&lock1);
    pthread_mutex_lock(&lock2);
}

void parent(void)
{
    printf("parent unlock locks...\n");
    pthread_mutex_unlock(&lock1);
    pthread_mutex_unlock(&lock2);
}

void child(void)
{
    printf("child unlocking locks...\n");
    pthread_mutex_unlock(&lock1);
    pthread_mutex_unlock(&lock2);
}

void *thr_fn(void *arg)
{
    printf("thread started...\n");
    pause();
    return 0;
}

int main(void)
{
    int err;
    pid_t pid;
    pthread_t tid;

    err=pthread_atfork(prepare,parent,child);
    pthread_create(&tid,NULL,thr_fn,0);

    sleep(2);
    printf("parent about to fork...\n");
    pid=fork();
    if(pid==0)
        printf("child return form fork\n");
    else
        printf("parent returned from fork\n");
    return 0;
}