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#include int pthread_create(pthread_t *restrict tidp,const pthread_attr_t *restrict attr, void *(*start_rtn)(void),void *restrict arg); Returns: 0 if OK, error number on failure 第一个参数为指向线程标识符的指针。 第二个参数用来设置线程属性。 第三个参数是线程运行函数的起始地址。 第四个参数是运行函数的参数。 当创建线程成功时，函数返回0，若不为0则说明创建线程失败，常见的错误返回代码为EAGAIN和EINVAL。前者表示系统限制创建新的线程，例如线程数目过多了；后者表示第二个参数代表的线程属性值非法. pthread_create的用法:由于pthread库不是Linux系统默认的库，所以在使用pthread_create创建线程时，需要在编译中请加-lpthread参数，eg：gcc -o test -lpthrea test.c 例1: #include "pthread.h" #include "stdio.h" void* thread_test(void* ptr) { while(1) printf("i am pthread\n"); } int main() { pthread_t pid; pthread_create(&pid, NULL, test_thread, NULL); while(1) printf("i am main pthread\n"); return 0; } 例2: #include #include pthread_t id; int ret; void thread_1() { while(1) {printf(“I am thread\n”); sleep(1); } } main() {ret = pthread_create(&id,NULL,(void*)thread_1,NULL); if(ret != 0) printf("Create pthread error!\n"); while(1) { printf(“I am main thread\n”); sleep(2); } } 例3: #include #include #include #include void *thread_function(void *arg); char message[] = "Hello World"; int main() { int res; pthread_t a_thread; void *thread_result; res = pthread_create(&a_thread, NULL, thread_function, (void *)message); if (res != 0) { perror("Thread creation failed"); exit(EXIT_FAILURE); } printf("Waiting for thread to finish...\n"); res = pthread_join(a_thread, &thread_result); //pthread_join 阻塞执行的线程直到某线程结束 if (res != 0) { perror("Thread join failed"); exit(EXIT_FAILURE); } printf("Thread joined, it returned %s\n", (char *)thread_result); printf("Message is now %s\n", message); exit(EXIT_SUCCESS); } void *thread_function(void *arg) { printf("thread_function is running. Argument was %s\n", (char *)arg); sleep(3); strcpy(message, "Bye!"); pthread_exit("Thank you for the CPU time"); } [iyunv@plinux tmp]# cc -D_REENTRANT -I/usr/include/nptl thread2.c -o thread2 -L/usr/lib/nptl -lpthread [iyunv@plinux tmp]# ./thread2 thread_function is running. Argument was Hello World Waiting for thread to finish... Thread joined, it returned Thank you for the CPU time Message is now Bye! pthread_join() void pthread_exit(void *retval) int pthread_join(pthread_t pid, void **thread_return) pthread_join()的调用者将挂起并等待th线程终止，retval是调用pthread_exit()的线程（线程ID为pid）的返回值，如果thread_return不为NULL，则*thread_return=retval。 需要注意的是一个线程仅允许唯一的另一个线程使用 pthread_join()等待本线程的终止，并且被等待的线程应该处于可join状态，即非DETACHED状态。 (责任编辑：IT) |