多线程函数系列pthread_create(), pthread_join(), pthread_self()，pthread_exit(), pthread_detach()实例详解
#include <pthread.h> int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine) (void *), void *arg)
创建线程，并可以向创建的线程传递一个参数（见实例3,向线程传递总的线程个数，一个int变量）；
#include <pthread.h> int pthread_join(pthread_t thread, void **retval)等待线程终止，并且可以获得线程的返回值；
#include <pthread.h> pthread_t pthread_self(void);获得线程自身的线程ID；
线程可以通过下面三种方式退出：
1.线程只是从启动例程中返回，返回值是线程的退出码；2.线程可以被同一进程中的其它线程取消；
3.线程调用pthread_exit
#include <pthread.h> void pthread_exit(void *retval);终止线程，并可以向主线程返回值；
#include <pthread.h> int pthread_detach(pthread_t thread);在创建的线程中调用该函数，使该线程脱离进程（这里的脱离并不是真正意义上的完全脱离；脱离之后，该线程仍然在该进程空间里运行，只不过是当该线程退出的时候，它的资源会自动释放，进程不用等待其并释放其资源；
总结：
1：如何创建一个或多个线程；
2：如何在主线程中等待刚才创建的线程；
3：如何获得线程的线程ID;
4：如何在向创建的线程传递信息；
5：如何在创建的线程中退出的时候向主线程传递信息；
6：如何使线程脱离主线程；
实例1：简单的创建两个线程，并在主线程中等待这两个线程，使用pthread_create， pthread_join, pthread_self
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task1(void *a)
{
cout << "This is threadA..." << "thread id is " << pthread_self() << endl;
sleep(2);
cout << "threadA exit.." << endl;
}
void *task2(void *b)
{
cout << "This is threadB..." << "thread id is " << pthread_self() << endl;
sleep(2);
cout << "ThreadB exit.." << endl;
}
int main()
{
int ret;
pthread_t threadA, threadB;
ret = pthread_create(&threadA, NULL, task1, NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
ret = pthread_create(&threadB, NULL, task2, NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
ret = pthread_join(threadA, NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
ret = pthread_join(threadB, NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
cout << "main thread exit..." << endl;
exit(0);
}
实例2：创建多个线程（个数自己指定），并在主线程中等待这些线程，使用pthread_create， pthread_join, pthread_self
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task(void *a)
{
cout << "This is thread..." << "thread id is " << pthread_self() << endl;
sleep(2);
cout << "thread exit.." << pthread_self() << endl;
}
int main(int argc, char *argv[])
{
int ret;
int i = 0;
if(argc != 2){
cout << "You must input the number of thread you want to create..." << endl;
exit(-1);
}
int thread_num = atoi(argv[1]);
pthread_t threadId[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_create(&threadId[i], NULL, task, NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
for (i = 0; i < thread_num; ++i){
ret = pthread_join(threadId[i], NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
cout << "main thread exit..." << endl;
exit(0);
}
实例3：创建多个线程（个数自己指定）同时向各个线程中传递一个整数值，并在主线程中等待这些线程，使用pthread_create， pthread_join, pthread_self
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task(void *a)
{
int i = 0;
int * loop;
loop = static_cast<int*> (a);
for (i = 0; i < *loop; ++i){
cout << i+1 << ": This is thread..." << "thread id is " << pthread_self() << endl;
sleep(1);
}
cout << "thread exit.." << pthread_self() << endl;
}
int main(int argc, char *argv[])
{
int ret;
int i = 0;
if(argc != 2){
cout << "You must input the number of thread you want to create..." << endl;
exit(-1);
}
int thread_num = atoi(argv[1]);
pthread_t threadId[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_create(&threadId[i], NULL, task, (void *)&thread_num);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
for (i = 0; i < thread_num; ++i){
ret = pthread_join(threadId[i], NULL);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
cout << "main thread exit..." << endl;
exit(0);
}
实例4：创建多个线程（个数自己指定）同时向各个线程中传递一个整数值，并在主线程中等待这些线程，线程退出的时候向主线程返回值（将自身的线程id传给主线程）；
使用pthread_create， pthread_join, pthread_self， pthread_exit
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task(void *a)
{
int i = 0;
int * loop;
pthread_t pid = pthread_self();
loop = static_cast<int*> (a);
for (i = 0; i < *loop; ++i){
cout << i+1 << ": This is thread..." << "thread id is " << pid << endl;
sleep(1);
}
cout << "thread exit.." << pid << endl;
pthread_exit((void *)&pid);
}
int main(int argc, char *argv[])
{
int ret;
int i = 0;
if(argc != 2){
cout << "You must input the number of thread you want to create..." << endl;
exit(-1);
}
int thread_num = atoi(argv[1]);
pthread_t threadId[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_create(&threadId[i], NULL, task, (void *)&thread_num);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
pthread_t * pid[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_join(threadId[i], (void **)&pid[i]);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
for (i = 0; i < thread_num; ++i){
cout << "main thread wait the thread id is " << *pid[i] << endl;
}
cout << "main thread exit..." << endl;
exit(0);
}
实例5：创建多个线程（个数自己指定）同时向各个线程中传递一个整数值，并在主线程中等待这些线程，线程退出的时候向主线程返回值（将自身的线程id传给主线程），最要的是让线程脱离主线程；使用pthread_create， pthread_join, pthread_self， pthread_exit， pthread_detach
第一:出错的例子
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task(void *a)
{
int i = 0;
int * loop;
pthread_t pid = pthread_self();
pthread_detach(pid);
loop = static_cast<int*> (a);
for (i = 0; i < *loop; ++i){
cout << i+1 << ": This is thread..." << "thread id is " << pid << endl;
sleep(1);
}
cout << "thread exit.." << pid << endl;
pthread_exit((void *)&pid);
}
int main(int argc, char *argv[])
{
int ret;
int i = 0;
if(argc != 2){
cout << "You must input the number of thread you want to create..." << endl;
exit(-1);
}
int thread_num = atoi(argv[1]);
pthread_t threadId[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_create(&threadId[i], NULL, task, (void *)&thread_num);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
pthread_t * pid[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_join(threadId[i], (void **)&pid[i]);
if(ret != 0){
cout << "pthread_join error..." << i+1 << endl;
exit(-1);
}
}
for (i = 0; i < thread_num; ++i){
cout << "main thread wait the thread id is " << *pid[i] << endl;
}
cout << "main thread exit..." << endl;
exit(0);
}
第二：正确的
/*************************************************************************
> File Name: create_join.cpp
> Author:
> Mail:
> Created Time: 2015年12月16日 星期三 10时41分19秒
************************************************************************/
#include<iostream>
#include <unistd.h>
#include <pthread.h>
#include <cstdlib>
using namespace std;
void *task(void *a)
{
int i = 0;
int * loop;
pthread_t pid = pthread_self();
pthread_detach(pid);
loop = static_cast<int*> (a);
for (i = 0; i < *loop; ++i){
cout << i+1 << ": This is thread..." << "thread id is " << pid << endl;
sleep(1);
}
cout << "thread exit.." << pid << endl;
}
int main(int argc, char *argv[])
{
int ret;
int i = 0;
if(argc != 2){
cout << "You must input the number of thread you want to create..." << endl;
exit(-1);
}
int thread_num = atoi(argv[1]);
pthread_t threadId[thread_num];
for (i = 0; i < thread_num; ++i){
ret = pthread_create(&threadId[i], NULL, task, (void *)&thread_num);
if(ret != 0){
cout << "pthread_create error..." << endl;
exit(-1);
}
}
sleep(5);//必须等待，如果不等待则该进程退出，那么创建的线程也会退出
cout << "main thread exit..." << endl;
exit(0);
}
再说一个linux下写程序的一个核武器--------------man手册；