Linux多线程Pthread学习小结

简介

POSIX thread 简称为pthread，Posix线程是一个POSIX标准线程.该标准定义内部API创建和操纵线程.

作用

线程库实行了POSIX线程标准通常称为pthreads.pthreads是最常用的POSIX系统如Linux和Unix,而微软Windowsimplementations同时存在.举例来说,pthreads-w32可支持MIDP的pthread 　　

Pthreads定义了一套 C程序语言类型、函数与常量，它以 pthread.h 头文件和一个线程库实现。

数据类型

pthread_t：线程句柄　　

pthread_attr_t：线程属性

线程操纵函数（简介起见，省略参数）

pthread_create()：创建一个线程　　

pthread_exit()：终止当前线程　　

pthread_cancel()：中断另外一个线程的运行　　

pthread_join()：阻塞当前的线程，直到另外一个线程运行结束　　

pthread_attr_init()：初始化线程的属性　　

pthread_attr_setdetachstate()：设置脱离状态的属性（决定这个线程在终止时是否可以被结合）

pthread_attr_getdetachstate()：获取脱离状态的属性　　

pthread_attr_destroy()：删除线程的属性　　

pthread_kill()：向线程发送一个信号

同步函数

用于 mutex 和条件变量　　

pthread_mutex_init() 初始化互斥锁　　

pthread_mutex_destroy() 删除互斥锁　　

pthread_mutex_lock()：占有互斥锁（阻塞操作）　　

pthread_mutex_trylock()：试图占有互斥锁（不阻塞操作）。当互斥锁空闲时将占有该锁；否则立即返回　　

pthread_mutex_unlock(): 释放互斥锁　　

pthread_cond_init()：初始化条件变量　　

pthread_cond_destroy()：销毁条件变量　　

pthread_cond_wait(): 等待条件变量的特殊条件发生

pthread_cond_signal(): 唤醒第一个调用pthread_cond_wait()而进入睡眠的线程　　　　

Thread-local storage（或者以Pthreads术语，称作 线程特有数据）: 　　

pthread_key_create(): 分配用于标识进程中线程特定数据的键　　

pthread_setspecific(): 为指定线程特定数据键设置线程特定绑定　　

pthread_getspecific(): 获取调用线程的键绑定，并将该绑定存储在 value 指向的位置中　　

pthread_key_delete(): 销毁现有线程特定数据键

与一起工作的工具函数

pthread_equal(): 对两个线程的线程标识号进行比较　　

pthread_detach(): 分离线程　　

pthread_self(): 查询线程自身线程标识号

详细请参见：

linux多线程pthread： http://blog.csdn.net/Sunboy_2050/archive/2010/10/04/5920936.aspx

Pthread多线程学习小结： http://blog.csdn.net/Sunboy_2050/archive/2010/10/04/5921003.aspx

===================================================================

多线程创建

参考代码：

[cpp] view plaincopy print?

#include<stdio.h>
#include<pthread.h>
#include<string.h>
#include<sys/types.h>
#include<unistd.h>
pthread_t main_tid;
void print_ids(const char *str)
{
pid_t pid; //进程id
pthread_t tid; //线程id
pid = getpid(); //获取当前进程id
tid = pthread_self(); //获取当前线程id
printf("%s pid: %u tid: %u (0x%x)/n",
str,
(unsigned int)pid,
(unsigned int)tid,
(unsigned int)tid);
}
void *func(void *arg)
{
print_ids("new thread:");
return ((void *)0);
}
int main()
{
int err;
err = pthread_create(&main_tid, NULL, func, NULL); //创建线程
if(err != 0){
printf("create thread error: %s/n",strerror(err));
return 1;
}
printf("main thread: pid: %u tid: %u (0x%x)/n",
(unsigned int)getpid(),
(unsigned int)pthread_self(),
(unsigned int)pthread_self());
print_ids("main thread:");
sleep(1);
return 0;
}

#include<stdio.h> #include<pthread.h> #include<string.h> #include<sys/types.h> #include<unistd.h> pthread_t main_tid; void print_ids(const char *str) {pid_t pid; //进程idpthread_t tid; //线程idpid = getpid(); //获取当前进程idtid = pthread_self(); //获取当前线程idprintf("%s pid: %u tid: %u (0x%x)/n",str,(unsigned int)pid,(unsigned int)tid,(unsigned int)tid); } void *func(void *arg) {print_ids("new thread:");return ((void *)0); } int main() {int err;err = pthread_create(&main_tid, NULL, func, NULL); //创建线程if(err != 0){printf("create thread error: %s/n",strerror(err));return 1;}printf("main thread: pid: %u tid: %u (0x%x)/n", (unsigned int)getpid(),(unsigned int)pthread_self(),(unsigned int)pthread_self());print_ids("main thread:");sleep(1);return 0; }

运行结果：

[work@db-testing-com06-vm3.db01.baidu.com pthread]$ gcc -Wall -o pthread_create pthread_create.c -lpthread

[work@db-testing-com06-vm3.db01.baidu.com pthread]$ ./pthread_create

main thread: pid: 12531 tid: 2505487232 (0x9556b380)

new thread: pid: 12531 tid: 1084229984 (0x40a00960)

===================================================================

多线程条件变量

参考代码：

[cpp] view plain copy print?

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
pthread_mutex_t counter_lock; //互斥锁
pthread_cond_t counter_nonzero; //条件变量
int counter = 0;
int estatus = -1;
void *decrement_counter(void *argv);
void *increment_counter(void *argv);
//******* 主函数 *******//
int main(int argc, char **argv)
{
printf("counter: %d/n", counter);
pthread_t thd1, thd2;
int ret;
//初始化
pthread_mutex_init(&counter_lock, NULL);
pthread_cond_init(&counter_nonzero, NULL);
ret = pthread_create(&thd1, NULL, decrement_counter, NULL); //创建线程1
if(ret){
perror("del:/n");
return 1;
}
ret = pthread_create(&thd2, NULL, increment_counter, NULL); //创建线程2
if(ret){
perror("inc: /n");
return 1;
}
int counter = 0;
while(counter != 10){
printf("counter(main): %d/n", counter); //主线程
sleep(1);
counter++;
}
pthread_exit(0);
return 0;
}
void *decrement_counter(void *argv)
{
printf("counter(decrement): %d/n", counter);
pthread_mutex_lock(&counter_lock);
while(counter == 0)
pthread_cond_wait(&counter_nonzero, &counter_lock); //进入阻塞(wait)，等待激活(signal)
printf("counter--(before): %d/n", counter);
counter--; //等待signal激活后再执行
printf("counter--(after): %d/n", counter);
pthread_mutex_unlock(&counter_lock);
return &estatus;
}
void *increment_counter(void *argv)
{
printf("counter(increment): %d/n", counter);
pthread_mutex_lock(&counter_lock);
if(counter == 0)
pthread_cond_signal(&counter_nonzero); //激活(signal)阻塞(wait)的线程(先执行完signal线程，然后再执行wait线程)
printf("counter++(before): %d/n", counter);
counter++;
printf("counter++(after): %d/n", counter);
pthread_mutex_unlock(&counter_lock);
return &estatus;
}

#include <stdio.h> #include <pthread.h> #include <unistd.h>pthread_mutex_t counter_lock; //互斥锁 pthread_cond_t counter_nonzero; //条件变量 int counter = 0; int estatus = -1;void *decrement_counter(void *argv); void *increment_counter(void *argv);//******* 主函数 *******// int main(int argc, char **argv) {printf("counter: %d/n", counter);pthread_t thd1, thd2;int ret;//初始化pthread_mutex_init(&counter_lock, NULL);pthread_cond_init(&counter_nonzero, NULL);ret = pthread_create(&thd1, NULL, decrement_counter, NULL); //创建线程1if(ret){perror("del:/n");return 1;}ret = pthread_create(&thd2, NULL, increment_counter, NULL); //创建线程2if(ret){perror("inc: /n");return 1;}int counter = 0;while(counter != 10){printf("counter(main): %d/n", counter); //主线程sleep(1);counter++;}pthread_exit(0);return 0; }void *decrement_counter(void *argv) {printf("counter(decrement): %d/n", counter);pthread_mutex_lock(&counter_lock);while(counter == 0)pthread_cond_wait(&counter_nonzero, &counter_lock); //进入阻塞(wait)，等待激活(signal)printf("counter--(before): %d/n", counter); counter--; //等待signal激活后再执行printf("counter--(after): %d/n", counter); pthread_mutex_unlock(&counter_lock); return &estatus; }void *increment_counter(void *argv) {printf("counter(increment): %d/n", counter);pthread_mutex_lock(&counter_lock);if(counter == 0)pthread_cond_signal(&counter_nonzero); //激活(signal)阻塞(wait)的线程(先执行完signal线程，然后再执行wait线程)printf("counter++(before): %d/n", counter); counter++; printf("counter++(after): %d/n", counter); pthread_mutex_unlock(&counter_lock);return &estatus; }

运行结果：

[work@db-testing-com06-vm3.db01.baidu.com pthread]$ gcc -Wall -o pthread_cond2 pthread_cond2.c -lpthread

[work@db-testing-com06-vm3.db01.baidu.com pthread]$ ./pthread_cond2

counter: 0

counter(main): 0

counter(decrement): 0

counter(increment): 0

counter++(before): 0

counter++(after): 1

counter--(before): 1

counter--(after): 0

counter(main): 1

counter(main): 2

counter(main): 3

counter(main): 4

counter(main): 5

counter(main): 6

counter(main): 7

counter(main): 8

counter(main): 9

详细解释，请见：http://blog.csdn.net/Sunboy_2050/archive/2010/11/24/6031723.aspx

===================================================================

多线程的创建特殊数据键

参考代码：

[cpp] view plaincopy print?

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
pthread_key_t key; //声明参数key
void echomsg(void *arg) //析构处理函数
{
printf("destruct executed in thread = %u, arg = %p/n",
(unsigned int)pthread_self(),
arg);
}
void *child_1(void *arg)
{
pthread_t tid;
tid = pthread_self();
printf("%s: thread %u enter/n", (char *)arg, (unsigned int)tid);
pthread_setspecific(key, (void *)tid); // 与key值绑定的value(tid)
printf("%s: thread %u returns %p/n", // %p 表示输出指针格式
(char *)arg,
(unsigned int)tid,
pthread_getspecific(key)); // 获取key值的value
sleep(1);
return NULL;
}
void *child_2(void *arg)
{
pthread_t tid;
tid = pthread_self();
printf("%s: thread %u enter/n", (char *)arg, (unsigned int)tid);
pthread_setspecific(key, (void *)tid);
printf("%s: thread %u returns %p/n",
(char *)arg,
(unsigned int)tid,
pthread_getspecific(key));
sleep(1);
return NULL;
}
//******* 主函数 *******//
int main(void)
{
pthread_t tid1, tid2;
printf("hello main/n");
pthread_key_create(&key, echomsg); //创建key
pthread_create(&tid1, NULL, child_1, (void *)"child_1"); //创建带参数的线程，需要强制转换
pthread_create(&tid2, NULL, child_2, (void *)"child_2");
sleep(3);
pthread_key_delete(key); //清除key
printf("bye main/n");
pthread_exit(0);
return 0;
}

#include <stdio.h> #include <pthread.h> #include <unistd.h>pthread_key_t key; //声明参数keyvoid echomsg(void *arg) //析构处理函数 {printf("destruct executed in thread = %u, arg = %p/n", (unsigned int)pthread_self(),arg); }void *child_1(void *arg) {pthread_t tid;tid = pthread_self();printf("%s: thread %u enter/n", (char *)arg, (unsigned int)tid);pthread_setspecific(key, (void *)tid); // 与key值绑定的value(tid)printf("%s: thread %u returns %p/n", // %p 表示输出指针格式 (char *)arg,(unsigned int)tid, pthread_getspecific(key)); // 获取key值的valuesleep(1);return NULL; }void *child_2(void *arg) {pthread_t tid;tid = pthread_self();printf("%s: thread %u enter/n", (char *)arg, (unsigned int)tid);pthread_setspecific(key, (void *)tid);printf("%s: thread %u returns %p/n", (char *)arg,(unsigned int)tid, pthread_getspecific(key));sleep(1);return NULL; }//******* 主函数 *******// int main(void) {pthread_t tid1, tid2;printf("hello main/n");pthread_key_create(&key, echomsg); //创建keypthread_create(&tid1, NULL, child_1, (void *)"child_1"); //创建带参数的线程，需要强制转换pthread_create(&tid2, NULL, child_2, (void *)"child_2");sleep(3);pthread_key_delete(key); //清除keyprintf("bye main/n");pthread_exit(0);return 0; }

运行结果：

[work@db-testing-com06-vm3.db01.baidu.com pthread]$ gcc -Wall -o pthread_setspecific pthread_setspecific.c -lpthread
[work@db-testing-com06-vm3.db01.baidu.com pthread]$ ./pthread_setspecific
hello main
child_1: thread 1084229984 enter
child_1: thread 1084229984 returns 0x40a00960
child_2: thread 1094719840 enter
child_2: thread 1094719840 returns 0x41401960
destruct executed in thread = 1084229984, arg = 0x40a00960
destruct executed in thread = 1094719840, arg = 0x41401960
bye main

附加参考——函数原型：

Posix定义了两个API分别用来创建和注销TSD：

int pthread_key_create(pthread_key_t *key, void (*destr_function) (void *))

注销一个TSD采用如下API：

int pthread_key_delete(pthread_key_t key)

int pthread_setspecific(pthread_key_t key, const void *pointer)
void * pthread_getspecific(pthread_key_t key)

参考网址：

http://blog.sina.com.cn/s/blog_46d528490100lxm0.html

http://xunet.blog.51cto.com/138167/22011（推荐）

===================================================================

多线程的创建特殊数据键

参考代码：

[cpp] view plain copy print?

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
pthread_once_t once = PTHREAD_ONCE_INIT; //声明变量
//once_run()函数仅执行一次，且究竟在哪个线程中执行是不定的
//尽管pthread_once(&once,once_run)出现在两个线程中
//函数原型：int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
void once_run(void)
{
printf("Func: %s in thread: %u/n",
__func__,
(unsigned int)pthread_self());
}
void *child_1(void *arg)
{
pthread_t tid;
tid = pthread_self();
pthread_once(&once, once_run); //调用once_run
printf("%s: thread %d returns/n", (char *)arg, (unsigned int)tid);
return NULL;
}
void *child_2(void *arg)
{
pthread_t tid;
tid = pthread_self();
pthread_once(&once, once_run); //调用once_run
printf("%s: thread %d returns/n", (char *)arg, (unsigned int)tid);
return NULL;
}
//******* main *******//
int main(void)
{
pthread_t tid1, tid2;
printf("hello main/n");
pthread_create(&tid1, NULL, child_1, (void *)"child_1");
pthread_create(&tid2, NULL, child_2, (void *)"child_2");
pthread_join(tid1, NULL); //main主线程等待线程tid1返回
pthread_join(tid2, NULL); //main主线程等待线程tid2返回
printf("bye main/n");
return 0;
}

#include <stdio.h> #include <pthread.h> #include <unistd.h>pthread_once_t once = PTHREAD_ONCE_INIT; //声明变量//once_run()函数仅执行一次，且究竟在哪个线程中执行是不定的 //尽管pthread_once(&once,once_run)出现在两个线程中 //函数原型：int pthread_once(pthread_once_t *once_control, void (*init_routine)(void)) void once_run(void) {printf("Func: %s in thread: %u/n", __func__, (unsigned int)pthread_self()); }void *child_1(void *arg) {pthread_t tid;tid = pthread_self();pthread_once(&once, once_run); //调用once_runprintf("%s: thread %d returns/n", (char *)arg, (unsigned int)tid);return NULL; }void *child_2(void *arg) {pthread_t tid;tid = pthread_self();pthread_once(&once, once_run); //调用once_runprintf("%s: thread %d returns/n", (char *)arg, (unsigned int)tid);return NULL; }//******* main *******// int main(void) {pthread_t tid1, tid2;printf("hello main/n");pthread_create(&tid1, NULL, child_1, (void *)"child_1");pthread_create(&tid2, NULL, child_2, (void *)"child_2");pthread_join(tid1, NULL); //main主线程等待线程tid1返回pthread_join(tid2, NULL); //main主线程等待线程tid2返回printf("bye main/n");return 0; }

运行结果：

work@db-testing-com06-vm3.db01.baidu.com pthread]$ gcc -Wall -o pthread_once pthread_once.c -lpthread
[work@db-testing-com06-vm3.db01.baidu.com pthread]$ ./pthread_once
hello main
Func: once_run in thread: 1084229984
child_1: thread 1084229984 returns
child_2: thread 1094719840 returns
bye main

Linux多线程Pthread学习小结相关推荐

Linux多线程基础学习（七）pthread一次性初始化
在多线程环境中,有些事仅需要执行一次.通常当初始化应用程序时,可以比较容易地将其放在main函数中.但当你写一个库时,就不能在main里面初始化了,你可以用静态初始化,但使用一次初始化(pthread ...
linux多线程 pthread用法
#include int pthread_create(pthread_t *restrict tidp,const pthread_attr_t *restrict attr, void *(*st ...
linux多线程编程--学习笔迹4
进程--资源分配的最小单位,线程--程序执行的最小单位进程有独立的地址空间,一个进程崩溃后,在保护模式下不会对其它进程产生影响,而线程只是一个进程中的不同执行路径.线程有自己的堆栈和局部变量,但线程 ...
linux初次入门学习小结
linux系统目录结构: 通过ls / 命令可以获得linux目录结构 bin boot dev etc home lib lib64 media mnt opt proc root sbin sel ...
Linux系统的学习小结
这两天在准备计算机三级--嵌入式的过程中,接触到了Linux系统,因此在这里把自己学到的东西总结一下. 一.Linux内核的结构与组成 Linux是一种自由软件,也是开源软件,它是一款类Unix系统. ...
pthread多线程编程的学习小结
pthread多线程编程的学习小结 pthread 同步3种方法: 1 mutex 2 条件变量 3 读写锁:支持多个线程同时读,或者一个线程写程序员必上的开发者服务平台 -- DevStore p ...
clone的fork与pthread_create创建线程有何不同pthread多线程编程的学习小结(转)
进程是一个指令执行流及其执行环境,其执行环境是一个系统资源的集合,这些资源在Linux中被抽象成各种数据对象:进程控制块.虚存空间.文件系统,文件I/O.信号处理函数.所以创建一个进程的过程就是这 ...
Linux与C++11多线程编程(学习笔记)
多线程编程与资源同步在Windows下,主线程退出后,子线程也会被关闭; 在Linux下,主线程退出后,系统不会关闭子线程,这样就产生了僵尸进程 3.2.1创建线程 Linux 线程的创建 #inc ...
ZT 为什么pthread_cond_t要和pthread_mutex_t同时使用 || pthread/Linux多线程编程
为什么线程同步的时候pthread_cond_t要和pthread_mutex_t同时使用 (2009-10-27 11:07:23) 转载▼ 标签: 杂谈分类: 计算机举一个例子(http:// ...

Linux多线程Pthread学习小结

Linux多线程Pthread学习小结相关推荐

最新文章

热门文章