#include<pthread.h>
#include<stdio.h>
#include<unistd.h>
#include<string.h>
#define MAX 10
pthread_t thread[2];
pthread_mutex_t mut;
int number = 0;
int i;
void* thread1( void *param )
{
printf( "thread1: I'm thread 1\n " );
for( i = 0; i < MAX; i++ )
{
printf( "thread1: number = %d\n", number );
pthread_mutex_lock( &mut );
++number;
pthread_mutex_unlock( &mut );
sleep( 2 );
}
printf( "thread1: 主函数等我完成任务吗? \n " );
pthread_exit( NULL );
return ( void* )0;
}
void* thread2( void* param )
{
printf( "thread2: I'm thread 2\n" );
for( i = 0; i < MAX; i++ )
{
printf( "thread2: number = %d\n", number );
pthread_mutex_lock( &mut );
++number;
pthread_mutex_unlock( &mut );
sleep( 3 );
}
printf( "thread2: 主函数在等我完成任务吗? \n" );
pthread_exit( NULL );
return ( void* )0;
}
void thread_create( void )
{
int temp;
memset( &thread, 0, sizeof( thread ) );
// 创建线程1
if( ( temp = pthread_create( &thread[0], NULL, thread1, NULL ) ) != 0 )
{
printf( "线程1创建失败!\n" );
}
else
{
printf( "线程1被创建\n" );
}
// 创建线程2
if( ( temp = pthread_create( &thread[1], NULL, thread2, NULL ) ) != 0 )
{
printf( "线程2创建失败!\n" );
}
else
{
printf( "线程2被创建\n" );
}
}
void thread_wait( void )
{
// 主函数等待线程1结束
if ( thread[0] != 0 )
{
pthread_join( thread[0], NULL );
printf( "线程1已经结束\n" );
}
// 主函数等待线程2结束
if ( thread[1] != 0 )
{
pthread_join( thread[1], NULL );
printf( "线程2已经结束\n" );
}
}
int main()
{
// 初始化互斥锁
pthread_mutex_init( &mut, NULL );
printf( "我是main函数，正在创建线程...\n" );
thread_create();
printf( "我是主函数，正在等待线程完成任务...\n" );
thread_wait();
printf( "main函数已退出\n" );
return 0;
}
// main output1
我是main函数，正在创建线程... 线程1被创建 线程2被创建 我是主函数，正在等待线程完成任务... thread1: I'm thread 1 thread2: I'm thread 2 thread1: number = 0 thread2: number = 0 thread1: number = 2 thread2: number = 3 thread1: number = 4 thread2: number = 5 thread1: number = 6 thread1: number = 7 thread2: number = 8 thread1: number = 9 thread2: number = 10 thread1: 主函数等我完成任务吗? 线程1已经结束 thread2: 主函数在等我完成任务吗? 线程2已经结束 main函数已退出
// main output2
我是main函数，正在创建线程... 线程1被创建 线程2被创建 我是主函数，正在等待线程完成任务... thread1: I'm thread 1 thread1: number = 0 thread2: I'm thread 2 thread2: number = 1 thread1: number = 2 thread2: number = 3 thread1: number = 4 thread2: number = 5 thread1: number = 6 thread1: number = 7 thread2: number = 8 thread1: number = 9 thread2: number = 10 thread1: 主函数等我完成任务吗? 线程1已经结束 thread2: 主函数在等我完成任务吗? 线程2已经结束 main函数已退出
g++编译命令如下： g++ -lpthread -o helloworld.out helloworld.cpp
问题：两个线程共同完成任务，但是对于共享变量 i
没有互斥加锁操作，所以以上多线程程序还是存在问题的！
为了达到兼容可移植的目的，POSIX给出了C语言下的多线程编程库 pthread，具体的学习资料请参考一下链接
http://blog.csdn.net/future_fighter/article/details/3865071
http://blog.csdn.net/sunboy_2050/article/details/5921003
http://www.ibm.com/developerworks/cn/linux/l-cn-mthreadps/index.html