linux 杂记

Linux线程同步机制示例

最新推荐文章于 2024-10-13 14:53:03 发布

原创最新推荐文章于 2024-10-13 14:53:03 发布 · 182 阅读

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线程同步：

1.互斥锁

2.读写锁

3.条件变量

4.信号量

5.自旋锁

6.屏障（barrier）

进程同步：

1.互斥锁

2.读写锁

3.条件变量

4.记录锁(record locking)

5.信号量

6.屏障（barrier）

-pthread Adds support for multithreading with the pthreads library. This option sets flags for both the preprocessor and linker.

pthread是linux下的线程库，用了多线程就要链接这个库，这时候要在编译选项上增加-pthread或者-lpthread

-pthread选项对预处理器和链接器起作用
而老式的-lpthread只对链接器起作用
推荐使用-pthread

#include <iostream>
#include <cstdlib>
#include <pthread.h>
#include <unistd.h>
 
using namespace std;
 
#define NUM_THREADS     5
 
void *wait(void *t)
{
   int i;
   long tid;
 
   tid = (long)t;
 
   sleep(1);
   cout << "Sleeping in thread " << endl;
   cout << "Thread with id : " << tid << "  ...exiting " << endl;
   pthread_exit(NULL);
}
 
int main ()
{
   int rc;
   int i;
   pthread_t threads[NUM_THREADS];
   pthread_attr_t attr;
   void *status;
 
   // 初始化并设置线程为可连接的（joinable）
   pthread_attr_init(&attr);
   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
 
   for( i=0; i < NUM_THREADS; i++ ){
      cout << "main() : creating thread, " << i << endl;
      rc = pthread_create(&threads[i], NULL, wait, (void *)&i );
      if (rc){
         cout << "Error:unable to create thread," << rc << endl;
         exit(-1);
      }
   }
 
   // 删除属性，并等待其他线程
   pthread_attr_destroy(&attr);
   for( i=0; i < NUM_THREADS; i++ ){
      rc = pthread_join(threads[i], &status);
      if (rc){
         cout << "Error:unable to join," << rc << endl;
         exit(-1);
      }
      cout << "Main: completed thread id :" << i ;
      cout << "  exiting with status :" << status << endl;
   }
 
   cout << "Main: program exiting." << endl;
   pthread_exit(NULL);
}