linux多线程在/proc目录的结构

linux的多线程，其实就是clone系统调用的实现的（共享文件等）

首先看个具体的例子：

#include <stdio.h>  #include <stdlib.h>  #include <pthread.h>  #include <unistd.h>#include <string.h>#include <sched.h>#include <errno.h>  void *print_message_function( void *ptr );  int main()  {        pthread_t thread1, thread2;        const char *message1 = "Thread 1";        const char *message2 = "Thread 2";        int  iret1, iret2;          /* Create independent threads each of which will execute function */       iret1 = pthread_create( &thread1, NULL, print_message_function, (void*) message1);        iret2 = pthread_create( &thread2, NULL, print_message_function, (void*) message2);        /* Wait till threads are complete before main continues. Unless we  */       /* wait we run the risk of executing an exit which will terminate   */       /* the process and all threads before the threads have completed.   */           pthread_join( thread1, NULL);        pthread_join( thread2, NULL);             printf("Thread 1 returns: %d\n",iret1);        printf("Thread 2 returns: %d\n",iret2);        for(;;)      {         usleep(250*1000);      }       return 0;      }      void *print_message_function( void *ptr )  {        char *message;        for(;;)      {         message = (char *) ptr;           printf("%s \n", message);         usleep(3*250*1000);      }        return 0;} 

此时一共有三个进程在跑（相对于kernel来说，只有进程的概念）

一般情况是，一个进程在/proc 目录下就对应一个，以该进程ID号名字的

文件目录，该目录下保存着该进程的所有信息。

但是对应，所谓的多线程，它的目录结构该会这么样呢？

假如该程序名为：thread

$ top -t | grep thread
PID TID PR CPU% S VSS RSS PCY UID Thread Proc

31694 31694 0 0% S 3008K 416K root thread system/bin/thread
31694 31695 0 0% S 3008K 416K root thread system/bin/thread
31694 31696 0 0% S 3008K 416K root thread system/bin/thread

可知他们对应于一个进程ID号，而在此目录下，分别在有其他三个线程目录信息：

proc/31694/task # ls
31694
31695
31696