请问：linux的线程是由新的进程运行的么 谢谢

wtwang1985

advance linux programing上说：
Whenever you call pthread_create to create a new thread, Linux creates a new process that runs that thread.
还附了一个程序：

1. #include <pthread.h>
   
2. #include <stdio.h>
   
3. #include <unistd.h>
   
4. void* thread_function (void* arg) {
   
5. fprintf (stderr, “child thread pid is %d\n”, (int) getpid ());
   
6. /* Spin forever. */
   
7. while (1);
   
8. return NULL;
   
9. }
   
10. int main () {
    
11. pthread_t thread;
    
12. fprintf (stderr, “main thread pid is %d\n”, (int) getpid ());
    
13. pthread_create (&thread, NULL, &thread_function, NULL);
    
14. /* Spin forever. */
    
15. while (1);
    
16. return 0;
    
17. }

复制代码

作者的运行结果是：
% ./thread-pid &
[1] 14608
main thread pid is 14608
child thread pid is 14610
% ps x
PID TTY STAT TIME COMMAND
14042 pts/9 S 0:00 bash
14608 pts/9 R 0:01 ./thread-pid
14609 pts/9 S 0:00 ./thread-pid
14610 pts/9 R 0:01 ./thread-pid
14611 pts/9 R 0:00 ps x
但我的机子上运行的结果是：
./thread-pid &
[1] 13071
david@david-desktop:~/alp/ALP-listings/chapter-4$ main thread pid is 13071
child thread pid is 13071
呵呵。小弟是个菜鸟。请各位指教。

[ 本帖最后由 wtwang1985 于 2007-2-9 23:17 编辑 ]

langue

你看看两个线程 thread id，和 process id，分别有什么关系没

wtwang1985

一样的。
david@david-desktop:~/alp/ALP-listings/chapter-4$ ./thread-pid
main thread pid is 13183
child thread pid is 13183
child thread pid is 13183

wtwang1985

david@david-desktop:~/alp/ALP-listings/chapter-4$ ./thread-pid &
[1] 13209
main thread pid is 13209
david@david-desktop:~/alp/ALP-listings/chapter-4$ child thread pid is 13209
child thread pid is 13209
david@david-desktop:~/alp/ALP-listings/chapter-4$ ps
  PID TTY          TIME CMD
12732 pts/0    00:00:00 bash
13209 pts/0    00:00:02 thread-pid
13212 pts/0    00:00:00 ps

wtwang1985

david@david-desktop:~/alp/ALP-listings/chapter-4$ ./thread-pid&
[1] 13318
main thread pid is 13318 and thread_id is 3084891840
david@david-desktop:~/alp/ALP-listings/chapter-4$ child thread pid is 13318 and thread_id is 3084889008
child thread pid is 13318 and thread_id is 3076496304

[ 本帖最后由 wtwang1985 于 2007-2-9 23:56 编辑 ]

langue

原帖由 wtwang1985 于 2007-2-9 23:51 发表
david@david-desktop:~/alp/ALP-listings/chapter-4$ ./thread-pid&
[1] 13318
main thread pid is 13318 and thread_id is 3084891840
david@david-desktop:~/alp/ALP-listings/chapter-4$ child thread ...

说明在你的系统上，进程的多个线程被封装到一个统一的进程里。别的系统可能不是这种情况。

--

wtwang1985

我在一台Linux sarge.lpicn.org 2.4.30-osl2.0 #9 Fri Jan 6 17:26:47 CST 2006 i686 GNU/Linux
机子上测试的结果是：
[root@sarge ~/public] ./thread-pid &
[1] 12350
[root@sarge ~/public] main thread pid is 12350 and thread_id is 16384
child thread pid is 12352 and thread_id is 16386

[root@sarge ~/public] ps
  PID TTY          TIME CMD
11978 pts/1    00:00:00 bash
12350 pts/1    00:00:01 thread-pid
12351 pts/1    00:00:00 thread-pid
12352 pts/1    00:00:01 thread-pid
12364 pts/1    00:00:00 ps
[root@sarge ~/public] killall thread-pid
[root@sarge ~/public] ps
  PID TTY          TIME CMD
11978 pts/1    00:00:00 bash
12453 pts/1    00:00:00 ps
[1]+  Terminated              ./thread-pid
我就想是不是2.6内核将pthread的实现改动了呢？

Iamlangue

--

correct

NPTL -- Native POSIX Threads Library

--

Cocory

[ 本帖最后由 Cocory 于 2007-2-10 08:26 编辑 ]

wolf0403

Advanced Linux Programming 那本书里线程部分和第二卷的部分内容有点过时了。