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标题: 请问：linux的线程是由新的进程运行的么谢谢 [打印本页]

作者: wtwang1985 时间: 2007-02-09 23:15
标题: 请问：linux的线程是由新的进程运行的么谢谢
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：

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
void* thread_function (void* arg) {
fprintf (stderr, “child thread pid is %d\n”, (int) getpid ());
/* Spin forever. */
while (1);
return NULL;
}
int main () {
pthread_t thread;
fprintf (stderr, “main thread pid is %d\n”, (int) getpid ());
pthread_create (&thread, NULL, &thread_function, NULL);
/* Spin forever. */
while (1);
return 0;
}

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 ]

作者: langue 时间: 2007-02-09 23:34
你看看两个线程 thread id，和 process id，分别有什么关系没

作者: wtwang1985 时间: 2007-02-09 23:41
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

作者: wtwang1985 时间: 2007-02-09 23:44
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

作者: wtwang1985 时间: 2007-02-09 23:51
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 ]

作者: langue 时间: 2007-02-10 00:28

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。

--

作者: wtwang1985 时间: 2007-02-10 00:47
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？

作者: Iamlangue 时间: 2007-02-10 01:18
--

correct

NPTL -- Native POSIX Threads Library

--

作者: Cocory 时间: 2007-02-10 08:21

[ 本帖最后由 Cocory 于 2007-2-10 08:26 编辑 ]

作者: wolf0403 时间: 2007-02-10 08:27
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。

作者: picobsd 时间: 2007-02-13 13:09
以前确实是这样
现在已经开始改观了，好像使用了新的线程库

作者: jackk294 时间: 2007-02-14 16:34

原帖由 picobsd 于 2007-2-13 13:09 发表
以前确实是这样
现在已经开始改观了，好像使用了新的线程库

就是，现在使用readhat开发的nptl线程库了
http://www.ibm.com/developerworks/cn/linux/l-threading.html

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