On Mar 11, 12:11 pm, Allen wrote:
> I want to get the pid of the thread created by pthread_create, so that
> I can know which thread is my working thread in the outputs of ps
> command.

U are referring to kernel right?

It is in fs/proc/base.c: proc_task_read() function (which is called
when u try to read the directory /proc/xxxx/task):

Following function is shown:

/* f_version caches the tgid value that the last readdir call
couldn't
* return. lseek aka telldir automagically resets f_version to
0.
*/
ns = filp->f_dentry->d_sb->s_fs_info;
tid = (int)filp->f_version;
filp->f_version = 0;
for (task = first_tid(leader, tid, pos - 2, ns);
task;
task = next_tid(task), pos++) {
tid = task_pid_nr_ns(task, ns);
if (proc_task_fill_cache(filp, dirent, filldir, task,
tid) < 0) {
/* returning this tgid failed, save it as the
first
* pid for the next readir call */
filp->f_version = (u64)tid;
put_task_struct(task);
break;
}
}
out:


The above for-loop will print out all the thread ID of the particular
process, eg:

ls /proc/3407/task/
3407 3413 3427 3435 3436 4303 4304 4798