Subj : Re: pthreads (linux) questions
To   : comp.programming.threads
From : Joe Seigh
Date : Fri Aug 19 2005 09:29 am

jacob navia wrote:
> Joe Seigh wrote:
> Or you could look into the
> 
>> /proc/<pid>/tasks/
>> directory to get the kernel thread ids.
> 
> 
> Ahh, VERY interesting. Actually the first piece of
> useful info I get.
> 
> Maybe you would be so kind to tell
> me if there is any documentation for /proc/<pid>/tasks?
> 
> (What should be in there, format of the info, etc)
> 
> Thanks for that piece of info, and thanks in advance for any
> documentation. If there was a document that would explain this stuff
> it would spare me the time of asking and you the time of
> answering...
> 

No documentation that I know of except source.  Most of the info
is process related and will be identical the main process.  What
would be related to the main thread in the process will be thread
related in the tasks directory, e.g. program and register state.
I don't have a Linux system up and running right now so you'll have
to poke around and figure out things for yourself.

The pthread id to task id mapping is provided by the gettid system
call.  There's no task id to pthread id mapping except through
implementation dependent register and memory, i.e. you'll have
to figure out where thread local storage is and where the pthread
id is.  I think pthread id is just an offset into the thread local
memory.


-- 
Joe Seigh

When you get lemons, you make lemonade.
When you get hardware, you make software.

.