Re: [LIP] NPTL behaviour differences

On Thu, Mar 04, 2004 at 12:57:01PM +0530, Shridhar Daithankar wrote:
> >- Signal handling (you can send signals to a whole process now)
> 
> I believe signals can be per thread now. Earlier it was to the entire 
> process.
> 

No, it's the other way around. You could always send a signal to a
thread in linuxthreads using kill(pid, SIG) where pid was the id of the
thread, modelled as a Linux task. The idea of a "process", a container
for threads didn't quite exist. getpid() returned the thread id, not a
process-wide id. So there was nothing to send a signal to.

With NPTL, you have two calls - getpid() and gettid(). If you send a
signal to a process, any eligible thread within the process can handle it.
Some special signals, such as SIGSTOP are handled by all threads within
a process, so that you can cleanly Ctrl+Z a multithreaded process.

	-Arun


-------------------------------------------------------
This SF.Net email is sponsored by: IBM Linux Tutorials
Free Linux tutorial presented by Daniel Robbins, President and CEO of
GenToo technologies. Learn everything from fundamentals to system
administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click