Subject: Re: select call implementation and threads
To: malleswararao venkatanaga <firstname.lastname@example.org>
From: Andrey Petrov <email@example.com>
Date: 05/24/2003 06:32:09
On Fri, May 23, 2003 at 09:50:02AM -0700, malleswararao venkatanaga wrote:
> I'm facing a problem and it is somewhat like this,
> 1)I spawn a thread using pthread_create()
> 2) In the thread I open a socket, bind it to a port
> say 10001 and block it in the select call for
> receiving a UDP message.
> In my main thread i open a socket and bind it to a
> port say 10000 and block the main thread in a select
> Both the main thread and the other thread are
> essentially waiting for different messages on
> different ports and different socket fds with their
> respective select calls.
> I observe that if i send a messages to both of them
> only one of them receives while the other one is still
> blocked in the select call though it has messages to
Good thing about userland's threads is that it's easy to debug:
build pth library and your applicarion with '-g' and you'll
get the full picture of what's going on.
The behavouir you described is strange: select is normally
redefined to pth_select and that supposed to take care of swiching
betwean threads. Well, you can post your application here...