Re: [Valgrind-users] valgrind and poll()

[Jeff J. <jb...@re...>]

On Wed, Apr 02, 2003 at 07:02:19PM +0200, David Eriksson wrote:
> Hello,
> 
> First, the obligatory credits: Thank you very much for writing valgrind!
> 
> When I recently subscribed to this mailing list I read a message from
> Nicholas Nethercote where he said that 1.9.4 was more stable and worked
> better than 1.0.4 so I thought I'd give it a try.
> 
> However, it seems to me like something has changed between the two
> versions, maybe regarding the combination threads and sockets.
> 
> I am running RedHat 8.0, with the latest updates installed:
> 
>   kernel-2.4.18-27.8.0
>   glibc-2.3.2-4.80
>   gcc-3.2-7
> 
> The application I'm examining with valgrind is a threaded server
> application written in C that uses glib. It is quite large and
> complicated to install, so there is no point in providing it.
> 
> I have tried to make a scaled-down example to reproduce my problem. It
> is not finished yet, but I thought that I'll try to describe the problem
> in case anyone has any suggestions:
> 
> The server creates a unix socket and makes glib poll() the socket for
> events. A client connects to the server, which accept() the connection
> and creates a new thread for handling the connection.
> 
> By using simple "printf debugging" it seems like the the new thread
> never gets scheduled to run in valgrind 1.9.4.
> 
> For the fun of it, I tried to send a SIGHUP to my process. There is
> singal handler installed with signal() for SIGHUP, which gets executed
> properly. What also happens is that all threads (one for each connection
> that have been made to the server) get to run!
> 
> Do you have any ideas?

FYI: You're running a NPTL capable library with a NPTL deprived kernel.

Meanwhile, prefix your valgrind command with
	LD_ASSUME_KERNEL=2.2.5 valgrind ...
to force use of Good Old libpthread.

73 de Jeff

-- 
Jeff Johnson	ARS N3NPQ
jb...@re... (jb...@jb...)
Chapel Hill, NC