Subj : dlopen and semaphores
To   : comp.programming.threads
From : Orioniz
Date : Mon Feb 14 2005 08:44 am

Hi,

I have a multithreaded program for linux. It has two threads (lets call
then A and B). B performs some function that A needs. A sends a message
to B to perform that function, and passes along a pointer to a sem_t
object. Once A has send the message, it calls sem_wait. When B receives
the msg, it performs the desired function and calls sem_post. This
works fine.

However, when I put the code for A into a dynamic library, and start
thread A with a pointer to a function in the dynamic library, things go
wrong. A starts fine and still sends the message, B still performs the
function and calls sem_post (returns 0) but A never gets past the
sem_wait, even though sem_post was called on it.

Why? I cannot find any reason. Any thoughts would be greatly
appreciated. 

Bart

.