Showing results for 
Search instead for 
Did you mean: 

Archives Discussions

Journeyman III

SDK registers a signal handler, which appears to just call exit()

I've been developing a multithreaded OpenCL/OpenGL application (see my website for more information).

I've got a problem in that the SDK registers a signal handler at some point, and responds to SIGINT with an exit(). This is very annoying as it doesn't give my threads a chance to clean themselves up as they don't exit cleanly. I'll have to use pthread cleanup handlers to fix this.

Does the SDK have to register a signal handler? Can someone explain why this behaviour is required and if it can be disabled?

3 Replies
Journeyman III

I've done some more research and programming. My threads now respond to an exit() correctly and clean up, but I would still like to stop a SIGINT from calling exit().

If I run my code in gdb, and trigger a SIGINT, the signal handler jumps straight to

#0  0x00007fffe3636ef0 in ?? () from /usr/lib/
#1  <signal handler called>

So I ran strace to find when the signal handler is registered by the library, but I cannot find it. I tried setting a new signal handler periodically and it still won't use my signal handler. My handler works great however if I don't boot the OpenCL part of the code.

I'm guessing it's registered in some unusual manner?

I would like to register my own handler for SIGINT, any clues on how I can do this?


In SDK 2.3 it is true that LLVM installed a SIGINT handler.  This has been changed for SDK 2.4, the system will no longer install a handler.  You can install your own handlers in your application if you want to.


Hey, thanks for the reply!

It's good to know the signal handler will be removed. I tried periodically installing my own signal handler in my program but it seems to ignore my sigaction call. I guess if you've changed the SDK my problem will go away soon enough.