Problems with multi-threaded application debugging

[Ulisses Furquim]

Hi,

I was doing some tests trying to debug a simple multi-threaded
application and noticed some strange gdb behaviors:

 - sometimes when you "continue" gdb doesn't stop at a breakpoint
inside some of the threads;
 - sometimes when you try to single step (with "next") all the threads
run until the program exits;
 - I was trying to use the scheduler-locking variable (setting it to
"on"), but it seems I can single step on only one thread. I mean, If I
switch to another thread and try to single step it, gdb switches back
to the previous thread.

Does anybody have any idea? Is this the expected behavior of gdb?

Best regards,

-- Ulisses