Re: GDB does not step into or over "sleep" function

[Denset dot Serralta at radisys dot com]

                    Jim Blandy                                                                                          
                    <jimb@zwingli.cygn        To:     Denset.Serralta@radisys.com                                       
                    us.com>                   cc:     gdb@sources.redhat.com                                            
                    Sent by:                  Subject:     Re: GDB does not step into or over "sleep" function          
                    gdb-owner@sources.                                                                                  
                    redhat.com                                                                                          
                                                                                                                        
                                                                                                                        
                    11/28/00 08:07 PM                                                                                   
                                                                                                                        
                                                                                                                        






Jim Blandy wrote:
>Let me make sure I understand.  If you have code like this:
>
>    ... some code ...
>    ProcessSleep (...);
>    ... some more code ...
>
>and you set a breakpoint on the `some more code' line, your program
>hangs and never reaches the breakpoint.

>But if you run the program without GDB, it sleeps the expected amount
>of time, and then continues normally.


Thanks for responding

You are correct. The breakpoint in  "...some more code ..." is never
reached. We are suspecting
at the moment that it is a problem with the ProcessSleep function since the
hang occurrs when we
'step into' or 'step over' it. What we don't know is whether it is a
problem with our underlying kernel
functions or whether GDB has a problem with a "sleep" function which
allocates a semaphore,
blocks on it subject to a user specified timeout and then returns the
semaphore. We are leaning
to suspecting that it is a problem with our custom kernel (i.e. GDB is
innocent). However I thought
I would ask the GDB group, with all the combined experience developing GDB,
just in case they
saw something obvious.

Thanks again
Denset.Serralta@radisys.com


>Denset.Serralta@radisys.com writes:
>> We are using GDB 4.18 on an NT host to debug target software running on
a
>> PowerPC based adapter. We are using a function called ProcessSleep which
is
>> a call to our kernel.  It basically allocates a semaphore, blocks on it
>> subject to a user specified timeout and then returns the semaphore.One
>> problem we can't seem to get around though is that if the process being
>> debugged makes a 'ProcessSleep' call, the debugger never gains control
when
>> we step over it.  Even if we set a breakpoint past the call and let it
run,
>> it never returns.  A status utility that we have shows the process as
>> queued, but we never regain control.  Does anybody know any reason(s)
why
>> this should happen.