Re: Can GDB support "temporal breakpoints"?

On 10/30/2014 12:18 PM, [email protected] wrote:

>> I can also imagine a hack where you run a side program
>> that sleeps for the specified period of time and it sends SIGUSR1
>> (or whatever) to the inferior, and then have gdb catch SIGUSR1,
>> do whatever you want at that time,
>> and then resume the inferior (discarding the signal).
> 
> I'll investigate this solution, although I think I'll have the sma  
> intrusion problem (in the Linux kernel).

Alternatively, write a little Python.  You can subclass python's
gdb.Breakpoint to create new breakpoint types, and implement
the Breakpoint.stop method to adjust when the breakpoint causes
a stop or not.

See https://sourceware.org/gdb/onlinedocs/gdb/Breakpoints-In-Python.html

In your case, you'd return false if the time hasn't passed yet.
Something like:

class bp_timer (gdb.Breakpoint):
   def stop (self):
      if timer has elapsed
        return True
      return False
end

(gdb) python bp = bp_timer("function_foo")

Alternatively, write a convenience function in Python,
that handles the "has time elapsed time" part.  Then use that as
breakpoint's condition predicate.  Something along the lines of:

 (gdb) python mytimer = MyTimer(10)
 (gdb) break foo if $my_timer_elapsed_predicate(mytimer)

https://sourceware.org/gdb/onlinedocs/gdb/Functions-In-Python.html

Thanks,
Pedro Alves