Re: Is the current gdb 5.1 broken for Linuxthreads?

[Andrew Cagney <ac131313 at cygnus dot com>]

> I already started a thread to explain that that stopping all threads in
> a synchronous way was an illusion: Think of a 2-way processor on which
> 2 threads are running on each processor: If one thread stops, the time
> required by one processor to handle the trap, discover that others
> threads must be stopped, makwe the interprocessor request, ... allows
> the other thread to run thousands of instructions on the second
> processor before being stopped. The result is that you think all threads
> have stopped at the same time, while it's false, even if you have the best
> interface you can think of.

Just an aside, everyone will agree with your point that synchronized 
thread stop model is an illusion.  However, that doesn't make the 
model/illusion wrong.  Most other systems still make a synchronised halt 
interface available since it is simple and fast - the complexity of 
having to suspend all related threads being constrained to the kernel.

As a separate issue, it would be good if GDB was able to control threads 
with a finer guranularity then all/none running.

enjoy,
Andrew