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Re: gdb drops out with 'I/O possible message'


On Monday 31 October 2005 09:43, Andreas Schwab wrote:
>
> Some process (ruby?) is probably enabling async I/O on stdin, which causes
> all processes in the same process group to receive SIGIO whenever
> something is available to be read on stdin.  Then the process crashes and
> has no chance to disable async I/O.  With the next debugging session a new
> process group is created, but the SIGIO signals are still sent to the old
> (now defunct) process group, effectively dropping them on the floor.

So is gdb in the same process group as the debug target process? (FWIW the 
process in question forks off several other processes) And will receive the 
same SIGIOs?

It just looks like gdb is catching a SIGIO and exiting...

In other (non ruby) applications where I have seen this problem, I do

	std::ios::sync_with_stdio(false)

which presumably enables async I/O on stdin/stdout etc.

Hmmm

Anyhow; I'll try the gdb inside gdb thing next time I can prodice this 
behaviour with any regularity.

Thanks

Andrew Walrond


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