Re: Running two processes rapidly makes Emacs eat 100% CPU on w32

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 12 Oct 2006 15:52:20 +0200
> From: Slawomir Nowaczyk <slawomir.nowaczyk.847@student.lu.se>
> 
> Thanks for the advice, I managed to activate DebPrint. I have added one
> which prints the return value of w32proc:sys_select, and it is "1"
> consistently. None of the DebPrint statements already present in this
> function gets executed, neither in normal work nor when Emacs eats all
> the CPU.
> 
> Your guess that sys_select is to be blamed was likely correct, though,
> as (under normal circumstances) my newly added DebPrint executes a
> couple of times per second, while after I execute the problematic code,
> it gets called thousands of times per second.
> 
> There were two DebPrint statements guarded by FULL_DEBUG, but I have
> activated those as well. Now the one from line 1175:
> 		DebPrint (("select waiting on child %d fd %d\n",
> 			   cp-child_procs, i));
> keeps printing "select waiting on child 0 fd 3" (thousands of times per
> second, every time sys_select is called.

Looks like somehow Emacs doesn't pay attention that the process
exited, and keeps trying to read its pipe.  Do you agree with this
conclusion?