Re: M-x compile output sometimes delayed

[Eli Zaretskii]

Dan Jacobson wrote:
> 
> In makefile I have
> z:
>         set -x;until test $$((retrys++)) -gt 9; do sleep 4;done
> 
> I do M-x compile.  I see the output in fits and starts, not every 4
> seconds.  Sometimes it comes out line by line, sometimes it takes me
> hitting say even the Shift key to stimulate it into spitting out
> output.  Odd, as my processor is 99% idle.

I think you forget about I/O buffering.  Emacs runs subordinate processes
via a pipe, and pipes are buffered by the system.

In addition, Emacs only checks whether there was input from a subprocess
when it's not busy doing other things, so that could account for additional
delays.