I'm trying to debug an emacs problem, and I'm running into something
I don't understand involving Cygwin's select. I'll try to make an
STC if necessary, but I thought I'd start with a verbal description
in case there's an easy answer. Here's the situation:
emacs creates a subprocess running gdb and sends a bunch of commands
to gdb without immediately reading the resulting output. emacs then
goes into a loop in which it waits for keyboard input and
periodically calls select to check for output from subprocesses.
The first call to select has a 30 second timeout and *always* fails
with EINTR. As a result, emacs doesn't read the output from gdb
right away and doesn't properly initialize the gdb buffer.
Subsequent calls to select sometimes succeed and sometimes fail.
When I'm running emacs under gdb and stepping through it, the buffer
eventually gets initialized. When I'm running emacs outside of gdb,
the buffer doesn't get initialized until I press Return.
I have a simple workaround for this, but I'd like to be sure there
isn't some underlying bug that I'm masking with the workaround. So
my question is this: Is there some reason that I should expect that
first call to select to consistently fail with EINTR, or might this
indicate a bug?
I realize that it might not be possible to answer the question based
on the information I've provided, but I thought it was worth a try.