From: cgf AT cygnus DOT com (Christopher G. Faylor)
Subject: Re: do_exit and signals?
12 Jun 1998 02:13:50 GMT
Message-ID: <6lq2su$fsj$1@cronkite.cygnus.com>
References: <m0ykAHT-00118cC DOT cygnus DOT cygwin32 DOT developers AT malasada DOT lava DOT net>
X-Newsreader: trn 4.0-test63 (15 March 1998)

In article <m0ykAHT-00118cC DOT cygnus DOT cygwin32 DOT developers AT malasada DOT lava DOT net>,
Tim Newsham <newsham AT lava DOT net> wrote:
>    Got a question.  The do_exit() function (in dcrt0.cc) closes
>all the open files and then does sigproc_terminate to stop signal
>processing.  Is there any reason the files should be closed first?

If the order is reversed then if there is a problem closing handles
that would have generated a signal, you'll never see the signal.

>During some high-load processing with lots of processes we occasionally
>see hung processes and once in a while a Dr Watson.  I attached to
>one of the hung process at one point and got a stack trace and noticed:
>
>       call handler
>       .... (2 0x77f6xxxx addresses) ...
>       _close
>       close_all_files
>       do_exit
>       _exit
>
>This process was unkillable in cygwin.  I'm not sure what was going
>on here.  Would it help to disable signals earlier in the _exit sequence?

A process could be unkillable if it is blocked in some kind of I/O when
cygwin tries to call a signal handler.

>We've also seen two other anomolies recently that we haven't seen
>more than once:
>
>    - commit_and_ic: Virtual Alloc Failed  (is this a standard
>          "out of memory" type of error?)

Don't know what this is.

>    - call_handler: ouldn't[sic] get context of main thread.  err 6
>          (this was printed every time we tried to kill the process)

Well, the misspelling is fixed, but other that that, I don't know what
could have caused this.  It sounds like the main thread died in that
process but other threads were still executing.
-- 
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