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Date: Fri, 18 May 2001 23:04:43 -0400
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin-developers AT cygwin DOT com
Subject: Re: pthread gotchas
Message-ID: <20010518230443.A26250@redhat.com>
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References: <20010518221107 DOT A12195 AT redhat DOT com> <021a01c0e00b$e8d48dc0$0200a8c0 AT lifelesswks> <20010518224535 DOT A26035 AT redhat DOT com> <023001c0e00e$9e96c9a0$0200a8c0 AT lifelesswks>
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In-Reply-To: <023001c0e00e$9e96c9a0$0200a8c0@lifelesswks>; from robert.collins@itdomain.com.au on Sat, May 19, 2001 at 12:51:34PM +1000

On Sat, May 19, 2001 at 12:51:34PM +1000, Robert Collins wrote:
>----- Original Message -----
>From: "Christopher Faylor" <cgf AT redhat DOT com>
>To: <cygwin-developers AT cygwin DOT com>
>Sent: Saturday, May 19, 2001 12:45 PM
>Subject: Re: pthread gotchas
>
>> On Sat, May 19, 2001 at 12:32:10PM +1000, Robert Collins wrote:
>> >>work with pthreads.  I ran the program on linux.
>>                        ^^^^^^^^^^^^^^^^^^^^^^^^^^
>
>I'm just guessing here, but you would like me to actually read what you
>write? I guess that mental telepathy isn't as good as we thought :]

:-)  I've been misreading so much email lately that it is very hard for
me to cast any stones.

>> This email was talking about linux.  I ran the program on linux first so
>> that I could get a feel for how it was supposed to work and was
>> surprised to find that linux broke my perceptions.
>
>openBSD  test results:
>
>in subproc, sleeping
>in parent, starting thread, pid 12819in tf, waiting for 12819
>0 = pthread_create
>in subproc, exiting
>12819 = waitpid
>waitpid: Undefined error: 0
>returning
>0 = pthread_join
>exiting

Phew.  This is what I was expecting.

>> I have included my test program below.  The waitpid, which is invoked
>in
>> the secondary thread fails unless I move the fork into the same
>thread.
>
>I haven't looked into why yet.
>
>> #include <stdio.h>
>> #include <pthread.h>
>> #include <wait.h>
>
>btw: wait.h should be sys/wait according to the SUS.

You're right.  I changed this but there was not difference in behavior,
of course.

cgf