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Mail Archives: cygwin/2008/08/19/05:43:00

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Date: Tue, 19 Aug 2008 11:43:59 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: cygwin 1.7 message queues can't open more than 1 queue?
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On Aug 18 18:43, Linh Phan wrote:
> Hi,
>
>  I downloaded cygwin 1.7 to use message queues but unfortunately, the 
> message queues only allows me to open
> 1 message queue.  If I try to open a second one, it fails with "Permission 
> denied".  Below is the test I used:
>
> #include <stdio.h>
> #include <mqueue.h>
> #include <fcntl.h>
> main()
> {
>  int flags = O_RDWR | O_NONBLOCK | O_CREAT | O_EXCL;
>  struct mq_attr attr;
>  char queue[33];
>  char *e;
>  mode_t mode = strtoul("644", &e, 8);
>  mqd_t mqd;
>
>  memset((void *) &attr, 0, sizeof(struct mq_attr));
>  attr.mq_maxmsg = (long) 10;
>  attr.mq_msgsize = (long) 24;
>
>  strcpy(queue, "/queue0");
>  mq_unlink(queue);
>  mqd = mq_open(queue, flags, mode, &attr);
>  strcpy(queue, "/queue1");
>  mq_unlink(queue);
>  mqd = mq_open(queue, flags, mode, &attr); // ALWAYS FAIL HERE WITH 
> "Permission denied"
>  perror("mq_open");
> }
>
> Does anyone know what I did wrong?

Nothing.  It's a bug in the DLL and while testing this, I found a
second one.  I'll apply the fixes shortly.

Thanks for the testcase!


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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