Date: Mon, 16 May 2005 22:17:04 +0200
From: Patrick Plattes <patrick@erdbeere.net>
To: linux-kernel@vger.kernel.org
Subject: semaphore understanding: sys_semtimedop()
Message-ID: <20050516201704.GA9836@erdbeere.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.5.9i
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1298
Lines: 40

Hello,

i have a question about this little code snippet, found in
sys_semtimedop() (ipc/sem.c):

        for (sop = sops; sop < sops + nsops; sop++) {
                if (sop->sem_num >= max)
                        max = sop->sem_num;
                if (sop->sem_flg & SEM_UNDO)
                        undos++;
                if (sop->sem_op < 0)
                        decrease = 1;
                if (sop->sem_op > 0)
                        alter = 1;
        }
        alter |= decrease;

The variable decrease will never be used again in this 
function, so why this intricate code? Isn't this much easier and works
also:

        for (sop = sops; sop < sops + nsops; sop++) {
                if (sop->sem_num >= max)
                        max = sop->sem_num;
                if (sop->sem_flg & SEM_UNDO)
                        undos++;
                if (sop->sem_op != 0)
                        alter = 1;
        }

Maybe i'm totally wrong, so please correct me and don't shoot me up,
'cause i'm not a os developer.

Thanks,
  Patrick
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/