From owner-freebsd-stable Fri Jul 9 20:56:14 1999 Delivered-To: freebsd-stable@freebsd.org Received: from netrinsics.com (unknown [210.74.177.14]) by hub.freebsd.org (Postfix) with ESMTP id 6ECFD14D07 for ; Fri, 9 Jul 1999 20:56:06 -0700 (PDT) (envelope-from robinson@netrinsics.com) Received: (from robinson@localhost) by netrinsics.com (8.9.3/8.8.7) id LAA24952 for freebsd-stable@freebsd.org; Sat, 10 Jul 1999 11:55:21 +0800 (CST) (envelope-from robinson) Date: Sat, 10 Jul 1999 11:55:21 +0800 (CST) From: Michael Robinson Message-Id: <199907100355.LAA24952@netrinsics.com> To: freebsd-stable@freebsd.org Subject: Persistent IPC locks in FreeBSD? Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Under Solaris, you can initialize a pthread_mutex_t in mmapped memory that can be shared by any process that mmaps the same object, even after the first process exits. This has the advantage that the mutex is tightly and unambiguously bound to the data in the mmapped file, even through reboots (or even kernel upgrades), and is automatically removed when the mmapped file is deleted or reinitialized. From what I can tell from the documentation, this sort of persistent IPC behavior is unavailable for a FreeBSD pthread_mutex. Furthermore, the alternative--SysV semaphores--have problematic creation, persistence, and destruction semantics. Is this basically the way it is, and I just have to live with it, or have I overlooked something? -Michael Robinson To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message