From owner-cvs-all@FreeBSD.ORG Sun Mar 11 00:11:33 2007 Return-Path: X-Original-To: cvs-all@freebsd.org Delivered-To: cvs-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B3D8516A404 for ; Sun, 11 Mar 2007 00:11:33 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.169]) by mx1.freebsd.org (Postfix) with ESMTP id 32FDC13C46B for ; Sun, 11 Mar 2007 00:11:33 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by ug-out-1314.google.com with SMTP id 71so1687980ugh for ; Sat, 10 Mar 2007 16:11:32 -0800 (PST) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=jtto1Y5cvq/AXU+YeUSlsr0V277ZZW8xmQDmpwu5GvI6qXuK+rwqq/ZzBg6Rdd4L9KcqJc7YrC0rNj8udZT0vjqGhxLbDh6awoDpNZFH2MqZGKSXKIulwZZEfFlYjZ9HCQc/gehQ6JBbS9WS+PFUvq7/eWusi82e1Vz1LoM7sy8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=t1m9F5aQ91zv2LScrbPrnErRCw/1W+8xhQIIbME2UMRhKeq3DFG7aKKiC6B7MuHpYp2VkVd+66JlmaojrQC25eDQMzvWN0Z094RAftDISLkXOAts+zXAJFDx+EOzhMsRAB3L8mUe/RQkXQVSzttGEo0OYQNSFoszViR1fphI6sM= Received: by 10.70.90.18 with SMTP id n18mr6545316wxb.1173571891599; Sat, 10 Mar 2007 16:11:31 -0800 (PST) Received: by 10.100.191.11 with HTTP; Sat, 10 Mar 2007 16:11:31 -0800 (PST) Message-ID: <3bbf2fe10703101611r60d6e1c5o8ef5fcf309fbf0e3@mail.gmail.com> Date: Sun, 11 Mar 2007 01:11:31 +0100 From: "Attilio Rao" Sender: asmrookie@gmail.com To: "Pawel Jakub Dawidek" In-Reply-To: <20070310205236.GA9185@garage.freebsd.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200703092241.l29Mf2Ds062856@repoman.freebsd.org> <200703091747.07617.jhb@freebsd.org> <3bbf2fe10703100344w1f2464f0q68086a5af7c4f63c@mail.gmail.com> <20070310205236.GA9185@garage.freebsd.pl> X-Google-Sender-Auth: 3bccc7bf73d47952 Cc: cvs-src@freebsd.org, src-committers@freebsd.org, John Baldwin , cvs-all@freebsd.org Subject: Re: cvs commit: src/share/man/man9 Makefile condvar.9 lock.9 mi_switch.9 mtx_pool.9 mutex.9 rwlock.9 sleep.9 sleepqueue.9 sx.9 thread_exit.9 src/sys/kern kern_synch.c src/sys/sys mutex.h rwlock.h sleepqueue.h sx.h systm.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Mar 2007 00:11:33 -0000 2007/3/10, Pawel Jakub Dawidek : > On Sat, Mar 10, 2007 at 12:44:26PM +0100, Attilio Rao wrote: > > 2007/3/9, John Baldwin : > > >I don't have a date set for removing msleep(), esp. given it's wide use. > > >I would like to remove it and all the spl*() functions in 8.0 if we can > > >swing it. > > > > > >I also have patches to let condition variables work with rwlocks and sx > > >locks, but the current implementation results in an API "explosion" > > >since each of the cv_*wait*() functions grows a cv_*wait*_rw() version for > > >rwlocks and a cv_*waut*_sx() version for use with sx locks. One possibility > > >would be to just cast the lock argument to (struct lock_object *) since all > > >of our locks have a lock_object as the first member, but then you use having > > >the compiler do type checking, and I'm really not willing to give up on > > >that. Too easy to have evil bugs that way. I suppose we could use some > > >evil macro that used typeof() but that would be very gcc specific? > > > > > >I guess one other possibility is to standardize on the field name for > > >the lock_object, calling it lo_object instead of mtx_object, rw_object, > > >sx_object, etc. Anyone else have any ideas? > > > > What about adding a new function like: > > > > static __inline struct lock_object * > > mtx_export_lc(struct mtx *m) > > { > > > > return (&m->mtx_object); > > } > > > > to be per-interface (so having sx_export_lc() and rw_export_lc() too) > > and than using in this way: > > > > static struct mtx foo_lock; > > static struct cv foo_cv; > > ... > > > > mtx_lock(&foo_lock); > > ... > > cv_wait(&foo_cv, mtx_export_lc(&foo_lock)); > > > > (obviously using new struct lock_object methods you added for locking/unlocking) > > > > It sounds reasonable to you? > > This is ugly. If we really need to provide information about which type > of lock we are using, I'd probably prefer cv_wait_(). > > What about something like this: > > #define cv_wait(cv, lock) do { > switch (LO_CLASSINDEX((struct lock_object *)(lock))) { > case 1: > cv_wait_mtx(cv, lock); > break; > case 2: > cv_wait_sx(cv, lock); > break; > case 3: > cv_wait_rw(cv, lock); > break; > default: > panic("Invalid lock."); > } > } while (0) This is exactly what John is trying to avoid. You have however to export cv_wait_*() & friends in the public namespace and at this point you don't need such wrapper. I know it is not so elegant, but the other solutions are uglier. Having a function returning the lock object per-primitive is the most suitable, IMHO. Attilio -- Peace can only be achieved by understanding - A. Einstein