From owner-cvs-all Thu Oct 1 07:41:00 1998 Return-Path: Received: (from daemon@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA28790 for cvs-all-outgoing; Thu, 1 Oct 1998 07:41:00 -0700 (PDT) (envelope-from owner-cvs-all) Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA28771; Thu, 1 Oct 1998 07:40:40 -0700 (PDT) (envelope-from wollman@khavrinen.lcs.mit.edu) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.1/8.9.1) id KAA20723; Thu, 1 Oct 1998 10:40:22 -0400 (EDT) (envelope-from wollman) Date: Thu, 1 Oct 1998 10:40:22 -0400 (EDT) From: Garrett Wollman Message-Id: <199810011440.KAA20723@khavrinen.lcs.mit.edu> To: Alex Nash Cc: Poul-Henning Kamp , John Birrell , cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/lib/libc_r/uthread uthread_gc.c Makefile.inc uthread_init.c uthread_find_thread.c uthread_kern.c uthread_create.c uthread_exit.c In-Reply-To: <19981001092857.C7057@mcs.net> References: <19980930192221.S9697@pr.mcs.net> <368.907228926@critter.freebsd.dk> <19981001092857.C7057@mcs.net> Sender: owner-cvs-all@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk < said: > On Thu, Oct 01, 1998 at 10:02:06AM +0200, Poul-Henning Kamp wrote: >> Alex, can we constrain ourselves to >actual< problems rather than >> theoretically-possible-on-really-stupid-machines-problems ? > The atomicity of malloc_active++ is compiler dependent, not > really-stupid-machine dependent. And, in particular, it may not be atomic on a three-operand RISC machine. Imagine the following code sequence on an imaginary processor: addil $malloc_active, %r0, %r1 addl (%r1), %r0, %r2 addil $1, %r2, %r3 addl %r3, %r0, (%r1) -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick