Date: Thu, 01 Oct 1998 16:41:49 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> Cc: Alex Nash <nash@mcs.net>, John Birrell <jb@FreeBSD.ORG>, 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 Message-ID: <2346.907252909@critter.freebsd.dk> In-Reply-To: Your message of "Thu, 01 Oct 1998 10:40:22 EDT." <199810011440.KAA20723@khavrinen.lcs.mit.edu>
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You guys are overlooking what the variable is there for. In message <199810011440.KAA20723@khavrinen.lcs.mit.edu>, Garrett Wollman write s: ><<On Thu, 1 Oct 1998 09:28:57 -0500, Alex Nash <nash@mcs.net> 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 > -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." "ttyv0" -- What UNIX calls a $20K state-of-the-art, 3D, hi-res color terminal
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