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Re: Recursive mutexes?
From: |
Rob Browning |
Subject: |
Re: Recursive mutexes? |
Date: |
Sun, 27 Oct 2002 12:44:55 -0600 |
User-agent: |
Gnus/5.090006 (Oort Gnus v0.06) Emacs/21.2 (i386-pc-linux-gnu) |
Marius Vollmer <address@hidden> writes:
> I meant: there is a good reason that waiting on a condition variable
> requires you to have a locked mutex that is the atomically unlocked.
> Without this, I guess you will have a hard time avoiding race
> conditions. Using mutexes in a strange way to simulate this is
> probably wrong.
Ahh, right. I presume you mean the deadlock case of blocking after
you've already been signalled -- yeah mutexes (at least posix style)
aren't the best thing there, but I'd generally use a 0 token sempahore
for that. Then if you're the one about to block, the signaller will
either already have deposited the token, or will after you block.
I have to keep reminding myself that mutexes aren't semaphores here.
I keep forgetting that because I did a whole lot of thread programming
in a system where we arranged for mutexes to be a special case
(one-token) semaphore. This meant it was supposed to be OK for others
to signal, etc.
--
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
GPG=1C58 8B2C FB5E 3F64 EA5C 64AE 78FE E5FE F0CB A0AD
- Re: Recursive mutexes?, (continued)
- Re: Recursive mutexes?, Thomas Bushnell, BSG, 2002/10/26
- Re: Recursive mutexes?, Tom Lord, 2002/10/26
- Re: Recursive mutexes?, Tom Lord, 2002/10/26
- Re: Recursive mutexes?, Thomas Bushnell, BSG, 2002/10/26
Re: Recursive mutexes?, Tom Lord, 2002/10/26
Re: Recursive mutexes?, Marius Vollmer, 2002/10/26