From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <ee9e417a0610221621h2a35a87bha7ff9c33f2d1c3b7@mail.gmail.com>
Date: Sun, 22 Oct 2006 19:21:37 -0400
From: "Russ Cox" <rsc@swtch.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: Re: [9fans] Semaphores
In-Reply-To: <7871fcf50610221605y124a0b9dnccd7e3e420a0ad03@mail.gmail.com>
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You can't use signals for wakeup on Plan 9.
There is no sigprocmask to turn off note delivery
(so no atomic sections) and no sigsuspend
(so no atomic check a condition and go to sleep).

Instead you need to use rendezvous(2).

For a good example of using rendezvous to
do sleep and wakeup, read the implementation
of qlock, in /sys/src/libc/9sys/qlock.c.  Everywhere
it says (*_rendezvousp) just pretend it says
rendezvous.  (The thread library replaces the
rendezvous that qlock uses, but that detail is
not relevant here.)

Russ