clic/3rdparties/software/bordeaux-threads-v0.8.7/src/condition-variables.lisp

3rdparties/software/bordeaux-threads-v0.8.7/src/condition-variables.lisp (1053 bytes)

1 ;;;; -*- indent-tabs-mode: nil -*-
2 
3 #|
4 Copyright 2006, 2007 Greg Pfeil
5 
6 Distributed under the MIT license (see LICENSE file)
7 |#
8 
9 (in-package #:bordeaux-threads)
10 
11 ;;; This file provides a portable implementation of condition
12 ;;; variables (given a working WITH-LOCK-HELD and THREAD-YIELD), and
13 ;;; should be used if there is no condition variable implementation in
14 ;;; the host Lisp.
15 
16 (defstruct condition-var
17   name
18   lock
19   active)
20 
21 (defun condition-wait (condition-variable lock &key timeout)
22   (signal-error-if-condition-wait-timeout timeout)
23   (check-type condition-variable condition-var)
24   (setf (condition-var-active condition-variable) nil)
25   (release-lock lock)
26   (do ()
27       ((when (condition-var-active condition-variable)
28          (acquire-lock lock)
29          t))
30     (thread-yield))
31   t)
32 
33 (define-condition-wait-compiler-macro)
34 
35 (defun condition-notify (condition-variable)
36   (check-type condition-variable condition-var)
37   (with-lock-held ((condition-var-lock condition-variable))
38     (setf (condition-var-active condition-variable) t)))