lib/thwait.rb
DEFINITIONS
This source file includes following functions.
1 #
2 # thwait.rb - thread synchronization class
3 # $Release Version: 0.9 $
4 # $Revision: 1.3 $
5 # $Date: 1998/06/26 03:19:34 $
6 # by Keiju ISHITSUKA(Nihpon Rational Software Co.,Ltd.)
7 #
8 # --
9 # feature:
10 # provides synchronization for multiple threads.
11 #
12 # class methods:
13 # * ThreadsWait.all_waits(thread1,...)
14 # waits until all of specified threads are terminated.
15 # if a block is supplied for the method, evaluates it for
16 # each thread termination.
17 # * th = ThreadsWait.new(thread1,...)
18 # creates synchronization object, specifying thread(s) to wait.
19 #
20 # methods:
21 # * th.threads
22 # list threads to be synchronized
23 # * th.empty?
24 # is there any thread to be synchronized.
25 # * th.finished?
26 # is there already terminated thread.
27 # * th.join(thread1,...)
28 # wait for specified thread(s).
29 # * th.join_nowait(threa1,...)
30 # specifies thread(s) to wait. non-blocking.
31 # * th.next_wait
32 # waits until any of specified threads is terminated.
33 # * th.all_waits
34 # waits until all of specified threads are terminated.
35 # if a block is supplied for the method, evaluates it for
36 # each thread termination.
37 #
38
39 require "thread.rb"
40 require "e2mmap.rb"
41
42 class ThreadsWait
43 RCS_ID='-$Id: thwait.rb,v 1.3 1998/06/26 03:19:34 keiju Exp keiju $-'
44
45 Exception2MessageMapper.extend_to(binding)
46 def_exception("ErrNoWaitingThread", "No threads for waiting.")
47 def_exception("ErrNoFinishedThread", "No finished threads.")
48
49 def ThreadsWait.all_waits(*threads)
50 tw = ThreadsWait.new(*threads)
51 if block_given?
52 tw.all_waits do |th|
53 yield th
54 end
55 else
56 tw.all_waits
57 end
58 end
59
60 def initialize(*threads)
61 @threads = []
62 @wait_queue = Queue.new
63 join_nowait(*threads) unless threads.empty?
64 end
65
66 # accessing
67 # threads - list threads to be synchronized
68 attr :threads
69
70 # testing
71 # empty?
72 # finished?
73
74 # is there any thread to be synchronized.
75 def empty?
76 @threads.empty?
77 end
78
79 # is there already terminated thread.
80 def finished?
81 !@wait_queue.empty?
82 end
83
84 # main process:
85 # join
86 # join_nowait
87 # next_wait
88 # all_wait
89
90 # adds thread(s) to join, waits for any of waiting threads to terminate.
91 def join(*threads)
92 join_nowait(*threads)
93 next_wait
94 end
95
96 # adds thread(s) to join, no wait.
97 def join_nowait(*threads)
98 threads.flatten!
99 @threads.concat threads
100 for th in threads
101 Thread.start(th) do |t|
102 t.join
103 @wait_queue.push t
104 end
105 end
106 end
107
108 # waits for any of waiting threads to terminate
109 # if there is no thread to wait, raises ErrNoWaitingThread.
110 # if `nonblock' is true, and there is no terminated thread,
111 # raises ErrNoFinishedThread.
112 def next_wait(nonblock = nil)
113 ThreadsWait.fail ErrNoWaitingThread if @threads.empty?
114 begin
115 @threads.delete(th = @wait_queue.pop(nonblock))
116 th
117 rescue ThreadError
118 ThreadsWait.fail ErrNoFinishedThread
119 end
120 end
121
122 # waits until all of specified threads are terminated.
123 # if a block is supplied for the method, evaluates it for
124 # each thread termination.
125 def all_waits
126 until @threads.empty?
127 th = next_wait
128 yield th if block_given?
129 end
130 end
131 end
132
133 ThWait = ThreadsWait