1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
|
require 'monitor'
require 'thread'
require 'drb/drb'
require 'rinda/rinda'
module Rinda
class TupleEntry
include DRbUndumped
def initialize(ary, sec=nil)
@cancel = false
@ary = make_tuple(ary)
@renewer = nil
renew(sec)
end
attr_accessor :expires
def cancel
@cancel = true
end
def alive?
!canceled? && !expired?
end
def value; @ary.value; end
def canceled?; @cancel; end
def expired?
return true unless @expires
return false if @expires > Time.now
return true if @renewer.nil?
renew(@renewer)
return true unless @expires
return @expires < Time.now
end
def renew(sec_or_renewer)
sec, @renewer = get_renewer(sec_or_renewer)
@expires = make_expires(sec)
end
def make_expires(sec=nil)
case sec
when Numeric
Time.now + sec
when true
Time.at(1)
when nil
Time.at(2**31-1)
end
end
def [](key)
@ary[key]
end
def size
@ary.size
end
def make_tuple(ary)
Rinda::Tuple.new(ary)
end
private
def get_renewer(it)
case it
when Numeric, true, nil
return it, nil
else
begin
return it.renew, it
rescue Exception
return it, nil
end
end
end
end
class TemplateEntry < TupleEntry
def initialize(ary, expires=nil)
super(ary, expires)
@template = Rinda::Template.new(ary)
end
def match(tuple)
@template.match(tuple)
end
def ===(tuple)
match(tuple)
end
def make_tuple(ary)
Rinda::Template.new(ary)
end
end
class WaitTemplateEntry < TemplateEntry
def initialize(place, ary, expires=nil)
super(ary, expires)
@place = place
@cond = place.new_cond
@found = nil
end
attr_reader :found
def cancel
super
signal
end
def wait
@cond.wait
end
def read(tuple)
@found = tuple
signal
end
def signal
@place.synchronize do
@cond.signal
end
end
end
class NotifyTemplateEntry < TemplateEntry
def initialize(place, event, tuple, expires=nil)
ary = [event, Rinda::Template.new(tuple)]
super(ary, expires)
@queue = Queue.new
@done = false
end
def notify(ev)
@queue.push(ev)
end
def pop
raise RequestExpiredError if @done
it = @queue.pop
@done = true if it[0] == 'close'
return it
end
def each
while !@done
it = pop
yield(it)
end
rescue
ensure
cancel
end
end
class TupleBag
def initialize
@hash = {}
end
def push(ary)
size = ary.size
@hash[size] ||= []
@hash[size].push(ary)
end
def delete(ary)
size = ary.size
@hash.fetch(size, []).delete(ary)
end
def find_all(template)
@hash.fetch(template.size, []).find_all do |tuple|
tuple.alive? && template.match(tuple)
end
end
def find(template)
@hash.fetch(template.size, []).find do |tuple|
tuple.alive? && template.match(tuple)
end
end
def find_all_template(tuple)
@hash.fetch(tuple.size, []).find_all do |template|
template.alive? && template.match(tuple)
end
end
def delete_unless_alive
deleted = []
@hash.keys.each do |size|
ary = []
@hash[size].each do |tuple|
if tuple.alive?
ary.push(tuple)
else
deleted.push(tuple)
end
end
@hash[size] = ary
end
deleted
end
end
class TupleSpace
include DRbUndumped
include MonitorMixin
def initialize(timeout=60)
super()
@bag = TupleBag.new
@read_waiter = TupleBag.new
@take_waiter = TupleBag.new
@notify_waiter = TupleBag.new
@timeout = timeout
@period = timeout * 2
@keeper = keeper
end
def write(tuple, sec=nil)
entry = TupleEntry.new(tuple, sec)
synchronize do
if entry.expired?
@read_waiter.find_all_template(entry).each do |template|
template.read(tuple)
end
notify_event('write', entry.value)
notify_event('delete', entry.value)
else
@bag.push(entry)
@read_waiter.find_all_template(entry).each do |template|
template.read(tuple)
end
@take_waiter.find_all_template(entry).each do |template|
template.signal
end
notify_event('write', entry.value)
end
end
entry
end
def take(tuple, sec=nil, &block)
move(nil, tuple, sec, &block)
end
def move(port, tuple, sec=nil)
template = WaitTemplateEntry.new(self, tuple, sec)
yield(template) if block_given?
synchronize do
entry = @bag.find(template)
if entry
port.push(entry.value) if port
@bag.delete(entry)
notify_event('take', entry.value)
return entry.value
end
raise RequestExpiredError if template.expired?
begin
@take_waiter.push(template)
while true
raise RequestCanceledError if template.canceled?
raise RequestExpiredError if template.expired?
entry = @bag.find(template)
if entry
port.push(entry.value) if port
@bag.delete(entry)
notify_event('take', entry.value)
return entry.value
end
template.wait
end
ensure
@take_waiter.delete(template)
end
end
end
def read(tuple, sec=nil)
template = WaitTemplateEntry.new(self, tuple, sec)
yield(template) if block_given?
synchronize do
entry = @bag.find(template)
return entry.value if entry
raise RequestExpiredError if template.expired?
begin
@read_waiter.push(template)
template.wait
raise RequestCanceledError if template.canceled?
raise RequestExpiredError if template.expired?
return template.found
ensure
@read_waiter.delete(template)
end
end
end
def read_all(tuple)
template = WaitTemplateEntry.new(self, tuple, nil)
synchronize do
entry = @bag.find_all(template)
entry.collect do |e|
e.value
end
end
end
def notify(event, tuple, sec=nil)
template = NotifyTemplateEntry.new(self, event, tuple, sec)
synchronize do
@notify_waiter.push(template)
end
template
end
private
def keep_clean
synchronize do
@read_waiter.delete_unless_alive.each do |e|
e.signal
end
@take_waiter.delete_unless_alive.each do |e|
e.signal
end
@notify_waiter.delete_unless_alive.each do |e|
e.notify(['close'])
end
@bag.delete_unless_alive.each do |e|
notify_event('delete', e.value)
end
end
end
def notify_event(event, tuple)
ev = [event, tuple]
@notify_waiter.find_all_template(ev).each do |template|
template.notify(ev)
end
end
def keeper
Thread.new do
loop do
sleep(@period)
keep_clean
end
end
end
end
end
|