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
|
require 'concurrent/utility/engine'
require 'concurrent/atomic/mutex_count_down_latch'
require 'concurrent/atomic/java_count_down_latch'
module Concurrent
###################################################################
# @!macro count_down_latch_method_initialize
#
# Create a new `CountDownLatch` with the initial `count`.
#
# @param [new] count the initial count
#
# @raise [ArgumentError] if `count` is not an integer or is less than zero
# @!macro count_down_latch_method_wait
#
# Block on the latch until the counter reaches zero or until `timeout` is reached.
#
# @param [Fixnum] timeout the number of seconds to wait for the counter or `nil`
# to block indefinitely
# @return [Boolean] `true` if the `count` reaches zero else false on `timeout`
# @!macro count_down_latch_method_count_down
#
# Signal the latch to decrement the counter. Will signal all blocked threads when
# the `count` reaches zero.
# @!macro count_down_latch_method_count
#
# The current value of the counter.
#
# @return [Fixnum] the current value of the counter
###################################################################
# @!macro count_down_latch_public_api
#
# @!method initialize(count = 1)
# @!macro count_down_latch_method_initialize
#
# @!method wait(timeout = nil)
# @!macro count_down_latch_method_wait
#
# @!method count_down
# @!macro count_down_latch_method_count_down
#
# @!method count
# @!macro count_down_latch_method_count
###################################################################
# @!visibility private
# @!macro internal_implementation_note
CountDownLatchImplementation = case
when Concurrent.on_jruby?
JavaCountDownLatch
else
MutexCountDownLatch
end
private_constant :CountDownLatchImplementation
# @!macro count_down_latch
#
# A synchronization object that allows one thread to wait on multiple other threads.
# The thread that will wait creates a `CountDownLatch` and sets the initial value
# (normally equal to the number of other threads). The initiating thread passes the
# latch to the other threads then waits for the other threads by calling the `#wait`
# method. Each of the other threads calls `#count_down` when done with its work.
# When the latch counter reaches zero the waiting thread is unblocked and continues
# with its work. A `CountDownLatch` can be used only once. Its value cannot be reset.
#
# @!macro count_down_latch_public_api
# @example Waiter and Decrementer
# latch = Concurrent::CountDownLatch.new(3)
#
# waiter = Thread.new do
# latch.wait()
# puts ("Waiter released")
# end
#
# decrementer = Thread.new do
# sleep(1)
# latch.count_down
# puts latch.count
#
# sleep(1)
# latch.count_down
# puts latch.count
#
# sleep(1)
# latch.count_down
# puts latch.count
# end
#
# [waiter, decrementer].each(&:join)
class CountDownLatch < CountDownLatchImplementation
end
end
|
