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
|
# Copyright, 2015, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
module Process
class Daemon
# This is a one shot cross-process notification mechanism using pipes. It can also be used in the same process if required, e.g. the self-pipe trick.
class Notification
def initialize
@output, @input = IO.pipe
@signalled = false
end
# Signal the notification.
def signal
@signalled = true
@input.puts
end
# Was this notification signalled?
def signalled?
@signalled
end
# Wait/block until a signal is received. Optional timeout.
# @param timeout [Integer] the time to wait in seconds.
def wait(timeout: nil)
if timeout
read_ready, _, _ = IO.select([@output], [], [], timeout)
return false unless read_ready and read_ready.any?
end
@signalled or @output.read(1)
# Just in case that this was split across multiple processes.
@signalled = true
end
end
end
end
|
