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@matthewd
Created Feb 18, 2016
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commit 604fd2cb227d92bed1b738e71feb4ff5360f4491
Author: Matthew Draper <matthew@trebex.net>
Date: Fri Feb 19 07:50:42 2016 +1030
Use a semaphore to signal message availability
The Event hack was too much of a hack: on actually thinking about it,
there's a rather obvious race.
diff --git a/actioncable/test/client_test.rb b/actioncable/test/client_test.rb
index d30c381..2662921 100644
--- a/actioncable/test/client_test.rb
+++ b/actioncable/test/client_test.rb
@@ -54,7 +54,7 @@ def initialize(port)
@ws = Faye::WebSocket::Client.new("ws://127.0.0.1:#{port}/")
@messages = Queue.new
@closed = Concurrent::Event.new
- @has_messages = Concurrent::Event.new
+ @has_messages = Concurrent::Semaphore.new(0)
@pings = 0
open = Concurrent::Event.new
@@ -79,7 +79,7 @@ def initialize(port)
@pings += 1
else
@messages << hash
- @has_messages.set
+ @has_messages.release
end
end
@@ -92,8 +92,7 @@ def initialize(port)
end
def read_message
- @has_messages.wait(WAIT_WHEN_EXPECTING_EVENT) if @messages.empty?
- @has_messages.reset if @messages.size < 2
+ @has_messages.try_acquire(1, WAIT_WHEN_EXPECTING_EVENT)
msg = @messages.pop(true)
raise msg if msg.is_a?(Exception)
@@ -104,9 +103,11 @@ def read_message
def read_messages(expected_size = 0)
list = []
loop do
- @has_messages.wait(list.size < expected_size ? WAIT_WHEN_EXPECTING_EVENT : WAIT_WHEN_NOT_EXPECTING_EVENT)
- if @has_messages.set?
- list << read_message
+ if @has_messages.try_acquire(1, list.size < expected_size ? WAIT_WHEN_EXPECTING_EVENT : WAIT_WHEN_NOT_EXPECTING_EVENT)
+ msg = @messages.pop(true)
+ raise msg if msg.is_a?(Exception)
+
+ list << msg
else
break
end
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