examples/basic_usage.rb
#!/usr/bin/env ruby
$LOAD_PATH.push File.expand_path("../lib", __dir__)
require "celluloid/autostart"
class Counter
# This is all you have to do to turn any Ruby class into one which creates
# Celluloid actors instead of normal objects
include Celluloid
# Now just define methods like you ordinarily would
attr_reader :count
def initialize
@count = 0
end
def increment(n = 1)
@count += n
end
end
# Create objects just like you normally would. 'actor' is now a proxy object
# which talks to a Celluloid actor running in its own thread
actor = Counter.new
# The proxy obeys normal method invocation the way we'd expect. This prints 0
p actor.count
# This increments @count by 1 and prints 1
p actor.increment
# By using actor.async, you can make calls asynchronously. This immediately
# requests execution of method by sending a message, and we have no idea
# whether or not that request will actually complete because we don't wait
# for a response. Async calls immediately return nil regardless of how long
# the method takes to execute. Therefore, this will print nil.
p actor.async.increment 41
# In practice, the asynchronous call made above will increment the count before
# we get here. However, do not rely on this behavior! Asynchronous methods are
# inherently uncoordinated. If you need to coordinate asynchronous activities,
# you will need to use futures or FSMs. See the corresponding examples for those.
# Signals can also be used to coordinate asynchronous activities.
#
# The following line could possibly print either 1 or 42, depending on if the
# asynchronous call above completed. In practice, it prints 42 on all Ruby
# implementations because the asynchronous call above will always execute
p actor.count