Permalink
Fetching contributors…
Cannot retrieve contributors at this time
89 lines (77 sloc) 2.36 KB
module Celluloid
# ConditionVariable-like signaling between tasks and threads
class Condition
class Waiter
def initialize(condition, task, mailbox, timeout)
@condition = condition
@task = task
@mailbox = mailbox
@timeout = timeout
end
attr_reader :condition, :task
def <<(message)
@mailbox << message
end
def wait
begin
message = @mailbox.receive(@timeout) do |msg|
msg.is_a?(SignalConditionRequest) && msg.task == Thread.current
end
rescue TimedOut
raise ConditionError, "timeout after #{@timeout.inspect} seconds"
end until message
message.value
end
end
def initialize
@mutex = Mutex.new
@waiters = []
end
# Wait for the given signal and return the associated value
def wait(timeout = nil)
raise ConditionError, "cannot wait for signals while exclusive" if Celluloid.exclusive?
if actor = Thread.current[:celluloid_actor]
task = Task.current
if timeout
bt = caller
timer = actor.timers.after(timeout) do
exception = ConditionError.new("timeout after #{timeout.inspect} seconds")
exception.set_backtrace bt
task.resume exception
end
end
else
task = Thread.current
end
waiter = Waiter.new(self, task, Celluloid.mailbox, timeout)
@mutex.synchronize do
@waiters << waiter
end
result = Celluloid.suspend :condwait, waiter
timer.cancel if timer
raise result if result.is_a?(ConditionError)
return yield(result) if block_given?
result
end
# Send a signal to the first task waiting on this condition
def signal(value = nil)
@mutex.synchronize do
if waiter = @waiters.shift
waiter << SignalConditionRequest.new(waiter.task, value)
else
Internals::Logger.with_backtrace(caller(3)) do |logger|
logger.debug("Celluloid::Condition signaled spuriously")
end
end
end
end
# Broadcast a value to all waiting tasks and threads
def broadcast(value = nil)
@mutex.synchronize do
@waiters.each { |waiter| waiter << SignalConditionRequest.new(waiter.task, value) }
@waiters.clear
end
end
alias inspect to_s
end
end