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# frozen_string_literal: true
# rubocop:todo all
# Copyright (C) 2020 MongoDB Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
module Mongo
# This is a semaphore that distinguishes waits ending due to the timeout
# being reached from waits ending due to the semaphore being signaled.
#
# @api private
class DistinguishingSemaphore
def initialize
@lock = Mutex.new
@cv = ::ConditionVariable.new
@queue = []
end
# Waits for the semaphore to be signaled up to timeout seconds.
# If semaphore is not signaled, returns after timeout seconds.
#
# @return [ true | false ] true if semaphore was signaled, false if
# timeout was reached.
def wait(timeout = nil)
@lock.synchronize do
@cv.wait(@lock, timeout)
(!@queue.empty?).tap do
@queue.clear
end
end
end
def broadcast
@lock.synchronize do
@queue.push(true)
@cv.broadcast
end
end
def signal
@lock.synchronize do
@queue.push(true)
@cv.signal
end
end
end
end
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