Class: Zookeeper::Common::QueueWithPipe

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Logger
Defined in:
lib/zookeeper/common/queue_with_pipe.rb

Overview

Ceci n'est pas une pipe

Defined Under Namespace

Classes: ShutdownException

Constant Summary collapse

KILL_TOKEN =
Object.new

Instance Method Summary collapse

Methods included from Logger

included, set_default

Constructor Details

#initializeQueueWithPipe


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 15

def initialize
  @array = []

  @mutex    = Mutex.new
  @cond     = ConditionVariable.new
  @closed   = false
  @graceful = false
end

Instance Method Details

#clearObject


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 24

def clear
  @mutex.lock
  begin
    @array.clear
  ensure
    @mutex.unlock rescue nil
  end
end

#closeObject


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 94

def close
  @mutex.lock
  begin
    return if @closed
    @closed = true
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
end

#closed?Boolean


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 105

def closed?
  @mutex.synchronize { !!@closed }
end

#graceful_close!Object

close the queue and causes ShutdownException to be raised on waiting threads


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 71

def graceful_close!
  @mutex.lock
  begin
    return if @graceful or @closed
    logger.debug { "#{self.class}##{__method__} gracefully closing" }
    @graceful = true
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
  nil
end

#openObject


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 84

def open
  @mutex.lock
  begin
    @closed = @graceful = false
    @cond.broadcast
  ensure
    @mutex.unlock rescue nil
  end
end

#pop(non_blocking = false) ⇒ Object


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 44

def pop(non_blocking=false)
  rval = nil

  @mutex.lock
  begin

    begin
      raise ShutdownException if @closed  # this may get us in trouble

      rval = @array.shift

      unless rval
        raise ThreadError if non_blocking     # sigh, ruby's stupid behavior
        raise ShutdownException if @graceful  # we've processed all the remaining mesages

        @cond.wait(@mutex) until (@closed or @graceful or (@array.length > 0))
      end
    end until rval

    return rval

  ensure
    @mutex.unlock rescue nil
  end
end

#push(obj) ⇒ Object


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# File 'lib/zookeeper/common/queue_with_pipe.rb', line 33

def push(obj)
  @mutex.lock
  begin
#         raise ShutdownException if (@closed or @graceful)
    @array << obj
    @cond.signal
  ensure
    @mutex.unlock rescue nil
  end
end