Class: Bunny::Concurrent::Condition

Inherits:
Object
  • Object
show all
Defined in:
lib/bunny/concurrent/condition.rb

Overview

Akin to java.util.concurrent.Condition and intrinsic object monitors (Object#wait, Object#notify, Object#notifyAll) in Java: threads can wait (block until notified) on a condition other threads notify them about. Unlike the j.u.c. version, this one has a single waiting set.

Conditions can optionally be annotated with a description string for ease of debugging.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(description = nil) ⇒ Condition

Returns a new instance of Condition.



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# File 'lib/bunny/concurrent/condition.rb', line 19

def initialize(description = nil)
  @mutex           = Monitor.new
  @waiting_threads = []
  @description     = description
end

Instance Attribute Details

#description ⇒ Object (readonly)

Returns the value of attribute description.



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# File 'lib/bunny/concurrent/condition.rb', line 16

def description
  @description
end

#waiting_threads ⇒ Object (readonly)

Returns the value of attribute waiting_threads.



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# File 'lib/bunny/concurrent/condition.rb', line 16

def waiting_threads
  @waiting_threads
end

Instance Method Details

#any_threads_waiting? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bunny/concurrent/condition.rb', line 59

def any_threads_waiting?
  @mutex.synchronize { !@waiting_threads.empty? }
end

#none_threads_waiting? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bunny/concurrent/condition.rb', line 63

def none_threads_waiting?
  @mutex.synchronize { @waiting_threads.empty? }
end

#notify ⇒ Object 



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# File 'lib/bunny/concurrent/condition.rb', line 34

def notify
  @mutex.synchronize do
    t = @waiting_threads.shift
    begin
      t.run if t
    rescue ThreadError
      retry
    end
  end
end

#notify_all ⇒ Object 



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# File 'lib/bunny/concurrent/condition.rb', line 45

def notify_all
  @mutex.synchronize do
    @waiting_threads.each do |t|
      t.run
    end

    @waiting_threads.clear
  end
end

#wait ⇒ Object 



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# File 'lib/bunny/concurrent/condition.rb', line 25

def wait
  @mutex.synchronize do
    t = Thread.current
    @waiting_threads.push(t)
  end

  Thread.stop
end

#waiting_set_size ⇒ Object 



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# File 'lib/bunny/concurrent/condition.rb', line 55

def waiting_set_size
  @mutex.synchronize { @waiting_threads.size }
end