Class: Concurrent::MVar

Inherits:
Object
  • Object
show all
Includes:
Dereferenceable
Defined in:
lib/concurrent/mvar.rb

Constant Summary collapse

EMPTY = 
Object.new
TIMEOUT = 
Object.new

Instance Method Summary collapse

Methods included from Dereferenceable

#init_mutex, #mutex, #set_deref_options, #value

Constructor Details

#initialize(value = EMPTY, opts = {}) ⇒ MVar

Returns a new instance of MVar.



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# File 'lib/concurrent/mvar.rb', line 13

def initialize(value = EMPTY, opts = {})
  @value = value
  @mutex = Mutex.new
  @empty_condition = Condition.new
  @full_condition = Condition.new
  set_deref_options(opts)
end

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/concurrent/mvar.rb', line 119

def empty?
  @mutex.synchronize { @value == EMPTY }
end

#full? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/concurrent/mvar.rb', line 123

def full?
  not empty?
end

#modify(timeout = nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/concurrent/mvar.rb', line 52

def modify(timeout = nil)
  raise ArgumentError.new('no block given') unless block_given?

  @mutex.synchronize do
    wait_for_full(timeout)

    # If we timed out we'll still be empty
    if unlocked_full?
      value = @value
      @value = yield value
      @full_condition.signal
      apply_deref_options(value)
    else
      TIMEOUT
    end
  end
end

#modify! ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/concurrent/mvar.rb', line 104

def modify!
  raise ArgumentError.new('no block given') unless block_given?

  @mutex.synchronize do
    value = @value
    @value = yield value
    if unlocked_empty?
      @empty_condition.signal
    else
      @full_condition.signal
    end
    apply_deref_options(value)
  end
end

#put(value, timeout = nil) ⇒ Object 



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# File 'lib/concurrent/mvar.rb', line 37

def put(value, timeout = nil)
  @mutex.synchronize do
    wait_for_empty(timeout)

    # If we timed out we won't be empty
    if unlocked_empty?
      @value = value
      @full_condition.signal
      apply_deref_options(value)
    else
      TIMEOUT
    end
  end
end

#set!(value) ⇒ Object 



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# File 'lib/concurrent/mvar.rb', line 95

def set!(value)
  @mutex.synchronize do
    old_value = @value
    @value = value
    @full_condition.signal
    apply_deref_options(old_value)
  end
end

#take(timeout = nil) ⇒ Object 



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# File 'lib/concurrent/mvar.rb', line 21

def take(timeout = nil)
  @mutex.synchronize do
    wait_for_full(timeout)

    # If we timed out we'll still be empty
    if unlocked_full?
      value = @value
      @value = EMPTY
      @empty_condition.signal
      apply_deref_options(value)
    else
      TIMEOUT
    end
  end
end

#try_put!(value) ⇒ Object 



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# File 'lib/concurrent/mvar.rb', line 83

def try_put!(value)
  @mutex.synchronize do
    if unlocked_empty?
      @value = value
      @full_condition.signal
      true
    else
      false
    end
  end
end

#try_take! ⇒ Object 



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# File 'lib/concurrent/mvar.rb', line 70

def try_take!
  @mutex.synchronize do
    if unlocked_full?
      value = @value
      @value = EMPTY
      @empty_condition.signal
      apply_deref_options(value)
    else
      EMPTY
    end
  end
end