Class: Extlib::Pooling::Pool

Inherits:
Object
  • Object
show all
Defined in:
lib/gems/extlib-0.9.8/lib/extlib/pooling.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max_size, resource, args) ⇒ Pool

Returns a new instance of Pool.

Raises:

  • (ArgumentError) 


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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 128

def initialize(max_size, resource, args)
  raise ArgumentError.new("+max_size+ should be a Fixnum but was #{max_size.inspect}") unless Fixnum === max_size
  raise ArgumentError.new("+resource+ should be a Class but was #{resource.inspect}") unless Class === resource

  @max_size = max_size
  @resource = resource
  @args = args

  @available = []
  @used      = {}
  Extlib::Pooling::append_pool(self)
end

Instance Attribute Details

#available ⇒ Object (readonly)

Returns the value of attribute available.



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 125

def available
  @available
end

#used ⇒ Object (readonly)

Returns the value of attribute used.



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 126

def used
  @used
end

Instance Method Details

#delete(instance) ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 195

def delete(instance)
  lock.synchronize do
    instance.instance_variable_set(:@__pool, nil)
    @used.delete(instance.object_id)
  end
  nil
end

#dispose ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 216

def dispose
  flush!
  @resource.__pools.delete(@args)
  !Extlib::Pooling::pools.delete?(self).nil?
end

#expired? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 222

def expired?
  @available.each do |instance|
    if Extlib.exiting || instance.instance_variable_get(:@__allocated_in_pool) + Extlib::Pooling.scavenger_interval <= Time.now
      instance.dispose
      @available.delete(instance)
    end
  end

  size == 0
end

#flush! ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 212

def flush!
  @available.pop.dispose until @available.empty?
end

#inspect ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 208

def inspect
  "#<Extlib::Pooling::Pool<#{@resource.name}> available=#{@available.size} used=#{@used.size} size=#{@max_size}>"
end

#lock ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 141

def lock
  @resource.__pool_lock
end

#new ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 153

def new
  instance = nil
  begin
    lock.synchronize do
      if @available.size > 0
        instance = @available.pop
        @used[instance.object_id] = instance
      elsif @used.size < @max_size
        instance = @resource.__new(*@args)
        raise InvalidResourceError.new("#{@resource} constructor created a nil object") if instance.nil?
        raise InvalidResourceError.new("#{instance} is already part of the pool") if @used.include? instance
        instance.instance_variable_set(:@__pool, self)
        instance.instance_variable_set(:@__allocated_in_pool, Time.now)
        @used[instance.object_id] = instance
      else
        # Let's see whether we have multiple threads
        # If we do, there is a chance we might be released
        # at some point in the future and thus we wait.
        # If there are no other threads, we exhaust the pool
        # here and there is no more hope... So we throw an
        # exception.
        if ThreadGroup::Default.list.size <= 2
          raise ThreadStopError.new(size)
        else
          wait.wait(lock)
        end
      end
    end
  end until instance
  instance
end

#release(instance) ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 185

def release(instance)
  instance.instance_variable_set(:@__allocated_in_pool, Time.now)
  lock.synchronize do
    @used.delete(instance.object_id)
    @available.push(instance)
    wait.signal
  end
  nil
end

#scavenge_interval ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 149

def scavenge_interval
  @resource.scavenge_interval
end

#size ⇒ Object Also known as: length 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 203

def size
  @used.size + @available.size
end

#wait ⇒ Object 



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# File 'lib/gems/extlib-0.9.8/lib/extlib/pooling.rb', line 145

def wait
  @resource.__pool_wait
end