Class: Async::MySQL::Pool

Inherits:
Object
  • Object
show all
Defined in:
lib/async/mysql/pool.rb

Overview

This pool doesn’t impose a maximum number of open resources, but it WILL block if there are no available resources and trying to allocate another one fails.

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ Pool

Returns a new instance of Pool.



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# File 'lib/async/mysql/pool.rb', line 65

def initialize(&block)
	@available = []
	@waiting = []
	
	@constructor = block
end

Instance Method Details

#acquire ⇒ Object 



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# File 'lib/async/mysql/pool.rb', line 72

def acquire
	resource = wait_for_next_available
	
	begin
		yield resource
	ensure
		@available << resource
		
		if task = @waiting.pop
			task.resume
		end
	end
end

#close ⇒ Object 



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# File 'lib/async/mysql/pool.rb', line 86

def close
	@available.each(&:close)
	@available.clear
end

#next_available ⇒ Object 



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# File 'lib/async/mysql/pool.rb', line 100

def next_available
	if @available.empty?
		return @constructor.call # This might fail, which is okay :)
	else
		return @available.pop
	end
rescue StandardError
	$stderr.puts $!.inspect
	return nil
end

#wait_for_next_available ⇒ Object 



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# File 'lib/async/mysql/pool.rb', line 91

def wait_for_next_available
	until resource = next_available
		@waiting << Fiber.current
		Task.yield
	end
	
	return resource
end