Module: Rainbows::WriterThreadPool

Includes:
Base
Defined in:
lib/rainbows/writer_thread_pool.rb

Overview

This concurrency model implements a single-threaded app dispatch with a separate thread pool for writing responses.

Unlike most Rainbows! concurrency models, WriterThreadPool is designed to run behind nginx just like Unicorn is. This concurrency model may be useful for existing Unicorn users looking for more output concurrency than socket buffers can provide while still maintaining a single-threaded application dispatch (though if the response body is dynamically generated, it must be thread safe).

For serving large or streaming responses, using more threads (via the worker_connections setting) and setting “proxy_buffering off” in nginx is recommended. If your application does not handle uploads, then using any HTTP-aware proxy like haproxy is fine. Using a non-HTTP-aware proxy will leave you vulnerable to slow client denial-of-service attacks.

Constant Summary collapse

@@nr = 
0
@@q = 
nil

Instance Method Summary collapse

Methods included from Base

included, #init_worker_process, #reopen_worker_logs, #sig_receiver

Instance Method Details

#process_client(client) ⇒ Object

:nodoc:



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# File 'lib/rainbows/writer_thread_pool.rb', line 27

def process_client(client) # :nodoc:
  @@nr += 1
  Client.new(client, @@q[@@nr %= @@q.size]).process_loop
end

#worker_loop(worker) ⇒ Object

:nodoc:



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# File 'lib/rainbows/writer_thread_pool.rb', line 32

def worker_loop(worker) # :nodoc:
  # we have multiple, single-thread queues since we don't want to
  # interleave writes from the same client
  qp = (1..worker_connections).map do |n|
    Rainbows::QueuePool.new(1) do |response|
      begin
        io, arg, *rest = response
        case arg
        when String
          io.kgio_write(arg)
        when :close
          io.close unless io.closed?
        else
          io.__send__(arg, *rest)
        end
      rescue => err
        Rainbows::Error.write(io, err)
      end
    end
  end

  @@q = qp.map(&:queue)
  super(worker) # accept loop from Unicorn
  qp.each(&:quit!)
end