preliminary NeverBlock support with EventMachine

1 files changed, 69 insertions, 0 deletions

diff --git a/lib/rainbows/never_block.rb b/lib/rainbows/never_block.rb
new file mode 100644
index 0000000..0933c73
--- /dev/null
+++ b/lib/rainbows/never_block.rb
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+# -*- encoding: binary -*-
+
+module Rainbows
+
+  # {NeverBlock}[www.espace.com.eg/neverblock/] library that combines
+  # the EventMachine library with Ruby Fibers.  This includes use of
+  # Thread-based Fibers under Ruby 1.8.  It currently does NOT support
+  # a streaming "rack.input" but is compatible with everything else
+  # EventMachine supports.
+  #
+  # In your Rainbows! config block, you may specify a Fiber pool size
+  # to limit your application concurrency (without using Rainbows::AppPool)
+  #
+  #   Rainbows! do
+  #     use :NeverBlock, :pool_size => 50
+  #     worker_connections 100
+  #   end
+  #
+  module NeverBlock
+
+    DEFAULTS = {
+      :pool_size => 20, # same default size used by NB
+      :backend => :EventMachine, # NeverBlock doesn't support Rev yet
+    }
+
+    # same pool size NB core itself uses
+    def self.setup
+      DEFAULTS.each { |k,v| O[k] ||= v }
+      Integer === O[:pool_size] && O[:pool_size] > 0 or
+        raise ArgumentError, "pool_size must a be an Integer > 0"
+      mod = Rainbows.const_get(O[:backend])
+      require "never_block" # require EM first since we need a higher version
+      G.server.extend(mod)
+      G.server.extend(Core)
+    end
+
+    module Client
+
+      def self.setup
+        const_set(:POOL, ::NB::Pool::FiberPool.new(O[:pool_size]))
+        Rainbows.const_get(O[:backend]).const_get(:Client).module_eval do
+          include Rainbows::NeverBlock::Client
+          alias _app_call app_call
+          undef_method :app_call
+          alias app_call nb_app_call
+        end
+      end
+
+      def nb_app_call
+        POOL.spawn do
+          begin
+            _app_call
+          rescue => e
+            handle_error(e)
+          end
+        end
+      end
+    end
+
+    module Core
+      def init_worker_process(worker)
+        super
+        Client.setup
+        logger.info "NeverBlock/#{O[:backend]} pool_size=#{O[:pool_size]}"
+      end
+    end
+
+  end
+end