sync-defer

by Lin Jen-Shin (godfat)

• github
• rubygems
• rdoc

Synchronous deferred operations with fibers (coroutines)

• Either eventmachine or cool.io
• Ruby 1.9+ (or if fibers could be used in Ruby 1.8)

gem install sync-defer

Remember to wrap a fiber around the client, and inside the client:

• Generic interface which would select underneath reactor automatically:

      # Single computation:
      puts(SyncDefer.defer{
                             sleep(5) # any CPU-bound operations
                             100})    # 100
      puts "DONE"
  
      # Multiple computations:
      puts(SyncDefer.defer(lambda{
                             sleep(5) # any CPU-bound operations
                             100
                           },
                           lambda{
                             sleep(2) # any CPU-bound operations
                             50}))    # [100, 50] # it would match the index
      puts "DONE"

  Full examples with reactor turned on:

• with eventmachine:

      EM.run{
        Fiber.new{
          # or EM::SyncDefer
          SyncDefer.defer{ sleep(5) }
          puts "DONE"
          EM.stop
        }.resume
      }

• with cool.io:

      # only for adding at least one watcher in the loop
      Coolio::TimerWatcher.new(1).
        attach(Coolio::Loop.default).on_timer{detach}
  
      Fiber.new{
        # or Coolio::SyncDefer
        SyncDefer.defer{ sleep(5) }
        puts "DONE"
      }.resume
      Coolio::Loop.default.run

• No problems with exceptions, use them as normal:

      EM.run{
        Fiber.new{
          begin
            SyncDefer.defer{ raise "BOOM" }
          rescue => e
            p e
          end
          EM.stop
        }.resume
      }

• Lin Jen-Shin (@godfat)

Apache License 2.0

Copyright (c) 2012, Lin Jen-Shin (godfat)

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.