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Class: WEBrick::Utils::TimeoutHandler

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, Singleton
Inherits: Object
Defined in: lib/webrick/utils.rb

Overview

Class used to manage timeout handlers across multiple threads.

Timeout handlers should be managed by using the class methods which are synchronized.

id = TimeoutHandler.register(10, Timeout::Error)
begin
  sleep 20
  puts 'foo'
ensure
  TimeoutHandler.cancel(id)
end

will raise Timeout::Error

id = TimeoutHandler.register(10, Timeout::Error)
begin
  sleep 5
  puts 'foo'
ensure
  TimeoutHandler.cancel(id)
end

will print 'foo'

Class Method Summary

Instance Method Summary

Constructor Details

.new ⇒ TimeoutHandler

Creates a new TimeoutHandler. You should use .register and .cancel instead of creating the timeout handler directly.

[ GitHub ] 

  


# File 'lib/webrick/utils.rb', line 154



def initialize
  TimeoutMutex.synchronize{
    @timeout_info = Hash.new
  }
  @queue = Thread::Queue.new
  @watcher = nil
end


  







Class Method Details



  

    .cancel(id)  
  



  

    

Cancels the timeout handler id


  



  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 143



def TimeoutHandler.cancel(id)
  instance.cancel(Thread.current, id)
end


  








  

    .register(seconds, exception)  
  



  

    

Registers a new timeout handler


time



Timeout in seconds


exception



Exception to raise when timeout elapsed




  



  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 136



def TimeoutHandler.register(seconds, exception)
  at = Process.clock_gettime(Process::CLOCK_MONOTONIC) + seconds
  instance.register(Thread.current, at, exception)
end


  








  

    .terminate  
  

  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 147



def self.terminate
  instance.terminate
end


  







Instance Method Details



  

    #cancel(thread, id)  
  



  

    

Cancels the timeout handler id


  



  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 232



def cancel(thread, id)
  TimeoutMutex.synchronize{
    if ary = @timeout_info[thread]
      ary.delete_if{|info| info.object_id == id }
      if ary.empty?
        @timeout_info.delete(thread)
      end
      return true
    end
    return false
  }
end


  








  

    #interrupt(thread, id, exception)  
  



  

    

Interrupts the timeout handler id and raises exception


  



  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 209



def interrupt(thread, id, exception)
  if cancel(thread, id) && thread.alive?
    thread.raise(exception, "execution timeout")
  end
end


  








  

    #register(thread, time, exception)  
  



  

    

Registers a new timeout handler


time



Timeout in seconds


exception



Exception to raise when timeout elapsed




  



  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 220



def register(thread, time, exception)
  info = nil
  TimeoutMutex.synchronize{
    (@timeout_info[thread] ||= []) << (info = [time, exception])
  }
  @queue.push nil
  watcher
  return info.object_id
end


  








  

    #terminate  
  

  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 246



def terminate
  TimeoutMutex.synchronize{
    @timeout_info.clear
    @watcher&.kill&.join
  }
end


  








  

    #watch   (private)
  

  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 164



private \
def watch
  to_interrupt = []
  while true
    now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    wakeup = nil
    to_interrupt.clear
    TimeoutMutex.synchronize{
      @timeout_info.each {|thread, ary|
        next unless ary
        ary.each{|info|
          time, exception = *info
          if time < now
            to_interrupt.push [thread, info.object_id, exception]
          elsif !wakeup || time < wakeup
            wakeup = time
          end
        }
      }
    }
    to_interrupt.each {|arg| interrupt(*arg)}
    if !wakeup
      @queue.pop
    elsif (wakeup -= now) > 0
      begin
        (th = Thread.start {@queue.pop}).join(wakeup)
      ensure
        th&.kill&.join
      end
    end
    @queue.clear
  end
end


  








  

    #watcher   (private)
  

  [ GitHub ]


  

  


# File 'lib/webrick/utils.rb', line 199



private \
def watcher
  (w = @watcher)&.alive? and return w # usual case
  TimeoutMutex.synchronize{
    (w = @watcher)&.alive? and next w # pathological check
    @watcher = Thread.start(&method(:watch))
  }
end