Class: WEBrick::Utils::TimeoutHandler

Inherits:
Object
  • Object
show all
Includes:
Singleton
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’

Defined Under Namespace

Classes: Thread

Constant Summary collapse

TimeoutMutex =

Mutex used to synchronize access across threads

Mutex.new

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ TimeoutHandler

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



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# File 'lib/webrick/utils.rb', line 151

def initialize
  TimeoutMutex.synchronize{
    @timeout_info = Hash.new
  }
  @queue = Queue.new
  @watcher = Thread.start{
    to_interrupt = []
    while true
      now = Time.now
      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

Class Method Details

.cancel(id) ⇒ Object

Cancels the timeout handler id



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# File 'lib/webrick/utils.rb', line 144

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

.register(seconds, exception) ⇒ Object

Registers a new timeout handler

time

Timeout in seconds

exception

Exception to raise when timeout elapsed



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# File 'lib/webrick/utils.rb', line 138

def TimeoutHandler.register(seconds, exception)
  instance.register(Thread.current, Time.now + seconds, exception)
end

Instance Method Details

#cancel(thread, id) ⇒ Object

Cancels the timeout handler id



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# File 'lib/webrick/utils.rb', line 215

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) ⇒ Object

Interrupts the timeout handler id and raises exception



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# File 'lib/webrick/utils.rb', line 192

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

#register(thread, time, exception) ⇒ Object

Registers a new timeout handler

time

Timeout in seconds

exception

Exception to raise when timeout elapsed



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# File 'lib/webrick/utils.rb', line 203

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