Class: Zoidberg::Proxy::Liberated

Inherits:
Zoidberg::Proxy show all
Defined in:
lib/zoidberg/proxy/liberated.rb

Constant Summary collapse

THREAD_KILL_AFTER =

Time allowed for threads to gracefully die

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Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Zoidberg::Proxy

#_zoidberg_handle_unexpected_error, #_zoidberg_link, #_zoidberg_link=, #_zoidberg_object, #_zoidberg_set_instance, #_zoidberg_signal, #_zoidberg_signal=, #_zoidberg_signal_interface, #_zoidberg_timer, #_zoidberg_unexpected_error, #_zoidberg_unsupervise, #async, inherited, #inspect, register, registry, scrub!, #signal, #terminate, #to_s

Constructor Details

#initialize(klass, *args, &block) ⇒ self

Create a new proxy instance, new real instance, and link them



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# File 'lib/zoidberg/proxy/liberated.rb', line 19

def initialize(klass, *args, &block)
  @_build_args = [klass, args, block]
  @_lock = ::Mutex.new
  @_count_lock = ::Mutex.new
  @_accessing_threads = []
  @_locker = nil
  @_locker_count = 0
  @_zoidberg_signal = nil
  @_raw_threads = []
  @_supervised = klass.ancestors.include?(::Zoidberg::Supervise)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args, &block) ⇒ Object

Used to proxy request to real instance



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# File 'lib/zoidberg/proxy/liberated.rb', line 32

def method_missing(*args, &block)
  res = nil
  @_accessing_threads << ::Thread.current
  begin
    _aquire_lock!
    @got_lock = true
    if(::ENV['ZOIDBERG_TESTING'])
      timer = ::Thread.new(::Thread.current) do |origin|
        begin
          time = ::ENV.fetch('ZOIDBERG_TESTING_TIMEOUT', 5).to_i
          ::Timeout.timeout(time) do
            ::Kernel.sleep(time)
          end
          nil
        rescue => error
          error
        end
      end
      res = @_raw_instance.__send__(*args, &block)
      if(timer.alive?)
        timer.kill
      else
        val = timer.value
        if(val.is_a?(Exception))
          raise val
        end
      end
    else
      res = @_raw_instance.__send__(*args, &block)
    end
  rescue ::Zoidberg::AbortException => e
    ::Kernel.raise e.original_exception
  rescue ::Exception => e
    ::Zoidberg.logger.debug "Exception on: #{_raw_instance.class.name}##{args.first}(#{args.slice(1, args.size).map(&:inspect).join(', ')})"
    _zoidberg_unexpected_error(e)
    ::Kernel.raise e
  ensure
    if(@got_lock)
      _release_lock!
      t_idx = @_accessing_threads.index(::Thread.current)
      @_accessing_threads.delete_at(t_idx) if t_idx
    end
  end
  res
end

Instance Attribute Details

#_locker ⇒ Thread (readonly)

Returns current owner of lock.

Returns:

  • (Thread) —

    current owner of lock



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# File 'lib/zoidberg/proxy/liberated.rb', line 12

def _locker
  @_locker
end

#_raw_threads ⇒ Hash<Integer:Thread> (readonly)

Returns:

  • (Hash<Integer:Thread>) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 14

def _raw_threads
  @_raw_threads
end

Instance Method Details

#_aquire_lock! ⇒ TrueClas

Aquire the lock to access real instance. If already locked, will wait until lock can be aquired.

Returns:

  • (TrueClas) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 111

def _aquire_lock!
  super do
    if(@_lock)
      if(::ENV['ZOIDBERG_DEBUG'] == 'true')
        ::Timeout.timeout(::ENV.fetch('ZOIDBERG_DEBUG_TIMEOUT', 10).to_i) do
          @_lock.lock unless @_locker == ::Thread.current
        end
      else
        @_lock.lock unless @_locker == ::Thread.current
      end
      @_locker = ::Thread.current
      @_locker_count += 1
    end
    true
  end
end

#_release_lock! ⇒ TrueClass

Release the lock to access real instance

Returns:

  • (TrueClass) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 131

def _release_lock!
  super do
    if(@_lock && @_locker == ::Thread.current)
      @_locker_count -= 1
      if(@_locker_count < 1)
        @_locker = nil
        @_lock.unlock if @_lock.locked?
      end
    else
      false
    end
  end
end

#_zoidberg_available? ⇒ TrueClass, FalseClass

Returns currently unlocked.

Returns:

  • (TrueClass, FalseClass) —

    currently unlocked



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# File 'lib/zoidberg/proxy/liberated.rb', line 84

def _zoidberg_available?
  !_zoidberg_locked?
end

#_zoidberg_destroy!(error = nil) ⇒ TrueClass

Ensure any async threads are killed and accessing threads are forced into error state.

Returns:

  • (TrueClass) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 149

def _zoidberg_destroy!(error=nil)
  object_string = self.inspect
  oid = _raw_instance.object_id
  ::Zoidberg.logger.debug "*** Destroying zoidberg instance #{object_string}"
  super do
    _raw_threads.map do |thread|
      thread.raise ::Zoidberg::DeadException.new('Instance in terminated state!', oid)
      ::Thread.new(thread) do |thread|
        next if thread == ::Thread.current
        thread.join(::Zoidberg::Proxy::Liberated::THREAD_KILL_AFTER)
        if(thread.alive?)
          ::Zoidberg.logger.error "Failed to halt async thread, killing: #{thread.inspect}"
          thread.kill
        end
      end
    end
    @_accessing_threads.each do |thread|
      if(thread.alive?)
        begin
          thread.raise ::Zoidberg::DeadException.new('Instance in terminated state!', oid)
          ::Thread.new(thread) do |thread|
            next if thread == ::Thread.current
            thread.join(::Zoidberg::Proxy::Liberated::THREAD_KILL_AFTER)
            if(thread.alive?)
              ::Zoidberg.logger.error "Failed to halt accessing thread, killing: #{thread.inspect}"
              thread.kill
            end
          end
        rescue
        end
      end
    end
    @_accessing_threads.clear
  end
  ::Zoidberg.logger.debug "!!! Destroyed zoidberg instance #{object_string}"
end

#_zoidberg_locked? ⇒ TrueClass, FalseClass

Returns currently locked.

Returns:

  • (TrueClass, FalseClass) —

    currently locked



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# File 'lib/zoidberg/proxy/liberated.rb', line 79

def _zoidberg_locked?
  @_lock && @_lock.locked?
end

#_zoidberg_thread(thread) ⇒ TrueClass

Register a running thread for this instance. Registered threads are tracked and killed on cleanup

Parameters:

  • thread (Thread)

Returns:

  • (TrueClass) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 93

def _zoidberg_thread(thread)
  _raw_threads.push(thread)
  true
end

#_zoidberg_unthread(thread) ⇒ TrueClass

Deregister a thread once it has completed

Parameters:

  • thread (Thread)

Returns:

  • (TrueClass) 


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# File 'lib/zoidberg/proxy/liberated.rb', line 102

def _zoidberg_unthread(thread)
  _raw_threads.delete(thread)
  true
end