Class: RbbtProcessQueue

Inherits:
Object
  • Object
show all
Defined in:
lib/rbbt/util/concurrency/processes.rb,
lib/rbbt/util/concurrency/processes/socket.rb,
lib/rbbt/util/concurrency/processes/worker.rb

Defined Under Namespace

Classes: RbbtProcessQueueWorker, RbbtProcessSocket

Constant Summary collapse

ABORT_SIGNAL = 
:INT
CLOSE_SIGNAL = 
:PIPE

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(num_processes, cleanup = nil, join = nil, reswpan = nil, offset = false) ⇒ RbbtProcessQueue

Returns a new instance of RbbtProcessQueue.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 7

def initialize(num_processes, cleanup = nil, join = nil, reswpan = nil, offset = false)
  @num_processes = num_processes
  @cleanup = cleanup
  @join = join
  @respawn = reswpan
  @offset = offset
  @queue = RbbtProcessSocket.new

  key = "/" << rand(1000000000).to_s << '.' << Process.pid.to_s;
  @sem = key + '.process'
  Log.debug "Creating process semaphore: #{@sem}"
  RbbtSemaphore.create_semaphore(@sem,1)
end

Instance Attribute Details

#callback(&block) ⇒ Object

Returns the value of attribute callback.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 25

def callback
  @callback
end

#callback_queue ⇒ Object

Returns the value of attribute callback_queue.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 25

def callback_queue
  @callback_queue
end

#callback_thread ⇒ Object

Returns the value of attribute callback_thread.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 25

def callback_thread
  @callback_thread
end

#cleanup ⇒ Object

Returns the value of attribute cleanup.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def cleanup
  @cleanup
end

#join ⇒ Object

Returns the value of attribute join.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def join
  @join
end

#num_processes ⇒ Object

Returns the value of attribute num_processes.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def num_processes
  @num_processes
end

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def offset
  @offset
end

#process_monitor ⇒ Object

Returns the value of attribute process_monitor.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def process_monitor
  @process_monitor
end

#queue ⇒ Object

Returns the value of attribute queue.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def queue
  @queue
end

#reswpan ⇒ Object

Returns the value of attribute reswpan.



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# File 'lib/rbbt/util/concurrency/processes.rb', line 6

def reswpan
  @reswpan
end

Class Method Details

.each(list, num = 3, &block) ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 375

def self.each(list, num = 3, &block)
  q = RbbtProcessQueue.new num
  q.init(&block)
  list.each do |elem| q.process elem end
  q.join
end

Instance Method Details

#_abort ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 335

def _abort
  begin
    Log.warn "Aborting process queue #{@master_pid}"
    Process.kill ABORT_SIGNAL, @master_pid
  rescue Errno::ECHILD, Errno::ESRCH
    Log.debug "Cannot abort #{@master_pid}: #{$!.message}"
  end
end

#_join ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 257

def _join
  error = :redo 
  begin
    pid, @status = Process.waitpid2 @master_pid unless @status
    error = true unless @status.success?
    begin
      @callback_thread.join if @callback_thread
      raise ProcessFailed.new @master_pid unless @status.success?
    rescue
      exception = $!
      raise $!
    end
    error = false
  rescue Aborted, Interrupt
    exception = $!
    Log.exception $!
    error = true
    if @aborted
      raise $!
    else
      self.abort
      Log.high "Process queue #{@master_pid} aborted"
      retry
    end
  rescue Errno::ESRCH, Errno::ECHILD
    retry if Misc.pid_exists? @master_pid
    error = ! @status.success?
  ensure
    begin
      begin
        self.abort
      ensure
        _join 
      end if error == :redo

      begin
        @callback_thread.join 
      rescue Exception
      end

      Log.medium "Joining process queue #{"(error) " if error}#{@master_pid} #{@join}" 
      begin
        if @join
          if @join.arity == 1
            @join.call(error) 
          else
            @join.call
          end
        end
      end
    ensure
      self.clean
    end

    if exception
      raise exception 
    else
      raise "Process queue #{@master_pid} failed" 
    end if error
  end
end

#abort ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 344

def abort
  _abort
  @callback_thread.raise(Aborted.new) if @callback_thread and @callback_thread.alive?
  @aborted = true
  begin
    _join
  rescue
  end
end

#add_process ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 249

def add_process
  Process.kill :USR1, @master_pid
end

#clean ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 354

def clean
  RbbtSemaphore.delete_semaphore(@sem)
  begin
    self.abort if Misc.pid_exists?(@master_pid)

  ensure
    @queue.clean if @queue
    #@callback_thread.push ClosedStream if @callback_thread && @callback_thread.alive?
    @callback_queue.clean if @callback_queue
  end
end

#close_up_queue ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 319

def close_up_queue
  begin
    RbbtSemaphore.synchronize(@sem) do
      Process.kill CLOSE_SIGNAL, @master_pid
    end
  rescue Errno::ECHILD, Errno::ESRCH
    Log.debug "Cannot kill (CLOSE) #{@master_pid}: #{$!.message}"
  end if Misc.pid_exists? @master_pid 
end

#init(&block) ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 212

def init(&block)
  @init_block = block

  init_master

  RbbtSemaphore.synchronize(@sem) do
  @callback_thread = Thread.new do
    begin
      loop do
        p = @callback_queue.pop unless @callback_queue.cleaned

        if Exception === p or (Array === p and Exception === p.first)
          e = Array === p ? p.first : p
          Log.low "Callback recieved exception from worker: #{e.message}" unless Aborted === e or ClosedStream === e
          raise e 
        end

        if @callback.arity == 0
          @callback.call
        else
          @callback.call p
        end
      end
    rescue ClosedStream
      Log.low "Callback thread closing"
    rescue Aborted
      Log.low "Callback thread aborted"
      raise $!
    rescue Exception
      Log.low "Exception captured in callback: #{$!.message}"
      raise $!
    end
  end if @callback_queue
  end

end

#init_master ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 38

def init_master
  RbbtSemaphore.wait_semaphore(@sem)
  @master_pid = Process.fork do
    @close_up = false
    processes_initiated = false
    processes = []
    process_mutex = Mutex.new

    Signal.trap(CLOSE_SIGNAL) do
      if ! @closing_thread
        @close_up = true 
        Misc.insist([0,0.01,0.1,0.2,0.5]) do
          if ! @manager_thread
            Thread.pass 
            raise "Manager thread for #{Process.pid} not found yet" 
          end

          if @manager_thread.alive?
            raise "Manager thread for #{Process.pid} not working yet" unless @manager_thread["working"]
            @manager_thread.raise TryAgain
          end
        end
      end
    end

    Signal.trap(:USR1) do
      @count += 1
      @manager_thread.raise TryAgain
    end

    Signal.trap(:USR2) do
      @count -= 1
      @manager_thread.raise TryAgain
    end

    Signal.trap(ABORT_SIGNAL) do
      @abort_monitor = true
      @monitor_thread.raise Aborted if @monitor_thread && @monitor_thread.alive?
    end

    if @callback_queue
      Misc.purge_pipes(@queue.swrite, @queue.sread, @callback_queue.swrite) 
    else
      Misc.purge_pipes(@queue.swrite, @queue.sread) 
    end

    @total = 0
    @count = 0

    @manager_thread = Thread.new do
      while true 
        break if processes_initiated && processes.empty? && (@monitor_thread && ! @monitor_thread.alive?)
        begin
          Thread.current["working"] = true
          if @close_up
            Thread.handle_interrupt(TryAgain => :never) do
              Log.debug "Closing up process queue #{Process.pid}"
              @count = 0
              @closing_thread = Thread.new do
                Thread.handle_interrupt(TryAgain => :never) do
                  Log.debug "Pushing closed stream #{Process.pid}"
                  while true
                    @queue.push ClosedStream.new unless @queue.cleaned 
                    break if processes_initiated && processes.empty?
                  end unless processes_initiated && processes.empty?
                end
              end
              @close_up = false
            end
          end

          begin
            sleep 3
          rescue TryAgain
          end

          raise TryAgain if @close_up

          process_mutex.synchronize do
            Thread.handle_interrupt(TryAgain => :never) do
              while @count > 0
                @count -= 1
                @total += 1
                processes << RbbtProcessQueueWorker.new(@queue, @callback_queue, @cleanup, @respawn, (@offset ? @total : false), &@init_block)
                Log.warn "Added process #{processes.last.pid} to #{Process.pid} (#{processes.length})"
              end

              while @count < 0
                @count += 1
                @total -= 1
                next unless processes.length > 1
                last = processes.reject{|p| p.stopping }.last
                last.stop
                Log.warn "Removed process #{last.pid} from #{Process.pid} (#{processes.length})"
              end
            end
          end
        rescue TryAgain
          retry
        rescue Aborted
          Log.low "Aborting manager thread #{Process.pid}"
          raise $!
        rescue Exception
          raise Exception
        end
      end
      Log.low "Manager thread stopped #{Process.pid}"
    end

    @callback_queue.close_read if @callback_queue

    num_processes.to_i.times do |i|
      @total += 1 
      process_mutex.synchronize do
        processes << RbbtProcessQueueWorker.new(@queue, @callback_queue, @cleanup, @respawn, (@offset ? @total : false), &@init_block)
      end
    end

    processes_initiated = true

    @monitor_thread = Thread.new do
      begin
        while processes.any?
          raise Aborted if @abort_monitor
          #processes[0].join
          #Log.debug "Joined process #{processes[0].pid} of queue #{Process.pid}"
          #processes.shift
          pid, status = Process.wait2
          Log.debug "Joined process #{pid} of queue #{Process.pid} (status: #{status})"
          processes.reject!{|p| p.pid == pid}
          raise ProcessFailed.new pid if not status.success?
        end
        Log.low "All processes completed #{Process.pid}"
      rescue Aborted
        Log.exception $!
        Log.low "Aborting process monitor #{Process.pid}"
        processes.each{|p|  p.abort_and_join}
        Log.low "Processes aborted #{Process.pid}"
        processes.clear

        @manager_thread.raise Aborted if @manager_thread.alive?
        raise Aborted, "Aborted monitor thread"
      rescue Exception
        Log.low "Process monitor exception [#{Process.pid}]: #{$!.message}"
        processes.each{|p| p.abort_and_join}
        Log.low "Processes aborted #{Process.pid}"
        processes.clear

        @manager_thread.raise $! if @manager_thread.alive?
        raise Aborted, "Aborted monitor thread with exception"
      end
    end

    RbbtSemaphore.post_semaphore(@sem)

    Log.low "Process monitor #{Process.pid} joining threads"
    begin
      @monitor_thread.join
      @manager_thread.raise TryAgain if @manager_thread.alive?
      @manager_thread.join 
      @callback_queue.push ClosedStream.new if @callback_queue
    rescue Exception
      Kernel.exit -1
    end
    Log.low "Process monitor #{Process.pid} threads joined successfully, now exit"

    Kernel.exit 0
  end

  @queue.close_read
  Log.info "Cpu process #{@master_pid} with #{num_processes} workers."
  Log.low "Signal #{@master_pid} USR1/USR2 (#10/#12) to increase/decrease workers."
end

#process(*e) ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 367

def process(*e)
  begin
    @queue.push e
  rescue Errno::EPIPE
    raise Aborted
  end
end

#remove_process ⇒ Object 



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# File 'lib/rbbt/util/concurrency/processes.rb', line 253

def remove_process
  Process.kill :USR2, @master_pid
end