Class: BackgroundQueue::ServerLib::ThreadManager

Inherits:
Object
  • Object
show all
Defined in:
lib/background_queue/server_lib/thread_manager.rb

Overview

make sure threads are schedules and the max number of threads is controlled

Defined Under Namespace

Classes: ForcedStop

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(server, max_threads) ⇒ ThreadManager

Returns a new instance of ThreadManager.



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 7

def initialize(server, max_threads)
  @server = server
  @max_threads = max_threads
  @running_threads = 0
  @mutex = Mutex.new
  @condvar = ConditionVariable.new
  @threads = []
end

Instance Attribute Details

#max_threads ⇒ Object

Returns the value of attribute max_threads.



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 4

def max_threads
  @max_threads
end

#running_threads ⇒ Object (readonly)

Returns the value of attribute running_threads.



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 5

def running_threads
  @running_threads
end

Instance Method Details

#change_concurrency(max_threads) ⇒ Object 



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 52

def change_concurrency(max_threads)
  @mutex.synchronize {
    if max_threads > @max_threads
      for i in @max_threads...max_threads
        @condvar.signal
      end
    end
    @max_threads = max_threads
  }
end

#control_access(&block) ⇒ Object 



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 22

def control_access(&block)
  @mutex.synchronize {
    if @running_threads >= @max_threads && @server.running?
      @running_threads -= 1
      @condvar.wait(@mutex)
      @running_threads += 1
    end
    block.call
  }
end

#protect_access(&block) ⇒ Object 



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 16

def protect_access(&block)
  @mutex.synchronize {
    block.call
  }
end

#signal_access ⇒ Object

signal any waiting threads this should only be called from with a protect_access/control_access block will do nothing if there are already too many threads running



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 36

def signal_access
  @condvar.signal unless @running_threads >= @max_threads
end

#start(clazz) ⇒ Object 



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 64

def start(clazz)
  @mutex.synchronize {
    for i in 0...@max_threads
      runner = clazz.new(@server)
      @running_threads += 1
      #puts "started thread, running=#{@running_threads}"
      @threads << Thread.new(runner) { |runner|
        begin
          runner.run
        rescue Exception=>e
          @server.logger.error("Error in thread: #{e.message}")
          @server.logger.debug(e.backtrace.join("\n"))
        end
        @mutex.synchronize {
          @running_threads -= 1
          #puts "finished thread, running=#{@running_threads}"
        }
      }
    end
  }
end

#wait(timeout_limit = 100) ⇒ Object 



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 86

def wait(timeout_limit = 100)
  #for thread in @threads
    @mutex.synchronize {
      @condvar.broadcast
    }
  #end
  #while @running_threads > 0
  #  @mutex.synchronize {
  #    @condvar.signal
  #  }
  #  sleep(0.01)
  #end
  begin
    Timeout::timeout(timeout_limit) {
      for thread in @threads
        thread.join
      end
    }
  rescue Timeout::Error => te
    for thread in @threads
      begin
        if thread.alive?
          thread.raise BackgroundQueue::ServerLib::ThreadManager::ForcedStop.new("Timeout when forcing threads to stop")
        end
      rescue Exception=>e
        #ignore
      end
    end
    
    begin
      Timeout::timeout(timeout_limit) {
        for thread in @threads
          thread.join
        end
      }
    rescue Timeout::Error => te2
      @server.logger.error("Timeout while waiting for forced stop threads to finish")
    end
  end
end

#wait_on_access ⇒ Object

wait for the condition must be called from within protect_access/control_access block



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# File 'lib/background_queue/server_lib/thread_manager.rb', line 42

def wait_on_access
  if @server.running?
    @running_threads -= 1
    #puts "waiting"
    @condvar.wait(@mutex)
    #puts "woken"
    @running_threads += 1
  end
end