Class: Higgs::ReadWriteLock

Inherits:
Object
  • Object
show all
Defined in:
lib/higgs/thread.rb

Defined Under Namespace

Classes: ChildLock, ReadLock, WriteLock

Constant Summary collapse

CVS_ID =

for ident(1)

'$Id: thread.rb 841 2008-12-24 09:23:20Z toki $'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ReadWriteLock

Returns a new instance of ReadWriteLock.



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# File 'lib/higgs/thread.rb', line 286

def initialize
  @lock = Mutex.new
  @read_cond = ConditionVariable.new
  @write_cond = ConditionVariable.new
  @count_of_working_readers = 0
  @count_of_standby_writers = 0
  @priority_to_writer = true
  @writing = false
  @read_lock = ReadLock.new(self)
  @write_lock = WriteLock.new(self)
end

Instance Attribute Details

#read_lock ⇒ Object (readonly)

Returns the value of attribute read_lock.



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# File 'lib/higgs/thread.rb', line 298

def read_lock
  @read_lock
end

#write_lock ⇒ Object (readonly)

Returns the value of attribute write_lock.



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# File 'lib/higgs/thread.rb', line 299

def write_lock
  @write_lock
end

Instance Method Details

#__read_lock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 301

def __read_lock__
  @lock.synchronize{
    while (@writing || (@priority_to_writer && @count_of_standby_writers > 0))
      @read_cond.wait(@lock)
    end
    @count_of_working_readers += 1
  }
  nil
end

#__read_try_lock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 311

def __read_try_lock__
  @lock.synchronize{
    if (@writing || (@priority_to_writer && @count_of_standby_writers > 0)) then
      return false
    else
      @count_of_working_readers += 1
      return true
    end
  }
end

#__read_unlock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 322

def __read_unlock__
  @lock.synchronize{
    @count_of_working_readers -= 1
    @priority_to_writer = true
    if (@count_of_standby_writers > 0) then
      @write_cond.signal
    else
      @read_cond.broadcast
    end
  }
  nil
end

#__write_lock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 335

def __write_lock__
  @lock.synchronize{
    @count_of_standby_writers += 1
    begin
      while (@writing || @count_of_working_readers > 0)
        @write_cond.wait(@lock)
      end
      @writing = true
    ensure
      @count_of_standby_writers -= 1
    end
  }
  nil
end

#__write_try_lock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 350

def __write_try_lock__
  @lock.synchronize{
    @count_of_standby_writers += 1
    begin
      if (@writing || @count_of_working_readers > 0) then
        return false
      else
        @writing = true
        return true
      end
    ensure
      @count_of_standby_writers -= 1
    end
  }
  raise 'not to reach'
end

#__write_unlock__ ⇒ Object 



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# File 'lib/higgs/thread.rb', line 367

def __write_unlock__
  @lock.synchronize{
    @writing = false
    @priority_to_writer = false
    @read_cond.broadcast
    if (@count_of_standby_writers > 0) then
      @write_cond.signal
    end
  }
  nil
end

#to_a ⇒ Object 



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# File 'lib/higgs/thread.rb', line 411

def to_a
  [ read_lock, write_lock ]
end