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Class: Concurrent::MutexAtomicBoolean

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Synchronization::SafeInitialization
Inherits: Object
Defined in: lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb

Overview

Note:

**Private Implementation:** This abstraction is a private, internal implementation detail. It should never be used directly.

A boolean value that can be updated atomically. Reads and writes to an atomic boolean and thread-safe and guaranteed to succeed. Reads and writes may block briefly but no explicit locking is required.

## Thread-safe Variable Classes

Each of the thread-safe variable classes is designed to solve a different problem. In general:

  • *Agent:* Shared, mutable variable providing independent, uncoordinated, asynchronous change of individual values. Best used when the value will undergo frequent, complex updates. Suitable when the result of an update does not need to be known immediately.

  • *Atom:* Shared, mutable variable providing independent, uncoordinated, synchronous change of individual values. Best used when the value will undergo frequent reads but only occasional, though complex, updates. Suitable when the result of an update must be known immediately.

  • *AtomicReference:* A simple object reference that can be updated atomically. Updates are synchronous but fast. Best used when updates a simple set operations. Not suitable when updates are complex. AtomicBoolean and AtomicFixnum are similar but optimized for the given data type.

  • *Exchanger:* Shared, stateless synchronization point. Used when two or more threads need to exchange data. The threads will pair then block on each other until the exchange is complete.

  • *MVar:* Shared synchronization point. Used when one thread must give a value to another, which must take the value. The threads will block on each other until the exchange is complete.

  • *ThreadLocalVar:* Shared, mutable, isolated variable which holds a different value for each thread which has access. Often used as an instance variable in objects which must maintain different state for different threads.

  • *TVar:* Shared, mutable variables which provide coordinated, synchronous, change of many stated. Used when multiple value must change together, in an all-or-nothing transaction.

Performance:

“‘ Testing with ruby 2.1.2 Testing with MutexAtomicBoolean…

2.790000   0.000000   2.790000 (  2.791454)

Testing with CAtomicBoolean…

0.740000   0.000000   0.740000 (  0.740206)

Testing with jruby 1.9.3 Testing with MutexAtomicBoolean…

5.240000   2.520000   7.760000 (  3.683000)

Testing with Concurrent::JavaAtomicBoolean…

3.340000   0.010000   3.350000 (  0.855000)

“‘

See Also:

Class Method Summary

Synchronization::SafeInitialization - Extended

new

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(initial = false) ⇒ MutexAtomicBoolean

Creates a new AtomicBoolean with the given initial value.

Parameters:

  • initial (Boolean) (defaults to: false) —

    the initial value

[ GitHub ] 

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 12



def initialize(initial = false)
  super()
  @Lock = ::Mutex.new
  @value = !!initial
end


  







Instance Attribute Details



  

    #false?  ⇒ Boolean  (readonly)
  



  

    

Is the current value false


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    true if the current value is false, else false
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 34



def false?
  synchronize { !@value }
end


  








  

    #true?  ⇒ Boolean  (readonly)
  



  

    

Is the current value true


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    true if the current value is true, else false
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 29



def true?
  synchronize { @value }
end


  








  

    #value  ⇒ Boolean  (rw)
  



  

    

Retrieves the current Boolean value.


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    the current value
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 19



def value
  synchronize { @value }
end


  








  

    #value=(value)  ⇒ Boolean  (rw)
  



  

    

Explicitly sets the value.


  





  
Parameters:


    
  
  • 
    value
    (Boolean)
—    
    

    the new value to be set
    

    
  
    • 



Returns:


    
  
  • 
    (Boolean)
—    
    

    the current value
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 24



def value=(value)
  synchronize { @value = !!value }
end


  







Instance Method Details



  

    #make_false  ⇒ Boolean 
  



  

    

Explicitly sets the value to false.


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    true if value has changed, otherwise false
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 44



def make_false
  synchronize { ns_make_value(false) }
end


  








  

    #make_true  ⇒ Boolean 
  



  

    

Explicitly sets the value to true.


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    true if value has changed, otherwise false
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 39



def make_true
  synchronize { ns_make_value(true) }
end


  








  

    #ns_make_value(value)   (private)
  

  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 62



def ns_make_value(value)
  old = @value
  @value = value
  old != @value
end


  








  

    #synchronize   (private)
  

  [ GitHub ]


  

  


# File 'lib/concurrent-ruby/concurrent/atomic/mutex_atomic_boolean.rb', line 51



def synchronize
  if @Lock.owned?
    yield
  else
    @Lock.synchronize { yield }
  end
end