class Concurrent::AtomicBoolean

@!macro atomic_boolean

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.

@!macro thread_safe_variable_comparison

Performance:

```
Testing with ruby 2.1.2
Testing with Concurrent::MutexAtomicBoolean...
  2.790000   0.000000   2.790000 (  2.791454)
Testing with Concurrent::CAtomicBoolean...
  0.740000   0.000000   0.740000 (  0.740206)

Testing with jruby 1.9.3
Testing with Concurrent::MutexAtomicBoolean...
  5.240000   2.520000   7.760000 (  3.683000)
Testing with Concurrent::JavaAtomicBoolean...
  3.340000   0.010000   3.350000 (  0.855000)
```

@see http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/atomic/AtomicBoolean.html java.util.concurrent.atomic.AtomicBoolean

@!macro atomic_boolean_public_api