Updated CHANGELOG and README.

Author: jdantonio

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### Next Release v0.7.2 (TBD)
 
+* New `Semaphore` class based on [java.util.concurrent.Semaphore](http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/Semaphore.html)
 * New `Promise.all?` and `Promise.any?` class methods
 * Renamed `:overflow_policy` on thread pools to `:fallback_policy`
 * Thread pools still accept the `:overflow_policy` option but display a warning

README.md

@@ -63,7 +63,6 @@ This library contains a variety of concurrency abstractions at high and low leve
 * [ScheduledTask](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/ScheduledTask.html): Like a Future scheduled for a specific future time.
 * [TimerTask](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/TimerTask.html): A Thread that periodically wakes up to perform work at regular intervals. 
 
-
 ### Java-inspired ThreadPools and other executors
 
 * See [ThreadPool](http://ruby-concurrency.github.io/concurrent-ruby/file.thread_pools.html) overview, which also contains a list of other Executors available.
@@ -75,17 +74,20 @@ This library contains a variety of concurrency abstractions at high and low leve
 * [CopyOnWriteObserverSet](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/CopyOnWriteObserverSet.html)
 
 ### Thread synchronization classes and algorithms
+
 Lower-level abstractions mainly used as building blocks. 
 
 * [condition](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/Condition.html)
 * [countdown latch](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/CountDownLatch.html)
 * [cyclic barrier](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/CyclicBarrier.html)
 * [event](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/Event.html)
 * [exchanger](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/Exchanger.html)
+* [semaphore](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/Semaphore.html)
 * [timeout](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent.html#timeout-class_method)
 * [timer](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent.html#timer-class_method)
 
 ### Thread-safe variables
+
 Lower-level abstractions mainly used as building blocks. 
 
 * [AtomicBoolean](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/AtomicBoolean.html)
@@ -96,8 +98,6 @@ Lower-level abstractions mainly used as building blocks.
 * [thread-local variables](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/ThreadLocalVar.html)
 * [software transactional memory](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/TVar.html) (TVar)
 
-
-
 ## Installing and Building
 
 This gem includes several platform-specific optimizations. To reduce the possibility of