prelude.rb: deprecate Thread.exclusive

* prelude.rb (Thread.exclusive): warn as deprecated.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52554 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Fri Nov 13 13:05:37 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* prelude.rb (Thread.exclusive): warn as deprecated.
+
 Fri Nov 13 10:36:39 2015  Victor Nawothnig  <Victor.Nawothnig@gmail.com>
 
 	* parse.y (new_unless): optimize constant condition for `unless`

prelude.rb

@@ -8,6 +8,7 @@ class Thread
   # value of the block. A thread executing inside the exclusive section will
   # only block other threads which also use the Thread.exclusive mechanism.
   def self.exclusive
+    warn "Thread.exclusive is deprecated, use Mutex", caller
     MUTEX_FOR_THREAD_EXCLUSIVE.synchronize{
       yield
     }