1 files changed, 44 insertions, 5 deletions
diff --git a/spec/ruby/core/mutex/synchronize_spec.rb b/spec/ruby/core/mutex/synchronize_spec.rb
index ec64aa60fa..823f29a634 100644
--- a/spec/ruby/core/mutex/synchronize_spec.rb
+++ b/spec/ruby/core/mutex/synchronize_spec.rb
@@ -1,4 +1,4 @@
-require File.expand_path('../../../spec_helper', __FILE__)
+require_relative '../../spec_helper'
 
 describe "Mutex#synchronize" do
   it "wraps the lock/unlock pair in an ensure" do
@@ -8,20 +8,59 @@ describe "Mutex#synchronize" do
     synchronized = false
 
     th = Thread.new do
-      lambda do
+      -> do
         m1.synchronize do
           synchronized = true
           m2.lock
           raise Exception
         end
-      end.should raise_error(Exception)
+      end.should.raise(Exception)
     end
 
     Thread.pass until synchronized
 
-    m1.locked?.should be_true
+    m1.locked?.should == true
     m2.unlock
     th.join
-    m1.locked?.should be_false
+    m1.locked?.should == false
+  end
+
+  it "blocks the caller if already locked" do
+    m = Mutex.new
+    m.lock
+    -> { m.synchronize { } }.should block_caller
+  end
+
+  it "does not block the caller if not locked" do
+    m = Mutex.new
+    -> { m.synchronize { } }.should_not block_caller
+  end
+
+  it "blocks the caller if another thread is also in the synchronize block" do
+    m = Mutex.new
+    q1 = Queue.new
+    q2 = Queue.new
+
+    t = Thread.new {
+      m.synchronize {
+        q1.push :ready
+        q2.pop
+      }
+    }
+
+    q1.pop.should == :ready
+
+    -> { m.synchronize { } }.should block_caller
+
+    q2.push :done
+    t.join
+  end
+
+  it "is not recursive" do
+    m = Mutex.new
+
+    m.synchronize do
+      -> { m.synchronize { } }.should.raise(ThreadError)
+    end
   end
 end