1 files changed, 66 insertions, 0 deletions
diff --git a/spec/ruby/core/mutex/synchronize_spec.rb b/spec/ruby/core/mutex/synchronize_spec.rb
new file mode 100644
index 0000000000..823f29a634
--- /dev/null
+++ b/spec/ruby/core/mutex/synchronize_spec.rb
@@ -0,0 +1,66 @@
+require_relative '../../spec_helper'
+
+describe "Mutex#synchronize" do
+  it "wraps the lock/unlock pair in an ensure" do
+    m1 = Mutex.new
+    m2 = Mutex.new
+    m2.lock
+    synchronized = false
+
+    th = Thread.new do
+      -> do
+        m1.synchronize do
+          synchronized = true
+          m2.lock
+          raise Exception
+        end
+      end.should.raise(Exception)
+    end
+
+    Thread.pass until synchronized
+
+    m1.locked?.should == true
+    m2.unlock
+    th.join
+    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