1 files changed, 36 insertions, 0 deletions
diff --git a/spec/ruby/core/mutex/locked_spec.rb b/spec/ruby/core/mutex/locked_spec.rb
new file mode 100644
index 0000000000..1818cdb4f3
--- /dev/null
+++ b/spec/ruby/core/mutex/locked_spec.rb
@@ -0,0 +1,36 @@
+require_relative '../../spec_helper'
+
+describe "Mutex#locked?" do
+  it "returns true if locked" do
+    m = Mutex.new
+    m.lock
+    m.locked?.should == true
+  end
+
+  it "returns false if unlocked" do
+    m = Mutex.new
+    m.locked?.should == false
+  end
+
+  it "returns the status of the lock" do
+    m1 = Mutex.new
+    m2 = Mutex.new
+
+    m2.lock # hold th with only m1 locked
+    m1_locked = false
+
+    th = Thread.new do
+      m1.lock
+      m1_locked = true
+      m2.lock
+    end
+
+    Thread.pass until m1_locked
+
+    m1.locked?.should == true
+    m2.unlock # release th
+    th.join
+    # A Thread releases its locks upon termination
+    m1.locked?.should == false
+  end
+end