Issue #4826 - Use latch to replace thread-sleeping in tests

test/LatchTest.cpp

Index: test/LatchTest.cpp
===================================================================
new file mode 100644
--- /dev/null
+++ b/test/LatchTest.cpp
@@ -0,0 +1,91 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2016 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gtest/gtest.h>
+#include "BaseJsTest.h"
+
+#include "JsLatch.h"
+#include "../src/JsEngineTransition.h"
+
+TEST(Latch, InstanceZero)
+{
+  Latch x(0);
+  ASSERT_TRUE(x.TryWait());
+}
+
+TEST(Latch, InstanceOne)
+{
+  Latch x(1);
+  ASSERT_FALSE(x.TryWait());
+}
+
+/*
+ * Verify that Wait() does not block when the latch is initialized to zero in the same thread.
+ */
+TEST(Latch, InitialZeroSameThread)
+{
+  ASSERT_NO_THROW(
+  {
+    Latch x(0);
+    x.Wait();
+  });
+}
+
+/*
+ * Verify that Wait() does not block when the latch becomes zero in the same thread.
+ */
+TEST(Latch, BecomesZeroSameThread)
+{
+  ASSERT_NO_THROW(
+  {
+    Latch x(1);
+    x.Arrive();
+    ASSERT_TRUE(x.TryWait());
+    x.Wait();
+  });
+}
+
+namespace
+{
+  struct JsTestingLatchTest
+    : public BaseJsTest
+  {
+    JsEngineInternal* engine;
+
+    void SetUp()
+    {
+      BaseJsTest::SetUp();
+      engine = ToInternal(jsEngine);
+    }
+  };
+}
+
+TEST_F(JsTestingLatchTest, Instance)
+{
+  JsTestingLatch x(engine, "foo");
+}
+
+TEST_F(JsTestingLatchTest, InstanceInIsolate)
+{
+  JsTestingLatch x(engine, "foo");
+  auto y = engine->Evaluate("foo");
+  ASSERT_FALSE(y->IsUndefined());
+  y = engine->Evaluate("foo.Arrive()");
+  ASSERT_TRUE(x.GetLatch().TryWait());
+  x.Wait();
+}
+