Tests: Added GTests for base/callback.cc

Change-Id: Icebd0fdec4be86e0f0fd86ef58f52ddbfdf8d714
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21619
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/base/SConscript b/src/base/SConscript
index efa7df7..8d17079 100644
--- a/src/base/SConscript
+++ b/src/base/SConscript
@@ -39,6 +39,7 @@
 Source('imgwriter.cc')
 Source('bmpwriter.cc')
 Source('callback.cc')
+GTest('callback.test', 'callback.test.cc', 'callback.cc')
 Source('cprintf.cc', add_tags='gtest lib')
 GTest('cprintf.test', 'cprintf.test.cc')
 Source('debug.cc')
diff --git a/src/base/callback.test.cc b/src/base/callback.test.cc
new file mode 100644
index 0000000..ff4ee8c
--- /dev/null
+++ b/src/base/callback.test.cc
@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2019 The Regents of the University of California
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Bobby R. Bruce
+ */
+
+#include <gtest/gtest.h>
+
+#include "base/callback.hh"
+
+class CallbackImpl : public Callback
+{
+    public:
+        bool processed = false;
+        void process()
+        {
+            processed = true;
+        }
+};
+
+class MockClass
+{
+    public:
+        bool methodExecuted = false;
+        void method()
+        {
+            methodExecuted = true;
+        }
+};
+
+TEST(CallbackQueueTest, GetName)
+{
+    CallbackQueue callbackQueue;
+    EXPECT_EQ("CallbackQueue", callbackQueue.name());
+}
+
+TEST(CallbackQueueTest, IsEmpty)
+{
+    CallbackQueue callbackQueue;
+    EXPECT_TRUE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, IsNotEmpty)
+{
+    CallbackQueue callbackQueue;
+    CallbackImpl impl;
+    callbackQueue.add(&impl);
+    EXPECT_FALSE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, AddOneAndProcess)
+{
+    CallbackQueue callbackQueue;
+    CallbackImpl impl;
+    callbackQueue.add(&impl);
+    EXPECT_FALSE(impl.processed);
+    callbackQueue.process();
+    EXPECT_TRUE(impl.processed);
+    // Processing a queue does not clear it.
+    EXPECT_FALSE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, AddManyAndProcess)
+{
+    CallbackQueue callbackQueue;
+    CallbackImpl impl1;
+    CallbackImpl impl2;
+    CallbackImpl impl3;
+    CallbackImpl impl4;
+    callbackQueue.add(&impl1);
+    callbackQueue.add(&impl2);
+    callbackQueue.add(&impl3);
+    callbackQueue.add(&impl4);
+    EXPECT_FALSE(impl1.processed);
+    EXPECT_FALSE(impl2.processed);
+    EXPECT_FALSE(impl3.processed);
+    EXPECT_FALSE(impl4.processed);
+    callbackQueue.process();
+    EXPECT_TRUE(impl1.processed);
+    EXPECT_TRUE(impl2.processed);
+    EXPECT_TRUE(impl3.processed);
+    EXPECT_TRUE(impl4.processed);
+    EXPECT_FALSE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, ClearQueue)
+{
+    CallbackQueue callbackQueue;
+    CallbackImpl callbackImpl;
+    callbackQueue.add(&callbackImpl);
+    EXPECT_FALSE(callbackQueue.empty());
+    callbackQueue.clear();
+    EXPECT_TRUE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, MakeCallbackAddByReference)
+{
+    CallbackQueue callbackQueue;
+    MockClass mockClass;
+    EXPECT_FALSE(mockClass.methodExecuted);
+    callbackQueue.add<MockClass, &MockClass::method>(mockClass);
+    callbackQueue.process();
+    EXPECT_TRUE(mockClass.methodExecuted);
+    EXPECT_FALSE(callbackQueue.empty());
+}
+
+TEST(CallbackQueueTest, MakeCallbackAddByPointer)
+{
+    CallbackQueue callbackQueue;
+    MockClass mockClass;
+    EXPECT_FALSE(mockClass.methodExecuted);
+    callbackQueue.add<MockClass, &MockClass::method>(&mockClass);
+    callbackQueue.process();
+    EXPECT_TRUE(mockClass.methodExecuted);
+    EXPECT_FALSE(callbackQueue.empty());
+}