SF: Adding tests to Scheduler class.

This is part of go/surface-flinger-scheduler project.

Test: SF tests pass.
Bug: 113612090
Change-Id: I3ef187d5b79f45c9e3962e1b2316f17b4813a2c7
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
new file mode 100644
index 0000000..c809e82
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -0,0 +1,186 @@
+#undef LOG_TAG
+#define LOG_TAG "SchedulerUnittests"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <log/log.h>
+
+#include "AsyncCallRecorder.h"
+#include "Scheduler/DispSync.h"
+#include "Scheduler/EventThread.h"
+#include "Scheduler/Scheduler.h"
+#include "mock/MockDispSync.h"
+#include "mock/MockEventThread.h"
+
+using testing::_;
+using testing::Return;
+
+namespace android {
+
+class SchedulerTest : public testing::Test {
+protected:
+    class MockEventThreadConnection : public BnDisplayEventConnection {
+    public:
+        MockEventThreadConnection() = default;
+        ~MockEventThreadConnection() = default;
+
+        MOCK_METHOD1(stealReceiveChannel, status_t(gui::BitTube* outChannel));
+        MOCK_METHOD1(setVsyncRate, status_t(uint32_t count));
+        MOCK_METHOD0(requestNextVsync, void());
+    };
+
+    /**
+     * This mock Scheduler class uses implementation of mock::EventThread but keeps everything else
+     * the same.
+     */
+    class MockScheduler : public android::Scheduler {
+    public:
+        MockScheduler(std::unique_ptr<EventThread> eventThread)
+              : mEventThread(std::move(eventThread)) {}
+
+        std::unique_ptr<EventThread> makeEventThread(
+                const char* /* connectionName */, DispSync* /* dispSync */,
+                nsecs_t /* phaseOffsetNs */,
+                impl::EventThread::ResyncWithRateLimitCallback /* resyncCallback */,
+                impl::EventThread::InterceptVSyncsCallback /* interceptCallback */) override {
+            return std::move(mEventThread);
+        }
+
+        MockScheduler() = default;
+        ~MockScheduler() override = default;
+
+        std::unique_ptr<EventThread> mEventThread;
+    };
+
+    SchedulerTest();
+    ~SchedulerTest() override;
+
+    sp<Scheduler::ConnectionHandle> mConnectionHandle;
+    mock::DispSync* mPrimaryDispSync = new mock::DispSync();
+    mock::EventThread* mEventThread;
+    std::unique_ptr<MockScheduler> mScheduler;
+    sp<MockEventThreadConnection> mEventThreadConnection;
+
+    AsyncCallRecorder<void (*)()> mResyncCallRecorder;
+    AsyncCallRecorder<void (*)(nsecs_t)> mInterceptVSyncCallRecorder;
+};
+
+SchedulerTest::SchedulerTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Setting up for %s.%s\n", test_info->test_case_name(), test_info->name());
+
+    std::unique_ptr<mock::EventThread> eventThread = std::make_unique<mock::EventThread>();
+    mEventThread = eventThread.get();
+    mScheduler = std::make_unique<MockScheduler>(std::move(eventThread));
+    mEventThreadConnection = new MockEventThreadConnection();
+
+    // createConnection call to scheduler makes a createEventConnection call to EventThread. Make
+    // sure that call gets executed and returns an EventThread::Connection object.
+    EXPECT_CALL(*mEventThread, createEventConnection())
+            .WillRepeatedly(Return(mEventThreadConnection));
+
+    mConnectionHandle = mScheduler->createConnection("appConnection", mPrimaryDispSync, 16,
+                                                     mResyncCallRecorder.getInvocable(),
+                                                     mInterceptVSyncCallRecorder.getInvocable());
+}
+
+SchedulerTest::~SchedulerTest() {
+    const ::testing::TestInfo* const test_info =
+            ::testing::UnitTest::GetInstance()->current_test_info();
+    ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
+}
+
+namespace {
+/* ------------------------------------------------------------------------
+ * Test cases
+ */
+TEST_F(SchedulerTest, canCreateAndDestroyTest) {
+    EXPECT_FALSE(mResyncCallRecorder.waitForCall().has_value());
+    EXPECT_FALSE(mInterceptVSyncCallRecorder.waitForCall().has_value());
+    EXPECT_EQ(0, mConnectionHandle->id);
+}
+
+TEST_F(SchedulerTest, testNullPtr) {
+    // Passing a null pointer for ConnectionHandle is a valid argument. The code doesn't throw any
+    // exceptions, just gracefully continues.
+    sp<IDisplayEventConnection> returnedValue;
+    ASSERT_NO_FATAL_FAILURE(returnedValue = mScheduler->createDisplayEventConnection(nullptr));
+    EXPECT_TRUE(returnedValue == nullptr);
+    EXPECT_TRUE(mScheduler->getEventThread(nullptr) == nullptr);
+    EXPECT_TRUE(mScheduler->getEventConnection(nullptr) == nullptr);
+    ASSERT_NO_FATAL_FAILURE(
+            mScheduler->hotplugReceived(nullptr, EventThread::DisplayType::Primary, false));
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenAcquired(nullptr));
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenReleased(nullptr));
+    String8 testString;
+    ASSERT_NO_FATAL_FAILURE(mScheduler->dump(nullptr, testString));
+    EXPECT_TRUE(testString == "");
+    ASSERT_NO_FATAL_FAILURE(mScheduler->setPhaseOffset(nullptr, 10));
+}
+
+TEST_F(SchedulerTest, invalidConnectionHandle) {
+    // Passing an invalid ConnectionHandle is a valid argument. The code doesn't throw any
+    // exceptions, just gracefully continues.
+    sp<Scheduler::ConnectionHandle> connectionHandle = new Scheduler::ConnectionHandle(20);
+
+    sp<IDisplayEventConnection> returnedValue;
+    ASSERT_NO_FATAL_FAILURE(returnedValue =
+                                    mScheduler->createDisplayEventConnection(connectionHandle));
+    EXPECT_TRUE(returnedValue == nullptr);
+    EXPECT_TRUE(mScheduler->getEventThread(connectionHandle) == nullptr);
+    EXPECT_TRUE(mScheduler->getEventConnection(connectionHandle) == nullptr);
+
+    // The EXPECT_CALLS make sure we don't call the functions on the subsequent event threads.
+    EXPECT_CALL(*mEventThread, onHotplugReceived(_, _)).Times(0);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->hotplugReceived(connectionHandle,
+                                                        EventThread::DisplayType::Primary, false));
+
+    EXPECT_CALL(*mEventThread, onScreenAcquired()).Times(0);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenAcquired(connectionHandle));
+
+    EXPECT_CALL(*mEventThread, onScreenReleased()).Times(0);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenReleased(connectionHandle));
+
+    String8 testString;
+    EXPECT_CALL(*mEventThread, dump(_)).Times(0);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->dump(connectionHandle, testString));
+    EXPECT_TRUE(testString == "");
+
+    EXPECT_CALL(*mEventThread, setPhaseOffset(_)).Times(0);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->setPhaseOffset(connectionHandle, 10));
+}
+
+TEST_F(SchedulerTest, validConnectionHandle) {
+    sp<IDisplayEventConnection> returnedValue;
+    ASSERT_NO_FATAL_FAILURE(returnedValue =
+                                    mScheduler->createDisplayEventConnection(mConnectionHandle));
+    EXPECT_TRUE(returnedValue != nullptr);
+    ASSERT_EQ(returnedValue, mEventThreadConnection);
+
+    EXPECT_TRUE(mScheduler->getEventThread(mConnectionHandle) != nullptr);
+    EXPECT_TRUE(mScheduler->getEventConnection(mConnectionHandle) != nullptr);
+
+    EXPECT_CALL(*mEventThread, onHotplugReceived(EventThread::DisplayType::Primary, false))
+            .Times(1);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->hotplugReceived(mConnectionHandle,
+                                                        EventThread::DisplayType::Primary, false));
+
+    EXPECT_CALL(*mEventThread, onScreenAcquired()).Times(1);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenAcquired(mConnectionHandle));
+
+    EXPECT_CALL(*mEventThread, onScreenReleased()).Times(1);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->onScreenReleased(mConnectionHandle));
+
+    String8 testString("dump");
+    EXPECT_CALL(*mEventThread, dump(testString)).Times(1);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->dump(mConnectionHandle, testString));
+    EXPECT_TRUE(testString != "");
+
+    EXPECT_CALL(*mEventThread, setPhaseOffset(10)).Times(1);
+    ASSERT_NO_FATAL_FAILURE(mScheduler->setPhaseOffset(mConnectionHandle, 10));
+}
+
+} // namespace
+} // namespace android
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