Add sequence number to events in inputflinger

This adds a sequece number field to NotifyArgs and EventEntry in order to
uniquely track individual events.

The sequence number for the events is added in InputReader, where the next
sequence number is an increment of the previous event's sequence number.
Synthesized events have a sequence number of 0.

Bug: 119312685
Test: inputflinger_tests
Change-Id: I1690979a5aa019e99ab89f5f7279a1b42068e658
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index b18cae3..855247f 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -853,13 +853,14 @@
     int32_t mGlobalMetaState;
     bool mUpdateGlobalMetaStateWasCalled;
     int32_t mGeneration;
+    uint32_t mNextSequenceNum;
 
 public:
     FakeInputReaderContext(const sp<EventHubInterface>& eventHub,
             const sp<InputReaderPolicyInterface>& policy,
             const sp<InputListenerInterface>& listener) :
             mEventHub(eventHub), mPolicy(policy), mListener(listener),
-            mGlobalMetaState(0) {
+            mGlobalMetaState(0), mNextSequenceNum(1) {
     }
 
     virtual ~FakeInputReaderContext() { }
@@ -923,6 +924,10 @@
     virtual void dispatchExternalStylusState(const StylusState&) {
 
     }
+
+    virtual uint32_t getNextSequenceNum() {
+        return mNextSequenceNum++;
+    }
 };
 
 
@@ -1568,6 +1573,39 @@
     ASSERT_EQ(1, event.value);
 }
 
+TEST_F(InputReaderTest, DeviceReset_IncrementsSequenceNumber) {
+    constexpr int32_t deviceId = 1;
+    constexpr uint32_t deviceClass = INPUT_DEVICE_CLASS_KEYBOARD;
+    InputDevice* device = mReader->newDevice(deviceId, 0, "fake", deviceClass);
+    // Must add at least one mapper or the device will be ignored!
+    FakeInputMapper* mapper = new FakeInputMapper(device, AINPUT_SOURCE_KEYBOARD);
+    device->addMapper(mapper);
+    mReader->setNextDevice(device);
+    addDevice(deviceId, "fake", deviceClass, nullptr);
+
+    NotifyDeviceResetArgs resetArgs;
+    ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled(&resetArgs));
+    uint32_t prevSequenceNum = resetArgs.sequenceNum;
+
+    disableDevice(deviceId, device);
+    mReader->loopOnce();
+    mFakeListener->assertNotifyDeviceResetWasCalled(&resetArgs);
+    ASSERT_TRUE(prevSequenceNum < resetArgs.sequenceNum);
+    prevSequenceNum = resetArgs.sequenceNum;
+
+    enableDevice(deviceId, device);
+    mReader->loopOnce();
+    mFakeListener->assertNotifyDeviceResetWasCalled(&resetArgs);
+    ASSERT_TRUE(prevSequenceNum < resetArgs.sequenceNum);
+    prevSequenceNum = resetArgs.sequenceNum;
+
+    disableDevice(deviceId, device);
+    mReader->loopOnce();
+    mFakeListener->assertNotifyDeviceResetWasCalled(&resetArgs);
+    ASSERT_TRUE(prevSequenceNum < resetArgs.sequenceNum);
+    prevSequenceNum = resetArgs.sequenceNum;
+}
+
 
 // --- InputDeviceTest ---