TouchpadInputMapper: add timer provider

Adding a timer provider allows the Gestures library to perform some
asynchronous tasks, including ones which improve tap-to-click detection.

Bug: 297192727
Test: set the
      persist.device_config.aconfig_flags.input.com.android.input.flags.enable_gestures_library_timer_provider
      sysprop to true, restart, then make fast tap-to-click gestures
      (where the finger is contacting for fewer than 3 frames) on the
      touchpad, and check they're reported immediately
Change-Id: Ib9b8dacc71c88b6fd47bdd747f90ef6a44b37cc4
diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 6410046..d87a5a7 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -63,6 +63,7 @@
         "PropertyProvider_test.cpp",
         "SlopController_test.cpp",
         "SyncQueue_test.cpp",
+        "TimerProvider_test.cpp",
         "TestInputListener.cpp",
         "TestInputListenerMatchers.cpp",
         "TouchpadInputMapper_test.cpp",
diff --git a/services/inputflinger/tests/TimerProvider_test.cpp b/services/inputflinger/tests/TimerProvider_test.cpp
new file mode 100644
index 0000000..cb28823
--- /dev/null
+++ b/services/inputflinger/tests/TimerProvider_test.cpp
@@ -0,0 +1,311 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "gestures/TimerProvider.h"
+
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include "InterfaceMocks.h"
+#include "TestConstants.h"
+#include "include/gestures.h"
+
+namespace android {
+
+namespace {
+
+class TestTimerProvider : public TimerProvider {
+public:
+    TestTimerProvider(InputReaderContext& context) : TimerProvider(context) {}
+
+    void setCurrentTime(nsecs_t time) { mCurrentTime = time; }
+
+protected:
+    nsecs_t getCurrentTime() override { return mCurrentTime; }
+
+private:
+    nsecs_t mCurrentTime = 0;
+};
+
+stime_t pushTimeOntoVector(stime_t triggerTime, void* data) {
+    std::vector<stime_t>* times = static_cast<std::vector<stime_t>*>(data);
+    times->push_back(triggerTime);
+    return NO_DEADLINE;
+}
+
+stime_t copyTimeToVariable(stime_t triggerTime, void* data) {
+    stime_t* time = static_cast<stime_t*>(data);
+    *time = triggerTime;
+    return NO_DEADLINE;
+}
+
+stime_t incrementInt(stime_t triggerTime, void* data) {
+    int* count = static_cast<int*>(data);
+    *count += 1;
+    return NO_DEADLINE;
+}
+
+} // namespace
+
+using testing::AtLeast;
+
+class TimerProviderTest : public testing::Test {
+public:
+    TimerProviderTest() : mProvider(mMockContext) {}
+
+protected:
+    void triggerCallbacksWithFakeTime(nsecs_t time) {
+        mProvider.setCurrentTime(time);
+        mProvider.triggerCallbacks(time);
+    }
+
+    MockInputReaderContext mMockContext;
+    TestTimerProvider mProvider;
+};
+
+TEST_F(TimerProviderTest, SingleDeadlineTriggersWhenTimeoutIsExactlyOnTime) {
+    GesturesTimer* timer = mProvider.createTimer();
+    std::vector<stime_t> callTimes;
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(3);
+
+    // Call through kGestureTimerProvider in this test case, so that we cover the stime_t to nsecs_t
+    // conversion code. This is why the delay is 1.0 rather than 1'000'000'000 here.
+    kGestureTimerProvider.set_fn(&mProvider, timer, 1.0, &pushTimeOntoVector, &callTimes);
+
+    triggerCallbacksWithFakeTime(900'000'000);
+    triggerCallbacksWithFakeTime(999'999'999);
+    EXPECT_EQ(0u, callTimes.size());
+    triggerCallbacksWithFakeTime(1'000'000'000);
+    ASSERT_EQ(1u, callTimes.size());
+    EXPECT_NEAR(1.0, callTimes[0], EPSILON);
+
+    // Now that the timer has triggered, it shouldn't trigger again if we get another timeout from
+    // InputReader.
+    triggerCallbacksWithFakeTime(1'300'000'000);
+    EXPECT_EQ(1u, callTimes.size());
+}
+
+TEST_F(TimerProviderTest, SingleDeadlineTriggersWhenTimeoutIsLate) {
+    GesturesTimer* timer = mProvider.createTimer();
+    stime_t callTime = -1.0;
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(1);
+    mProvider.setDeadline(timer, 1'000'000'000, &copyTimeToVariable, &callTime);
+
+    triggerCallbacksWithFakeTime(1'010'000'000);
+    EXPECT_NEAR(1.01, callTime, EPSILON);
+}
+
+TEST_F(TimerProviderTest, SingleRescheduledDeadlineTriggers) {
+    GesturesTimer* timer = mProvider.createTimer();
+    std::vector<stime_t> callTimes;
+    auto callback = [](stime_t triggerTime, void* callbackData) {
+        std::vector<stime_t>* times = static_cast<std::vector<stime_t>*>(callbackData);
+        times->push_back(triggerTime);
+        if (times->size() < 2) {
+            return 1.0;
+        } else {
+            return NO_DEADLINE;
+        }
+    };
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(1);
+    // The deadline should be rescheduled for 2.01s, since the first triggerCallbacks call is 0.01s
+    // late.
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(2'010'000'000)).Times(1);
+
+    mProvider.setDeadline(timer, 1'000'000'000, callback, &callTimes);
+
+    triggerCallbacksWithFakeTime(1'010'000'000);
+    ASSERT_EQ(1u, callTimes.size());
+    EXPECT_NEAR(1.01, callTimes[0], EPSILON);
+
+    triggerCallbacksWithFakeTime(2'020'000'000);
+    ASSERT_EQ(2u, callTimes.size());
+    EXPECT_NEAR(1.01, callTimes[0], EPSILON);
+    EXPECT_NEAR(2.02, callTimes[1], EPSILON);
+
+    triggerCallbacksWithFakeTime(3'000'000'000);
+    EXPECT_EQ(2u, callTimes.size());
+}
+
+TEST_F(TimerProviderTest, MultipleDeadlinesTriggerWithMultipleTimeouts) {
+    GesturesTimer* timer = mProvider.createTimer();
+    std::vector<stime_t> callTimes1;
+    std::vector<stime_t> callTimes2;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(AtLeast(1));
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'500'000'000)).Times(1);
+
+    mProvider.setDeadline(timer, 1'000'000'000, &pushTimeOntoVector, &callTimes1);
+    mProvider.setDeadline(timer, 1'500'000'000, &pushTimeOntoVector, &callTimes2);
+
+    EXPECT_EQ(0u, callTimes1.size());
+    EXPECT_EQ(0u, callTimes2.size());
+
+    triggerCallbacksWithFakeTime(1'010'000'000);
+    ASSERT_EQ(1u, callTimes1.size());
+    EXPECT_NEAR(1.01, callTimes1[0], EPSILON);
+    EXPECT_EQ(0u, callTimes2.size());
+
+    triggerCallbacksWithFakeTime(1'500'000'000);
+    EXPECT_EQ(1u, callTimes1.size());
+    ASSERT_EQ(1u, callTimes2.size());
+    EXPECT_NEAR(1.5, callTimes2[0], EPSILON);
+}
+
+TEST_F(TimerProviderTest, MultipleDeadlinesTriggerWithOneLateTimeout) {
+    GesturesTimer* timer = mProvider.createTimer();
+    stime_t callTime1 = -1.0;
+    stime_t callTime2 = -1.0;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(AtLeast(1));
+
+    mProvider.setDeadline(timer, 1'000'000'000, &copyTimeToVariable, &callTime1);
+    mProvider.setDeadline(timer, 1'500'000'000, &copyTimeToVariable, &callTime2);
+
+    triggerCallbacksWithFakeTime(1'510'000'000);
+    EXPECT_NEAR(1.51, callTime1, EPSILON);
+    EXPECT_NEAR(1.51, callTime2, EPSILON);
+}
+
+TEST_F(TimerProviderTest, MultipleDeadlinesAtSameTimeTriggerTogether) {
+    GesturesTimer* timer = mProvider.createTimer();
+    stime_t callTime1 = -1.0;
+    stime_t callTime2 = -1.0;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(AtLeast(1));
+
+    mProvider.setDeadline(timer, 1'000'000'000, &copyTimeToVariable, &callTime1);
+    mProvider.setDeadline(timer, 1'000'000'000, &copyTimeToVariable, &callTime2);
+
+    triggerCallbacksWithFakeTime(1'000'000'000);
+    EXPECT_NEAR(1.0, callTime1, EPSILON);
+    EXPECT_NEAR(1.0, callTime2, EPSILON);
+}
+
+TEST_F(TimerProviderTest, MultipleTimersTriggerCorrectly) {
+    GesturesTimer* timer1 = mProvider.createTimer();
+    GesturesTimer* timer2 = mProvider.createTimer();
+    std::vector<stime_t> callTimes1;
+    std::vector<stime_t> callTimes2;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(500'000'000)).Times(AtLeast(1));
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'250'000'000)).Times(1);
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'500'000'000)).Times(1);
+
+    mProvider.setDeadline(timer1, 500'000'000, &pushTimeOntoVector, &callTimes1);
+    mProvider.setDeadline(timer1, 1'250'000'000, &pushTimeOntoVector, &callTimes1);
+    mProvider.setDeadline(timer1, 1'500'000'000, &pushTimeOntoVector, &callTimes1);
+    mProvider.setDeadline(timer2, 750'000'000, &pushTimeOntoVector, &callTimes2);
+    mProvider.setDeadline(timer2, 1'250'000'000, &pushTimeOntoVector, &callTimes2);
+
+    triggerCallbacksWithFakeTime(800'000'000);
+    ASSERT_EQ(1u, callTimes1.size());
+    EXPECT_NEAR(0.8, callTimes1[0], EPSILON);
+    ASSERT_EQ(1u, callTimes2.size());
+    EXPECT_NEAR(0.8, callTimes2[0], EPSILON);
+
+    triggerCallbacksWithFakeTime(1'250'000'000);
+    ASSERT_EQ(2u, callTimes1.size());
+    EXPECT_NEAR(1.25, callTimes1[1], EPSILON);
+    ASSERT_EQ(2u, callTimes2.size());
+    EXPECT_NEAR(1.25, callTimes2[1], EPSILON);
+
+    triggerCallbacksWithFakeTime(1'501'000'000);
+    ASSERT_EQ(3u, callTimes1.size());
+    EXPECT_NEAR(1.501, callTimes1[2], EPSILON);
+    EXPECT_EQ(2u, callTimes2.size());
+}
+
+TEST_F(TimerProviderTest, CancelledTimerDoesntTrigger) {
+    GesturesTimer* timer = mProvider.createTimer();
+    int numCalls = 0;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(500'000'000)).Times(AtLeast(1));
+    mProvider.setDeadline(timer, 500'000'000, &incrementInt, &numCalls);
+    mProvider.setDeadline(timer, 1'000'000'000, &incrementInt, &numCalls);
+    mProvider.cancelTimer(timer);
+
+    triggerCallbacksWithFakeTime(1'100'000'000);
+    EXPECT_EQ(0, numCalls);
+}
+
+TEST_F(TimerProviderTest, CancellingOneTimerDoesntAffectOthers) {
+    GesturesTimer* timer1 = mProvider.createTimer();
+    GesturesTimer* timer2 = mProvider.createTimer();
+    int numCalls1 = 0;
+    int numCalls2 = 0;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(500'000'000)).Times(AtLeast(1));
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(1);
+
+    mProvider.setDeadline(timer1, 500'000'000, &incrementInt, &numCalls1);
+    mProvider.setDeadline(timer2, 500'000'000, &incrementInt, &numCalls2);
+    mProvider.setDeadline(timer2, 1'000'000'000, &incrementInt, &numCalls2);
+    mProvider.cancelTimer(timer1);
+
+    triggerCallbacksWithFakeTime(501'000'000);
+    EXPECT_EQ(0, numCalls1);
+    EXPECT_EQ(1, numCalls2);
+
+    triggerCallbacksWithFakeTime(1'000'000'000);
+    EXPECT_EQ(0, numCalls1);
+    EXPECT_EQ(2, numCalls2);
+}
+
+TEST_F(TimerProviderTest, CancellingOneTimerCausesNewTimeoutRequestForAnother) {
+    GesturesTimer* timer1 = mProvider.createTimer();
+    GesturesTimer* timer2 = mProvider.createTimer();
+    auto callback = [](stime_t, void*) { return NO_DEADLINE; };
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(500'000'000)).Times(AtLeast(1));
+
+    mProvider.setDeadline(timer1, 500'000'000, callback, nullptr);
+    mProvider.setDeadline(timer2, 1'000'000'000, callback, nullptr);
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(1);
+    mProvider.cancelTimer(timer1);
+}
+
+TEST_F(TimerProviderTest, CancelledTimerCanBeReused) {
+    GesturesTimer* timer = mProvider.createTimer();
+    int numCallsBeforeCancellation = 0;
+    int numCallsAfterCancellation = 0;
+
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(500'000'000)).Times(1);
+    EXPECT_CALL(mMockContext, requestTimeoutAtTime(1'000'000'000)).Times(1);
+
+    mProvider.setDeadline(timer, 500'000'000, &incrementInt, &numCallsBeforeCancellation);
+    mProvider.cancelTimer(timer);
+    mProvider.setDeadline(timer, 1'000'000'000, &incrementInt, &numCallsAfterCancellation);
+
+    triggerCallbacksWithFakeTime(1'000'000'000);
+    EXPECT_EQ(0, numCallsBeforeCancellation);
+    EXPECT_EQ(1, numCallsAfterCancellation);
+}
+
+TEST_F(TimerProviderTest, FreeingTimerCancelsFirst) {
+    GesturesTimer* timer = mProvider.createTimer();
+    int numCalls = 0;
+
+    mProvider.setDeadline(timer, 1'000'000'000, &incrementInt, &numCalls);
+    mProvider.freeTimer(timer);
+
+    triggerCallbacksWithFakeTime(1'000'000'000);
+    EXPECT_EQ(0, numCalls);
+}
+
+} // namespace android
\ No newline at end of file