SurfaceFlinger: introduce PhaseOffsetsAsDurations

Currently we define phase offset for each refresh rate. This works for
<= 2 refresh rates, but doesn't scale well. This change is introducing
a new way to calculate phase offsets, which is based on duration. Then,
based on the duration and refresh rate, a phase offset is calculated.

The calculation is captured here: https://docs.google.com/spreadsheets/d/1a_5cVNY3LUAkeg-yL56rYQNwved6Hy-dvEcKSxp6f8k/edit#gid=0

Bug: 145561086
Bug: 141329414
Test: jank tests
Test: adb shell /data/nativetest64/libsurfaceflinger_unittest/libsurfaceflinger_unittest
Change-Id: I16aaf7437d30c4b12f955bdaac36582dd100519f
diff --git a/services/surfaceflinger/tests/unittests/PhaseOffsetsTest.cpp b/services/surfaceflinger/tests/unittests/PhaseOffsetsTest.cpp
new file mode 100644
index 0000000..6360ec1
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/PhaseOffsetsTest.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright 2019 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.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "SchedulerUnittests"
+
+#include <gmock/gmock.h>
+#include <log/log.h>
+#include <thread>
+
+#include "Scheduler/PhaseOffsets.h"
+
+using namespace testing;
+
+namespace android {
+namespace scheduler {
+
+class TestablePhaseOffsetsAsDurations : public impl::PhaseDurations {
+public:
+    TestablePhaseOffsetsAsDurations(float currentFps, nsecs_t sfDuration, nsecs_t appDuration,
+                                    nsecs_t sfEarlyDuration, nsecs_t appEarlyDuration,
+                                    nsecs_t sfEarlyGlDuration, nsecs_t appEarlyGlDuration)
+          : impl::PhaseDurations({60.0f, 90.0f}, currentFps, sfDuration, appDuration,
+                                 sfEarlyDuration, appEarlyDuration, sfEarlyGlDuration,
+                                 appEarlyGlDuration) {}
+};
+
+class PhaseOffsetsTest : public testing::Test {
+protected:
+    PhaseOffsetsTest()
+          : mPhaseOffsets(60.0f, 10'500'000, 20'500'000, 16'000'000, 33'500'000, 13'500'000,
+                          38'000'000) {}
+
+    ~PhaseOffsetsTest() = default;
+
+    TestablePhaseOffsetsAsDurations mPhaseOffsets;
+};
+
+namespace {
+/* ------------------------------------------------------------------------
+ * Test cases
+ */
+TEST_F(PhaseOffsetsTest, getOffsetsForRefreshRate_60Hz) {
+    mPhaseOffsets.setRefreshRateFps(60.0f);
+    auto currentOffsets = mPhaseOffsets.getCurrentOffsets();
+    auto offsets = mPhaseOffsets.getOffsetsForRefreshRate(60.0f);
+
+    EXPECT_EQ(currentOffsets, offsets);
+    EXPECT_EQ(offsets.late.sf, 6'166'667);
+
+    EXPECT_EQ(offsets.late.app, 2'333'334);
+
+    EXPECT_EQ(offsets.early.sf, 666'667);
+
+    EXPECT_EQ(offsets.early.app, 500'001);
+
+    EXPECT_EQ(offsets.earlyGl.sf, 3'166'667);
+
+    EXPECT_EQ(offsets.earlyGl.app, 15'166'668);
+}
+
+TEST_F(PhaseOffsetsTest, getOffsetsForRefreshRate_90Hz) {
+    mPhaseOffsets.setRefreshRateFps(90.0f);
+    auto currentOffsets = mPhaseOffsets.getCurrentOffsets();
+    auto offsets = mPhaseOffsets.getOffsetsForRefreshRate(90.0f);
+
+    EXPECT_EQ(currentOffsets, offsets);
+    EXPECT_EQ(offsets.late.sf, 611'111);
+
+    EXPECT_EQ(offsets.late.app, 2'333'333);
+
+    EXPECT_EQ(offsets.early.sf, -4'888'889);
+
+    EXPECT_EQ(offsets.early.app, 6'055'555);
+
+    EXPECT_EQ(offsets.earlyGl.sf, -2'388'889);
+
+    EXPECT_EQ(offsets.earlyGl.app, 4'055'555);
+}
+
+TEST_F(PhaseOffsetsTest, getOffsetsForRefreshRate_DefaultOffsets) {
+    TestablePhaseOffsetsAsDurations phaseOffsetsWithDefaultValues(60.0f, -1, -1, -1, -1, -1, -1);
+
+    auto validateOffsets = [](auto& offsets) {
+        EXPECT_EQ(offsets.late.sf, 1'000'000);
+
+        EXPECT_EQ(offsets.late.app, 1'000'000);
+
+        EXPECT_EQ(offsets.early.sf, 1'000'000);
+
+        EXPECT_EQ(offsets.early.app, 1'000'000);
+
+        EXPECT_EQ(offsets.earlyGl.sf, 1'000'000);
+
+        EXPECT_EQ(offsets.earlyGl.app, 1'000'000);
+    };
+
+    phaseOffsetsWithDefaultValues.setRefreshRateFps(90.0f);
+    auto currentOffsets = phaseOffsetsWithDefaultValues.getCurrentOffsets();
+    auto offsets = phaseOffsetsWithDefaultValues.getOffsetsForRefreshRate(90.0f);
+    EXPECT_EQ(currentOffsets, offsets);
+    validateOffsets(offsets);
+
+    phaseOffsetsWithDefaultValues.setRefreshRateFps(60.0f);
+    currentOffsets = phaseOffsetsWithDefaultValues.getCurrentOffsets();
+    offsets = phaseOffsetsWithDefaultValues.getOffsetsForRefreshRate(90.0f);
+    EXPECT_EQ(currentOffsets, offsets);
+    validateOffsets(offsets);
+}
+
+} // namespace
+} // namespace scheduler
+} // namespace android