SF: Adding Layer History to SF.
Calculate average and median between the timestamp differences that come in for
individual layers, and store them to systrace.
See go/surface-flinger-scheduler for more details and systrace links.
Test: SF tests updated.
Bug: 113612090
Change-Id: I934bbe36ab57d16a5b219c7cb8e0580112238671
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index 78ab23a..162f391 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -352,9 +352,10 @@
void BufferQueueLayer::onFrameAvailable(const BufferItem& item) {
// Add this buffer from our internal queue tracker
{ // Autolock scope
- // Report the timestamp to the Scheduler.
+ // Report the requested present time to the Scheduler.
if (mFlinger->mUseScheduler) {
- mFlinger->mScheduler->addNewFrameTimestamp(item.mTimestamp, item.mIsAutoTimestamp);
+ mFlinger->mScheduler->addFramePresentTimeForLayer(item.mTimestamp,
+ item.mIsAutoTimestamp, mName.c_str());
}
Mutex::Autolock lock(mQueueItemLock);
@@ -382,7 +383,7 @@
mFlinger->mInterceptor->saveBufferUpdate(this, item.mGraphicBuffer->getWidth(),
item.mGraphicBuffer->getHeight(), item.mFrameNumber);
-
+
// If this layer is orphaned, then we run a fake vsync pulse so that
// dequeueBuffer doesn't block indefinitely.
if (isRemovedFromCurrentState()) {
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.cpp b/services/surfaceflinger/Scheduler/LayerHistory.cpp
index e944eb9..1f47949 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.cpp
+++ b/services/surfaceflinger/Scheduler/LayerHistory.cpp
@@ -39,11 +39,15 @@
void LayerHistory::incrementCounter() {
mCounter++;
mCounter = mCounter % ARRAY_SIZE;
+ // Clear all the previous data from the history. This is a ring buffer, so we are
+ // reusing memory.
mElements[mCounter].clear();
}
const std::unordered_map<std::string, nsecs_t>& LayerHistory::get(size_t index) const {
- return mElements.at(index);
+ // For the purposes of the layer history, the index = 0 always needs to start at the
+ // current counter, and then decrement to access the layers in correct historical order.
+ return mElements.at((ARRAY_SIZE + (mCounter - (index % ARRAY_SIZE))) % ARRAY_SIZE);
}
} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.h b/services/surfaceflinger/Scheduler/LayerHistory.h
index 1a7f9cd..76c1352 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.h
+++ b/services/surfaceflinger/Scheduler/LayerHistory.h
@@ -42,14 +42,17 @@
~LayerHistory();
// Method for inserting layers and their requested present time into the ring buffer.
- // The elements are going to be inserted into an unordered_map at the position of
- // mCounter.
+ // The elements are going to be inserted into an unordered_map at the position 'now'.
void insert(const std::string layerName, nsecs_t presentTime);
// Method for incrementing the current slot in the ring buffer. It also clears the
// unordered_map, if it was created previously.
void incrementCounter();
- // Returns unordered_map at the given at index.
+ // Returns unordered_map at the given at index. The index is decremented from 'now'. For
+ // example, 0 is now, 1 is previous frame.
const std::unordered_map<std::string, nsecs_t>& get(size_t index) const;
+ // Returns the total size of the ring buffer. The value is always the same regardless
+ // of how many slots we filled in.
+ static constexpr size_t getSize() { return ARRAY_SIZE; }
private:
size_t mCounter = 0;
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 4286cc9..4d3ae33 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -30,6 +30,7 @@
#include <gui/ISurfaceComposer.h>
#include <ui/DisplayStatInfo.h>
+#include <utils/Timers.h>
#include <utils/Trace.h>
#include "DispSync.h"
@@ -205,15 +206,95 @@
mHWVsyncAvailable = makeAvailable;
}
-void Scheduler::addNewFrameTimestamp(const nsecs_t newFrameTimestamp, bool isAutoTimestamp) {
+void Scheduler::addFramePresentTimeForLayer(const nsecs_t framePresentTime, bool isAutoTimestamp,
+ const std::string layerName) {
+ // This is V1 logic. It calculates the average FPS based on the timestamp frequency
+ // regardless of which layer the timestamp came from.
+ // For now, the averages and FPS are recorded in the systrace.
+ determineTimestampAverage(isAutoTimestamp, framePresentTime);
+
+ // This is V2 logic. It calculates the average and median timestamp difference based on the
+ // individual layer history. The results are recorded in the systrace.
+ determineLayerTimestampStats(layerName, framePresentTime);
+}
+
+void Scheduler::incrementFrameCounter() {
+ mLayerHistory.incrementCounter();
+}
+
+nsecs_t Scheduler::calculateAverage() const {
+ nsecs_t sum = std::accumulate(mTimeDifferences.begin(), mTimeDifferences.end(), 0);
+ return (sum / ARRAY_SIZE);
+}
+
+void Scheduler::updateFrameSkipping(const int64_t skipCount) {
+ ATRACE_INT("FrameSkipCount", skipCount);
+ if (mSkipCount != skipCount) {
+ // Only update DispSync if it hasn't been updated yet.
+ mPrimaryDispSync->setRefreshSkipCount(skipCount);
+ mSkipCount = skipCount;
+ }
+}
+
+void Scheduler::determineLayerTimestampStats(const std::string layerName,
+ const nsecs_t framePresentTime) {
+ mLayerHistory.insert(layerName, framePresentTime);
+ std::vector<int64_t> differencesMs;
+
+ // Traverse through the layer history, and determine the differences in present times.
+ nsecs_t newestPresentTime = framePresentTime;
+ for (int i = 1; i < mLayerHistory.getSize(); i++) {
+ std::unordered_map<std::string, nsecs_t> layers = mLayerHistory.get(i);
+ for (auto layer : layers) {
+ if (layer.first != layerName) {
+ continue;
+ }
+ int64_t differenceMs = (newestPresentTime - layer.second) / 1000000;
+ ALOGD("%d Layer %s: %" PRId64, i, layerName.c_str(), differenceMs);
+ // Dismiss noise.
+ if (differenceMs > 10 && differenceMs < 60) {
+ differencesMs.push_back(differenceMs);
+ }
+ newestPresentTime = layer.second;
+ }
+ }
+ // Average is a good indicator for when 24fps videos are playing, because the frames come in
+ // 33, and 49 ms intervals with occasional 41ms.
+ int64_t average =
+ std::accumulate(differencesMs.begin(), differencesMs.end(), 0) / differencesMs.size();
+ const auto tag = "TimestampAvg_" + layerName;
+ ATRACE_INT(tag.c_str(), average);
+
+ // Mode and median are good indicators for 30 and 60 fps videos, because the majority of frames
+ // come in 16, or 33 ms intervals.
+ // TODO(b/113612090): Calculate mode. Median is good for now, since we want a given interval to
+ // repeat at least ARRAY_SIZE/2 + 1 times.
+ if (differencesMs.size() > 0) {
+ const auto tagMedian = "TimestampMedian_" + layerName;
+ ATRACE_INT(tagMedian.c_str(), calculateMedian(&differencesMs));
+ }
+}
+
+int64_t Scheduler::calculateMedian(std::vector<int64_t>* v) {
+ if (!v || v->size() == 0) {
+ return 0;
+ }
+
+ size_t n = v->size() / 2;
+ nth_element(v->begin(), v->begin() + n, v->end());
+ return v->at(n);
+}
+
+void Scheduler::determineTimestampAverage(bool isAutoTimestamp, const nsecs_t framePresentTime) {
ATRACE_INT("AutoTimestamp", isAutoTimestamp);
+
// Video does not have timestamp automatically set, so we discard timestamps that are
// coming in from other sources for now.
if (isAutoTimestamp) {
return;
}
- int64_t differenceMs = (newFrameTimestamp - mPreviousFrameTimestamp) / 1000000;
- mPreviousFrameTimestamp = newFrameTimestamp;
+ int64_t differenceMs = (framePresentTime - mPreviousFrameTimestamp) / 1000000;
+ mPreviousFrameTimestamp = framePresentTime;
if (differenceMs < 10 || differenceMs > 100) {
// Dismiss noise.
@@ -240,18 +321,4 @@
updateFrameSkipping(0);
}
-nsecs_t Scheduler::calculateAverage() const {
- nsecs_t sum = std::accumulate(mTimeDifferences.begin(), mTimeDifferences.end(), 0);
- return (sum / ARRAY_SIZE);
-}
-
-void Scheduler::updateFrameSkipping(const int64_t skipCount) {
- ATRACE_INT("FrameSkipCount", skipCount);
- if (mSkipCount != skipCount) {
- // Only update DispSync if it hasn't been updated yet.
- mPrimaryDispSync->setRefreshSkipCount(skipCount);
- mSkipCount = skipCount;
- }
-}
-
} // namespace android
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index dd1f24b..adfc071 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -26,6 +26,7 @@
#include "EventControlThread.h"
#include "EventThread.h"
#include "InjectVSyncSource.h"
+#include "LayerHistory.h"
namespace android {
@@ -103,9 +104,15 @@
void addPresentFence(const std::shared_ptr<FenceTime>& fenceTime);
void setIgnorePresentFences(bool ignore);
void makeHWSyncAvailable(bool makeAvailable);
- void addNewFrameTimestamp(const nsecs_t newFrameTimestamp, bool isAutoTimestamp);
+ // Adds the present time for given layer to the history of present times.
+ void addFramePresentTimeForLayer(const nsecs_t framePresentTime, bool isAutoTimestamp,
+ const std::string layerName);
+ // Increments counter in the layer history to indicate that SF has started a new frame.
+ void incrementFrameCounter();
protected:
+ friend class SchedulerTest;
+
virtual std::unique_ptr<EventThread> makeEventThread(
const std::string& connectionName, DispSync* dispSync, int64_t phaseOffsetNs,
impl::EventThread::ResyncWithRateLimitCallback resyncCallback,
@@ -114,6 +121,15 @@
private:
nsecs_t calculateAverage() const;
void updateFrameSkipping(const int64_t skipCount);
+ // Collects the statistical mean (average) and median between timestamp
+ // intervals for each frame for each layer.
+ void determineLayerTimestampStats(const std::string layerName, const nsecs_t framePresentTime);
+ // Calculates the statistical median in the vector. Return 0 if the vector is empty. The
+ // function modifies the vector contents.
+ int64_t calculateMedian(std::vector<int64_t>* v);
+ // Collects the average difference between timestamps for each frame regardless
+ // of which layer the timestamp came from.
+ void determineTimestampAverage(bool isAutoTimestamp, const nsecs_t framePresentTime);
// TODO(b/113612090): Instead of letting BufferQueueLayer to access mDispSync directly, it
// should make request to Scheduler to compute next refresh.
@@ -150,6 +166,8 @@
static constexpr size_t ARRAY_SIZE = 30;
std::array<int64_t, ARRAY_SIZE> mTimeDifferences;
size_t mCounter = 0;
+
+ LayerHistory mLayerHistory;
};
} // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 7150660..d81dea9 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1489,6 +1489,10 @@
ATRACE_CALL();
switch (what) {
case MessageQueue::INVALIDATE: {
+ if (mUseScheduler) {
+ // This call is made each time SF wakes up and creates a new frame.
+ mScheduler->incrementFrameCounter();
+ }
bool frameMissed = !mHadClientComposition &&
mPreviousPresentFence != Fence::NO_FENCE &&
(mPreviousPresentFence->getSignalTime() ==
diff --git a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
index b518f10..3fb1a6e 100644
--- a/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerHistoryTest.cpp
@@ -85,11 +85,13 @@
// Because the counter was incremented, the elements were inserted into different
// containers.
+ // We expect the get method to access the slot at the current counter of the index
+ // is 0.
const std::unordered_map<std::string, nsecs_t>& testMap1 = mLayerHistory->get(0);
EXPECT_EQ(1, testMap1.size());
- auto element = testMap1.find("TestLayer0");
- EXPECT_EQ("TestLayer0", element->first);
- EXPECT_EQ(0, element->second);
+ auto element = testMap1.find("TestLayer3");
+ EXPECT_EQ("TestLayer3", element->first);
+ EXPECT_EQ(3, element->second);
const std::unordered_map<std::string, nsecs_t>& testMap2 = mLayerHistory->get(1);
EXPECT_EQ(2, testMap2.size());
@@ -102,9 +104,9 @@
const std::unordered_map<std::string, nsecs_t>& testMap3 = mLayerHistory->get(2);
EXPECT_EQ(1, testMap3.size());
- element = testMap3.find("TestLayer3");
- EXPECT_EQ("TestLayer3", element->first);
- EXPECT_EQ(3, element->second);
+ element = testMap3.find("TestLayer0");
+ EXPECT_EQ("TestLayer0", element->first);
+ EXPECT_EQ(0, element->second);
// Testing accessing object at an empty container will return an empty map.
const std::unordered_map<std::string, nsecs_t>& emptyMap = mLayerHistory->get(3);
@@ -113,7 +115,6 @@
TEST_F(LayerHistoryTest, clearTheMap) {
mLayerHistory->insert("TestLayer0", 0);
- mLayerHistory->incrementCounter();
const std::unordered_map<std::string, nsecs_t>& testMap1 = mLayerHistory->get(0);
EXPECT_EQ(1, testMap1.size());
@@ -121,6 +122,7 @@
EXPECT_EQ("TestLayer0", element->first);
EXPECT_EQ(0, element->second);
+ mLayerHistory->incrementCounter();
// The array currently contains 30 elements.
for (int i = 1; i < 30; ++i) {
mLayerHistory->insert("TestLayer0", i);
@@ -140,5 +142,33 @@
EXPECT_EQ(testMap3.end(), element);
}
+TEST_F(LayerHistoryTest, testingGet) {
+ // The array currently contains 30 elements.
+ for (int i = 0; i < 30; ++i) {
+ const auto name = "TestLayer" + std::to_string(i);
+ mLayerHistory->insert(name, i);
+ mLayerHistory->incrementCounter();
+ }
+
+ // The counter should be set to 0, and the map at 0 should be cleared.
+ const std::unordered_map<std::string, nsecs_t>& testMap1 = mLayerHistory->get(0);
+ EXPECT_EQ(0, testMap1.size());
+
+ // This should return (ARRAY_SIZE + (counter - 3)) % ARRAY_SIZE
+ const std::unordered_map<std::string, nsecs_t>& testMap2 = mLayerHistory->get(3);
+ EXPECT_EQ(1, testMap2.size());
+ auto element = testMap2.find("TestLayer27");
+ EXPECT_EQ("TestLayer27", element->first);
+ EXPECT_EQ(27, element->second);
+
+ // If the user gives an out of bound index, we should mod it with ARRAY_SIZE first,
+ // so requesting element 40 would be the same as requesting element 10.
+ const std::unordered_map<std::string, nsecs_t>& testMap3 = mLayerHistory->get(40);
+ EXPECT_EQ(1, testMap3.size());
+ element = testMap3.find("TestLayer20");
+ EXPECT_EQ("TestLayer20", element->first);
+ EXPECT_EQ(20, element->second);
+}
+
} // namespace
} // namespace android
\ No newline at end of file
diff --git a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
index be91a9c..e967742 100644
--- a/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/SchedulerTest.cpp
@@ -59,6 +59,8 @@
SchedulerTest();
~SchedulerTest() override;
+ int64_t calculateMedian(std::vector<int64_t>* v);
+
sp<Scheduler::ConnectionHandle> mConnectionHandle;
mock::DispSync* mPrimaryDispSync = new mock::DispSync();
mock::EventThread* mEventThread;
@@ -95,6 +97,10 @@
ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
}
+int64_t SchedulerTest::calculateMedian(std::vector<int64_t>* v) {
+ return mScheduler->calculateMedian(v);
+}
+
namespace {
/* ------------------------------------------------------------------------
* Test cases
@@ -185,5 +191,37 @@
ASSERT_NO_FATAL_FAILURE(mScheduler->setPhaseOffset(mConnectionHandle, 10));
}
+TEST_F(SchedulerTest, calculateMedian) {
+ std::vector<int64_t> testVector;
+ // Calling the function on empty vector returns 0.
+ EXPECT_EQ(0, calculateMedian(&testVector));
+
+ testVector.push_back(33);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(33);
+ testVector.push_back(33);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(42);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(33);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(42);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(42);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+ testVector.push_back(42);
+ EXPECT_EQ(42, calculateMedian(&testVector));
+ testVector.push_back(60);
+ EXPECT_EQ(42, calculateMedian(&testVector));
+ testVector.push_back(60);
+ EXPECT_EQ(42, calculateMedian(&testVector));
+ testVector.push_back(33);
+ EXPECT_EQ(42, calculateMedian(&testVector));
+ testVector.push_back(33);
+ EXPECT_EQ(42, calculateMedian(&testVector));
+ testVector.push_back(33);
+ EXPECT_EQ(33, calculateMedian(&testVector));
+}
+
} // namespace
-} // namespace android
\ No newline at end of file
+} // namespace android