BufferQueue/SF: Add OccupancyTracker
Adds an OccupancyTracker to BufferQueue. This module keeps track of
how many buffers are in the queue over time, which, in combination
with various aggregation of these statistics, allows SurfaceFlinger
to report what fraction of the time a given layer was double- or
triple-buffered.
Change-Id: Ida6e967dc5483c00a633e9fe03998e420dd88502
diff --git a/include/gui/BufferQueueConsumer.h b/include/gui/BufferQueueConsumer.h
index b2daae4..a9fce1a 100644
--- a/include/gui/BufferQueueConsumer.h
+++ b/include/gui/BufferQueueConsumer.h
@@ -136,6 +136,10 @@
// Retrieve the sideband buffer stream, if any.
virtual sp<NativeHandle> getSidebandStream() const;
+ // See IGraphicBufferConsumer::getOccupancyHistory
+ virtual status_t getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory) override;
+
// dump our state in a String
virtual void dump(String8& result, const char* prefix) const;
diff --git a/include/gui/BufferQueueCore.h b/include/gui/BufferQueueCore.h
index 4337da9..6c69d69 100644
--- a/include/gui/BufferQueueCore.h
+++ b/include/gui/BufferQueueCore.h
@@ -20,6 +20,7 @@
#include <gui/BufferItem.h>
#include <gui/BufferQueueDefs.h>
#include <gui/BufferSlot.h>
+#include <gui/OccupancyTracker.h>
#include <utils/Condition.h>
#include <utils/Mutex.h>
@@ -322,6 +323,8 @@
// The slot of the last queued buffer
int mLastQueuedSlot;
+ OccupancyTracker mOccupancyTracker;
+
}; // class BufferQueueCore
} // namespace android
diff --git a/include/gui/ConsumerBase.h b/include/gui/ConsumerBase.h
index 9307a26..d1f4cdd 100644
--- a/include/gui/ConsumerBase.h
+++ b/include/gui/ConsumerBase.h
@@ -85,6 +85,10 @@
// See IGraphicBufferConsumer::setDefaultBufferDataSpace
status_t setDefaultBufferDataSpace(android_dataspace defaultDataSpace);
+ // See IGraphicBufferConsumer::getOccupancyHistory
+ status_t getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory);
+
private:
ConsumerBase(const ConsumerBase&);
void operator=(const ConsumerBase&);
diff --git a/include/gui/IGraphicBufferConsumer.h b/include/gui/IGraphicBufferConsumer.h
index e983c16..4915478 100644
--- a/include/gui/IGraphicBufferConsumer.h
+++ b/include/gui/IGraphicBufferConsumer.h
@@ -27,6 +27,7 @@
#include <binder/IInterface.h>
#include <ui/PixelFormat.h>
#include <ui/Rect.h>
+#include <gui/OccupancyTracker.h>
#include <EGL/egl.h>
#include <EGL/eglext.h>
@@ -265,6 +266,12 @@
// Retrieve the sideband buffer stream, if any.
virtual sp<NativeHandle> getSidebandStream() const = 0;
+ // Retrieves any stored segments of the occupancy history of this
+ // BufferQueue and clears them. Optionally closes out the pending segment if
+ // forceFlush is true.
+ virtual status_t getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory) = 0;
+
// dump state into a string
virtual void dump(String8& result, const char* prefix) const = 0;
diff --git a/include/gui/OccupancyTracker.h b/include/gui/OccupancyTracker.h
new file mode 100644
index 0000000..1d15e7f
--- /dev/null
+++ b/include/gui/OccupancyTracker.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2016 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.
+ */
+
+
+#ifndef ANDROID_GUI_OCCUPANCYTRACKER_H
+#define ANDROID_GUI_OCCUPANCYTRACKER_H
+
+#include <binder/Parcelable.h>
+
+#include <utils/Timers.h>
+
+#include <deque>
+#include <unordered_map>
+
+namespace android {
+
+class String8;
+
+class OccupancyTracker
+{
+public:
+ OccupancyTracker()
+ : mPendingSegment(),
+ mSegmentHistory(),
+ mLastOccupancy(0),
+ mLastOccupancyChangeTime(0) {}
+
+ struct Segment : public Parcelable {
+ Segment()
+ : totalTime(0),
+ numFrames(0),
+ occupancyAverage(0.0f),
+ usedThirdBuffer(false) {}
+
+ Segment(nsecs_t totalTime, size_t numFrames, float occupancyAverage,
+ bool usedThirdBuffer)
+ : totalTime(totalTime),
+ numFrames(numFrames),
+ occupancyAverage(occupancyAverage),
+ usedThirdBuffer(usedThirdBuffer) {}
+
+ // Parcelable interface
+ virtual status_t writeToParcel(Parcel* parcel) const override;
+ virtual status_t readFromParcel(const Parcel* parcel) override;
+
+ nsecs_t totalTime;
+ size_t numFrames;
+
+ // Average occupancy of the queue over this segment. (0.0, 1.0) implies
+ // double-buffered, (1.0, 2.0) implies triple-buffered.
+ float occupancyAverage;
+
+ // Whether a third buffer was used at all during this segment (since a
+ // segment could read as double-buffered on average, but still require a
+ // third buffer to avoid jank for some smaller portion)
+ bool usedThirdBuffer;
+ };
+
+ void registerOccupancyChange(size_t occupancy);
+ std::vector<Segment> getSegmentHistory(bool forceFlush);
+
+private:
+ static constexpr size_t MAX_HISTORY_SIZE = 10;
+ static constexpr nsecs_t NEW_SEGMENT_DELAY = ms2ns(100);
+ static constexpr size_t LONG_SEGMENT_THRESHOLD = 3;
+
+ struct PendingSegment {
+ void clear() {
+ totalTime = 0;
+ numFrames = 0;
+ mOccupancyTimes.clear();
+ }
+
+ nsecs_t totalTime;
+ size_t numFrames;
+ std::unordered_map<size_t, nsecs_t> mOccupancyTimes;
+ };
+
+ void recordPendingSegment();
+
+ PendingSegment mPendingSegment;
+ std::deque<Segment> mSegmentHistory;
+
+ size_t mLastOccupancy;
+ nsecs_t mLastOccupancyChangeTime;
+
+}; // class OccupancyTracker
+
+} // namespace android
+
+#endif
diff --git a/libs/gui/Android.mk b/libs/gui/Android.mk
index 6e92a47..3e30bb2 100644
--- a/libs/gui/Android.mk
+++ b/libs/gui/Android.mk
@@ -64,6 +64,7 @@
ISurfaceComposer.cpp \
ISurfaceComposerClient.cpp \
LayerState.cpp \
+ OccupancyTracker.cpp \
Sensor.cpp \
SensorEventQueue.cpp \
SensorManager.cpp \
diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index cbc8893..e8860d1 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -260,6 +260,7 @@
mCore->mDequeueCondition.broadcast();
ATRACE_INT(mCore->mConsumerName.string(), mCore->mQueue.size());
+ mCore->mOccupancyTracker.registerOccupancyChange(mCore->mQueue.size());
VALIDATE_CONSISTENCY();
}
@@ -717,6 +718,13 @@
return mCore->mSidebandStream;
}
+status_t BufferQueueConsumer::getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory) {
+ Mutex::Autolock lock(mCore->mMutex);
+ *outHistory = mCore->mOccupancyTracker.getSegmentHistory(forceFlush);
+ return NO_ERROR;
+}
+
void BufferQueueConsumer::dump(String8& result, const char* prefix) const {
const IPCThreadState* ipc = IPCThreadState::self();
const pid_t pid = ipc->getCallingPid();
diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index 3e26e05..65f8255 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -886,6 +886,7 @@
static_cast<uint32_t>(mCore->mQueue.size()));
ATRACE_INT(mCore->mConsumerName.string(), mCore->mQueue.size());
+ mCore->mOccupancyTracker.registerOccupancyChange(mCore->mQueue.size());
// Take a ticket for the callback functions
callbackTicket = mNextCallbackTicket++;
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index a6a9712..84965ef 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -235,6 +235,16 @@
return mConsumer->setDefaultBufferDataSpace(defaultDataSpace);
}
+status_t ConsumerBase::getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory) {
+ Mutex::Autolock _l(mMutex);
+ if (mAbandoned) {
+ CB_LOGE("getOccupancyHistory: ConsumerBase is abandoned!");
+ return NO_INIT;
+ }
+ return mConsumer->getOccupancyHistory(forceFlush, outHistory);
+}
+
void ConsumerBase::dump(String8& result) const {
dump(result, "");
}
diff --git a/libs/gui/IGraphicBufferConsumer.cpp b/libs/gui/IGraphicBufferConsumer.cpp
index cb1ad35..7c4379f 100644
--- a/libs/gui/IGraphicBufferConsumer.cpp
+++ b/libs/gui/IGraphicBufferConsumer.cpp
@@ -51,6 +51,7 @@
SET_CONSUMER_USAGE_BITS,
SET_TRANSFORM_HINT,
GET_SIDEBAND_STREAM,
+ GET_OCCUPANCY_HISTORY,
DUMP,
};
@@ -260,6 +261,31 @@
return stream;
}
+ virtual status_t getOccupancyHistory(bool forceFlush,
+ std::vector<OccupancyTracker::Segment>* outHistory) {
+ Parcel data, reply;
+ data.writeInterfaceToken(IGraphicBufferConsumer::getInterfaceDescriptor());
+ status_t error = data.writeBool(forceFlush);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ error = remote()->transact(GET_OCCUPANCY_HISTORY, data,
+ &reply);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ error = reply.readParcelableVector(outHistory);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ status_t result = NO_ERROR;
+ error = reply.readInt32(&result);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ return result;
+ }
+
virtual void dump(String8& result, const char* prefix) const {
Parcel data, reply;
data.writeInterfaceToken(IGraphicBufferConsumer::getInterfaceDescriptor());
@@ -409,6 +435,25 @@
}
return NO_ERROR;
}
+ case GET_OCCUPANCY_HISTORY: {
+ CHECK_INTERFACE(IGraphicBufferConsumer, data, reply);
+ bool forceFlush = false;
+ status_t error = data.readBool(&forceFlush);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ std::vector<OccupancyTracker::Segment> history;
+ status_t result = getOccupancyHistory(forceFlush, &history);
+ error = reply->writeParcelableVector(history);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ error = reply->writeInt32(result);
+ if (error != NO_ERROR) {
+ return error;
+ }
+ return NO_ERROR;
+ }
case DUMP: {
CHECK_INTERFACE(IGraphicBufferConsumer, data, reply);
String8 result = data.readString8();
diff --git a/libs/gui/OccupancyTracker.cpp b/libs/gui/OccupancyTracker.cpp
new file mode 100644
index 0000000..9687aaf
--- /dev/null
+++ b/libs/gui/OccupancyTracker.cpp
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2016 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 "OccupancyTracker"
+
+#include <gui/OccupancyTracker.h>
+#include <binder/Parcel.h>
+#include <utils/String8.h>
+#include <utils/Trace.h>
+
+#include <inttypes.h>
+
+namespace android {
+
+status_t OccupancyTracker::Segment::writeToParcel(Parcel* parcel) const {
+ status_t result = parcel->writeInt64(totalTime);
+ if (result != OK) {
+ return result;
+ }
+ result = parcel->writeUint64(static_cast<uint64_t>(numFrames));
+ if (result != OK) {
+ return result;
+ }
+ result = parcel->writeFloat(occupancyAverage);
+ if (result != OK) {
+ return result;
+ }
+ return parcel->writeBool(usedThirdBuffer);
+}
+
+status_t OccupancyTracker::Segment::readFromParcel(const Parcel* parcel) {
+ status_t result = parcel->readInt64(&totalTime);
+ if (result != OK) {
+ return result;
+ }
+ uint64_t uintNumFrames = 0;
+ result = parcel->readUint64(&uintNumFrames);
+ if (result != OK) {
+ return result;
+ }
+ numFrames = static_cast<size_t>(uintNumFrames);
+ result = parcel->readFloat(&occupancyAverage);
+ if (result != OK) {
+ return result;
+ }
+ return parcel->readBool(&usedThirdBuffer);
+}
+
+void OccupancyTracker::registerOccupancyChange(size_t occupancy) {
+ ATRACE_CALL();
+ nsecs_t now = systemTime();
+ nsecs_t delta = now - mLastOccupancyChangeTime;
+ if (delta > NEW_SEGMENT_DELAY) {
+ recordPendingSegment();
+ } else {
+ mPendingSegment.totalTime += delta;
+ if (mPendingSegment.mOccupancyTimes.count(mLastOccupancy)) {
+ mPendingSegment.mOccupancyTimes[mLastOccupancy] += delta;
+ } else {
+ mPendingSegment.mOccupancyTimes[mLastOccupancy] = delta;
+ }
+ }
+ if (occupancy > mLastOccupancy) {
+ ++mPendingSegment.numFrames;
+ }
+ mLastOccupancyChangeTime = now;
+ mLastOccupancy = occupancy;
+}
+
+std::vector<OccupancyTracker::Segment> OccupancyTracker::getSegmentHistory(
+ bool forceFlush) {
+ if (forceFlush) {
+ recordPendingSegment();
+ }
+ std::vector<Segment> segments(mSegmentHistory.cbegin(),
+ mSegmentHistory.cend());
+ mSegmentHistory.clear();
+ return segments;
+}
+
+void OccupancyTracker::recordPendingSegment() {
+ // Only record longer segments to get a better measurement of actual double-
+ // vs. triple-buffered time
+ if (mPendingSegment.numFrames > LONG_SEGMENT_THRESHOLD) {
+ float occupancyAverage = 0.0f;
+ bool usedThirdBuffer = false;
+ for (const auto& timePair : mPendingSegment.mOccupancyTimes) {
+ size_t occupancy = timePair.first;
+ float timeRatio = static_cast<float>(timePair.second) /
+ mPendingSegment.totalTime;
+ occupancyAverage += timeRatio * occupancy;
+ usedThirdBuffer = usedThirdBuffer || (occupancy > 1);
+ }
+ mSegmentHistory.push_front({mPendingSegment.totalTime,
+ mPendingSegment.numFrames, occupancyAverage, usedThirdBuffer});
+ if (mSegmentHistory.size() > MAX_HISTORY_SIZE) {
+ mSegmentHistory.pop_back();
+ }
+ }
+ mPendingSegment.clear();
+}
+
+} // namespace android
diff --git a/libs/gui/tests/BufferQueue_test.cpp b/libs/gui/tests/BufferQueue_test.cpp
index 85d63b4..210ce8c 100644
--- a/libs/gui/tests/BufferQueue_test.cpp
+++ b/libs/gui/tests/BufferQueue_test.cpp
@@ -34,6 +34,10 @@
#include <gtest/gtest.h>
+#include <thread>
+
+using namespace std::chrono_literals;
+
namespace android {
class BufferQueueTest : public ::testing::Test {
@@ -850,4 +854,140 @@
returnedBuffer->getNativeBuffer()->handle);
}
+TEST_F(BufferQueueTest, TestOccupancyHistory) {
+ createBufferQueue();
+ sp<DummyConsumer> dc(new DummyConsumer);
+ ASSERT_EQ(OK, mConsumer->consumerConnect(dc, false));
+ IGraphicBufferProducer::QueueBufferOutput output;
+ ASSERT_EQ(OK, mProducer->connect(new DummyProducerListener,
+ NATIVE_WINDOW_API_CPU, false, &output));
+
+ int slot = BufferQueue::INVALID_BUFFER_SLOT;
+ sp<Fence> fence = Fence::NO_FENCE;
+ sp<GraphicBuffer> buffer = nullptr;
+ IGraphicBufferProducer::QueueBufferInput input(0ull, true,
+ HAL_DATASPACE_UNKNOWN, Rect::INVALID_RECT,
+ NATIVE_WINDOW_SCALING_MODE_FREEZE, 0, Fence::NO_FENCE);
+ BufferItem item{};
+
+ // Preallocate, dequeue, request, and cancel 3 buffers so we don't get
+ // BUFFER_NEEDS_REALLOCATION below
+ int slots[3] = {};
+ mProducer->setMaxDequeuedBufferCount(3);
+ for (size_t i = 0; i < 3; ++i) {
+ status_t result = mProducer->dequeueBuffer(&slots[i], &fence,
+ 0, 0, 0, 0);
+ ASSERT_EQ(IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION, result);
+ ASSERT_EQ(OK, mProducer->requestBuffer(slots[i], &buffer));
+ }
+ for (size_t i = 0; i < 3; ++i) {
+ ASSERT_EQ(OK, mProducer->cancelBuffer(slots[i], Fence::NO_FENCE));
+ }
+
+ // Create 3 segments
+
+ // The first segment is a two-buffer segment, so we only put one buffer into
+ // the queue at a time
+ for (size_t i = 0; i < 5; ++i) {
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+ std::this_thread::sleep_for(16ms);
+ }
+
+ // Sleep between segments
+ std::this_thread::sleep_for(500ms);
+
+ // The second segment is a double-buffer segment. It starts the same as the
+ // two-buffer segment, but then at the end, we put two buffers in the queue
+ // at the same time before draining it.
+ for (size_t i = 0; i < 5; ++i) {
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+ std::this_thread::sleep_for(16ms);
+ }
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+ std::this_thread::sleep_for(16ms);
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+
+ // Sleep between segments
+ std::this_thread::sleep_for(500ms);
+
+ // The third segment is a triple-buffer segment, so the queue is switching
+ // between one buffer and two buffers deep.
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ for (size_t i = 0; i < 5; ++i) {
+ ASSERT_EQ(OK, mProducer->dequeueBuffer(&slot, &fence, 0, 0, 0, 0));
+ ASSERT_EQ(OK, mProducer->queueBuffer(slot, input, &output));
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+ std::this_thread::sleep_for(16ms);
+ }
+ ASSERT_EQ(OK, mConsumer->acquireBuffer(&item, 0));
+ ASSERT_EQ(OK, mConsumer->releaseBuffer(item.mSlot, item.mFrameNumber,
+ EGL_NO_DISPLAY, EGL_NO_SYNC_KHR, Fence::NO_FENCE));
+
+ // Now we read the segments
+ std::vector<OccupancyTracker::Segment> history;
+ ASSERT_EQ(OK, mConsumer->getOccupancyHistory(false, &history));
+
+ // Since we didn't force a flush, we should only get the first two segments
+ // (since the third segment hasn't been closed out by the appearance of a
+ // new segment yet)
+ ASSERT_EQ(2u, history.size());
+
+ // The first segment (which will be history[1], since the newest segment
+ // should be at the front of the vector) should be a two-buffer segment,
+ // which implies that the occupancy average should be between 0 and 1, and
+ // usedThirdBuffer should be false
+ const auto& firstSegment = history[1];
+ ASSERT_EQ(5u, firstSegment.numFrames);
+ ASSERT_LT(0, firstSegment.occupancyAverage);
+ ASSERT_GT(1, firstSegment.occupancyAverage);
+ ASSERT_EQ(false, firstSegment.usedThirdBuffer);
+
+ // The second segment should be a double-buffered segment, which implies that
+ // the occupancy average should be between 0 and 1, but usedThirdBuffer
+ // should be true
+ const auto& secondSegment = history[0];
+ ASSERT_EQ(7u, secondSegment.numFrames);
+ ASSERT_LT(0, secondSegment.occupancyAverage);
+ ASSERT_GT(1, secondSegment.occupancyAverage);
+ ASSERT_EQ(true, secondSegment.usedThirdBuffer);
+
+ // If we read the segments again without flushing, we shouldn't get any new
+ // segments
+ ASSERT_EQ(OK, mConsumer->getOccupancyHistory(false, &history));
+ ASSERT_EQ(0u, history.size());
+
+ // Read the segments again, this time forcing a flush so we get the third
+ // segment
+ ASSERT_EQ(OK, mConsumer->getOccupancyHistory(true, &history));
+ ASSERT_EQ(1u, history.size());
+
+ // This segment should be a triple-buffered segment, which implies that the
+ // occupancy average should be between 1 and 2, and usedThirdBuffer should
+ // be true
+ const auto& thirdSegment = history[0];
+ ASSERT_EQ(6u, thirdSegment.numFrames);
+ ASSERT_LT(1, thirdSegment.occupancyAverage);
+ ASSERT_GT(2, thirdSegment.occupancyAverage);
+ ASSERT_EQ(true, thirdSegment.usedThirdBuffer);
+}
+
} // namespace android
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index ed320cb..59a604a 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1680,7 +1680,8 @@
return mQueuedFrames > 0 || mSidebandStreamChanged || mAutoRefresh;
}
-void Layer::onPostComposition() {
+bool Layer::onPostComposition() {
+ bool frameLatencyNeeded = mFrameLatencyNeeded;
if (mFrameLatencyNeeded) {
nsecs_t desiredPresentTime = mSurfaceFlingerConsumer->getTimestamp();
mFrameTracker.setDesiredPresentTime(desiredPresentTime);
@@ -1712,6 +1713,7 @@
mFrameTracker.advanceFrame();
mFrameLatencyNeeded = false;
}
+ return frameLatencyNeeded;
}
#ifdef USE_HWC2
@@ -2185,6 +2187,20 @@
*outAcquireFence = mSurfaceFlingerConsumer->getCurrentFence();
*outPrevReleaseFence = mSurfaceFlingerConsumer->getPrevReleaseFence();
}
+
+std::vector<OccupancyTracker::Segment> Layer::getOccupancyHistory(
+ bool forceFlush) {
+ std::vector<OccupancyTracker::Segment> history;
+ status_t result = mSurfaceFlingerConsumer->getOccupancyHistory(forceFlush,
+ &history);
+ if (result != NO_ERROR) {
+ ALOGW("[%s] Failed to obtain occupancy history (%d)", mName.string(),
+ result);
+ return {};
+ }
+ return history;
+}
+
// ---------------------------------------------------------------------------
Layer::LayerCleaner::LayerCleaner(const sp<SurfaceFlinger>& flinger,
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 7d085a4..79750a6 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -274,9 +274,10 @@
bool onPreComposition();
/*
- * called after composition.
+ * called after composition.
+ * returns true if the layer latched a new buffer this frame.
*/
- void onPostComposition();
+ bool onPostComposition();
#ifdef USE_HWC2
// If a buffer was replaced this frame, release the former buffer
@@ -406,6 +407,8 @@
bool* outIsGlesComposition, nsecs_t* outPostedTime,
sp<Fence>* outAcquireFence, sp<Fence>* outPrevReleaseFence) const;
+ std::vector<OccupancyTracker::Segment> getOccupancyHistory(bool forceFlush);
+
protected:
// constant
sp<SurfaceFlinger> mFlinger;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 91815f3..a730ac6 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1049,7 +1049,11 @@
const LayerVector& layers(mDrawingState.layersSortedByZ);
const size_t count = layers.size();
for (size_t i=0 ; i<count ; i++) {
- layers[i]->onPostComposition();
+ bool frameLatched = layers[i]->onPostComposition();
+ if (frameLatched) {
+ recordBufferingStats(layers[i]->getName().string(),
+ layers[i]->getOccupancyHistory(false));
+ }
}
sp<Fence> presentFence = mHwc->getRetireFence(HWC_DISPLAY_PRIMARY);
@@ -1641,6 +1645,8 @@
if (!mLayersPendingRemoval.isEmpty()) {
// Notify removed layers now that they can't be drawn from
for (size_t i = 0; i < mLayersPendingRemoval.size(); i++) {
+ recordBufferingStats(mLayersPendingRemoval[i]->getName().string(),
+ mLayersPendingRemoval[i]->getOccupancyHistory(true));
mLayersPendingRemoval[i]->onRemoved();
}
mLayersPendingRemoval.clear();
@@ -2720,6 +2726,59 @@
NUM_BUCKETS - 1, bucketTimeSec, percent);
}
+void SurfaceFlinger::recordBufferingStats(const char* layerName,
+ std::vector<OccupancyTracker::Segment>&& history) {
+ Mutex::Autolock lock(mBufferingStatsMutex);
+ auto& stats = mBufferingStats[layerName];
+ for (const auto& segment : history) {
+ if (!segment.usedThirdBuffer) {
+ stats.twoBufferTime += segment.totalTime;
+ }
+ if (segment.occupancyAverage < 1.0f) {
+ stats.doubleBufferedTime += segment.totalTime;
+ } else if (segment.occupancyAverage < 2.0f) {
+ stats.tripleBufferedTime += segment.totalTime;
+ }
+ ++stats.numSegments;
+ stats.totalTime += segment.totalTime;
+ }
+}
+
+void SurfaceFlinger::dumpBufferingStats(String8& result) const {
+ result.append("Buffering stats:\n");
+ result.append(" [Layer name] <Active time> <Two buffer> "
+ "<Double buffered> <Triple buffered>\n");
+ Mutex::Autolock lock(mBufferingStatsMutex);
+ typedef std::tuple<std::string, float, float, float> BufferTuple;
+ std::map<float, BufferTuple, std::greater<float>> sorted;
+ for (const auto& statsPair : mBufferingStats) {
+ const char* name = statsPair.first.c_str();
+ const BufferingStats& stats = statsPair.second;
+ if (stats.numSegments == 0) {
+ continue;
+ }
+ float activeTime = ns2ms(stats.totalTime) / 1000.0f;
+ float twoBufferRatio = static_cast<float>(stats.twoBufferTime) /
+ stats.totalTime;
+ float doubleBufferRatio = static_cast<float>(
+ stats.doubleBufferedTime) / stats.totalTime;
+ float tripleBufferRatio = static_cast<float>(
+ stats.tripleBufferedTime) / stats.totalTime;
+ sorted.insert({activeTime, {name, twoBufferRatio,
+ doubleBufferRatio, tripleBufferRatio}});
+ }
+ for (const auto& sortedPair : sorted) {
+ float activeTime = sortedPair.first;
+ const BufferTuple& values = sortedPair.second;
+ result.appendFormat(" [%s] %.2f %.3f %.3f %.3f\n",
+ std::get<0>(values).c_str(), activeTime,
+ std::get<1>(values), std::get<2>(values),
+ std::get<3>(values));
+ }
+ result.append("\n");
+}
+
+
void SurfaceFlinger::dumpAllLocked(const Vector<String16>& args, size_t& index,
String8& result) const
{
@@ -2773,6 +2832,8 @@
dumpStaticScreenStats(result);
result.append("\n");
+ dumpBufferingStats(result);
+
/*
* Dump the visible layer list
*/
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 633e956..8263994 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -42,6 +42,7 @@
#include <gui/ISurfaceComposer.h>
#include <gui/ISurfaceComposerClient.h>
+#include <gui/OccupancyTracker.h>
#include <hardware/hwcomposer_defs.h>
@@ -57,6 +58,9 @@
#include "DisplayHardware/HWComposer.h"
#include "Effects/Daltonizer.h"
+#include <map>
+#include <string>
+
namespace android {
// ---------------------------------------------------------------------------
@@ -432,6 +436,10 @@
void dumpStaticScreenStats(String8& result) const;
+ void recordBufferingStats(const char* layerName,
+ std::vector<OccupancyTracker::Segment>&& history);
+ void dumpBufferingStats(String8& result) const;
+
/* ------------------------------------------------------------------------
* Attributes
*/
@@ -526,6 +534,29 @@
nsecs_t mFrameBuckets[NUM_BUCKETS];
nsecs_t mTotalTime;
std::atomic<nsecs_t> mLastSwapTime;
+
+ // Double- vs. triple-buffering stats
+ struct BufferingStats {
+ BufferingStats()
+ : numSegments(0),
+ totalTime(0),
+ twoBufferTime(0),
+ doubleBufferedTime(0),
+ tripleBufferedTime(0) {}
+
+ size_t numSegments;
+ nsecs_t totalTime;
+
+ // "Two buffer" means that a third buffer was never used, whereas
+ // "double-buffered" means that on average the segment only used two
+ // buffers (though it may have used a third for some part of the
+ // segment)
+ nsecs_t twoBufferTime;
+ nsecs_t doubleBufferedTime;
+ nsecs_t tripleBufferedTime;
+ };
+ mutable Mutex mBufferingStatsMutex;
+ std::unordered_map<std::string, BufferingStats> mBufferingStats;
};
}; // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
index de46dfa..ef4861d 100644
--- a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
+++ b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
@@ -1042,7 +1042,11 @@
const LayerVector& layers(mDrawingState.layersSortedByZ);
const size_t count = layers.size();
for (size_t i=0 ; i<count ; i++) {
- layers[i]->onPostComposition();
+ bool frameLatched = layers[i]->onPostComposition();
+ if (frameLatched) {
+ recordBufferingStats(layers[i]->getName().string(),
+ layers[i]->getOccupancyHistory(false));
+ }
}
const HWComposer& hwc = getHwComposer();
@@ -1670,6 +1674,8 @@
if (!mLayersPendingRemoval.isEmpty()) {
// Notify removed layers now that they can't be drawn from
for (size_t i = 0; i < mLayersPendingRemoval.size(); i++) {
+ recordBufferingStats(mLayersPendingRemoval[i]->getName().string(),
+ mLayersPendingRemoval[i]->getOccupancyHistory(true));
mLayersPendingRemoval[i]->onRemoved();
}
mLayersPendingRemoval.clear();
@@ -2745,6 +2751,58 @@
NUM_BUCKETS - 1, bucketTimeSec, percent);
}
+void SurfaceFlinger::recordBufferingStats(const char* layerName,
+ std::vector<OccupancyTracker::Segment>&& history) {
+ Mutex::Autolock lock(mBufferingStatsMutex);
+ auto& stats = mBufferingStats[layerName];
+ for (const auto& segment : history) {
+ if (!segment.usedThirdBuffer) {
+ stats.twoBufferTime += segment.totalTime;
+ }
+ if (segment.occupancyAverage < 1.0f) {
+ stats.doubleBufferedTime += segment.totalTime;
+ } else if (segment.occupancyAverage < 2.0f) {
+ stats.tripleBufferedTime += segment.totalTime;
+ }
+ ++stats.numSegments;
+ stats.totalTime += segment.totalTime;
+ }
+}
+
+void SurfaceFlinger::dumpBufferingStats(String8& result) const {
+ result.append("Buffering stats:\n");
+ result.append(" [Layer name] <Active time> <Two buffer> "
+ "<Double buffered> <Triple buffered>\n");
+ Mutex::Autolock lock(mBufferingStatsMutex);
+ typedef std::tuple<std::string, float, float, float> BufferTuple;
+ std::map<float, BufferTuple, std::greater<float>> sorted;
+ for (const auto& statsPair : mBufferingStats) {
+ const char* name = statsPair.first.c_str();
+ const BufferingStats& stats = statsPair.second;
+ if (stats.numSegments == 0) {
+ continue;
+ }
+ float activeTime = ns2ms(stats.totalTime) / 1000.0f;
+ float twoBufferRatio = static_cast<float>(stats.twoBufferTime) /
+ stats.totalTime;
+ float doubleBufferRatio = static_cast<float>(
+ stats.doubleBufferedTime) / stats.totalTime;
+ float tripleBufferRatio = static_cast<float>(
+ stats.tripleBufferedTime) / stats.totalTime;
+ sorted.insert({activeTime, {name, twoBufferRatio,
+ doubleBufferRatio, tripleBufferRatio}});
+ }
+ for (const auto& sortedPair : sorted) {
+ float activeTime = sortedPair.first;
+ const BufferTuple& values = sortedPair.second;
+ result.appendFormat(" [%s] %.2f %.3f %.3f %.3f\n",
+ std::get<0>(values).c_str(), activeTime,
+ std::get<1>(values), std::get<2>(values),
+ std::get<3>(values));
+ }
+ result.append("\n");
+}
+
void SurfaceFlinger::dumpAllLocked(const Vector<String16>& args, size_t& index,
String8& result) const
{
@@ -2796,6 +2854,8 @@
dumpStaticScreenStats(result);
result.append("\n");
+ dumpBufferingStats(result);
+
/*
* Dump the visible layer list
*/