Maintain the active buffer when clearing buffer slots
When an app discards graphic buffers, for example when a MediaCodec
disconnects from a surface, those buffers will be uncached and removed
from HWC buffer slots. The active buffer, however, should still remain
active until the next buffer is queued up.
Bug: 262037933
Bug: 258196272
Test: atest OutputLayerUncacheBufferTest
Test: atest VtsHalGraphicsComposer3_TargetTest
Test: atest VtsHalGraphicsComposerV2_2TargetTest
Change-Id: I7c4eefb17e8bad694d698f9ad6d1d289f4af8d2c
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/HwcBufferCache.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/HwcBufferCache.h
index 6e9ea6f..b6a4240 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/HwcBufferCache.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/HwcBufferCache.h
@@ -83,7 +83,7 @@
// If the buffer is already in the cache, the buffer is null to optimize away sending HWC the
// buffer handle.
//
- HwcSlotAndBuffer getHwcSlotAndBufferForOverride(const sp<GraphicBuffer>& buffer);
+ HwcSlotAndBuffer getOverrideHwcSlotAndBuffer(const sp<GraphicBuffer>& buffer);
//
// When a client process discards a buffer, it needs to be purged from the HWC cache.
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
index 2b383c1..2a5bfae 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputLayerCompositionState.h
@@ -136,6 +136,9 @@
// cost of sending reused buffers to the HWC.
HwcBufferCache hwcBufferCache;
+ // The previously-active buffer for this layer.
+ uint32_t activeBufferSlot;
+
// Set to true when overridden info has been sent to HW composer
bool stateOverridden = false;
diff --git a/services/surfaceflinger/CompositionEngine/src/HwcBufferCache.cpp b/services/surfaceflinger/CompositionEngine/src/HwcBufferCache.cpp
index e2c0acf..34ed214 100644
--- a/services/surfaceflinger/CompositionEngine/src/HwcBufferCache.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/HwcBufferCache.cpp
@@ -42,7 +42,7 @@
return {cache(buffer), buffer};
}
-HwcSlotAndBuffer HwcBufferCache::getHwcSlotAndBufferForOverride(const sp<GraphicBuffer>& buffer) {
+HwcSlotAndBuffer HwcBufferCache::getOverrideHwcSlotAndBuffer(const sp<GraphicBuffer>& buffer) {
if (buffer == mLastOverrideBuffer) {
return {kOverrideBufferSlot, nullptr};
}
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
index 0ac2d43..766d7ea 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputLayer.cpp
@@ -610,21 +610,27 @@
}
}
-void OutputLayer::uncacheBuffers(std::vector<uint64_t> const& bufferIdsToUncache) {
+void OutputLayer::uncacheBuffers(const std::vector<uint64_t>& bufferIdsToUncache) {
auto& state = editState();
// Skip doing this if there is no HWC interface
if (!state.hwc) {
return;
}
- for (auto bufferId : bufferIdsToUncache) {
+ std::vector<uint32_t> slotsToClear;
+ for (uint64_t bufferId : bufferIdsToUncache) {
uint32_t slot = state.hwc->hwcBufferCache.uncache(bufferId);
- if (slot != UINT32_MAX && state.hwc->hwcLayer) {
- hal::Error error = state.hwc->hwcLayer->clearBufferSlot(slot);
- ALOGE("[%s] Failed to clear buffer slot %d: %s (%d)", getLayerFE().getDebugName(), slot,
- to_string(error).c_str(), static_cast<int32_t>(error));
+ if (slot != UINT32_MAX) {
+ slotsToClear.push_back(slot);
}
}
+
+ hal::Error error =
+ state.hwc->hwcLayer->setBufferSlotsToClear(slotsToClear, state.hwc->activeBufferSlot);
+ if (error != hal::Error::NONE) {
+ ALOGE("[%s] Failed to clear buffer slots: %s (%d)", getLayerFE().getDebugName(),
+ to_string(error).c_str(), static_cast<int32_t>(error));
+ }
}
void OutputLayer::writeBufferStateToHWC(HWC2::Layer* hwcLayer,
@@ -641,15 +647,25 @@
HwcSlotAndBuffer hwcSlotAndBuffer;
sp<Fence> hwcFence;
- // Override buffers use a special cache slot so that they don't evict client buffers.
- if (getState().overrideInfo.buffer != nullptr && !skipLayer) {
- hwcSlotAndBuffer = editState().hwc->hwcBufferCache.getHwcSlotAndBufferForOverride(
- getState().overrideInfo.buffer->getBuffer());
- hwcFence = getState().overrideInfo.acquireFence;
- } else {
- hwcSlotAndBuffer =
- editState().hwc->hwcBufferCache.getHwcSlotAndBuffer(outputIndependentState.buffer);
- hwcFence = outputIndependentState.acquireFence;
+ {
+ // Editing the state only because we update the HWC buffer cache and active buffer.
+ auto& state = editState();
+ // Override buffers use a special cache slot so that they don't evict client buffers.
+ if (state.overrideInfo.buffer != nullptr && !skipLayer) {
+ hwcSlotAndBuffer = state.hwc->hwcBufferCache.getOverrideHwcSlotAndBuffer(
+ state.overrideInfo.buffer->getBuffer());
+ hwcFence = state.overrideInfo.acquireFence;
+ } else {
+ hwcSlotAndBuffer =
+ state.hwc->hwcBufferCache.getHwcSlotAndBuffer(outputIndependentState.buffer);
+ hwcFence = outputIndependentState.acquireFence;
+ }
+
+ // Keep track of the active buffer slot, so we can restore it after clearing other buffer
+ // slots.
+ if (hwcSlotAndBuffer.buffer) {
+ state.hwc->activeBufferSlot = hwcSlotAndBuffer.slot;
+ }
}
if (auto error = hwcLayer->setBuffer(hwcSlotAndBuffer.slot, hwcSlotAndBuffer.buffer, hwcFence);
diff --git a/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp b/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
index cf72e8f..c5fb594 100644
--- a/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/HwcBufferCacheTest.cpp
@@ -115,20 +115,20 @@
EXPECT_EQ(cache.uncache(mBuffer2->getId()), UINT32_MAX);
}
-TEST_F(HwcBufferCacheTest, getHwcSlotAndBufferForOverride_whenCached_returnsSameSlotAndNullBuffer) {
+TEST_F(HwcBufferCacheTest, getOverrideHwcSlotAndBuffer_whenCached_returnsSameSlotAndNullBuffer) {
HwcBufferCache cache;
sp<GraphicBuffer> outBuffer;
- HwcSlotAndBuffer originalSlotAndBuffer = cache.getHwcSlotAndBufferForOverride(mBuffer1);
+ HwcSlotAndBuffer originalSlotAndBuffer = cache.getOverrideHwcSlotAndBuffer(mBuffer1);
EXPECT_NE(originalSlotAndBuffer.slot, UINT32_MAX);
EXPECT_EQ(originalSlotAndBuffer.buffer, mBuffer1);
- HwcSlotAndBuffer finalSlotAndBuffer = cache.getHwcSlotAndBufferForOverride(mBuffer1);
+ HwcSlotAndBuffer finalSlotAndBuffer = cache.getOverrideHwcSlotAndBuffer(mBuffer1);
EXPECT_EQ(finalSlotAndBuffer.slot, originalSlotAndBuffer.slot);
EXPECT_EQ(finalSlotAndBuffer.buffer, nullptr);
}
-TEST_F(HwcBufferCacheTest, getHwcSlotAndBufferForOverride_whenSlotsFull_returnsIndependentSlot) {
+TEST_F(HwcBufferCacheTest, getOverrideHwcSlotAndBuffer_whenSlotsFull_returnsIndependentSlot) {
HwcBufferCache cache;
sp<GraphicBuffer> outBuffer;
@@ -149,7 +149,7 @@
sp<GraphicBuffer> overrideBuffer =
sp<GraphicBuffer>::make(1u, 1u, HAL_PIXEL_FORMAT_RGBA_8888, 1u, 0u);
- HwcSlotAndBuffer overrideSlotAndBuffer = cache.getHwcSlotAndBufferForOverride(overrideBuffer);
+ HwcSlotAndBuffer overrideSlotAndBuffer = cache.getOverrideHwcSlotAndBuffer(overrideBuffer);
// expect us to have a slot number
EXPECT_NE(overrideSlotAndBuffer.slot, UINT32_MAX);
// expect this to be the first time we cached the buffer
@@ -173,7 +173,7 @@
HwcBufferCache cache;
sp<GraphicBuffer> outBuffer;
- HwcSlotAndBuffer hwcSlotAndBuffer = cache.getHwcSlotAndBufferForOverride(mBuffer1);
+ HwcSlotAndBuffer hwcSlotAndBuffer = cache.getOverrideHwcSlotAndBuffer(mBuffer1);
ASSERT_NE(hwcSlotAndBuffer.slot, UINT32_MAX);
EXPECT_EQ(cache.uncache(mBuffer1->getId()), hwcSlotAndBuffer.slot);
@@ -184,7 +184,7 @@
HwcBufferCache cache;
sp<GraphicBuffer> outBuffer;
- HwcSlotAndBuffer hwcSlotAndBuffer = cache.getHwcSlotAndBufferForOverride(mBuffer1);
+ HwcSlotAndBuffer hwcSlotAndBuffer = cache.getOverrideHwcSlotAndBuffer(mBuffer1);
ASSERT_NE(hwcSlotAndBuffer.slot, UINT32_MAX);
EXPECT_EQ(cache.uncache(mBuffer2->getId()), UINT32_MAX);
diff --git a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
index c7f9c69..b0b1a02 100644
--- a/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
+++ b/services/surfaceflinger/CompositionEngine/tests/MockHWC2.h
@@ -56,7 +56,7 @@
MOCK_METHOD3(setBuffer,
Error(uint32_t, const android::sp<android::GraphicBuffer>&,
const android::sp<android::Fence>&));
- MOCK_METHOD1(clearBufferSlot, Error(uint32_t));
+ MOCK_METHOD2(setBufferSlotsToClear, Error(const std::vector<uint32_t>&, uint32_t));
MOCK_METHOD1(setSurfaceDamage, Error(const android::Region&));
MOCK_METHOD1(setBlendMode, Error(hal::BlendMode));
MOCK_METHOD1(setColor, Error(aidl::android::hardware::graphics::composer3::Color));
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
index f2128c9..0edc226 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputLayerTest.cpp
@@ -1361,19 +1361,21 @@
Mock::VerifyAndClearExpectations(&mHwcLayer);
// buffer slots are cleared in HWC
- EXPECT_CALL(mHwcLayer, clearBufferSlot(/*slot*/ 0));
- EXPECT_CALL(mHwcLayer, clearBufferSlot(/*slot*/ 1));
+ std::vector<uint32_t> slotsToClear = {0, 1};
+ EXPECT_CALL(mHwcLayer,
+ setBufferSlotsToClear(/*slotsToClear*/ slotsToClear, /*activeBufferSlot*/ 1));
mOutputLayer.uncacheBuffers({kBuffer1->getId(), kBuffer2->getId()});
Mock::VerifyAndClearExpectations(&mHwcLayer);
- // slot 1 is reused for Buffer1
+ // rather than allocating a new slot, the active buffer slot (slot 1) is reused first to free
+ // the memory as soon as possible
mLayerFEState.buffer = kBuffer1;
EXPECT_CALL(mHwcLayer, setBuffer(/*slot*/ 1, kBuffer1, kFence));
mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0,
/*zIsOverridden*/ false, /*isPeekingThrough*/ false);
Mock::VerifyAndClearExpectations(&mHwcLayer);
- // slot 0 is reused for Buffer2
+ // rather than allocating a new slot, slot 0 is reused
mLayerFEState.buffer = kBuffer2;
EXPECT_CALL(mHwcLayer, setBuffer(/*slot*/ 0, kBuffer2, kFence));
mOutputLayer.writeStateToHWC(/*includeGeometry*/ false, /*skipLayer*/ false, 0,