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/DisplayHardware/AidlComposerHal.cpp b/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
index a93bd95..36da2c3 100644
--- a/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
@@ -820,13 +820,35 @@
return error;
}
-Error AidlComposer::clearLayerBufferSlot(Display display, Layer layer, uint32_t slot) {
+Error AidlComposer::setLayerBufferSlotsToClear(Display display, Layer layer,
+ const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) {
+ if (slotsToClear.empty()) {
+ return Error::NONE;
+ }
+
Error error = Error::NONE;
mMutex.lock_shared();
if (auto writer = getWriter(display)) {
+ // Backwards compatible way of clearing buffer slots is tricky...
+ for (uint32_t slot : slotsToClear) {
+ // Don't clear the active buffer slot because we need to restore the active buffer
+ // after clearing the requested buffer slots with a placeholder buffer.
+ if (slot != activeBufferSlot) {
+ writer->get().setLayerBufferWithNewCommand(translate<int64_t>(display),
+ translate<int64_t>(layer), slot,
+ mClearSlotBuffer->handle, /*fence*/ -1);
+ }
+ }
+ // Since we clear buffers by setting them to a placeholder buffer, we want to make
+ // sure that the last setLayerBuffer command is sent with the currently active
+ // buffer, not the placeholder buffer, so that there is no perceptual change when
+ // buffers are discarded.
writer->get().setLayerBufferWithNewCommand(translate<int64_t>(display),
- translate<int64_t>(layer), slot,
- mClearSlotBuffer->handle, /*fence*/ -1);
+ translate<int64_t>(layer), activeBufferSlot,
+ // The active buffer is still cached in
+ // its slot and doesn't need a fence.
+ /*buffer*/ nullptr, /*fence*/ -1);
} else {
error = Error::BAD_DISPLAY;
}
diff --git a/services/surfaceflinger/DisplayHardware/AidlComposerHal.h b/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
index 5128648..9a7ade7 100644
--- a/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
@@ -143,7 +143,9 @@
/* see setClientTarget for the purpose of slot */
Error setLayerBuffer(Display display, Layer layer, uint32_t slot,
const sp<GraphicBuffer>& buffer, int acquireFence) override;
- Error clearLayerBufferSlot(Display display, Layer layer, uint32_t slot) override;
+ Error setLayerBufferSlotsToClear(Display display, Layer layer,
+ const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) override;
Error setLayerSurfaceDamage(Display display, Layer layer,
const std::vector<IComposerClient::Rect>& damage) override;
Error setLayerBlendMode(Display display, Layer layer, IComposerClient::BlendMode mode) override;
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.h b/services/surfaceflinger/DisplayHardware/ComposerHal.h
index 821025c..1c2b8b5 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.h
@@ -179,7 +179,9 @@
/* see setClientTarget for the purpose of slot */
virtual Error setLayerBuffer(Display display, Layer layer, uint32_t slot,
const sp<GraphicBuffer>& buffer, int acquireFence) = 0;
- virtual Error clearLayerBufferSlot(Display display, Layer layer, uint32_t slot) = 0;
+ virtual Error setLayerBufferSlotsToClear(Display display, Layer layer,
+ const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) = 0;
virtual Error setLayerSurfaceDamage(Display display, Layer layer,
const std::vector<IComposerClient::Rect>& damage) = 0;
virtual Error setLayerBlendMode(Display display, Layer layer,
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index b5f91a6..6738f00 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -717,11 +717,13 @@
return static_cast<Error>(intError);
}
-Error Layer::clearBufferSlot(uint32_t slot) {
+Error Layer::setBufferSlotsToClear(const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) {
if (CC_UNLIKELY(!mDisplay)) {
return Error::BAD_DISPLAY;
}
- auto intError = mComposer.clearLayerBufferSlot(mDisplay->getId(), mId, slot);
+ auto intError = mComposer.setLayerBufferSlotsToClear(mDisplay->getId(), mId, slotsToClear,
+ activeBufferSlot);
return static_cast<Error>(intError);
}
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index 13edb13..c1c7070 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -310,7 +310,8 @@
[[nodiscard]] virtual hal::Error setBuffer(uint32_t slot,
const android::sp<android::GraphicBuffer>& buffer,
const android::sp<android::Fence>& acquireFence) = 0;
- [[nodiscard]] virtual hal::Error clearBufferSlot(uint32_t slot) = 0;
+ [[nodiscard]] virtual hal::Error setBufferSlotsToClear(
+ const std::vector<uint32_t>& slotsToClear, uint32_t activeBufferSlot) = 0;
[[nodiscard]] virtual hal::Error setSurfaceDamage(const android::Region& damage) = 0;
[[nodiscard]] virtual hal::Error setBlendMode(hal::BlendMode mode) = 0;
@@ -361,7 +362,8 @@
hal::Error setCursorPosition(int32_t x, int32_t y) override;
hal::Error setBuffer(uint32_t slot, const android::sp<android::GraphicBuffer>& buffer,
const android::sp<android::Fence>& acquireFence) override;
- hal::Error clearBufferSlot(uint32_t slot) override;
+ hal::Error setBufferSlotsToClear(const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) override;
hal::Error setSurfaceDamage(const android::Region& damage) override;
hal::Error setBlendMode(hal::BlendMode mode) override;
diff --git a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
index 9a49d94..c9e1e79 100644
--- a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
@@ -712,10 +712,29 @@
return Error::NONE;
}
-Error HidlComposer::clearLayerBufferSlot(Display display, Layer layer, uint32_t slot) {
+Error HidlComposer::setLayerBufferSlotsToClear(Display display, Layer layer,
+ const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) {
+ if (slotsToClear.empty()) {
+ return Error::NONE;
+ }
+ // Backwards compatible way of clearing buffer is to set the layer buffer with a placeholder
+ // buffer, using the slot that needs to cleared... tricky.
+ for (uint32_t slot : slotsToClear) {
+ // Don't clear the active buffer slot because we need to restore the active buffer after
+ // setting the requested buffer slots with a placeholder buffer.
+ if (slot != activeBufferSlot) {
+ mWriter.selectDisplay(display);
+ mWriter.selectLayer(layer);
+ mWriter.setLayerBuffer(slot, mClearSlotBuffer->handle, /*fence*/ -1);
+ }
+ }
+ // Since we clear buffers by setting them to a placeholder buffer, we want to make sure that the
+ // last setLayerBuffer command is sent with the currently active buffer, not the placeholder
+ // buffer, so that there is no perceptual change.
mWriter.selectDisplay(display);
mWriter.selectLayer(layer);
- mWriter.setLayerBuffer(slot, mClearSlotBuffer->handle, /*fence*/ -1);
+ mWriter.setLayerBuffer(activeBufferSlot, /*buffer*/ nullptr, /*fence*/ -1);
return Error::NONE;
}
diff --git a/services/surfaceflinger/DisplayHardware/HidlComposerHal.h b/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
index dc115b2..921add5 100644
--- a/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
@@ -248,7 +248,9 @@
/* see setClientTarget for the purpose of slot */
Error setLayerBuffer(Display display, Layer layer, uint32_t slot,
const sp<GraphicBuffer>& buffer, int acquireFence) override;
- Error clearLayerBufferSlot(Display display, Layer layer, uint32_t slot) override;
+ Error setLayerBufferSlotsToClear(Display display, Layer layer,
+ const std::vector<uint32_t>& slotsToClear,
+ uint32_t activeBufferSlot) override;
Error setLayerSurfaceDamage(Display display, Layer layer,
const std::vector<IComposerClient::Rect>& damage) override;
Error setLayerBlendMode(Display display, Layer layer, IComposerClient::BlendMode mode) override;