| /* |
| * Copyright (C) 2017 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. |
| */ |
| |
| #pragma once |
| |
| #include <cstdint> |
| #include <vector> |
| |
| // TODO(b/129481165): remove the #pragma below and fix conversion issues |
| #pragma clang diagnostic push |
| #pragma clang diagnostic ignored "-Wconversion" |
| |
| #include <gui/BufferQueue.h> |
| |
| // TODO(b/129481165): remove the #pragma below and fix conversion issues |
| #pragma clang diagnostic pop // ignored "-Wconversion" |
| |
| #include <utils/StrongPointer.h> |
| |
| namespace android { |
| |
| class GraphicBuffer; |
| |
| namespace compositionengine::impl { |
| |
| // With HIDLized hwcomposer HAL, the HAL can maintain a buffer cache for each |
| // HWC display and layer. When updating a display target or a layer buffer, |
| // we have the option to send the buffer handle over or to request the HAL to |
| // retrieve it from its cache. The latter is cheaper since it eliminates the |
| // overhead to transfer the handle over the trasport layer, and the overhead |
| // for the HAL to clone and retain the handle. |
| // |
| // To be able to find out whether a buffer is already in the HAL's cache, we |
| // use HWComposerBufferCache to mirror the cache in SF. |
| class HwcBufferCache { |
| public: |
| HwcBufferCache(); |
| // Given a buffer, return the HWC cache slot and |
| // buffer to be sent to HWC. |
| // |
| // outBuffer is set to buffer when buffer is not in the HWC cache; |
| // otherwise, outBuffer is set to nullptr. |
| void getHwcBuffer(int slot, const sp<GraphicBuffer>& buffer, uint32_t* outSlot, |
| sp<GraphicBuffer>* outBuffer); |
| |
| private: |
| // an array where the index corresponds to a slot and the value corresponds to a (counter, |
| // buffer) pair. "counter" is a unique value that indicates the last time this slot was updated |
| // or used and allows us to keep track of the least-recently used buffer. |
| wp<GraphicBuffer> mBuffers[BufferQueue::NUM_BUFFER_SLOTS]; |
| }; |
| |
| } // namespace compositionengine::impl |
| } // namespace android |