| /** |
| * Copyright (C) 2024 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 <ui/Fence.h> |
| |
| namespace android { |
| |
| // TODO: measure if Fence::merge is cheaper |
| inline void mergeFence(const char* debugName, sp<Fence>&& incomingFence, sp<Fence>& prevFence) { |
| if (prevFence == nullptr && incomingFence->getStatus() != Fence::Status::Invalid) { |
| prevFence = std::move(incomingFence); |
| } else if (prevFence != nullptr) { |
| // If both fences are signaled or both are unsignaled, we need to merge |
| // them to get an accurate timestamp. |
| if (prevFence->getStatus() != Fence::Status::Invalid && |
| prevFence->getStatus() == incomingFence->getStatus()) { |
| char fenceName[32] = {}; |
| snprintf(fenceName, 32, "%.28s", debugName); |
| sp<Fence> mergedFence = Fence::merge(fenceName, prevFence, incomingFence); |
| if (mergedFence->isValid()) { |
| prevFence = std::move(mergedFence); |
| } |
| } else if (incomingFence->getStatus() == Fence::Status::Unsignaled) { |
| // If one fence has signaled and the other hasn't, the unsignaled |
| // fence will approximately correspond with the correct timestamp. |
| // There's a small race if both fences signal at about the same time |
| // and their statuses are retrieved with unfortunate timing. However, |
| // by this point, they will have both signaled and only the timestamp |
| // will be slightly off; any dependencies after this point will |
| // already have been met. |
| prevFence = std::move(incomingFence); |
| } |
| } |
| } |
| |
| } // namespace android |