1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include "host/libs/screen_connector/screen_connector.h"
20 
21 #include <atomic>
22 #include <cinttypes>
23 #include <condition_variable>
24 #include <mutex>
25 #include <thread>
26 #include <vector>
27 
28 namespace cvd {
29 
30 class SocketBasedScreenConnector : public ScreenConnector {
31  public:
32   explicit SocketBasedScreenConnector(int frames_fd);
33 
34   bool OnFrameAfter(std::uint32_t frame_number,
35                     const FrameCallback& frame_callback) override;
36 
37  private:
38   static constexpr int NUM_BUFFERS_ = 4;
39 
40   int WaitForNewFrameSince(std::uint32_t* seq_num);
41   void* GetBuffer(int buffer_idx);
42   void ServerLoop(int frames_fd);
43   void BroadcastNewFrame(int buffer_idx);
44 
45   std::vector<std::uint8_t> buffer_ =
46       std::vector<std::uint8_t>(NUM_BUFFERS_ * ScreenSizeInBytes());
47   std::uint32_t seq_num_{0};
48   int newest_buffer_ = 0;
49   std::condition_variable new_frame_cond_var_;
50   std::mutex new_frame_mtx_;
51   std::thread screen_server_thread_;
52 };
53 
54 } // namespace cvd