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 #include "host/libs/screen_connector/socket_based_screen_connector.h"
18
19 #include <glog/logging.h>
20
21 #include "common/libs/fs/shared_fd.h"
22
23 namespace cvd {
24
SocketBasedScreenConnector(int frames_fd)25 SocketBasedScreenConnector::SocketBasedScreenConnector(int frames_fd) {
26 screen_server_thread_ =
27 std::thread([this, frames_fd]() { ServerLoop(frames_fd); });
28 }
29
OnFrameAfter(std::uint32_t frame_number,const FrameCallback & frame_callback)30 bool SocketBasedScreenConnector::OnFrameAfter(
31 std::uint32_t frame_number, const FrameCallback& frame_callback) {
32 int buffer_idx = WaitForNewFrameSince(&frame_number);
33 void* buffer = GetBuffer(buffer_idx);
34 frame_callback(frame_number, reinterpret_cast<uint8_t*>(buffer));
35 return true;
36 }
37
WaitForNewFrameSince(std::uint32_t * seq_num)38 int SocketBasedScreenConnector::WaitForNewFrameSince(std::uint32_t* seq_num) {
39 std::unique_lock<std::mutex> lock(new_frame_mtx_);
40 while (seq_num_ == *seq_num) {
41 new_frame_cond_var_.wait(lock);
42 }
43 *seq_num = seq_num_;
44 return newest_buffer_;
45 }
46
GetBuffer(int buffer_idx)47 void* SocketBasedScreenConnector::GetBuffer(int buffer_idx) {
48 if (buffer_idx < 0) return nullptr;
49 buffer_idx %= NUM_BUFFERS_;
50 return &buffer_[buffer_idx * ScreenSizeInBytes()];
51 }
52
ServerLoop(int frames_fd)53 void SocketBasedScreenConnector::ServerLoop(int frames_fd) {
54 if (frames_fd < 0) {
55 LOG(FATAL) << "Invalid file descriptor: " << frames_fd;
56 return;
57 }
58 auto server = SharedFD::Dup(frames_fd);
59 close(frames_fd);
60 if (!server->IsOpen()) {
61 LOG(FATAL) << "Unable to dup screen server: " << server->StrError();
62 return;
63 }
64
65 int current_buffer = 0;
66
67 while (1) {
68 LOG(INFO) << "Screen Connector accepting connections...";
69 auto conn = SharedFD::Accept(*server);
70 if (!conn->IsOpen()) {
71 LOG(ERROR) << "Disconnected fd returned from accept";
72 continue;
73 }
74 while (conn->IsOpen()) {
75 int32_t size = 0;
76 if (conn->Read(&size, sizeof(size)) < 0) {
77 LOG(ERROR) << "Failed to read from hwcomposer: " << conn->StrError();
78 break;
79 }
80 auto buff = reinterpret_cast<uint8_t*>(GetBuffer(current_buffer));
81 while (size > 0) {
82 auto read = conn->Read(buff, size);
83 if (read < 0) {
84 LOG(ERROR) << "Failed to read from hwcomposer: " << conn->StrError();
85 conn->Close();
86 break;
87 }
88 size -= read;
89 buff += read;
90 }
91 BroadcastNewFrame(current_buffer);
92 current_buffer = (current_buffer + 1) % NUM_BUFFERS_;
93 }
94 }
95 }
96
BroadcastNewFrame(int buffer_idx)97 void SocketBasedScreenConnector::BroadcastNewFrame(int buffer_idx) {
98 {
99 std::lock_guard<std::mutex> lock(new_frame_mtx_);
100 seq_num_++;
101 newest_buffer_ = buffer_idx;
102 }
103 new_frame_cond_var_.notify_all();
104 }
105 } // namespace cvd
106