1 /* 2 * Copyright (C) 2018 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 #pragma once 17 18 #include <memory> 19 #include <mutex> 20 #include <thread> 21 #include <vector> 22 23 #include "common/libs/utils/result.h" 24 #include "common/libs/utils/subprocess.h" 25 26 namespace cuttlefish { 27 28 struct MonitorEntry { 29 std::unique_ptr<Command> cmd; 30 std::unique_ptr<Subprocess> proc; 31 }; 32 33 // Keeps track of launched subprocesses, restarts them if they unexpectedly exit 34 class ProcessMonitor { 35 public: 36 class Properties { 37 public: 38 Properties& RestartSubprocesses(bool) &; 39 Properties RestartSubprocesses(bool) &&; 40 41 Properties& AddCommand(Command) &; 42 Properties AddCommand(Command) &&; 43 44 template <typename T> AddCommands(T commands)45 Properties& AddCommands(T commands) & { 46 for (auto& command : commands) { 47 AddCommand(std::move(command)); 48 } 49 return *this; 50 } 51 52 template <typename T> AddCommands(T commands)53 Properties AddCommands(T commands) && { 54 for (auto& command : commands) { 55 AddCommand(std::move(command)); 56 } 57 return std::move(*this); 58 } 59 60 private: 61 bool restart_subprocesses_; 62 std::vector<MonitorEntry> entries_; 63 64 friend class ProcessMonitor; 65 }; 66 ProcessMonitor(Properties&&); 67 68 // Start all processes given by AddCommand. 69 Result<void> StartAndMonitorProcesses(); 70 // Stops all monitored subprocesses. 71 Result<void> StopMonitoredProcesses(); 72 73 private: 74 Result<void> MonitorRoutine(); 75 76 Properties properties_; 77 pid_t monitor_; 78 SharedFD monitor_socket_; 79 }; 80 81 } // namespace cuttlefish 82