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 <utility> 22 #include <vector> 23 24 #include "common/libs/utils/result.h" 25 #include "common/libs/utils/subprocess.h" 26 #include "host/libs/config/command_source.h" 27 28 namespace cuttlefish { 29 30 struct MonitorEntry { 31 std::unique_ptr<Command> cmd; 32 std::unique_ptr<Subprocess> proc; 33 bool is_critical; 34 MonitorEntryMonitorEntry35 MonitorEntry(Command command, bool is_critical) 36 : cmd(new Command(std::move(command))), is_critical(is_critical) {} 37 }; 38 39 // Launches and keeps track of subprocesses, decides response if they 40 // unexpectedly exit 41 class ProcessMonitor { 42 public: 43 class Properties { 44 public: 45 Properties& RestartSubprocesses(bool) &; 46 Properties RestartSubprocesses(bool) &&; 47 48 Properties& AddCommand(MonitorCommand) &; 49 Properties AddCommand(MonitorCommand) &&; 50 51 template <typename T> AddCommands(T commands)52 Properties& AddCommands(T commands) & { 53 for (auto& command : commands) { 54 AddCommand(std::move(command)); 55 } 56 return *this; 57 } 58 59 template <typename T> AddCommands(T commands)60 Properties AddCommands(T commands) && { 61 return std::move(AddCommands(std::move(commands))); 62 } 63 64 private: 65 bool restart_subprocesses_; 66 std::vector<MonitorEntry> entries_; 67 68 friend class ProcessMonitor; 69 }; 70 ProcessMonitor(Properties&&); 71 72 // Start all processes given by AddCommand. 73 Result<void> StartAndMonitorProcesses(); 74 // Stops all monitored subprocesses. 75 Result<void> StopMonitoredProcesses(); 76 77 private: 78 Result<void> MonitorRoutine(); 79 80 Properties properties_; 81 pid_t monitor_; 82 SharedFD monitor_socket_; 83 }; 84 85 } // namespace cuttlefish 86