1 /* 2 * Copyright (C) 2022 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 <set> 19 #include <string> 20 21 #include <fruit/fruit.h> 22 23 #include "host/commands/cvd/lock_file.h" 24 25 namespace cuttlefish { 26 27 // This class is not thread safe. 28 class InstanceLockFile { 29 friend class InstanceLockFileManager; 30 using LockFile = cvd_impl::LockFile; 31 32 public: 33 int Instance() const; 34 Result<InUseState> Status() const; 35 Result<void> Status(InUseState); 36 37 bool operator<(const InstanceLockFile&) const; 38 39 private: 40 InstanceLockFile(LockFile&& lock_file, const int instance_num); 41 LockFile lock_file_; 42 const int instance_num_; 43 }; 44 45 class InstanceLockFileManager { 46 using LockFile = cvd_impl::LockFile; 47 using LockFileManager = cvd_impl::LockFileManager; 48 49 public: 50 INJECT(InstanceLockFileManager()); 51 52 Result<InstanceLockFile> AcquireLock(int instance_num); 53 Result<std::set<InstanceLockFile>> AcquireLocks(const std::set<int>& nums); 54 55 Result<std::optional<InstanceLockFile>> TryAcquireLock(int instance_num); 56 Result<std::set<InstanceLockFile>> TryAcquireLocks(const std::set<int>& nums); 57 58 // Best-effort attempt to find a free instance id. 59 Result<std::optional<InstanceLockFile>> TryAcquireUnusedLock(); 60 61 Result<std::vector<InstanceLockFile>> LockAllAvailable(); 62 63 private: 64 /* 65 * Generate value to initialize 66 */ 67 Result<std::set<int>> FindPotentialInstanceNumsFromNetDevices(); 68 static Result<std::string> LockFilePath(int instance_num); 69 std::optional<std::set<int>> all_instance_nums_; 70 LockFileManager lock_file_manager_; 71 }; 72 73 } // namespace cuttlefish 74