1 /* 2 * Copyright 2021 Google, Inc 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 <condition_variable> 20 #include <mutex> 21 #include <vector> 22 23 class Reaper { 24 public: 25 struct target_proc { 26 int pidfd; 27 int pid; 28 uid_t uid; 29 }; 30 private: 31 // mutex_ and cond_ are used to wakeup the reaper thread. 32 std::mutex mutex_; 33 std::condition_variable cond_; 34 // mutex_ protects queue_ and active_requests_ access. 35 std::vector<struct target_proc> queue_; 36 int active_requests_; 37 // write side of the pipe to communicate kill failures with the main thread 38 int comm_fd_; 39 int thread_cnt_; 40 pthread_t* thread_pool_; 41 bool debug_enabled_; 42 43 bool async_kill(const struct target_proc& target); 44 public: Reaper()45 Reaper() : active_requests_(0), thread_cnt_(0), debug_enabled_(false) {} 46 47 static bool is_reaping_supported(); 48 49 bool init(int comm_fd); thread_cnt()50 int thread_cnt() const { return thread_cnt_; } enable_debug(bool enable)51 void enable_debug(bool enable) { debug_enabled_ = enable; } debug_enabled()52 bool debug_enabled() const { return debug_enabled_; } 53 54 // return 0 on success or error code returned by the syscall 55 int kill(const struct target_proc& target, bool synchronous); 56 // below members are used only by reaper_main 57 target_proc dequeue_request(); 58 void request_complete(); 59 void notify_kill_failure(int pid); 60 }; 61