| /** @file |
| |
| Definitions for the Lockfile class. |
| |
| @section license License |
| |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| #pragma once |
| |
| #include "tscore/ink_defs.h" |
| #include "tscore/ink_string.h" |
| |
| #define COP_LOCK "cop.lock" |
| #define MANAGER_LOCK "manager.lock" |
| #define SERVER_LOCK "server.lock" |
| |
| class Lockfile |
| { |
| public: |
| Lockfile() { fname[0] = '\0'; } |
| // coverity[uninit_member] |
| Lockfile(const char *filename) { ink_strlcpy(fname, filename, sizeof(fname)); } |
| ~Lockfile() {} |
| void |
| SetLockfileName(const char *filename) |
| { |
| ink_strlcpy(fname, filename, sizeof(fname)); |
| } |
| |
| const char * |
| GetLockfileName() |
| { |
| return fname; |
| } |
| |
| // Open() |
| // |
| // Tries to open a lock file, returning: |
| // -errno on error |
| // 0 if someone is holding the lock (with holding_pid set) |
| // 1 if we now have a writable lock file |
| int Open(pid_t *holding_pid); |
| |
| // Get() |
| // |
| // Gets write access to a lock file, and if successful, truncates |
| // file, and writes the current process ID. Returns: |
| // -errno on error |
| // 0 if someone is holding the lock (with holding_pid set) |
| // 1 if we now have a writable lock file |
| int Get(pid_t *holding_pid); |
| |
| // Close() |
| // |
| // Closes the file handle on the opened Lockfile. |
| void Close(); |
| |
| // Kill() |
| // KillGroup() |
| // |
| // Ensures no one is holding the lock. It tries to open the lock file |
| // and if that does not succeed, it kills the process holding the lock. |
| // If the lock file open succeeds, it closes the lock file releasing |
| // the lock. |
| // |
| // The initial signal can be used to generate a core from the process while |
| // still ensuring it dies. |
| void Kill(int sig, int initial_sig = 0, const char *pname = nullptr); |
| void KillGroup(int sig, int initial_sig = 0, const char *pname = nullptr); |
| |
| private: |
| char fname[PATH_NAME_MAX]; |
| int fd = 0; |
| }; |