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Diffstat (limited to 'modules/core/mod_watchdog.h')
| -rw-r--r-- | modules/core/mod_watchdog.h | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/modules/core/mod_watchdog.h b/modules/core/mod_watchdog.h new file mode 100644 index 0000000..8e7112c --- /dev/null +++ b/modules/core/mod_watchdog.h @@ -0,0 +1,213 @@ +/* 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. + */ + +#ifndef MOD_WATCHDOG_H +#define MOD_WATCHDOG_H + +/** + * @file mod_watchdog.h + * @brief Watchdog module for Apache + * + * @defgroup MOD_WATCHDOG mod_watchdog + * @ingroup APACHE_MODS + * @{ + */ + +#include "httpd.h" +#include "http_config.h" +#include "http_log.h" +#include "ap_provider.h" + +#include "apr.h" +#include "apr_strings.h" +#include "apr_pools.h" +#include "apr_shm.h" +#include "apr_hash.h" +#include "apr_hooks.h" +#include "apr_optional.h" +#include "apr_file_io.h" +#include "apr_time.h" +#include "apr_thread_proc.h" +#include "apr_global_mutex.h" +#include "apr_thread_mutex.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * Default singleton watchdog instance name. + * Singleton watchdog is protected by mutex and + * guaranteed to be run inside a single child process + * at any time. + */ +#define AP_WATCHDOG_SINGLETON "_singleton_" + +/** + * Default watchdog instance name + */ +#define AP_WATCHDOG_DEFAULT "_default_" + +/** + * Default Watchdog interval + */ +#define AP_WD_TM_INTERVAL APR_TIME_C(1000000) /* 1 second */ + +/** + * Watchdog thread timer resolution + */ +#define AP_WD_TM_SLICE APR_TIME_C(100000) /* 100 ms */ + +/* State values for callback */ +#define AP_WATCHDOG_STATE_STARTING 1 +#define AP_WATCHDOG_STATE_RUNNING 2 +#define AP_WATCHDOG_STATE_STOPPING 3 + +typedef struct ap_watchdog_t ap_watchdog_t; + +/* Create a set of AP_WD_DECLARE(type), AP_WD_DECLARE_NONSTD(type) and + * AP_WD_DECLARE_DATA with appropriate export and import tags for the platform + */ +#if !defined(AP_WD_DECLARE) +#if !defined(WIN32) +#define AP_WD_DECLARE(type) type +#define AP_WD_DECLARE_NONSTD(type) type +#define AP_WD_DECLARE_DATA +#elif defined(AP_WD_DECLARE_STATIC) +#define AP_WD_DECLARE(type) type __stdcall +#define AP_WD_DECLARE_NONSTD(type) type +#define AP_WD_DECLARE_DATA +#elif defined(AP_WD_DECLARE_EXPORT) +#define AP_WD_DECLARE(type) __declspec(dllexport) type __stdcall +#define AP_WD_DECLARE_NONSTD(type) __declspec(dllexport) type +#define AP_WD_DECLARE_DATA __declspec(dllexport) +#else +#define AP_WD_DECLARE(type) __declspec(dllimport) type __stdcall +#define AP_WD_DECLARE_NONSTD(type) __declspec(dllimport) type +#define AP_WD_DECLARE_DATA __declspec(dllimport) +#endif +#endif + +/** + * Callback function used for watchdog. + * @param state Watchdog state function. See @p AP_WATCHDOG_STATE_ . + * @param data is what was passed to @p ap_watchdog_register_callback function. + * @param pool Temporary callback pool destroyed after the call. + * @return APR_SUCCESS to continue calling this callback. + */ +typedef apr_status_t ap_watchdog_callback_fn_t(int state, void *data, + apr_pool_t *pool); + +/** + * Get watchdog instance. + * @param watchdog Storage for watchdog instance. + * @param name Watchdog name. + * @param parent Non-zero to get the parent process watchdog instance. + * @param singleton Non-zero to get the singleton watchdog instance. + * @param p The pool to use. + * @return APR_SUCCESS if all went well + * @remark Use @p AP_WATCHDOG_DEFAULT to get default watchdog instance. + * If separate watchdog thread is needed provide unique name + * and function will create a new watchdog instance. + * Note that default client process watchdog works in singleton mode. + */ +APR_DECLARE_OPTIONAL_FN(apr_status_t, ap_watchdog_get_instance, + (ap_watchdog_t **watchdog, const char *name, int parent, + int singleton, apr_pool_t *p)); + +/** + * Register watchdog callback. + * @param watchdog Watchdog to use + * @param interval Interval on which the callback function will execute. + * @param callback The function to call on watchdog event. + * @param data The data to pass to the callback function. + * @return APR_SUCCESS if all went well. APR_EEXIST if already registered. + */ +APR_DECLARE_OPTIONAL_FN(apr_status_t, ap_watchdog_register_callback, + (ap_watchdog_t *watchdog, apr_interval_time_t interval, + const void *data, ap_watchdog_callback_fn_t *callback)); + +/** + * Update registered watchdog callback interval. + * @param w Watchdog to use + * @param interval New interval on which the callback function will execute. + * @param callback The function to call on watchdog event. + * @param data The data to pass to the callback function. + * @return APR_SUCCESS if all went well. APR_EOF if callback was not found. + */ +APR_DECLARE_OPTIONAL_FN(apr_status_t, ap_watchdog_set_callback_interval, + (ap_watchdog_t *w, apr_interval_time_t interval, + const void *data, ap_watchdog_callback_fn_t *callback)); + +/** + * Watchdog require hook. + * @param s The server record + * @param name Watchdog name. + * @param parent Non-zero to indicate the parent process watchdog mode. + * @param singleton Non-zero to indicate the singleton watchdog mode. + * @return OK to enable notifications from this watchdog, DECLINED otherwise. + * @remark This is called in post config phase for all watchdog instances + * that have no callbacks registered. Modules using this hook + * should ensure that their post_config hook is called after watchdog + * post_config. + */ +APR_DECLARE_EXTERNAL_HOOK(ap, AP_WD, int, watchdog_need, (server_rec *s, + const char *name, + int parent, int singleton)) + + +/** + * Watchdog initialize hook. + * It is called after the watchdog thread is initialized. + * @param s The server record + * @param name Watchdog name. + * @param pool The pool used to create the watchdog. + */ +APR_DECLARE_EXTERNAL_HOOK(ap, AP_WD, int, watchdog_init, ( + server_rec *s, + const char *name, + apr_pool_t *pool)) + +/** + * Watchdog terminate hook. + * It is called when the watchdog thread is terminated. + * @param s The server record + * @param name Watchdog name. + * @param pool The pool used to create the watchdog. + */ +APR_DECLARE_EXTERNAL_HOOK(ap, AP_WD, int, watchdog_exit, ( + server_rec *s, + const char *name, + apr_pool_t *pool)) + +/** + * Fixed interval watchdog hook. + * It is called regularly on @p AP_WD_TM_INTERVAL interval. + * @param s The server record + * @param name Watchdog name. + * @param pool Temporary pool destroyed after the call. + */ +APR_DECLARE_EXTERNAL_HOOK(ap, AP_WD, int, watchdog_step, ( + server_rec *s, + const char *name, + apr_pool_t *pool)) + +#ifdef __cplusplus +} +#endif + +#endif /* MOD_WATCHDOG_H */ +/** @} */ |