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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 06:33:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 06:33:50 +0000 |
commit | fe39ffb8b90ae4e002ed73fe98617cd590abb467 (patch) | |
tree | b80e5956907d8aeaaffe4e4f0c068c0e6157ce8b /modules/core/mod_watchdog.c | |
parent | Initial commit. (diff) | |
download | apache2-upstream.tar.xz apache2-upstream.zip |
Adding upstream version 2.4.56.upstream/2.4.56upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | modules/core/mod_watchdog.c | 718 |
1 files changed, 718 insertions, 0 deletions
diff --git a/modules/core/mod_watchdog.c b/modules/core/mod_watchdog.c new file mode 100644 index 0000000..99ec7cf --- /dev/null +++ b/modules/core/mod_watchdog.c @@ -0,0 +1,718 @@ +/* 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. + */ + +/* Watchdog module. + */ + +#include "apr.h" +#include "mod_watchdog.h" +#include "ap_provider.h" +#include "ap_mpm.h" +#include "http_core.h" +#include "util_mutex.h" + +#include "apr_atomic.h" + +#define AP_WATCHDOG_PGROUP "watchdog" +#define AP_WATCHDOG_PVERSION "parent" +#define AP_WATCHDOG_CVERSION "child" + +typedef struct watchdog_list_t watchdog_list_t; + +struct watchdog_list_t +{ + struct watchdog_list_t *next; + ap_watchdog_t *wd; + apr_status_t status; + apr_interval_time_t interval; + apr_interval_time_t step; + const void *data; + ap_watchdog_callback_fn_t *callback_fn; +}; + +struct ap_watchdog_t +{ + apr_uint32_t thread_started; /* set to 1 once thread running */ + apr_proc_mutex_t *mutex; + const char *name; + watchdog_list_t *callbacks; + int is_running; + int singleton; + int active; + apr_interval_time_t step; + apr_thread_t *thread; + apr_pool_t *pool; +}; + +typedef struct wd_server_conf_t wd_server_conf_t; +struct wd_server_conf_t +{ + int child_workers; + int parent_workers; + apr_pool_t *pool; + server_rec *s; +}; + +static wd_server_conf_t *wd_server_conf = NULL; +static apr_interval_time_t wd_interval = AP_WD_TM_INTERVAL; +static int mpm_is_forked = AP_MPMQ_NOT_SUPPORTED; +static const char *wd_proc_mutex_type = "watchdog-callback"; + +static apr_status_t wd_worker_cleanup(void *data) +{ + apr_status_t rv; + ap_watchdog_t *w = (ap_watchdog_t *)data; + + /* Do nothing if the thread wasn't started. */ + if (apr_atomic_read32(&w->thread_started) != 1) + return APR_SUCCESS; + + if (w->is_running) { + watchdog_list_t *wl = w->callbacks; + while (wl) { + if (wl->status == APR_SUCCESS) { + /* Execute watchdog callback with STOPPING state */ + (*wl->callback_fn)(AP_WATCHDOG_STATE_STOPPING, + (void *)wl->data, w->pool); + wl->status = APR_EOF; + } + wl = wl->next; + } + } + w->is_running = 0; + apr_thread_join(&rv, w->thread); + return rv; +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* Main watchdog worker thread. */ +/* For singleton workers child thread that first obtains the process */ +/* mutex is running. Threads in other child's are locked on mutex. */ +/* */ +/*--------------------------------------------------------------------------*/ +static void* APR_THREAD_FUNC wd_worker(apr_thread_t *thread, void *data) +{ + ap_watchdog_t *w = (ap_watchdog_t *)data; + apr_status_t rv; + int locked = 0; + int probed = 0; + int inited = 0; + int mpmq_s = 0; + apr_pool_t *temp_pool = NULL; + + w->pool = apr_thread_pool_get(thread); + w->is_running = 1; + + apr_atomic_set32(&w->thread_started, 1); /* thread started */ + + if (w->mutex) { + while (w->is_running) { + if (ap_mpm_query(AP_MPMQ_MPM_STATE, &mpmq_s) != APR_SUCCESS) { + w->is_running = 0; + break; + } + if (mpmq_s == AP_MPMQ_STOPPING) { + w->is_running = 0; + break; + } + rv = apr_proc_mutex_trylock(w->mutex); + if (rv == APR_SUCCESS) { + if (probed) { + /* Sleep after we were locked + * up to 1 second. Httpd can be + * in the middle of shutdown, and + * our child didn't yet received + * the shutdown signal. + */ + probed = 10; + while (w->is_running && probed > 0) { + apr_sleep(AP_WD_TM_INTERVAL); + probed--; + if (ap_mpm_query(AP_MPMQ_MPM_STATE, &mpmq_s) != APR_SUCCESS) { + w->is_running = 0; + break; + } + if (mpmq_s == AP_MPMQ_STOPPING) { + w->is_running = 0; + break; + } + } + } + locked = 1; + break; + } + probed = 1; + apr_sleep(AP_WD_TM_SLICE); + } + } + + apr_pool_create(&temp_pool, w->pool); + apr_pool_tag(temp_pool, "wd_running"); + + if (w->is_running) { + watchdog_list_t *wl = w->callbacks; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, wd_server_conf->s, + APLOGNO(02972) "%sWatchdog (%s) running", + w->singleton ? "Singleton " : "", w->name); + apr_time_clock_hires(w->pool); + if (wl) { + while (wl && w->is_running) { + /* Execute watchdog callback */ + wl->status = (*wl->callback_fn)(AP_WATCHDOG_STATE_STARTING, + (void *)wl->data, temp_pool); + wl = wl->next; + } + apr_pool_clear(temp_pool); + } + else { + ap_run_watchdog_init(wd_server_conf->s, w->name, w->pool); + inited = 1; + } + } + + /* Main execution loop */ + while (w->is_running) { + apr_time_t curr; + watchdog_list_t *wl = w->callbacks; + + apr_sleep(AP_WD_TM_SLICE); + if (ap_mpm_query(AP_MPMQ_MPM_STATE, &mpmq_s) != APR_SUCCESS) { + w->is_running = 0; + } + if (mpmq_s == AP_MPMQ_STOPPING) { + w->is_running = 0; + } + if (!w->is_running) { + break; + } + curr = apr_time_now() - AP_WD_TM_SLICE; + while (wl && w->is_running) { + if (wl->status == APR_SUCCESS) { + wl->step += (apr_time_now() - curr); + if (wl->step >= wl->interval) { + wl->step = 0; + /* Execute watchdog callback */ + wl->status = (*wl->callback_fn)(AP_WATCHDOG_STATE_RUNNING, + (void *)wl->data, temp_pool); + if (ap_mpm_query(AP_MPMQ_MPM_STATE, &mpmq_s) != APR_SUCCESS) { + w->is_running = 0; + } + if (mpmq_s == AP_MPMQ_STOPPING) { + w->is_running = 0; + } + } + } + wl = wl->next; + } + if (w->is_running && w->callbacks == NULL) { + /* This is hook mode watchdog + * running on WatchogInterval + */ + w->step += (apr_time_now() - curr); + if (w->step >= wd_interval) { + w->step = 0; + /* Run watchdog step hook */ + ap_run_watchdog_step(wd_server_conf->s, w->name, temp_pool); + } + } + + apr_pool_clear(temp_pool); + } + + apr_pool_destroy(temp_pool); + + if (inited) { + /* Run the watchdog exit hooks. + * If this was singleton watchdog the init hook + * might never been called, so skip the exit hook + * in that case as well. + */ + ap_run_watchdog_exit(wd_server_conf->s, w->name, w->pool); + } + else { + watchdog_list_t *wl = w->callbacks; + while (wl) { + if (wl->status == APR_SUCCESS) { + /* Execute watchdog callback with STOPPING state */ + (*wl->callback_fn)(AP_WATCHDOG_STATE_STOPPING, + (void *)wl->data, w->pool); + } + wl = wl->next; + } + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, wd_server_conf->s, + APLOGNO(02973) "%sWatchdog (%s) stopping", + w->singleton ? "Singleton " : "", w->name); + + if (locked) + apr_proc_mutex_unlock(w->mutex); + apr_thread_exit(w->thread, APR_SUCCESS); + + return NULL; +} + +static apr_status_t wd_startup(ap_watchdog_t *w, apr_pool_t *p) +{ + apr_status_t rc; + + apr_atomic_set32(&w->thread_started, 0); + + if (w->singleton) { + /* Initialize singleton mutex in child */ + rc = apr_proc_mutex_child_init(&w->mutex, + apr_proc_mutex_lockfile(w->mutex), p); + if (rc != APR_SUCCESS) + return rc; + } + + /* Start the newly created watchdog */ + rc = ap_thread_create(&w->thread, NULL, wd_worker, w, p); + if (rc == APR_SUCCESS) { + apr_pool_pre_cleanup_register(p, w, wd_worker_cleanup); + } + + return rc; +} + +static apr_status_t ap_watchdog_get_instance(ap_watchdog_t **watchdog, + const char *name, + int parent, + int singleton, + apr_pool_t *p) +{ + ap_watchdog_t *w; + const char *pver = parent ? AP_WATCHDOG_PVERSION : AP_WATCHDOG_CVERSION; + + if (parent && mpm_is_forked != AP_MPMQ_NOT_SUPPORTED) { + /* Parent threads are not supported for + * forked mpm's + */ + *watchdog = NULL; + return APR_ENOTIMPL; + } + w = ap_lookup_provider(AP_WATCHDOG_PGROUP, name, pver); + if (w) { + *watchdog = w; + return APR_SUCCESS; + } + w = apr_pcalloc(p, sizeof(ap_watchdog_t)); + w->name = name; + w->pool = p; + w->singleton = parent ? 0 : singleton; + *watchdog = w; + return ap_register_provider(p, AP_WATCHDOG_PGROUP, name, + pver, *watchdog); +} + +static 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_list_t *c = w->callbacks; + apr_status_t rv = APR_EOF; + + while (c) { + if (c->data == data && c->callback_fn == callback) { + /* We have existing callback. + * Update the interval and reset status, so the + * callback and continue execution if stopped earlier. + */ + c->interval = interval; + c->step = 0; + c->status = APR_SUCCESS; + rv = APR_SUCCESS; + break; + } + c = c->next; + } + return rv; +} + +static apr_status_t ap_watchdog_register_callback(ap_watchdog_t *w, + apr_interval_time_t interval, + const void *data, + ap_watchdog_callback_fn_t *callback) +{ + watchdog_list_t *c = w->callbacks; + + while (c) { + if (c->data == data && c->callback_fn == callback) { + /* We have already registered callback. + * Do not allow callbacks that have the same + * function and data pointers. + */ + return APR_EEXIST; + } + c = c->next; + } + c = apr_palloc(w->pool, sizeof(watchdog_list_t)); + c->data = data; + c->callback_fn = callback; + c->interval = interval; + c->step = 0; + c->status = APR_EINIT; + + c->wd = w; + c->next = w->callbacks; + w->callbacks = c; + w->active++; + + return APR_SUCCESS; +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* Pre config hook. */ +/* Create default watchdogs for parent and child */ +/* Parent watchdog executes inside parent process so it doesn't need the */ +/* singleton mutex */ +/* */ +/*--------------------------------------------------------------------------*/ +static int wd_pre_config_hook(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp) +{ + apr_status_t rv; + ap_watchdog_t *w; + + ap_mpm_query(AP_MPMQ_IS_FORKED, &mpm_is_forked); + if ((rv = ap_watchdog_get_instance(&w, + AP_WATCHDOG_SINGLETON, 0, 1, pconf)) != APR_SUCCESS) { + return rv; + } + if ((rv = ap_watchdog_get_instance(&w, + AP_WATCHDOG_DEFAULT, 0, 0, pconf)) != APR_SUCCESS) { + return rv; + } + if (mpm_is_forked == AP_MPMQ_NOT_SUPPORTED) { + /* Create parent process watchdog for + * non forked mpm's only. + */ + if ((rv = ap_watchdog_get_instance(&w, + AP_WATCHDOG_DEFAULT, 1, 0, pconf)) != APR_SUCCESS) { + return rv; + } + } + + if ((rv = ap_mutex_register(pconf, wd_proc_mutex_type, NULL, + APR_LOCK_DEFAULT, 0)) != APR_SUCCESS) { + return rv; + } + + return OK; +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* Post config hook. */ +/* Create watchdog thread in parent and initializes Watchdog module */ +/* */ +/*--------------------------------------------------------------------------*/ +static int wd_post_config_hook(apr_pool_t *pconf, apr_pool_t *plog, + apr_pool_t *ptemp, server_rec *s) +{ + apr_status_t rv; + const char *pk = "watchdog_init_module_tag"; + apr_pool_t *ppconf = pconf; + const apr_array_header_t *wl; + + if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) + /* First time config phase -- skip. */ + return OK; + + apr_pool_userdata_get((void *)&wd_server_conf, pk, ppconf); + if (!wd_server_conf) { + if (!(wd_server_conf = apr_pcalloc(ppconf, sizeof(wd_server_conf_t)))) + return APR_ENOMEM; + apr_pool_create(&wd_server_conf->pool, ppconf); + apr_pool_tag(wd_server_conf->pool, "wd_server_conf"); + apr_pool_userdata_set(wd_server_conf, pk, apr_pool_cleanup_null, ppconf); + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(010033) + "Watchdog: Running with WatchdogInterval %" + APR_TIME_T_FMT "ms", apr_time_as_msec(wd_interval)); + wd_server_conf->s = s; + if ((wl = ap_list_provider_names(pconf, AP_WATCHDOG_PGROUP, + AP_WATCHDOG_PVERSION))) { + const ap_list_provider_names_t *wn; + int i; + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02974) + "Watchdog: found parent providers."); + + wn = (ap_list_provider_names_t *)wl->elts; + for (i = 0; i < wl->nelts; i++) { + ap_watchdog_t *w = ap_lookup_provider(AP_WATCHDOG_PGROUP, + wn[i].provider_name, + AP_WATCHDOG_PVERSION); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02975) + "Watchdog: Looking for parent (%s).", wn[i].provider_name); + if (w) { + if (!w->active) { + int status = ap_run_watchdog_need(s, w->name, 1, + w->singleton); + if (status == OK) { + /* One of the modules returned OK to this watchdog. + * Mark it as active + */ + w->active = 1; + } + } + if (w->active) { + /* We have active watchdog. + * Create the watchdog thread + */ + if ((rv = wd_startup(w, wd_server_conf->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(01571) + "Watchdog: Failed to create parent worker thread."); + return rv; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(02976) + "Watchdog: Created parent worker thread (%s).", w->name); + wd_server_conf->parent_workers++; + } + } + } + } + if (wd_server_conf->parent_workers) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01572) + "Spawned %d parent worker threads.", + wd_server_conf->parent_workers); + } + if ((wl = ap_list_provider_names(pconf, AP_WATCHDOG_PGROUP, + AP_WATCHDOG_CVERSION))) { + const ap_list_provider_names_t *wn; + int i; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02977) + "Watchdog: found child providers."); + + wn = (ap_list_provider_names_t *)wl->elts; + for (i = 0; i < wl->nelts; i++) { + ap_watchdog_t *w = ap_lookup_provider(AP_WATCHDOG_PGROUP, + wn[i].provider_name, + AP_WATCHDOG_CVERSION); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(02978) + "Watchdog: Looking for child (%s).", wn[i].provider_name); + if (w) { + if (!w->active) { + int status = ap_run_watchdog_need(s, w->name, 0, + w->singleton); + if (status == OK) { + /* One of the modules returned OK to this watchdog. + * Mark it as active + */ + w->active = 1; + } + } + if (w->active) { + /* We have some callbacks registered. + * Create mutexes for singleton watchdogs + */ + if (w->singleton) { + rv = ap_proc_mutex_create(&w->mutex, NULL, wd_proc_mutex_type, + w->name, s, + wd_server_conf->pool, 0); + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(10095) + "Watchdog: Failed to create singleton mutex."); + return rv; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(02979) + "Watchdog: Created singleton mutex (%s).", w->name); + } + wd_server_conf->child_workers++; + } + } + } + } + return OK; +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* Child init hook. */ +/* Create watchdog threads and initializes Mutexes in child */ +/* */ +/*--------------------------------------------------------------------------*/ +static void wd_child_init_hook(apr_pool_t *p, server_rec *s) +{ + apr_status_t rv = OK; + const apr_array_header_t *wl; + + if (!wd_server_conf->child_workers) { + /* We don't have anything configured, bail out. + */ + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(02980) + "Watchdog: nothing configured?"); + return; + } + if ((wl = ap_list_provider_names(p, AP_WATCHDOG_PGROUP, + AP_WATCHDOG_CVERSION))) { + const ap_list_provider_names_t *wn; + int i; + wn = (ap_list_provider_names_t *)wl->elts; + for (i = 0; i < wl->nelts; i++) { + ap_watchdog_t *w = ap_lookup_provider(AP_WATCHDOG_PGROUP, + wn[i].provider_name, + AP_WATCHDOG_CVERSION); + if (w && w->active) { + /* We have some callbacks registered. + * Kick of the watchdog + */ + if ((rv = wd_startup(w, wd_server_conf->pool)) != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(01573) + "Watchdog: Failed to create child worker thread."); + /* No point to continue */ + return; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(02981) + "Watchdog: Created child worker thread (%s).", wn[i].provider_name); + } + } + } +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* WatchdogInterval directive */ +/* */ +/*--------------------------------------------------------------------------*/ +static const char *wd_cmd_watchdog_int(cmd_parms *cmd, void *dummy, + const char *arg) +{ + apr_status_t rv; + const char *errs = ap_check_cmd_context(cmd, GLOBAL_ONLY); + + if (errs != NULL) + return errs; + rv = ap_timeout_parameter_parse(arg, &wd_interval, "s"); + + if (rv != APR_SUCCESS) + return "Unparse-able WatchdogInterval setting"; + if (wd_interval < AP_WD_TM_SLICE) { + return apr_psprintf(cmd->pool, "Invalid WatchdogInterval: minimal value %" + APR_TIME_T_FMT "ms", apr_time_as_msec(AP_WD_TM_SLICE)); + } + + return NULL; +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* List of directives specific to our module. */ +/* */ +/*--------------------------------------------------------------------------*/ +static const command_rec wd_directives[] = +{ + AP_INIT_TAKE1( + "WatchdogInterval", /* directive name */ + wd_cmd_watchdog_int, /* config action routine */ + NULL, /* argument to include in call */ + RSRC_CONF, /* where available */ + "Watchdog interval in seconds" + ), + {NULL} +}; + +/*--------------------------------------------------------------------------*/ +/* */ +/* Which functions are responsible for which hooks in the server. */ +/* */ +/*--------------------------------------------------------------------------*/ +static void wd_register_hooks(apr_pool_t *p) +{ + + /* Only the mpm_winnt has child init hook handler. + * Make sure that we are called after the mpm child init handler + * initializes. + */ + static const char *const after_mpm[] = { "mpm_winnt.c", NULL}; + + /* Pre config handling + */ + ap_hook_pre_config(wd_pre_config_hook, + NULL, + NULL, + APR_HOOK_FIRST); + + /* Post config handling + */ + ap_hook_post_config(wd_post_config_hook, + NULL, + NULL, + APR_HOOK_LAST); + + /* Child init hook + */ + ap_hook_child_init(wd_child_init_hook, + after_mpm, + NULL, + APR_HOOK_MIDDLE); + + APR_REGISTER_OPTIONAL_FN(ap_watchdog_get_instance); + APR_REGISTER_OPTIONAL_FN(ap_watchdog_register_callback); + APR_REGISTER_OPTIONAL_FN(ap_watchdog_set_callback_interval); +} + +/*--------------------------------------------------------------------------*/ +/* */ +/* The list of callback routines and data structures that provide */ +/* the static hooks into our module from the other parts of the server. */ +/* */ +/*--------------------------------------------------------------------------*/ +AP_DECLARE_MODULE(watchdog) = { + STANDARD20_MODULE_STUFF, + NULL, /* create per-directory config structure */ + NULL, /* merge per-directory config structures */ + NULL, /* create per-server config structure */ + NULL, /* merge per-server config structures */ + wd_directives, /* command apr_table_t */ + wd_register_hooks /* register hooks */ +}; + +/*--------------------------------------------------------------------------*/ +/* */ +/* The list of optional hooks that we provide */ +/* */ +/*--------------------------------------------------------------------------*/ +APR_HOOK_STRUCT( + APR_HOOK_LINK(watchdog_need) + APR_HOOK_LINK(watchdog_init) + APR_HOOK_LINK(watchdog_exit) + APR_HOOK_LINK(watchdog_step) +) + +APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap, AP_WD, int, watchdog_need, + (server_rec *s, const char *name, + int parent, int singleton), + (s, name, parent, singleton), + DECLINED) +APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, AP_WD, int, watchdog_init, + (server_rec *s, const char *name, + apr_pool_t *pool), + (s, name, pool), + OK, DECLINED) +APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, AP_WD, int, watchdog_exit, + (server_rec *s, const char *name, + apr_pool_t *pool), + (s, name, pool), + OK, DECLINED) +APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, AP_WD, int, watchdog_step, + (server_rec *s, const char *name, + apr_pool_t *pool), + (s, name, pool), + OK, DECLINED) |