sys/sys/eventhandler.h

   1 /*-
   2  * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28
  29 #ifndef SYS_EVENTHANDLER_H
  30 #define SYS_EVENTHANDLER_H
  31
  32 #include <sys/lock.h>
  33 #include <sys/ktr.h>
  34 #include <sys/mutex.h>
  35 #include <sys/queue.h>
  36
  37 struct eventhandler_entry {
  38         TAILQ_ENTRY(eventhandler_entry) ee_link;
  39         int                             ee_priority;
  40 #define EHE_DEAD_PRIORITY       (-1)
  41         void                            *ee_arg;
  42 };
  43
  44 #ifdef VIMAGE
  45 struct eventhandler_entry_vimage {
  46         void    (* func)(void);         /* Original function registered. */
  47         void    *ee_arg;                /* Original argument registered. */
  48         void    *sparep[2];
  49 };
  50 #endif
  51
  52 struct eventhandler_list {
  53         char                            *el_name;
  54         int                             el_flags;
  55 #define EHL_INITTED     (1<<0)
  56         u_int                           el_runcount;
  57         struct mtx                      el_lock;
  58         TAILQ_ENTRY(eventhandler_list)  el_link;
  59         TAILQ_HEAD(,eventhandler_entry) el_entries;
  60 };
  61
  62 typedef struct eventhandler_entry       *eventhandler_tag;
  63
  64 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  65 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  66 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  67
  68 /*
  69  * Macro to invoke the handlers for a given event.
  70  */
  71 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  72         struct eventhandler_entry *_ep;                                 \
  73         struct eventhandler_entry_ ## name *_t;                         \
  74                                                                         \
  75         KASSERT((list)->el_flags & EHL_INITTED,                         \
  76            ("eventhandler_invoke: running non-inited list"));           \
  77         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  78         (list)->el_runcount++;                                          \
  79         KASSERT((list)->el_runcount > 0,                                \
  80             ("eventhandler_invoke: runcount overflow"));                \
  81         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  82         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  83                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  84                         EHL_UNLOCK((list));                             \
  85                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  86                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  87                             (void *)_t->eh_func);                       \
  88                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  89                         EHL_LOCK((list));                               \
  90                 }                                                       \
  91         }                                                               \
  92         KASSERT((list)->el_runcount > 0,                                \
  93             ("eventhandler_invoke: runcount underflow"));               \
  94         (list)->el_runcount--;                                          \
  95         if ((list)->el_runcount == 0)                                   \
  96                 eventhandler_prune_list(list);                          \
  97         EHL_UNLOCK((list));                                             \
  98 } while (0)
  99
 100 /*
 101  * Slow handlers are entirely dynamic; lists are created
 102  * when entries are added to them, and thus have no concept of "owner",
 103  *
 104  * Slow handlers need to be declared, but do not need to be defined. The
 105  * declaration must be in scope wherever the handler is to be invoked.
 106  */
 107 #define EVENTHANDLER_DECLARE(name, type)                                \
 108 struct eventhandler_entry_ ## name                                      \
 109 {                                                                       \
 110         struct eventhandler_entry       ee;                             \
 111         type                            eh_func;                        \
 112 };                                                                      \
 113 struct __hack
 114
 115 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 116         static eventhandler_tag name ## _tag;                           \
 117         static void name ## _evh_init(void *ctx)                        \
 118         {                                                               \
 119                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 120                     priority);                                          \
 121         }                                                               \
 122         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 123             name ## _evh_init, arg);                                    \
 124         struct __hack
 125
 126 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 127 do {                                                                    \
 128         struct eventhandler_list *_el;                                  \
 129                                                                         \
 130         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 131                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 132 } while (0)
 133
 134 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 135         eventhandler_register(NULL, #name, func, arg, priority)
 136
 137 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 138 do {                                                                    \
 139         struct eventhandler_list *_el;                                  \
 140                                                                         \
 141         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 142                 eventhandler_deregister(_el, tag);                      \
 143 } while(0)
 144
 145
 146 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 147             const char *name, void *func, void *arg, int priority);
 148 void    eventhandler_deregister(struct eventhandler_list *list,
 149             eventhandler_tag tag);
 150 struct eventhandler_list *eventhandler_find_list(const char *name);
 151 void    eventhandler_prune_list(struct eventhandler_list *list);
 152
 153 #ifdef VIMAGE
 154 typedef void (*vimage_iterator_func_t)(void *, ...);
 155
 156 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 157             const char *name, void *func, void *arg, int priority,
 158             vimage_iterator_func_t);
 159 #endif
 160
 161 /*
 162  * Standard system event queues.
 163  */
 164
 165 /* Generic priority levels */
 166 #define EVENTHANDLER_PRI_FIRST  0
 167 #define EVENTHANDLER_PRI_ANY    10000
 168 #define EVENTHANDLER_PRI_LAST   20000
 169
 170 /* Shutdown events */
 171 typedef void (*shutdown_fn)(void *, int);
 172
 173 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 174 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 175 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 176
 177 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 178 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 179 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 180
 181 /* Power state change events */
 182 typedef void (*power_change_fn)(void *);
 183 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 184 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 185
 186 /* Low memory event */
 187 typedef void (*vm_lowmem_handler_t)(void *, int);
 188 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 189 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 190
 191 /* Root mounted event */
 192 typedef void (*mountroot_handler_t)(void *);
 193 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 194
 195 /* File system mount events */
 196 struct mount;
 197 struct vnode;
 198 struct thread;
 199 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 200     struct thread *);
 201 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 202     struct thread *);
 203 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 204 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 205
 206 /* VLAN state change events */
 207 struct ifnet;
 208 typedef void (*vlan_config_fn)(void *, struct ifnet *, uint16_t);
 209 typedef void (*vlan_unconfig_fn)(void *, struct ifnet *, uint16_t);
 210 EVENTHANDLER_DECLARE(vlan_config, vlan_config_fn);
 211 EVENTHANDLER_DECLARE(vlan_unconfig, vlan_unconfig_fn);
 212
 213 /* BPF attach/detach events */
 214 struct ifnet;
 215 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
 216     int /* 1 =>'s attach */);
 217 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
 218
 219 /*
 220  * Process events
 221  * process_fork and exit handlers are called without Giant.
 222  * exec handlers are called with Giant, but that is by accident.
 223  */
 224 struct proc;
 225 struct image_params;
 226
 227 typedef void (*exitlist_fn)(void *, struct proc *);
 228 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 229 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 230 typedef void (*proc_ctor_fn)(void *, struct proc *);
 231 typedef void (*proc_dtor_fn)(void *, struct proc *);
 232 typedef void (*proc_init_fn)(void *, struct proc *);
 233 typedef void (*proc_fini_fn)(void *, struct proc *);
 234 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 235 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 236 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 237 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 238 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 239 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 240 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 241
 242 /*
 243  * application dump event
 244  */
 245 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 246 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 247 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 248 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 249
 250 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 251 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 252 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 253 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 254
 255 typedef void (*thread_ctor_fn)(void *, struct thread *);
 256 typedef void (*thread_dtor_fn)(void *, struct thread *);
 257 typedef void (*thread_fini_fn)(void *, struct thread *);
 258 typedef void (*thread_init_fn)(void *, struct thread *);
 259 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 260 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 261 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 262 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 263
 264 typedef void (*uma_zone_chfn)(void *);
 265 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 266 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 267 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 268
 269 /* Kernel linker file load and unload events */
 270 struct linker_file;
 271 typedef void (*kld_load_fn)(void *, struct linker_file *);
 272 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 273 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 274 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 275 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 276 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 277
 278 #endif /* SYS_EVENTHANDLER_H */