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;       /* Unused. */
  55         u_int                           el_runcount;
  56         struct mtx                      el_lock;
  57         TAILQ_ENTRY(eventhandler_list)  el_link;
  58         TAILQ_HEAD(,eventhandler_entry) el_entries;
  59 };
  60
  61 typedef struct eventhandler_entry       *eventhandler_tag;
  62
  63 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  64 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  65 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  66
  67 /*
  68  * Macro to invoke the handlers for a given event.
  69  */
  70 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  71         struct eventhandler_entry *_ep;                                 \
  72         struct eventhandler_entry_ ## name *_t;                         \
  73                                                                         \
  74         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  75         (list)->el_runcount++;                                          \
  76         KASSERT((list)->el_runcount > 0,                                \
  77             ("eventhandler_invoke: runcount overflow"));                \
  78         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  79         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  80                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  81                         EHL_UNLOCK((list));                             \
  82                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  83                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  84                             (void *)_t->eh_func);                       \
  85                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  86                         EHL_LOCK((list));                               \
  87                 }                                                       \
  88         }                                                               \
  89         KASSERT((list)->el_runcount > 0,                                \
  90             ("eventhandler_invoke: runcount underflow"));               \
  91         (list)->el_runcount--;                                          \
  92         if ((list)->el_runcount == 0)                                   \
  93                 eventhandler_prune_list(list);                          \
  94         EHL_UNLOCK((list));                                             \
  95 } while (0)
  96
  97 /*
  98  * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros
  99  * to pre-define a symbol for the eventhandler list. This symbol can be used by
 100  * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a
 101  * locked search of the global list of eventhandler lists. At least
 102  * EVENTHANDLER_LIST_DEFINE must be be used for EVENTHANDLER_DIRECT_INVOKE to
 103  * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to
 104  * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from
 105  * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency
 106  * it is suggested that you directly define a list for them.
 107  */
 108 #define EVENTHANDLER_LIST_DECLARE(name)                                 \
 109 extern struct eventhandler_list *_eventhandler_list_ ## name            \
 110
 111 #define EVENTHANDLER_LIST_DEFINE(name)                                  \
 112 struct eventhandler_list *_eventhandler_list_ ## name ;                 \
 113 static void _ehl_init_ ## name (void * ctx __unused)                    \
 114 {                                                                       \
 115         _eventhandler_list_ ## name = eventhandler_create_list(#name);  \
 116 }                                                                       \
 117 SYSINIT(name ## _ehl_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY,           \
 118             _ehl_init_ ## name, NULL);                                  \
 119         struct __hack
 120
 121 #define EVENTHANDLER_DIRECT_INVOKE(name, ...) do {                      \
 122         struct eventhandler_list *_el;                                  \
 123                                                                         \
 124         _el = _eventhandler_list_ ## name ;                             \
 125         if (!TAILQ_EMPTY(&_el->el_entries)) {                           \
 126                 EHL_LOCK(_el);                                          \
 127                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 128         }                                                               \
 129 } while (0)
 130
 131 /*
 132  * Event handlers need to be declared, but do not need to be defined. The
 133  * declaration must be in scope wherever the handler is to be invoked.
 134  */
 135 #define EVENTHANDLER_DECLARE(name, type)                                \
 136 struct eventhandler_entry_ ## name                                      \
 137 {                                                                       \
 138         struct eventhandler_entry       ee;                             \
 139         type                            eh_func;                        \
 140 };                                                                      \
 141 struct __hack
 142
 143 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 144         static eventhandler_tag name ## _tag;                           \
 145         static void name ## _evh_init(void *ctx)                        \
 146         {                                                               \
 147                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 148                     priority);                                          \
 149         }                                                               \
 150         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 151             name ## _evh_init, arg);                                    \
 152         struct __hack
 153
 154 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 155 do {                                                                    \
 156         struct eventhandler_list *_el;                                  \
 157                                                                         \
 158         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 159                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 160 } while (0)
 161
 162 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 163         eventhandler_register(NULL, #name, func, arg, priority)
 164
 165 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 166 do {                                                                    \
 167         struct eventhandler_list *_el;                                  \
 168                                                                         \
 169         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 170                 eventhandler_deregister(_el, tag);                      \
 171 } while(0)
 172
 173 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)                       \
 174 do {                                                                    \
 175         struct eventhandler_list *_el;                                  \
 176                                                                         \
 177         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 178                 eventhandler_deregister_nowait(_el, tag);               \
 179 } while(0)
 180
 181 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 182             const char *name, void *func, void *arg, int priority);
 183 void    eventhandler_deregister(struct eventhandler_list *list,
 184             eventhandler_tag tag);
 185 void    eventhandler_deregister_nowait(struct eventhandler_list *list,
 186             eventhandler_tag tag);
 187 struct eventhandler_list *eventhandler_find_list(const char *name);
 188 void    eventhandler_prune_list(struct eventhandler_list *list);
 189 struct eventhandler_list *eventhandler_create_list(const char *name);
 190
 191 #ifdef VIMAGE
 192 typedef void (*vimage_iterator_func_t)(void *, ...);
 193
 194 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 195             const char *name, void *func, void *arg, int priority,
 196             vimage_iterator_func_t);
 197 #endif
 198
 199 /*
 200  * Standard system event queues.
 201  */
 202
 203 /* Generic priority levels */
 204 #define EVENTHANDLER_PRI_FIRST  0
 205 #define EVENTHANDLER_PRI_ANY    10000
 206 #define EVENTHANDLER_PRI_LAST   20000
 207
 208 /* Shutdown events */
 209 typedef void (*shutdown_fn)(void *, int);
 210
 211 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 212 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 213 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 214
 215 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 216 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 217 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 218
 219 /* Power state change events */
 220 typedef void (*power_change_fn)(void *);
 221 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 222 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 223 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
 224
 225 /* Low memory event */
 226 typedef void (*vm_lowmem_handler_t)(void *, int);
 227 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 228 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 229
 230 /* Root mounted event */
 231 typedef void (*mountroot_handler_t)(void *);
 232 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 233
 234 /* File system mount events */
 235 struct mount;
 236 struct vnode;
 237 struct thread;
 238 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 239     struct thread *);
 240 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 241     struct thread *);
 242 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 243 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 244
 245 /*
 246  * Process events
 247  * process_fork and exit handlers are called without Giant.
 248  * exec handlers are called with Giant, but that is by accident.
 249  */
 250 struct proc;
 251 struct image_params;
 252
 253 typedef void (*exitlist_fn)(void *, struct proc *);
 254 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 255 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 256 typedef void (*proc_ctor_fn)(void *, struct proc *);
 257 typedef void (*proc_dtor_fn)(void *, struct proc *);
 258 typedef void (*proc_init_fn)(void *, struct proc *);
 259 typedef void (*proc_fini_fn)(void *, struct proc *);
 260 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 261 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 262 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 263 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 264 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 265 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 266 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 267
 268 /*
 269  * application dump event
 270  */
 271 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 272 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 273 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 274 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 275
 276 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 277 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 278 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 279 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 280
 281 typedef void (*thread_ctor_fn)(void *, struct thread *);
 282 typedef void (*thread_dtor_fn)(void *, struct thread *);
 283 typedef void (*thread_fini_fn)(void *, struct thread *);
 284 typedef void (*thread_init_fn)(void *, struct thread *);
 285 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 286 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 287 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 288 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 289
 290 typedef void (*uma_zone_chfn)(void *);
 291 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 292 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 293 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 294
 295 /* Kernel linker file load and unload events */
 296 struct linker_file;
 297 typedef void (*kld_load_fn)(void *, struct linker_file *);
 298 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 299 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 300 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 301 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 302 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 303
 304 /* Generic graphics framebuffer interface */
 305 struct fb_info;
 306 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
 307 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
 308 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
 309 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
 310
 311 /* Veto ada attachment */
 312 struct cam_path;
 313 struct ata_params;
 314 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
 315     struct ata_params *, int *);
 316 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
 317
 318 /* newbus device events */
 319 enum evhdev_detach {
 320         EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
 321         EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
 322         EVHDEV_DETACH_FAILED    /* After detach() returns err */
 323 };
 324 typedef void (*device_attach_fn)(void *, device_t);
 325 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
 326 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
 327 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
 328
 329 #endif /* _SYS_EVENTHANDLER_H_ */