1fcb893a8SMike Smith /*- 2fcb893a8SMike Smith * Copyright (c) 1999 Michael Smith <msmith@freebsd.org> 3fcb893a8SMike Smith * All rights reserved. 4fcb893a8SMike Smith * 5fcb893a8SMike Smith * Redistribution and use in source and binary forms, with or without 6fcb893a8SMike Smith * modification, are permitted provided that the following conditions 7fcb893a8SMike Smith * are met: 8fcb893a8SMike Smith * 1. Redistributions of source code must retain the above copyright 9fcb893a8SMike Smith * notice, this list of conditions and the following disclaimer. 10fcb893a8SMike Smith * 2. Redistributions in binary form must reproduce the above copyright 11fcb893a8SMike Smith * notice, this list of conditions and the following disclaimer in the 12fcb893a8SMike Smith * documentation and/or other materials provided with the distribution. 13fcb893a8SMike Smith * 14fcb893a8SMike Smith * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15fcb893a8SMike Smith * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16fcb893a8SMike Smith * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17fcb893a8SMike Smith * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18fcb893a8SMike Smith * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19fcb893a8SMike Smith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20fcb893a8SMike Smith * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21fcb893a8SMike Smith * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22fcb893a8SMike Smith * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23fcb893a8SMike Smith * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24fcb893a8SMike Smith * SUCH DAMAGE. 25fcb893a8SMike Smith */ 26fcb893a8SMike Smith 27677b542eSDavid E. O'Brien #include <sys/cdefs.h> 28677b542eSDavid E. O'Brien __FBSDID("$FreeBSD$"); 29677b542eSDavid E. O'Brien 30fcb893a8SMike Smith #include <sys/param.h> 31fcb893a8SMike Smith #include <sys/kernel.h> 32f34fa851SJohn Baldwin #include <sys/lock.h> 33fcb893a8SMike Smith #include <sys/malloc.h> 3406592dd1SJohn Baldwin #include <sys/mutex.h> 35fb919e4dSMark Murray #include <sys/proc.h> 36fcb893a8SMike Smith #include <sys/systm.h> 37fcb893a8SMike Smith #include <sys/eventhandler.h> 38fcb893a8SMike Smith 39959b7375SPoul-Henning Kamp static MALLOC_DEFINE(M_EVENTHANDLER, "eventhandler", "Event handler records"); 40fcb893a8SMike Smith 41fcb893a8SMike Smith /* List of 'slow' lists */ 42e3975643SJake Burkholder static TAILQ_HEAD(, eventhandler_list) eventhandler_lists; 43fcb893a8SMike Smith static int eventhandler_lists_initted = 0; 44d543796fSJohn Baldwin static struct mtx eventhandler_mutex; 45fcb893a8SMike Smith 46fcb893a8SMike Smith struct eventhandler_entry_generic 47fcb893a8SMike Smith { 48fcb893a8SMike Smith struct eventhandler_entry ee; 49fcb893a8SMike Smith void (* func)(void); 50fcb893a8SMike Smith }; 51fcb893a8SMike Smith 52fdf20233SJoseph Koshy static struct eventhandler_list *_eventhandler_find_list(const char *name); 53ecdf4409SJohn Baldwin 54fcb893a8SMike Smith /* 5506592dd1SJohn Baldwin * Initialize the eventhandler mutex and list. 5606592dd1SJohn Baldwin */ 5706592dd1SJohn Baldwin static void 5806592dd1SJohn Baldwin eventhandler_init(void *dummy __unused) 5906592dd1SJohn Baldwin { 6006592dd1SJohn Baldwin TAILQ_INIT(&eventhandler_lists); 61ecdf4409SJohn Baldwin mtx_init(&eventhandler_mutex, "eventhandler", NULL, MTX_DEF); 62ecdf4409SJohn Baldwin atomic_store_rel_int(&eventhandler_lists_initted, 1); 6306592dd1SJohn Baldwin } 6406592dd1SJohn Baldwin SYSINIT(eventhandlers, SI_SUB_EVENTHANDLER, SI_ORDER_FIRST, eventhandler_init, 65237fdd78SRobert Watson NULL); 6606592dd1SJohn Baldwin 6706592dd1SJohn Baldwin /* 68fcb893a8SMike Smith * Insertion is O(n) due to the priority scan, but optimises to O(1) 69fcb893a8SMike Smith * if all priorities are identical. 70fcb893a8SMike Smith */ 7142eedeacSBjoern A. Zeeb static eventhandler_tag 7242eedeacSBjoern A. Zeeb eventhandler_register_internal(struct eventhandler_list *list, 7342eedeacSBjoern A. Zeeb const char *name, eventhandler_tag epn) 74fcb893a8SMike Smith { 75ecdf4409SJohn Baldwin struct eventhandler_list *new_list; 76fcb893a8SMike Smith struct eventhandler_entry *ep; 77fcb893a8SMike Smith 7806592dd1SJohn Baldwin KASSERT(eventhandler_lists_initted, ("eventhandler registered too early")); 7942eedeacSBjoern A. Zeeb KASSERT(epn != NULL, ("%s: cannot register NULL event", __func__)); 80fcb893a8SMike Smith 816595c331SMike Smith /* lock the eventhandler lists */ 829ed346baSBosko Milekic mtx_lock(&eventhandler_mutex); 836595c331SMike Smith 84fcb893a8SMike Smith /* Do we need to find/create the (slow) list? */ 85fcb893a8SMike Smith if (list == NULL) { 86fcb893a8SMike Smith /* look for a matching, existing list */ 87ecdf4409SJohn Baldwin list = _eventhandler_find_list(name); 88fcb893a8SMike Smith 89fcb893a8SMike Smith /* Do we need to create the list? */ 90fcb893a8SMike Smith if (list == NULL) { 919ed346baSBosko Milekic mtx_unlock(&eventhandler_mutex); 92ecdf4409SJohn Baldwin 93ecdf4409SJohn Baldwin new_list = malloc(sizeof(struct eventhandler_list) + 94ecdf4409SJohn Baldwin strlen(name) + 1, M_EVENTHANDLER, M_WAITOK); 95ecdf4409SJohn Baldwin 96ecdf4409SJohn Baldwin /* If someone else created it already, then use that one. */ 97ecdf4409SJohn Baldwin mtx_lock(&eventhandler_mutex); 98ecdf4409SJohn Baldwin list = _eventhandler_find_list(name); 99ecdf4409SJohn Baldwin if (list != NULL) { 100ecdf4409SJohn Baldwin free(new_list, M_EVENTHANDLER); 101ecdf4409SJohn Baldwin } else { 102ecdf4409SJohn Baldwin CTR2(KTR_EVH, "%s: creating list \"%s\"", __func__, name); 103ecdf4409SJohn Baldwin list = new_list; 104fcb893a8SMike Smith list->el_flags = 0; 105ecdf4409SJohn Baldwin list->el_runcount = 0; 10628fe1a71SAlfred Perlstein bzero(&list->el_lock, sizeof(list->el_lock)); 107fcb893a8SMike Smith list->el_name = (char *)list + sizeof(struct eventhandler_list); 108fcb893a8SMike Smith strcpy(list->el_name, name); 109fcb893a8SMike Smith TAILQ_INSERT_HEAD(&eventhandler_lists, list, el_link); 110fcb893a8SMike Smith } 111fcb893a8SMike Smith } 112ecdf4409SJohn Baldwin } 113ecdf4409SJohn Baldwin if (!(list->el_flags & EHL_INITTED)) { 114fcb893a8SMike Smith TAILQ_INIT(&list->el_entries); 115ecdf4409SJohn Baldwin mtx_init(&list->el_lock, name, "eventhandler list", MTX_DEF); 116ecdf4409SJohn Baldwin atomic_store_rel_int(&list->el_flags, EHL_INITTED); 117fcb893a8SMike Smith } 11819a0f7e1SAlfred Perlstein mtx_unlock(&eventhandler_mutex); 119fcb893a8SMike Smith 12042eedeacSBjoern A. Zeeb KASSERT(epn->ee_priority != EHE_DEAD_PRIORITY, 12142eedeacSBjoern A. Zeeb ("%s: handler for %s registered with dead priority", __func__, name)); 12242eedeacSBjoern A. Zeeb 12342eedeacSBjoern A. Zeeb /* sort it into the list */ 12442eedeacSBjoern A. Zeeb CTR4(KTR_EVH, "%s: adding item %p (function %p) to \"%s\"", __func__, epn, 12542eedeacSBjoern A. Zeeb ((struct eventhandler_entry_generic *)epn)->func, name); 12642eedeacSBjoern A. Zeeb EHL_LOCK(list); 12742eedeacSBjoern A. Zeeb TAILQ_FOREACH(ep, &list->el_entries, ee_link) { 12842eedeacSBjoern A. Zeeb if (ep->ee_priority != EHE_DEAD_PRIORITY && 12942eedeacSBjoern A. Zeeb epn->ee_priority < ep->ee_priority) { 13042eedeacSBjoern A. Zeeb TAILQ_INSERT_BEFORE(ep, epn, ee_link); 13142eedeacSBjoern A. Zeeb break; 13242eedeacSBjoern A. Zeeb } 13342eedeacSBjoern A. Zeeb } 13442eedeacSBjoern A. Zeeb if (ep == NULL) 13542eedeacSBjoern A. Zeeb TAILQ_INSERT_TAIL(&list->el_entries, epn, ee_link); 13642eedeacSBjoern A. Zeeb EHL_UNLOCK(list); 13742eedeacSBjoern A. Zeeb return(epn); 13842eedeacSBjoern A. Zeeb } 13942eedeacSBjoern A. Zeeb 14042eedeacSBjoern A. Zeeb eventhandler_tag 14142eedeacSBjoern A. Zeeb eventhandler_register(struct eventhandler_list *list, const char *name, 14242eedeacSBjoern A. Zeeb void *func, void *arg, int priority) 14342eedeacSBjoern A. Zeeb { 14442eedeacSBjoern A. Zeeb struct eventhandler_entry_generic *eg; 14542eedeacSBjoern A. Zeeb 146fcb893a8SMike Smith /* allocate an entry for this handler, populate it */ 147ecdf4409SJohn Baldwin eg = malloc(sizeof(struct eventhandler_entry_generic), M_EVENTHANDLER, 148ecdf4409SJohn Baldwin M_WAITOK | M_ZERO); 149fcb893a8SMike Smith eg->func = func; 150fcb893a8SMike Smith eg->ee.ee_arg = arg; 151fcb893a8SMike Smith eg->ee.ee_priority = priority; 152fcb893a8SMike Smith 15342eedeacSBjoern A. Zeeb return (eventhandler_register_internal(list, name, &eg->ee)); 154fcb893a8SMike Smith } 15542eedeacSBjoern A. Zeeb 15642eedeacSBjoern A. Zeeb #ifdef VIMAGE 15742eedeacSBjoern A. Zeeb struct eventhandler_entry_generic_vimage 15842eedeacSBjoern A. Zeeb { 15942eedeacSBjoern A. Zeeb struct eventhandler_entry ee; 16042eedeacSBjoern A. Zeeb vimage_iterator_func_t func; /* Vimage iterator function. */ 16142eedeacSBjoern A. Zeeb struct eventhandler_entry_vimage v_ee; /* Original func, arg. */ 16242eedeacSBjoern A. Zeeb }; 16342eedeacSBjoern A. Zeeb 16442eedeacSBjoern A. Zeeb eventhandler_tag 16542eedeacSBjoern A. Zeeb vimage_eventhandler_register(struct eventhandler_list *list, const char *name, 16642eedeacSBjoern A. Zeeb void *func, void *arg, int priority, vimage_iterator_func_t iterfunc) 16742eedeacSBjoern A. Zeeb { 16842eedeacSBjoern A. Zeeb struct eventhandler_entry_generic_vimage *eg; 16942eedeacSBjoern A. Zeeb 17042eedeacSBjoern A. Zeeb /* allocate an entry for this handler, populate it */ 17142eedeacSBjoern A. Zeeb eg = malloc(sizeof(struct eventhandler_entry_generic_vimage), 17242eedeacSBjoern A. Zeeb M_EVENTHANDLER, M_WAITOK | M_ZERO); 17342eedeacSBjoern A. Zeeb eg->func = iterfunc; 17442eedeacSBjoern A. Zeeb eg->v_ee.func = func; 17542eedeacSBjoern A. Zeeb eg->v_ee.ee_arg = arg; 17642eedeacSBjoern A. Zeeb eg->ee.ee_arg = &eg->v_ee; 17742eedeacSBjoern A. Zeeb eg->ee.ee_priority = priority; 17842eedeacSBjoern A. Zeeb 17942eedeacSBjoern A. Zeeb return (eventhandler_register_internal(list, name, &eg->ee)); 180fcb893a8SMike Smith } 18142eedeacSBjoern A. Zeeb #endif 182fcb893a8SMike Smith 183fc091646SIan Lepore static void 184fc091646SIan Lepore _eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag, 185fc091646SIan Lepore bool wait) 186fcb893a8SMike Smith { 187fcb893a8SMike Smith struct eventhandler_entry *ep = tag; 188fcb893a8SMike Smith 189ecdf4409SJohn Baldwin EHL_LOCK_ASSERT(list, MA_OWNED); 190fcb893a8SMike Smith if (ep != NULL) { 191fcb893a8SMike Smith /* remove just this entry */ 192ecdf4409SJohn Baldwin if (list->el_runcount == 0) { 193ecdf4409SJohn Baldwin CTR3(KTR_EVH, "%s: removing item %p from \"%s\"", __func__, ep, 194ecdf4409SJohn Baldwin list->el_name); 195fcb893a8SMike Smith TAILQ_REMOVE(&list->el_entries, ep, ee_link); 196fcb893a8SMike Smith free(ep, M_EVENTHANDLER); 197fcb893a8SMike Smith } else { 198ecdf4409SJohn Baldwin CTR3(KTR_EVH, "%s: marking item %p from \"%s\" as dead", __func__, 199ecdf4409SJohn Baldwin ep, list->el_name); 200ecdf4409SJohn Baldwin ep->ee_priority = EHE_DEAD_PRIORITY; 201ecdf4409SJohn Baldwin } 202ecdf4409SJohn Baldwin } else { 203fcb893a8SMike Smith /* remove entire list */ 204ecdf4409SJohn Baldwin if (list->el_runcount == 0) { 205ecdf4409SJohn Baldwin CTR2(KTR_EVH, "%s: removing all items from \"%s\"", __func__, 206ecdf4409SJohn Baldwin list->el_name); 207fcb893a8SMike Smith while (!TAILQ_EMPTY(&list->el_entries)) { 208fcb893a8SMike Smith ep = TAILQ_FIRST(&list->el_entries); 2091b727751SPoul-Henning Kamp TAILQ_REMOVE(&list->el_entries, ep, ee_link); 210fcb893a8SMike Smith free(ep, M_EVENTHANDLER); 211fcb893a8SMike Smith } 212ecdf4409SJohn Baldwin } else { 213ecdf4409SJohn Baldwin CTR2(KTR_EVH, "%s: marking all items from \"%s\" as dead", 214ecdf4409SJohn Baldwin __func__, list->el_name); 215ecdf4409SJohn Baldwin TAILQ_FOREACH(ep, &list->el_entries, ee_link) 216ecdf4409SJohn Baldwin ep->ee_priority = EHE_DEAD_PRIORITY; 217fcb893a8SMike Smith } 218ecdf4409SJohn Baldwin } 219fc091646SIan Lepore while (wait && list->el_runcount > 0) 2202b543150SAndrew Thompson mtx_sleep(list, &list->el_lock, 0, "evhrm", 0); 221ecdf4409SJohn Baldwin EHL_UNLOCK(list); 222fcb893a8SMike Smith } 223fcb893a8SMike Smith 224fc091646SIan Lepore void 225fc091646SIan Lepore eventhandler_deregister(struct eventhandler_list *list, eventhandler_tag tag) 226fc091646SIan Lepore { 227fc091646SIan Lepore 228fc091646SIan Lepore _eventhandler_deregister(list, tag, true); 229fc091646SIan Lepore } 230fc091646SIan Lepore 231fc091646SIan Lepore void 232fc091646SIan Lepore eventhandler_deregister_nowait(struct eventhandler_list *list, 233fc091646SIan Lepore eventhandler_tag tag) 234fc091646SIan Lepore { 235fc091646SIan Lepore 236fc091646SIan Lepore _eventhandler_deregister(list, tag, false); 237fc091646SIan Lepore } 238fc091646SIan Lepore 239ecdf4409SJohn Baldwin /* 240ecdf4409SJohn Baldwin * Internal version for use when eventhandler list is already locked. 241ecdf4409SJohn Baldwin */ 242ecdf4409SJohn Baldwin static struct eventhandler_list * 243fdf20233SJoseph Koshy _eventhandler_find_list(const char *name) 244ecdf4409SJohn Baldwin { 245ecdf4409SJohn Baldwin struct eventhandler_list *list; 246ecdf4409SJohn Baldwin 247ecdf4409SJohn Baldwin mtx_assert(&eventhandler_mutex, MA_OWNED); 248ecdf4409SJohn Baldwin TAILQ_FOREACH(list, &eventhandler_lists, el_link) { 249ecdf4409SJohn Baldwin if (!strcmp(name, list->el_name)) 250ecdf4409SJohn Baldwin break; 251ecdf4409SJohn Baldwin } 252ecdf4409SJohn Baldwin return (list); 253ecdf4409SJohn Baldwin } 254ecdf4409SJohn Baldwin 255ecdf4409SJohn Baldwin /* 256ecdf4409SJohn Baldwin * Lookup a "slow" list by name. Returns with the list locked. 257ecdf4409SJohn Baldwin */ 258fcb893a8SMike Smith struct eventhandler_list * 259fdf20233SJoseph Koshy eventhandler_find_list(const char *name) 260fcb893a8SMike Smith { 261fcb893a8SMike Smith struct eventhandler_list *list; 262146be906SJake Burkholder 263146be906SJake Burkholder if (!eventhandler_lists_initted) 264146be906SJake Burkholder return(NULL); 265fcb893a8SMike Smith 266fcb893a8SMike Smith /* scan looking for the requested list */ 2679ed346baSBosko Milekic mtx_lock(&eventhandler_mutex); 268ecdf4409SJohn Baldwin list = _eventhandler_find_list(name); 269ecdf4409SJohn Baldwin if (list != NULL) 270ecdf4409SJohn Baldwin EHL_LOCK(list); 2719ed346baSBosko Milekic mtx_unlock(&eventhandler_mutex); 2726595c331SMike Smith 273fcb893a8SMike Smith return(list); 274fcb893a8SMike Smith } 2756595c331SMike Smith 276ecdf4409SJohn Baldwin /* 277ecdf4409SJohn Baldwin * Prune "dead" entries from an eventhandler list. 278ecdf4409SJohn Baldwin */ 279ecdf4409SJohn Baldwin void 280ecdf4409SJohn Baldwin eventhandler_prune_list(struct eventhandler_list *list) 281ecdf4409SJohn Baldwin { 282ecdf4409SJohn Baldwin struct eventhandler_entry *ep, *en; 2832b543150SAndrew Thompson int pruned = 0; 284ecdf4409SJohn Baldwin 285ecdf4409SJohn Baldwin CTR2(KTR_EVH, "%s: pruning list \"%s\"", __func__, list->el_name); 286ecdf4409SJohn Baldwin EHL_LOCK_ASSERT(list, MA_OWNED); 2872b543150SAndrew Thompson TAILQ_FOREACH_SAFE(ep, &list->el_entries, ee_link, en) { 288ecdf4409SJohn Baldwin if (ep->ee_priority == EHE_DEAD_PRIORITY) { 289ecdf4409SJohn Baldwin TAILQ_REMOVE(&list->el_entries, ep, ee_link); 290ecdf4409SJohn Baldwin free(ep, M_EVENTHANDLER); 2912b543150SAndrew Thompson pruned++; 292ecdf4409SJohn Baldwin } 293ecdf4409SJohn Baldwin } 2942b543150SAndrew Thompson if (pruned > 0) 2952b543150SAndrew Thompson wakeup(list); 296ecdf4409SJohn Baldwin } 297