1 /* 2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (c) 1996-1999 by Internet Software Consortium 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* ev_waits.c - implement deferred function calls for the eventlib 19 * vix 05dec95 [initial] 20 */ 21 22 #include "port_before.h" 23 #include "fd_setsize.h" 24 25 #include <errno.h> 26 27 #include <isc/eventlib.h> 28 #include <isc/assertions.h> 29 #include "eventlib_p.h" 30 31 #include "port_after.h" 32 33 /* Forward. */ 34 35 static void print_waits(evContext_p *ctx); 36 static evWaitList * evNewWaitList(evContext_p *); 37 static void evFreeWaitList(evContext_p *, evWaitList *); 38 static evWaitList * evGetWaitList(evContext_p *, const void *, int); 39 40 41 /* Public. */ 42 43 /*% 44 * Enter a new wait function on the queue. 45 */ 46 int 47 evWaitFor(evContext opaqueCtx, const void *tag, 48 evWaitFunc func, void *uap, evWaitID *id) 49 { 50 evContext_p *ctx = opaqueCtx.opaque; 51 evWait *new; 52 evWaitList *wl = evGetWaitList(ctx, tag, 1); 53 54 OKNEW(new); 55 new->func = func; 56 new->uap = uap; 57 new->tag = tag; 58 new->next = NULL; 59 if (wl->last != NULL) 60 wl->last->next = new; 61 else 62 wl->first = new; 63 wl->last = new; 64 if (id != NULL) 65 id->opaque = new; 66 if (ctx->debug >= 9) 67 print_waits(ctx); 68 return (0); 69 } 70 71 /*% 72 * Mark runnable all waiting functions having a certain tag. 73 */ 74 int 75 evDo(evContext opaqueCtx, const void *tag) { 76 evContext_p *ctx = opaqueCtx.opaque; 77 evWaitList *wl = evGetWaitList(ctx, tag, 0); 78 evWait *first; 79 80 if (!wl) { 81 errno = ENOENT; 82 return (-1); 83 } 84 85 first = wl->first; 86 INSIST(first != NULL); 87 88 if (ctx->waitDone.last != NULL) 89 ctx->waitDone.last->next = first; 90 else 91 ctx->waitDone.first = first; 92 ctx->waitDone.last = wl->last; 93 evFreeWaitList(ctx, wl); 94 95 return (0); 96 } 97 98 /*% 99 * Remove a waiting (or ready to run) function from the queue. 100 */ 101 int 102 evUnwait(evContext opaqueCtx, evWaitID id) { 103 evContext_p *ctx = opaqueCtx.opaque; 104 evWait *this, *prev; 105 evWaitList *wl; 106 int found = 0; 107 108 this = id.opaque; 109 INSIST(this != NULL); 110 wl = evGetWaitList(ctx, this->tag, 0); 111 if (wl != NULL) { 112 for (prev = NULL, this = wl->first; 113 this != NULL; 114 prev = this, this = this->next) 115 if (this == (evWait *)id.opaque) { 116 found = 1; 117 if (prev != NULL) 118 prev->next = this->next; 119 else 120 wl->first = this->next; 121 if (wl->last == this) 122 wl->last = prev; 123 if (wl->first == NULL) 124 evFreeWaitList(ctx, wl); 125 break; 126 } 127 } 128 129 if (!found) { 130 /* Maybe it's done */ 131 for (prev = NULL, this = ctx->waitDone.first; 132 this != NULL; 133 prev = this, this = this->next) 134 if (this == (evWait *)id.opaque) { 135 found = 1; 136 if (prev != NULL) 137 prev->next = this->next; 138 else 139 ctx->waitDone.first = this->next; 140 if (ctx->waitDone.last == this) 141 ctx->waitDone.last = prev; 142 break; 143 } 144 } 145 146 if (!found) { 147 errno = ENOENT; 148 return (-1); 149 } 150 151 FREE(this); 152 153 if (ctx->debug >= 9) 154 print_waits(ctx); 155 156 return (0); 157 } 158 159 int 160 evDefer(evContext opaqueCtx, evWaitFunc func, void *uap) { 161 evContext_p *ctx = opaqueCtx.opaque; 162 evWait *new; 163 164 OKNEW(new); 165 new->func = func; 166 new->uap = uap; 167 new->tag = NULL; 168 new->next = NULL; 169 if (ctx->waitDone.last != NULL) 170 ctx->waitDone.last->next = new; 171 else 172 ctx->waitDone.first = new; 173 ctx->waitDone.last = new; 174 if (ctx->debug >= 9) 175 print_waits(ctx); 176 return (0); 177 } 178 179 /* Private. */ 180 181 static void 182 print_waits(evContext_p *ctx) { 183 evWaitList *wl; 184 evWait *this; 185 186 evPrintf(ctx, 9, "wait waiting:\n"); 187 for (wl = ctx->waitLists; wl != NULL; wl = wl->next) { 188 INSIST(wl->first != NULL); 189 evPrintf(ctx, 9, " tag %p:", wl->first->tag); 190 for (this = wl->first; this != NULL; this = this->next) 191 evPrintf(ctx, 9, " %p", this); 192 evPrintf(ctx, 9, "\n"); 193 } 194 evPrintf(ctx, 9, "wait done:"); 195 for (this = ctx->waitDone.first; this != NULL; this = this->next) 196 evPrintf(ctx, 9, " %p", this); 197 evPrintf(ctx, 9, "\n"); 198 } 199 200 static evWaitList * 201 evNewWaitList(evContext_p *ctx) { 202 evWaitList *new; 203 204 NEW(new); 205 if (new == NULL) 206 return (NULL); 207 new->first = new->last = NULL; 208 new->prev = NULL; 209 new->next = ctx->waitLists; 210 if (new->next != NULL) 211 new->next->prev = new; 212 ctx->waitLists = new; 213 return (new); 214 } 215 216 static void 217 evFreeWaitList(evContext_p *ctx, evWaitList *this) { 218 219 INSIST(this != NULL); 220 221 if (this->prev != NULL) 222 this->prev->next = this->next; 223 else 224 ctx->waitLists = this->next; 225 if (this->next != NULL) 226 this->next->prev = this->prev; 227 FREE(this); 228 } 229 230 static evWaitList * 231 evGetWaitList(evContext_p *ctx, const void *tag, int should_create) { 232 evWaitList *this; 233 234 for (this = ctx->waitLists; this != NULL; this = this->next) { 235 if (this->first != NULL && this->first->tag == tag) 236 break; 237 } 238 if (this == NULL && should_create) 239 this = evNewWaitList(ctx); 240 return (this); 241 } 242 243 /*! \file */ 244