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_streams.c - implement asynch stream file IO for the eventlib 19 * vix 04mar96 [initial] 20 */ 21 22 #include "port_before.h" 23 #include "fd_setsize.h" 24 25 #include <sys/types.h> 26 #include <sys/uio.h> 27 28 #include <errno.h> 29 30 #include <isc/eventlib.h> 31 #include <isc/assertions.h> 32 #include "eventlib_p.h" 33 34 #include "port_after.h" 35 36 static int copyvec(evStream *str, const struct iovec *iov, int iocnt); 37 static void consume(evStream *str, size_t bytes); 38 static void done(evContext opaqueCtx, evStream *str); 39 static void writable(evContext opaqueCtx, void *uap, int fd, int evmask); 40 static void readable(evContext opaqueCtx, void *uap, int fd, int evmask); 41 42 struct iovec 43 evConsIovec(void *buf, size_t cnt) { 44 struct iovec ret; 45 46 memset(&ret, 0xf5, sizeof ret); 47 ret.iov_base = buf; 48 ret.iov_len = cnt; 49 return (ret); 50 } 51 52 int 53 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 54 evStreamFunc func, void *uap, evStreamID *id) 55 { 56 evContext_p *ctx = opaqueCtx.opaque; 57 evStream *new; 58 int save; 59 60 OKNEW(new); 61 new->func = func; 62 new->uap = uap; 63 new->fd = fd; 64 new->flags = 0; 65 if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0) 66 goto free; 67 if (copyvec(new, iov, iocnt) < 0) 68 goto free; 69 new->prevDone = NULL; 70 new->nextDone = NULL; 71 if (ctx->streams != NULL) 72 ctx->streams->prev = new; 73 new->prev = NULL; 74 new->next = ctx->streams; 75 ctx->streams = new; 76 if (id != NULL) 77 id->opaque = new; 78 return (0); 79 free: 80 save = errno; 81 FREE(new); 82 errno = save; 83 return (-1); 84 } 85 86 int 87 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 88 evStreamFunc func, void *uap, evStreamID *id) 89 { 90 evContext_p *ctx = opaqueCtx.opaque; 91 evStream *new; 92 int save; 93 94 OKNEW(new); 95 new->func = func; 96 new->uap = uap; 97 new->fd = fd; 98 new->flags = 0; 99 if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0) 100 goto free; 101 if (copyvec(new, iov, iocnt) < 0) 102 goto free; 103 new->prevDone = NULL; 104 new->nextDone = NULL; 105 if (ctx->streams != NULL) 106 ctx->streams->prev = new; 107 new->prev = NULL; 108 new->next = ctx->streams; 109 ctx->streams = new; 110 if (id) 111 id->opaque = new; 112 return (0); 113 free: 114 save = errno; 115 FREE(new); 116 errno = save; 117 return (-1); 118 } 119 120 int 121 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ { 122 evStream *str = id.opaque; 123 124 UNUSED(opaqueCtx); 125 126 str->timer = timer; 127 str->flags |= EV_STR_TIMEROK; 128 return (0); 129 } 130 131 int 132 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ { 133 evStream *str = id.opaque; 134 135 UNUSED(opaqueCtx); 136 137 str->flags &= ~EV_STR_TIMEROK; 138 return (0); 139 } 140 141 int 142 evCancelRW(evContext opaqueCtx, evStreamID id) { 143 evContext_p *ctx = opaqueCtx.opaque; 144 evStream *old = id.opaque; 145 146 /* 147 * The streams list is doubly threaded. First, there's ctx->streams 148 * that's used by evDestroy() to find and cancel all streams. Second, 149 * there's ctx->strDone (head) and ctx->strLast (tail) which thread 150 * through the potentially smaller number of "IO completed" streams, 151 * used in evGetNext() to avoid scanning the entire list. 152 */ 153 154 /* Unlink from ctx->streams. */ 155 if (old->prev != NULL) 156 old->prev->next = old->next; 157 else 158 ctx->streams = old->next; 159 if (old->next != NULL) 160 old->next->prev = old->prev; 161 162 /* 163 * If 'old' is on the ctx->strDone list, remove it. Update 164 * ctx->strLast if necessary. 165 */ 166 if (old->prevDone == NULL && old->nextDone == NULL) { 167 /* 168 * Either 'old' is the only item on the done list, or it's 169 * not on the done list. If the former, then we unlink it 170 * from the list. If the latter, we leave the list alone. 171 */ 172 if (ctx->strDone == old) { 173 ctx->strDone = NULL; 174 ctx->strLast = NULL; 175 } 176 } else { 177 if (old->prevDone != NULL) 178 old->prevDone->nextDone = old->nextDone; 179 else 180 ctx->strDone = old->nextDone; 181 if (old->nextDone != NULL) 182 old->nextDone->prevDone = old->prevDone; 183 else 184 ctx->strLast = old->prevDone; 185 } 186 187 /* Deallocate the stream. */ 188 if (old->file.opaque) 189 evDeselectFD(opaqueCtx, old->file); 190 memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount); 191 FREE(old); 192 return (0); 193 } 194 195 /* Copy a scatter/gather vector and initialize a stream handler's IO. */ 196 static int 197 copyvec(evStream *str, const struct iovec *iov, int iocnt) { 198 int i; 199 200 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt); 201 if (str->iovOrig == NULL) { 202 errno = ENOMEM; 203 return (-1); 204 } 205 str->ioTotal = 0; 206 for (i = 0; i < iocnt; i++) { 207 str->iovOrig[i] = iov[i]; 208 str->ioTotal += iov[i].iov_len; 209 } 210 str->iovOrigCount = iocnt; 211 str->iovCur = str->iovOrig; 212 str->iovCurCount = str->iovOrigCount; 213 str->ioDone = 0; 214 return (0); 215 } 216 217 /* Pull off or truncate lead iovec(s). */ 218 static void 219 consume(evStream *str, size_t bytes) { 220 while (bytes > 0U) { 221 if (bytes < (size_t)str->iovCur->iov_len) { 222 str->iovCur->iov_len -= bytes; 223 str->iovCur->iov_base = (void *) 224 ((u_char *)str->iovCur->iov_base + bytes); 225 str->ioDone += bytes; 226 bytes = 0; 227 } else { 228 bytes -= str->iovCur->iov_len; 229 str->ioDone += str->iovCur->iov_len; 230 str->iovCur++; 231 str->iovCurCount--; 232 } 233 } 234 } 235 236 /* Add a stream to Done list and deselect the FD. */ 237 static void 238 done(evContext opaqueCtx, evStream *str) { 239 evContext_p *ctx = opaqueCtx.opaque; 240 241 if (ctx->strLast != NULL) { 242 str->prevDone = ctx->strLast; 243 ctx->strLast->nextDone = str; 244 ctx->strLast = str; 245 } else { 246 INSIST(ctx->strDone == NULL); 247 ctx->strDone = ctx->strLast = str; 248 } 249 evDeselectFD(opaqueCtx, str->file); 250 str->file.opaque = NULL; 251 /* evDrop() will call evCancelRW() on us. */ 252 } 253 254 /* Dribble out some bytes on the stream. (Called by evDispatch().) */ 255 static void 256 writable(evContext opaqueCtx, void *uap, int fd, int evmask) { 257 evStream *str = uap; 258 int bytes; 259 260 UNUSED(evmask); 261 262 bytes = writev(fd, str->iovCur, str->iovCurCount); 263 if (bytes > 0) { 264 if ((str->flags & EV_STR_TIMEROK) != 0) 265 evTouchIdleTimer(opaqueCtx, str->timer); 266 consume(str, bytes); 267 } else { 268 if (bytes < 0 && errno != EINTR) { 269 str->ioDone = -1; 270 str->ioErrno = errno; 271 } 272 } 273 if (str->ioDone == -1 || str->ioDone == str->ioTotal) 274 done(opaqueCtx, str); 275 } 276 277 /* Scoop up some bytes from the stream. (Called by evDispatch().) */ 278 static void 279 readable(evContext opaqueCtx, void *uap, int fd, int evmask) { 280 evStream *str = uap; 281 int bytes; 282 283 UNUSED(evmask); 284 285 bytes = readv(fd, str->iovCur, str->iovCurCount); 286 if (bytes > 0) { 287 if ((str->flags & EV_STR_TIMEROK) != 0) 288 evTouchIdleTimer(opaqueCtx, str->timer); 289 consume(str, bytes); 290 } else { 291 if (bytes == 0) 292 str->ioDone = 0; 293 else { 294 if (errno != EINTR) { 295 str->ioDone = -1; 296 str->ioErrno = errno; 297 } 298 } 299 } 300 if (str->ioDone <= 0 || str->ioDone == str->ioTotal) 301 done(opaqueCtx, str); 302 } 303 304 /*! \file */ 305