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 #if !defined(LINT) && !defined(CODECENTER) 23 static const char rcsid[] = "$Id: ev_streams.c,v 1.5 2005/04/27 04:56:36 sra Exp $"; 24 #endif 25 26 #include "port_before.h" 27 #include "fd_setsize.h" 28 29 #include <sys/types.h> 30 #include <sys/uio.h> 31 32 #include <errno.h> 33 34 #include <isc/eventlib.h> 35 #include <isc/assertions.h> 36 #include "eventlib_p.h" 37 38 #include "port_after.h" 39 40 static int copyvec(evStream *str, const struct iovec *iov, int iocnt); 41 static void consume(evStream *str, size_t bytes); 42 static void done(evContext opaqueCtx, evStream *str); 43 static void writable(evContext opaqueCtx, void *uap, int fd, int evmask); 44 static void readable(evContext opaqueCtx, void *uap, int fd, int evmask); 45 46 struct iovec 47 evConsIovec(void *buf, size_t cnt) { 48 struct iovec ret; 49 50 memset(&ret, 0xf5, sizeof ret); 51 ret.iov_base = buf; 52 ret.iov_len = cnt; 53 return (ret); 54 } 55 56 int 57 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 58 evStreamFunc func, void *uap, evStreamID *id) 59 { 60 evContext_p *ctx = opaqueCtx.opaque; 61 evStream *new; 62 int save; 63 64 OKNEW(new); 65 new->func = func; 66 new->uap = uap; 67 new->fd = fd; 68 new->flags = 0; 69 if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0) 70 goto free; 71 if (copyvec(new, iov, iocnt) < 0) 72 goto free; 73 new->prevDone = NULL; 74 new->nextDone = NULL; 75 if (ctx->streams != NULL) 76 ctx->streams->prev = new; 77 new->prev = NULL; 78 new->next = ctx->streams; 79 ctx->streams = new; 80 if (id != NULL) 81 id->opaque = new; 82 return (0); 83 free: 84 save = errno; 85 FREE(new); 86 errno = save; 87 return (-1); 88 } 89 90 int 91 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, 92 evStreamFunc func, void *uap, evStreamID *id) 93 { 94 evContext_p *ctx = opaqueCtx.opaque; 95 evStream *new; 96 int save; 97 98 OKNEW(new); 99 new->func = func; 100 new->uap = uap; 101 new->fd = fd; 102 new->flags = 0; 103 if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0) 104 goto free; 105 if (copyvec(new, iov, iocnt) < 0) 106 goto free; 107 new->prevDone = NULL; 108 new->nextDone = NULL; 109 if (ctx->streams != NULL) 110 ctx->streams->prev = new; 111 new->prev = NULL; 112 new->next = ctx->streams; 113 ctx->streams = new; 114 if (id) 115 id->opaque = new; 116 return (0); 117 free: 118 save = errno; 119 FREE(new); 120 errno = save; 121 return (-1); 122 } 123 124 int 125 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ { 126 evStream *str = id.opaque; 127 128 UNUSED(opaqueCtx); 129 130 str->timer = timer; 131 str->flags |= EV_STR_TIMEROK; 132 return (0); 133 } 134 135 int 136 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ { 137 evStream *str = id.opaque; 138 139 UNUSED(opaqueCtx); 140 141 str->flags &= ~EV_STR_TIMEROK; 142 return (0); 143 } 144 145 int 146 evCancelRW(evContext opaqueCtx, evStreamID id) { 147 evContext_p *ctx = opaqueCtx.opaque; 148 evStream *old = id.opaque; 149 150 /* 151 * The streams list is doubly threaded. First, there's ctx->streams 152 * that's used by evDestroy() to find and cancel all streams. Second, 153 * there's ctx->strDone (head) and ctx->strLast (tail) which thread 154 * through the potentially smaller number of "IO completed" streams, 155 * used in evGetNext() to avoid scanning the entire list. 156 */ 157 158 /* Unlink from ctx->streams. */ 159 if (old->prev != NULL) 160 old->prev->next = old->next; 161 else 162 ctx->streams = old->next; 163 if (old->next != NULL) 164 old->next->prev = old->prev; 165 166 /* 167 * If 'old' is on the ctx->strDone list, remove it. Update 168 * ctx->strLast if necessary. 169 */ 170 if (old->prevDone == NULL && old->nextDone == NULL) { 171 /* 172 * Either 'old' is the only item on the done list, or it's 173 * not on the done list. If the former, then we unlink it 174 * from the list. If the latter, we leave the list alone. 175 */ 176 if (ctx->strDone == old) { 177 ctx->strDone = NULL; 178 ctx->strLast = NULL; 179 } 180 } else { 181 if (old->prevDone != NULL) 182 old->prevDone->nextDone = old->nextDone; 183 else 184 ctx->strDone = old->nextDone; 185 if (old->nextDone != NULL) 186 old->nextDone->prevDone = old->prevDone; 187 else 188 ctx->strLast = old->prevDone; 189 } 190 191 /* Deallocate the stream. */ 192 if (old->file.opaque) 193 evDeselectFD(opaqueCtx, old->file); 194 memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount); 195 FREE(old); 196 return (0); 197 } 198 199 /* Copy a scatter/gather vector and initialize a stream handler's IO. */ 200 static int 201 copyvec(evStream *str, const struct iovec *iov, int iocnt) { 202 int i; 203 204 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt); 205 if (str->iovOrig == NULL) { 206 errno = ENOMEM; 207 return (-1); 208 } 209 str->ioTotal = 0; 210 for (i = 0; i < iocnt; i++) { 211 str->iovOrig[i] = iov[i]; 212 str->ioTotal += iov[i].iov_len; 213 } 214 str->iovOrigCount = iocnt; 215 str->iovCur = str->iovOrig; 216 str->iovCurCount = str->iovOrigCount; 217 str->ioDone = 0; 218 return (0); 219 } 220 221 /* Pull off or truncate lead iovec(s). */ 222 static void 223 consume(evStream *str, size_t bytes) { 224 while (bytes > 0U) { 225 if (bytes < (size_t)str->iovCur->iov_len) { 226 str->iovCur->iov_len -= bytes; 227 str->iovCur->iov_base = (void *) 228 ((u_char *)str->iovCur->iov_base + bytes); 229 str->ioDone += bytes; 230 bytes = 0; 231 } else { 232 bytes -= str->iovCur->iov_len; 233 str->ioDone += str->iovCur->iov_len; 234 str->iovCur++; 235 str->iovCurCount--; 236 } 237 } 238 } 239 240 /* Add a stream to Done list and deselect the FD. */ 241 static void 242 done(evContext opaqueCtx, evStream *str) { 243 evContext_p *ctx = opaqueCtx.opaque; 244 245 if (ctx->strLast != NULL) { 246 str->prevDone = ctx->strLast; 247 ctx->strLast->nextDone = str; 248 ctx->strLast = str; 249 } else { 250 INSIST(ctx->strDone == NULL); 251 ctx->strDone = ctx->strLast = str; 252 } 253 evDeselectFD(opaqueCtx, str->file); 254 str->file.opaque = NULL; 255 /* evDrop() will call evCancelRW() on us. */ 256 } 257 258 /* Dribble out some bytes on the stream. (Called by evDispatch().) */ 259 static void 260 writable(evContext opaqueCtx, void *uap, int fd, int evmask) { 261 evStream *str = uap; 262 int bytes; 263 264 UNUSED(evmask); 265 266 bytes = writev(fd, str->iovCur, str->iovCurCount); 267 if (bytes > 0) { 268 if ((str->flags & EV_STR_TIMEROK) != 0) 269 evTouchIdleTimer(opaqueCtx, str->timer); 270 consume(str, bytes); 271 } else { 272 if (bytes < 0 && errno != EINTR) { 273 str->ioDone = -1; 274 str->ioErrno = errno; 275 } 276 } 277 if (str->ioDone == -1 || str->ioDone == str->ioTotal) 278 done(opaqueCtx, str); 279 } 280 281 /* Scoop up some bytes from the stream. (Called by evDispatch().) */ 282 static void 283 readable(evContext opaqueCtx, void *uap, int fd, int evmask) { 284 evStream *str = uap; 285 int bytes; 286 287 UNUSED(evmask); 288 289 bytes = readv(fd, str->iovCur, str->iovCurCount); 290 if (bytes > 0) { 291 if ((str->flags & EV_STR_TIMEROK) != 0) 292 evTouchIdleTimer(opaqueCtx, str->timer); 293 consume(str, bytes); 294 } else { 295 if (bytes == 0) 296 str->ioDone = 0; 297 else { 298 if (errno != EINTR) { 299 str->ioDone = -1; 300 str->ioErrno = errno; 301 } 302 } 303 } 304 if (str->ioDone <= 0 || str->ioDone == str->ioTotal) 305 done(opaqueCtx, str); 306 } 307 308 /*! \file */ 309