other-licenses/android/ev_streams.c

   1 /*      $NetBSD: ev_streams.c,v 1.2 2004/05/20 19:52:31 christos Exp $  */
   2
   3 /*
   4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (c) 1996-1999 by Internet Software Consortium
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  17  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* ev_streams.c - implement asynch stream file IO for the eventlib
  21  * vix 04mar96 [initial]
  22  */
  23
  24 /*
  25  * This version of this file is derived from Android 2.3 "Gingerbread",
  26  * which contains uncredited changes by Android/Google developers.  It has
  27  * been modified in 2011 for use in the Android build of Mozilla Firefox by
  28  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
  29  * and Steve Workman <sjhworkman@gmail.com>).
  30  * These changes are offered under the same license as the original NetBSD
  31  * file, whose copyright and license are unchanged above.
  32  */
  33
  34 #define ANDROID_CHANGES 1
  35 #define MOZILLA_NECKO_EXCLUDE_CODE 1
  36
  37 #include <sys/cdefs.h>
  38 #if !defined(LINT) && !defined(CODECENTER) && !defined(lint)
  39 #ifdef notdef
  40 static const char rcsid[] = "Id: ev_streams.c,v 1.2.206.2 2004/03/17 00:29:51 marka Exp";
  41 #else
  42 __RCSID("$NetBSD: ev_streams.c,v 1.2 2004/05/20 19:52:31 christos Exp $");
  43 #endif
  44 #endif
  45
  46 #include <sys/types.h>
  47 #include <sys/uio.h>
  48
  49 #include <errno.h>
  50
  51 #include "eventlib.h"
  52 #include "eventlib_p.h"
  53
  54 #ifndef MOZILLA_NECKO_EXCLUDE_CODE
  55 #ifndef _LIBC
  56 static int      copyvec(evStream *str, const struct iovec *iov, int iocnt);
  57 static void     consume(evStream *str, size_t bytes);
  58 static void     done(evContext opaqueCtx, evStream *str);
  59 static void     writable(evContext opaqueCtx, void *uap, int fd, int evmask);
  60 static void     readable(evContext opaqueCtx, void *uap, int fd, int evmask);
  61 #endif
  62 #endif
  63
  64 struct iovec
  65 evConsIovec(void *buf, size_t cnt) {
  66         struct iovec ret;
  67
  68         memset(&ret, 0xf5, sizeof ret);
  69         ret.iov_base = buf;
  70         ret.iov_len = cnt;
  71         return (ret);
  72 }
  73
  74 #ifndef MOZILLA_NECKO_EXCLUDE_CODE
  75 #ifndef _LIBC
  76 int
  77 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
  78         evStreamFunc func, void *uap, evStreamID *id)
  79 {
  80         evContext_p *ctx = opaqueCtx.opaque;
  81         evStream *new;
  82         int save;
  83
  84         OKNEW(new);
  85         new->func = func;
  86         new->uap = uap;
  87         new->fd = fd;
  88         new->flags = 0;
  89         if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0)
  90                 goto free;
  91         if (copyvec(new, iov, iocnt) < 0)
  92                 goto free;
  93         new->prevDone = NULL;
  94         new->nextDone = NULL;
  95         if (ctx->streams != NULL)
  96                 ctx->streams->prev = new;
  97         new->prev = NULL;
  98         new->next = ctx->streams;
  99         ctx->streams = new;
 100         if (id != NULL)
 101                 id->opaque = new;
 102         return (0);
 103  free:
 104         save = errno;
 105         FREE(new);
 106         errno = save;
 107         return (-1);
 108 }
 109
 110 int
 111 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
 112        evStreamFunc func, void *uap, evStreamID *id)
 113 {
 114         evContext_p *ctx = opaqueCtx.opaque;
 115         evStream *new;
 116         int save;
 117
 118         OKNEW(new);
 119         new->func = func;
 120         new->uap = uap;
 121         new->fd = fd;
 122         new->flags = 0;
 123         if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0)
 124                 goto free;
 125         if (copyvec(new, iov, iocnt) < 0)
 126                 goto free;
 127         new->prevDone = NULL;
 128         new->nextDone = NULL;
 129         if (ctx->streams != NULL)
 130                 ctx->streams->prev = new;
 131         new->prev = NULL;
 132         new->next = ctx->streams;
 133         ctx->streams = new;
 134         if (id)
 135                 id->opaque = new;
 136         return (0);
 137  free:
 138         save = errno;
 139         FREE(new);
 140         errno = save;
 141         return (-1);
 142 }
 143
 144 int
 145 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
 146         evStream *str = id.opaque;
 147
 148         UNUSED(opaqueCtx);
 149
 150         str->timer = timer;
 151         str->flags |= EV_STR_TIMEROK;
 152         return (0);
 153 }
 154
 155 int
 156 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
 157         evStream *str = id.opaque;
 158
 159         UNUSED(opaqueCtx);
 160
 161         str->flags &= ~EV_STR_TIMEROK;
 162         return (0);
 163 }
 164
 165 int
 166 evCancelRW(evContext opaqueCtx, evStreamID id) {
 167         evContext_p *ctx = opaqueCtx.opaque;
 168         evStream *old = id.opaque;
 169
 170         /*
 171          * The streams list is doubly threaded.  First, there's ctx->streams
 172          * that's used by evDestroy() to find and cancel all streams.  Second,
 173          * there's ctx->strDone (head) and ctx->strLast (tail) which thread
 174          * through the potentially smaller number of "IO completed" streams,
 175          * used in evGetNext() to avoid scanning the entire list.
 176          */
 177
 178         /* Unlink from ctx->streams. */
 179         if (old->prev != NULL)
 180                 old->prev->next = old->next;
 181         else
 182                 ctx->streams = old->next;
 183         if (old->next != NULL)
 184                 old->next->prev = old->prev;
 185
 186         /*
 187          * If 'old' is on the ctx->strDone list, remove it.  Update
 188          * ctx->strLast if necessary.
 189          */
 190         if (old->prevDone == NULL && old->nextDone == NULL) {
 191                 /*
 192                  * Either 'old' is the only item on the done list, or it's
 193                  * not on the done list.  If the former, then we unlink it
 194                  * from the list.  If the latter, we leave the list alone.
 195                  */
 196                 if (ctx->strDone == old) {
 197                         ctx->strDone = NULL;
 198                         ctx->strLast = NULL;
 199                 }
 200         } else {
 201                 if (old->prevDone != NULL)
 202                         old->prevDone->nextDone = old->nextDone;
 203                 else
 204                         ctx->strDone = old->nextDone;
 205                 if (old->nextDone != NULL)
 206                         old->nextDone->prevDone = old->prevDone;
 207                 else
 208                         ctx->strLast = old->prevDone;
 209         }
 210
 211         /* Deallocate the stream. */
 212         if (old->file.opaque)
 213                 evDeselectFD(opaqueCtx, old->file);
 214         memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount);
 215         FREE(old);
 216         return (0);
 217 }
 218
 219 /* Copy a scatter/gather vector and initialize a stream handler's IO. */
 220 static int
 221 copyvec(evStream *str, const struct iovec *iov, int iocnt) {
 222         int i;
 223
 224         str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
 225         if (str->iovOrig == NULL) {
 226                 errno = ENOMEM;
 227                 return (-1);
 228         }
 229         str->ioTotal = 0;
 230         for (i = 0; i < iocnt; i++) {
 231                 str->iovOrig[i] = iov[i];
 232                 str->ioTotal += iov[i].iov_len;
 233         }
 234         str->iovOrigCount = iocnt;
 235         str->iovCur = str->iovOrig;
 236         str->iovCurCount = str->iovOrigCount;
 237         str->ioDone = 0;
 238         return (0);
 239 }
 240
 241 /* Pull off or truncate lead iovec(s). */
 242 static void
 243 consume(evStream *str, size_t bytes) {
 244         while (bytes > 0U) {
 245                 if (bytes < (size_t)str->iovCur->iov_len) {
 246                         str->iovCur->iov_len -= bytes;
 247                         str->iovCur->iov_base = (void *)
 248                                 ((u_char *)str->iovCur->iov_base + bytes);
 249                         str->ioDone += bytes;
 250                         bytes = 0;
 251                 } else {
 252                         bytes -= str->iovCur->iov_len;
 253                         str->ioDone += str->iovCur->iov_len;
 254                         str->iovCur++;
 255                         str->iovCurCount--;
 256                 }
 257         }
 258 }
 259
 260 /* Add a stream to Done list and deselect the FD. */
 261 static void
 262 done(evContext opaqueCtx, evStream *str) {
 263         evContext_p *ctx = opaqueCtx.opaque;
 264
 265         if (ctx->strLast != NULL) {
 266                 str->prevDone = ctx->strLast;
 267                 ctx->strLast->nextDone = str;
 268                 ctx->strLast = str;
 269         } else {
 270                 INSIST(ctx->strDone == NULL);
 271                 ctx->strDone = ctx->strLast = str;
 272         }
 273         evDeselectFD(opaqueCtx, str->file);
 274         str->file.opaque = NULL;
 275         /* evDrop() will call evCancelRW() on us. */
 276 }
 277
 278 /* Dribble out some bytes on the stream.  (Called by evDispatch().) */
 279 static void
 280 writable(evContext opaqueCtx, void *uap, int fd, int evmask) {
 281         evStream *str = uap;
 282         int bytes;
 283
 284         UNUSED(evmask);
 285
 286         bytes = writev(fd, str->iovCur, str->iovCurCount);
 287         if (bytes > 0) {
 288                 if ((str->flags & EV_STR_TIMEROK) != 0)
 289                         evTouchIdleTimer(opaqueCtx, str->timer);
 290                 consume(str, bytes);
 291         } else {
 292                 if (bytes < 0 && errno != EINTR) {
 293                         str->ioDone = -1;
 294                         str->ioErrno = errno;
 295                 }
 296         }
 297         if (str->ioDone == -1 || str->ioDone == str->ioTotal)
 298                 done(opaqueCtx, str);
 299 }
 300
 301 /* Scoop up some bytes from the stream.  (Called by evDispatch().) */
 302 static void
 303 readable(evContext opaqueCtx, void *uap, int fd, int evmask) {
 304         evStream *str = uap;
 305         int bytes;
 306
 307         UNUSED(evmask);
 308
 309         bytes = readv(fd, str->iovCur, str->iovCurCount);
 310         if (bytes > 0) {
 311                 if ((str->flags & EV_STR_TIMEROK) != 0)
 312                         evTouchIdleTimer(opaqueCtx, str->timer);
 313                 consume(str, bytes);
 314         } else {
 315                 if (bytes == 0)
 316                         str->ioDone = 0;
 317                 else {
 318                         if (errno != EINTR) {
 319                                 str->ioDone = -1;
 320                                 str->ioErrno = errno;
 321                         }
 322                 }
 323         }
 324         if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
 325                 done(opaqueCtx, str);
 326 }
 327 #endif
 328 #endif