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[dragonfly.git] / contrib / bind-9.2.4rc7 / lib / bind / isc / ev_streams.c
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1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996-1999 by Internet Software Consortium
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.
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.
18 /* ev_streams.c - implement asynch stream file IO for the eventlib
19 * vix 04mar96 [initial]
22 #if !defined(LINT) && !defined(CODECENTER)
23 static const char rcsid[] = "$Id: ev_streams.c,v 1.2.2.2 2004/03/17 00:40:14 marka Exp $";
24 #endif
26 #include "port_before.h"
27 #include "fd_setsize.h"
29 #include <sys/types.h>
30 #include <sys/uio.h>
32 #include <errno.h>
34 #include <isc/eventlib.h>
35 #include <isc/assertions.h>
36 #include "eventlib_p.h"
38 #include "port_after.h"
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);
46 struct iovec
47 evConsIovec(void *buf, size_t cnt) {
48 struct iovec ret;
50 memset(&ret, 0xf5, sizeof ret);
51 ret.iov_base = buf;
52 ret.iov_len = cnt;
53 return (ret);
56 int
57 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
58 evStreamFunc func, void *uap, evStreamID *id)
60 evContext_p *ctx = opaqueCtx.opaque;
61 evStream *new;
62 int save;
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);
90 int
91 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
92 evStreamFunc func, void *uap, evStreamID *id)
94 evContext_p *ctx = opaqueCtx.opaque;
95 evStream *new;
96 int save;
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);
125 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
126 evStream *str = id.opaque;
128 UNUSED(opaqueCtx);
130 str->timer = timer;
131 str->flags |= EV_STR_TIMEROK;
132 return (0);
136 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
137 evStream *str = id.opaque;
139 UNUSED(opaqueCtx);
141 str->flags &= ~EV_STR_TIMEROK;
142 return (0);
146 evCancelRW(evContext opaqueCtx, evStreamID id) {
147 evContext_p *ctx = opaqueCtx.opaque;
148 evStream *old = id.opaque;
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.
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;
167 * If 'old' is on the ctx->strDone list, remove it. Update
168 * ctx->strLast if necessary.
170 if (old->prevDone == NULL && old->nextDone == NULL) {
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.
176 if (ctx->strDone == old) {
177 ctx->strDone = NULL;
178 ctx->strLast = NULL;
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;
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);
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;
204 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
205 if (str->iovOrig == NULL) {
206 errno = ENOMEM;
207 return (-1);
209 str->ioTotal = 0;
210 for (i = 0; i < iocnt; i++) {
211 str->iovOrig[i] = iov[i];
212 str->ioTotal += iov[i].iov_len;
214 str->iovOrigCount = iocnt;
215 str->iovCur = str->iovOrig;
216 str->iovCurCount = str->iovOrigCount;
217 str->ioDone = 0;
218 return (0);
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--;
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;
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;
253 evDeselectFD(opaqueCtx, str->file);
254 str->file.opaque = NULL;
255 /* evDrop() will call evCancelRW() on us. */
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;
264 UNUSED(evmask);
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;
277 if (str->ioDone == -1 || str->ioDone == str->ioTotal)
278 done(opaqueCtx, str);
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;
287 UNUSED(evmask);
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;
304 if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
305 done(opaqueCtx, str);