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 #include <sys/cdefs.h>
25 #if !defined(LINT) && !defined(CODECENTER) && !defined(lint)
26 #ifdef notdef
27 static const char rcsid[] = "Id: ev_streams.c,v 1.2.206.2 2004/03/17 00:29:51 marka Exp";
28 #else
29 __RCSID("$NetBSD: ev_streams.c,v 1.2 2004/05/20 19:52:31 christos Exp $");
30 #endif
31 #endif
32
33 #include <sys/types.h>
34 #include <sys/uio.h>
35
36 #include <errno.h>
37
38 #include <isc/eventlib.h>
39 #include "eventlib_p.h"
40
41 #ifndef _LIBC
42 static int copyvec(evStream *str, const struct iovec *iov, int iocnt);
43 static void consume(evStream *str, size_t bytes);
44 static void done(evContext opaqueCtx, evStream *str);
45 static void writable(evContext opaqueCtx, void *uap, int fd, int evmask);
46 static void readable(evContext opaqueCtx, void *uap, int fd, int evmask);
47 #endif
48
49 struct iovec
evConsIovec(void * buf,size_t cnt)50 evConsIovec(void *buf, size_t cnt) {
51 struct iovec ret;
52
53 memset(&ret, 0xf5, sizeof ret);
54 ret.iov_base = buf;
55 ret.iov_len = cnt;
56 return (ret);
57 }
58
59 #ifndef _LIBC
60 int
evWrite(evContext opaqueCtx,int fd,const struct iovec * iov,int iocnt,evStreamFunc func,void * uap,evStreamID * id)61 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
62 evStreamFunc func, void *uap, evStreamID *id)
63 {
64 evContext_p *ctx = opaqueCtx.opaque;
65 evStream *new;
66 int save;
67
68 OKNEW(new);
69 new->func = func;
70 new->uap = uap;
71 new->fd = fd;
72 new->flags = 0;
73 if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0)
74 goto free;
75 if (copyvec(new, iov, iocnt) < 0)
76 goto free;
77 new->prevDone = NULL;
78 new->nextDone = NULL;
79 if (ctx->streams != NULL)
80 ctx->streams->prev = new;
81 new->prev = NULL;
82 new->next = ctx->streams;
83 ctx->streams = new;
84 if (id != NULL)
85 id->opaque = new;
86 return (0);
87 free:
88 save = errno;
89 FREE(new);
90 errno = save;
91 return (-1);
92 }
93
94 int
evRead(evContext opaqueCtx,int fd,const struct iovec * iov,int iocnt,evStreamFunc func,void * uap,evStreamID * id)95 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
96 evStreamFunc func, void *uap, evStreamID *id)
97 {
98 evContext_p *ctx = opaqueCtx.opaque;
99 evStream *new;
100 int save;
101
102 OKNEW(new);
103 new->func = func;
104 new->uap = uap;
105 new->fd = fd;
106 new->flags = 0;
107 if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0)
108 goto free;
109 if (copyvec(new, iov, iocnt) < 0)
110 goto free;
111 new->prevDone = NULL;
112 new->nextDone = NULL;
113 if (ctx->streams != NULL)
114 ctx->streams->prev = new;
115 new->prev = NULL;
116 new->next = ctx->streams;
117 ctx->streams = new;
118 if (id)
119 id->opaque = new;
120 return (0);
121 free:
122 save = errno;
123 FREE(new);
124 errno = save;
125 return (-1);
126 }
127
128 int
evTimeRW(evContext opaqueCtx,evStreamID id,evTimerID timer)129 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
130 evStream *str = id.opaque;
131
132 UNUSED(opaqueCtx);
133
134 str->timer = timer;
135 str->flags |= EV_STR_TIMEROK;
136 return (0);
137 }
138
139 int
evUntimeRW(evContext opaqueCtx,evStreamID id)140 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
141 evStream *str = id.opaque;
142
143 UNUSED(opaqueCtx);
144
145 str->flags &= ~EV_STR_TIMEROK;
146 return (0);
147 }
148
149 int
evCancelRW(evContext opaqueCtx,evStreamID id)150 evCancelRW(evContext opaqueCtx, evStreamID id) {
151 evContext_p *ctx = opaqueCtx.opaque;
152 evStream *old = id.opaque;
153
154 /*
155 * The streams list is doubly threaded. First, there's ctx->streams
156 * that's used by evDestroy() to find and cancel all streams. Second,
157 * there's ctx->strDone (head) and ctx->strLast (tail) which thread
158 * through the potentially smaller number of "IO completed" streams,
159 * used in evGetNext() to avoid scanning the entire list.
160 */
161
162 /* Unlink from ctx->streams. */
163 if (old->prev != NULL)
164 old->prev->next = old->next;
165 else
166 ctx->streams = old->next;
167 if (old->next != NULL)
168 old->next->prev = old->prev;
169
170 /*
171 * If 'old' is on the ctx->strDone list, remove it. Update
172 * ctx->strLast if necessary.
173 */
174 if (old->prevDone == NULL && old->nextDone == NULL) {
175 /*
176 * Either 'old' is the only item on the done list, or it's
177 * not on the done list. If the former, then we unlink it
178 * from the list. If the latter, we leave the list alone.
179 */
180 if (ctx->strDone == old) {
181 ctx->strDone = NULL;
182 ctx->strLast = NULL;
183 }
184 } else {
185 if (old->prevDone != NULL)
186 old->prevDone->nextDone = old->nextDone;
187 else
188 ctx->strDone = old->nextDone;
189 if (old->nextDone != NULL)
190 old->nextDone->prevDone = old->prevDone;
191 else
192 ctx->strLast = old->prevDone;
193 }
194
195 /* Deallocate the stream. */
196 if (old->file.opaque)
197 evDeselectFD(opaqueCtx, old->file);
198 memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount);
199 FREE(old);
200 return (0);
201 }
202
203 /* Copy a scatter/gather vector and initialize a stream handler's IO. */
204 static int
copyvec(evStream * str,const struct iovec * iov,int iocnt)205 copyvec(evStream *str, const struct iovec *iov, int iocnt) {
206 int i;
207
208 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
209 if (str->iovOrig == NULL) {
210 errno = ENOMEM;
211 return (-1);
212 }
213 str->ioTotal = 0;
214 for (i = 0; i < iocnt; i++) {
215 str->iovOrig[i] = iov[i];
216 str->ioTotal += iov[i].iov_len;
217 }
218 str->iovOrigCount = iocnt;
219 str->iovCur = str->iovOrig;
220 str->iovCurCount = str->iovOrigCount;
221 str->ioDone = 0;
222 return (0);
223 }
224
225 /* Pull off or truncate lead iovec(s). */
226 static void
consume(evStream * str,size_t bytes)227 consume(evStream *str, size_t bytes) {
228 while (bytes > 0U) {
229 if (bytes < (size_t)str->iovCur->iov_len) {
230 str->iovCur->iov_len -= bytes;
231 str->iovCur->iov_base = (void *)
232 ((u_char *)str->iovCur->iov_base + bytes);
233 str->ioDone += bytes;
234 bytes = 0;
235 } else {
236 bytes -= str->iovCur->iov_len;
237 str->ioDone += str->iovCur->iov_len;
238 str->iovCur++;
239 str->iovCurCount--;
240 }
241 }
242 }
243
244 /* Add a stream to Done list and deselect the FD. */
245 static void
done(evContext opaqueCtx,evStream * str)246 done(evContext opaqueCtx, evStream *str) {
247 evContext_p *ctx = opaqueCtx.opaque;
248
249 if (ctx->strLast != NULL) {
250 str->prevDone = ctx->strLast;
251 ctx->strLast->nextDone = str;
252 ctx->strLast = str;
253 } else {
254 INSIST(ctx->strDone == NULL);
255 ctx->strDone = ctx->strLast = str;
256 }
257 evDeselectFD(opaqueCtx, str->file);
258 str->file.opaque = NULL;
259 /* evDrop() will call evCancelRW() on us. */
260 }
261
262 /* Dribble out some bytes on the stream. (Called by evDispatch().) */
263 static void
writable(evContext opaqueCtx,void * uap,int fd,int evmask)264 writable(evContext opaqueCtx, void *uap, int fd, int evmask) {
265 evStream *str = uap;
266 int bytes;
267
268 UNUSED(evmask);
269
270 bytes = writev(fd, str->iovCur, str->iovCurCount);
271 if (bytes > 0) {
272 if ((str->flags & EV_STR_TIMEROK) != 0)
273 evTouchIdleTimer(opaqueCtx, str->timer);
274 consume(str, bytes);
275 } else {
276 if (bytes < 0 && errno != EINTR) {
277 str->ioDone = -1;
278 str->ioErrno = errno;
279 }
280 }
281 if (str->ioDone == -1 || str->ioDone == str->ioTotal)
282 done(opaqueCtx, str);
283 }
284
285 /* Scoop up some bytes from the stream. (Called by evDispatch().) */
286 static void
readable(evContext opaqueCtx,void * uap,int fd,int evmask)287 readable(evContext opaqueCtx, void *uap, int fd, int evmask) {
288 evStream *str = uap;
289 int bytes;
290
291 UNUSED(evmask);
292
293 bytes = readv(fd, str->iovCur, str->iovCurCount);
294 if (bytes > 0) {
295 if ((str->flags & EV_STR_TIMEROK) != 0)
296 evTouchIdleTimer(opaqueCtx, str->timer);
297 consume(str, bytes);
298 } else {
299 if (bytes == 0)
300 str->ioDone = 0;
301 else {
302 if (errno != EINTR) {
303 str->ioDone = -1;
304 str->ioErrno = errno;
305 }
306 }
307 }
308 if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
309 done(opaqueCtx, str);
310 }
311 #endif
312