1 /* $NetBSD: ev_streams.c,v 1.6 2009/04/12 17:07:17 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 1.5 2005/04/27 04:56:36 sra Exp";
28 #else
29 __RCSID("$NetBSD: ev_streams.c,v 1.6 2009/04/12 17:07:17 christos Exp $");
30 #endif
31 #endif
32
33 #include "port_before.h"
34 #include "fd_setsize.h"
35
36 #include <sys/types.h>
37 #include <sys/uio.h>
38
39 #include <errno.h>
40
41 #include <isc/eventlib.h>
42 #include <isc/assertions.h>
43 #include "eventlib_p.h"
44
45 #include "port_after.h"
46
47 #ifndef _LIBC
48 static int copyvec(evStream *str, const struct iovec *iov, int iocnt);
49 static void consume(evStream *str, size_t bytes);
50 static void done(evContext opaqueCtx, evStream *str);
51 static void writable(evContext opaqueCtx, void *uap, int fd, int evmask);
52 static void readable(evContext opaqueCtx, void *uap, int fd, int evmask);
53 #endif
54
55 struct iovec
evConsIovec(void * buf,size_t cnt)56 evConsIovec(void *buf, size_t cnt) {
57 struct iovec ret;
58
59 memset(&ret, 0xf5, sizeof ret);
60 ret.iov_base = buf;
61 ret.iov_len = cnt;
62 return (ret);
63 }
64
65 #ifndef _LIBC
66 int
evWrite(evContext opaqueCtx,int fd,const struct iovec * iov,int iocnt,evStreamFunc func,void * uap,evStreamID * id)67 evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
68 evStreamFunc func, void *uap, evStreamID *id)
69 {
70 evContext_p *ctx = opaqueCtx.opaque;
71 evStream *new;
72 int save;
73
74 OKNEW(new);
75 new->func = func;
76 new->uap = uap;
77 new->fd = fd;
78 new->flags = 0;
79 if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0)
80 goto free;
81 if (copyvec(new, iov, iocnt) < 0)
82 goto free;
83 new->prevDone = NULL;
84 new->nextDone = NULL;
85 if (ctx->streams != NULL)
86 ctx->streams->prev = new;
87 new->prev = NULL;
88 new->next = ctx->streams;
89 ctx->streams = new;
90 if (id != NULL)
91 id->opaque = new;
92 return (0);
93 free:
94 save = errno;
95 FREE(new);
96 errno = save;
97 return (-1);
98 }
99
100 int
evRead(evContext opaqueCtx,int fd,const struct iovec * iov,int iocnt,evStreamFunc func,void * uap,evStreamID * id)101 evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
102 evStreamFunc func, void *uap, evStreamID *id)
103 {
104 evContext_p *ctx = opaqueCtx.opaque;
105 evStream *new;
106 int save;
107
108 OKNEW(new);
109 new->func = func;
110 new->uap = uap;
111 new->fd = fd;
112 new->flags = 0;
113 if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0)
114 goto free;
115 if (copyvec(new, iov, iocnt) < 0)
116 goto free;
117 new->prevDone = NULL;
118 new->nextDone = NULL;
119 if (ctx->streams != NULL)
120 ctx->streams->prev = new;
121 new->prev = NULL;
122 new->next = ctx->streams;
123 ctx->streams = new;
124 if (id)
125 id->opaque = new;
126 return (0);
127 free:
128 save = errno;
129 FREE(new);
130 errno = save;
131 return (-1);
132 }
133
134 int
evTimeRW(evContext opaqueCtx,evStreamID id,evTimerID timer)135 evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
136 evStream *str = id.opaque;
137
138 UNUSED(opaqueCtx);
139
140 str->timer = timer;
141 str->flags |= EV_STR_TIMEROK;
142 return (0);
143 }
144
145 int
evUntimeRW(evContext opaqueCtx,evStreamID id)146 evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
147 evStream *str = id.opaque;
148
149 UNUSED(opaqueCtx);
150
151 str->flags &= ~EV_STR_TIMEROK;
152 return (0);
153 }
154
155 int
evCancelRW(evContext opaqueCtx,evStreamID id)156 evCancelRW(evContext opaqueCtx, evStreamID id) {
157 evContext_p *ctx = opaqueCtx.opaque;
158 evStream *old = id.opaque;
159
160 /*
161 * The streams list is doubly threaded. First, there's ctx->streams
162 * that's used by evDestroy() to find and cancel all streams. Second,
163 * there's ctx->strDone (head) and ctx->strLast (tail) which thread
164 * through the potentially smaller number of "IO completed" streams,
165 * used in evGetNext() to avoid scanning the entire list.
166 */
167
168 /* Unlink from ctx->streams. */
169 if (old->prev != NULL)
170 old->prev->next = old->next;
171 else
172 ctx->streams = old->next;
173 if (old->next != NULL)
174 old->next->prev = old->prev;
175
176 /*
177 * If 'old' is on the ctx->strDone list, remove it. Update
178 * ctx->strLast if necessary.
179 */
180 if (old->prevDone == NULL && old->nextDone == NULL) {
181 /*
182 * Either 'old' is the only item on the done list, or it's
183 * not on the done list. If the former, then we unlink it
184 * from the list. If the latter, we leave the list alone.
185 */
186 if (ctx->strDone == old) {
187 ctx->strDone = NULL;
188 ctx->strLast = NULL;
189 }
190 } else {
191 if (old->prevDone != NULL)
192 old->prevDone->nextDone = old->nextDone;
193 else
194 ctx->strDone = old->nextDone;
195 if (old->nextDone != NULL)
196 old->nextDone->prevDone = old->prevDone;
197 else
198 ctx->strLast = old->prevDone;
199 }
200
201 /* Deallocate the stream. */
202 if (old->file.opaque)
203 evDeselectFD(opaqueCtx, old->file);
204 memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount);
205 FREE(old);
206 return (0);
207 }
208
209 /* Copy a scatter/gather vector and initialize a stream handler's IO. */
210 static int
copyvec(evStream * str,const struct iovec * iov,int iocnt)211 copyvec(evStream *str, const struct iovec *iov, int iocnt) {
212 int i;
213
214 str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
215 if (str->iovOrig == NULL) {
216 errno = ENOMEM;
217 return (-1);
218 }
219 str->ioTotal = 0;
220 for (i = 0; i < iocnt; i++) {
221 str->iovOrig[i] = iov[i];
222 str->ioTotal += iov[i].iov_len;
223 }
224 str->iovOrigCount = iocnt;
225 str->iovCur = str->iovOrig;
226 str->iovCurCount = str->iovOrigCount;
227 str->ioDone = 0;
228 return (0);
229 }
230
231 /* Pull off or truncate lead iovec(s). */
232 static void
consume(evStream * str,size_t bytes)233 consume(evStream *str, size_t bytes) {
234 while (bytes > 0U) {
235 if (bytes < (size_t)str->iovCur->iov_len) {
236 str->iovCur->iov_len -= bytes;
237 str->iovCur->iov_base = (void *)
238 ((u_char *)str->iovCur->iov_base + bytes);
239 str->ioDone += bytes;
240 bytes = 0;
241 } else {
242 bytes -= str->iovCur->iov_len;
243 str->ioDone += str->iovCur->iov_len;
244 str->iovCur++;
245 str->iovCurCount--;
246 }
247 }
248 }
249
250 /* Add a stream to Done list and deselect the FD. */
251 static void
done(evContext opaqueCtx,evStream * str)252 done(evContext opaqueCtx, evStream *str) {
253 evContext_p *ctx = opaqueCtx.opaque;
254
255 if (ctx->strLast != NULL) {
256 str->prevDone = ctx->strLast;
257 ctx->strLast->nextDone = str;
258 ctx->strLast = str;
259 } else {
260 INSIST(ctx->strDone == NULL);
261 ctx->strDone = ctx->strLast = str;
262 }
263 evDeselectFD(opaqueCtx, str->file);
264 str->file.opaque = NULL;
265 /* evDrop() will call evCancelRW() on us. */
266 }
267
268 /* Dribble out some bytes on the stream. (Called by evDispatch().) */
269 static void
writable(evContext opaqueCtx,void * uap,int fd,int evmask)270 writable(evContext opaqueCtx, void *uap, int fd, int evmask) {
271 evStream *str = uap;
272 int bytes;
273
274 UNUSED(evmask);
275
276 bytes = writev(fd, str->iovCur, str->iovCurCount);
277 if (bytes > 0) {
278 if ((str->flags & EV_STR_TIMEROK) != 0)
279 evTouchIdleTimer(opaqueCtx, str->timer);
280 consume(str, bytes);
281 } else {
282 if (bytes < 0 && errno != EINTR) {
283 str->ioDone = -1;
284 str->ioErrno = errno;
285 }
286 }
287 if (str->ioDone == -1 || str->ioDone == str->ioTotal)
288 done(opaqueCtx, str);
289 }
290
291 /* Scoop up some bytes from the stream. (Called by evDispatch().) */
292 static void
readable(evContext opaqueCtx,void * uap,int fd,int evmask)293 readable(evContext opaqueCtx, void *uap, int fd, int evmask) {
294 evStream *str = uap;
295 int bytes;
296
297 UNUSED(evmask);
298
299 bytes = readv(fd, str->iovCur, str->iovCurCount);
300 if (bytes > 0) {
301 if ((str->flags & EV_STR_TIMEROK) != 0)
302 evTouchIdleTimer(opaqueCtx, str->timer);
303 consume(str, bytes);
304 } else {
305 if (bytes == 0)
306 str->ioDone = 0;
307 else {
308 if (errno != EINTR) {
309 str->ioDone = -1;
310 str->ioErrno = errno;
311 }
312 }
313 }
314 if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
315 done(opaqueCtx, str);
316 }
317 #endif
318
319 /*! \file */
320