1/*	$NetBSD$	*/
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#if !defined(LINT) && !defined(CODECENTER)
25static const char rcsid[] = "Id: ev_streams.c,v 1.5 2005/04/27 04:56:36 sra Exp ";
26#endif
27
28#include "port_before.h"
29#include "fd_setsize.h"
30
31#include <sys/types.h>
32#include <sys/uio.h>
33
34#include <errno.h>
35
36#include <isc/eventlib.h>
37#include <isc/assertions.h>
38#include "eventlib_p.h"
39
40#include "port_after.h"
41
42static int	copyvec(evStream *str, const struct iovec *iov, int iocnt);
43static void	consume(evStream *str, size_t bytes);
44static void	done(evContext opaqueCtx, evStream *str);
45static void	writable(evContext opaqueCtx, void *uap, int fd, int evmask);
46static void	readable(evContext opaqueCtx, void *uap, int fd, int evmask);
47
48struct iovec
49evConsIovec(void *buf, size_t cnt) {
50	struct iovec ret;
51
52	memset(&ret, 0xf5, sizeof ret);
53	ret.iov_base = buf;
54	ret.iov_len = cnt;
55	return (ret);
56}
57
58int
59evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
60	evStreamFunc func, void *uap, evStreamID *id)
61{
62	evContext_p *ctx = opaqueCtx.opaque;
63	evStream *new;
64	int save;
65
66	OKNEW(new);
67	new->func = func;
68	new->uap = uap;
69	new->fd = fd;
70	new->flags = 0;
71	if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0)
72		goto free;
73	if (copyvec(new, iov, iocnt) < 0)
74		goto free;
75	new->prevDone = NULL;
76	new->nextDone = NULL;
77	if (ctx->streams != NULL)
78		ctx->streams->prev = new;
79	new->prev = NULL;
80	new->next = ctx->streams;
81	ctx->streams = new;
82	if (id != NULL)
83		id->opaque = new;
84	return (0);
85 free:
86	save = errno;
87	FREE(new);
88	errno = save;
89	return (-1);
90}
91
92int
93evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt,
94       evStreamFunc func, void *uap, evStreamID *id)
95{
96	evContext_p *ctx = opaqueCtx.opaque;
97	evStream *new;
98	int save;
99
100	OKNEW(new);
101	new->func = func;
102	new->uap = uap;
103	new->fd = fd;
104	new->flags = 0;
105	if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0)
106		goto free;
107	if (copyvec(new, iov, iocnt) < 0)
108		goto free;
109	new->prevDone = NULL;
110	new->nextDone = NULL;
111	if (ctx->streams != NULL)
112		ctx->streams->prev = new;
113	new->prev = NULL;
114	new->next = ctx->streams;
115	ctx->streams = new;
116	if (id)
117		id->opaque = new;
118	return (0);
119 free:
120	save = errno;
121	FREE(new);
122	errno = save;
123	return (-1);
124}
125
126int
127evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ {
128	evStream *str = id.opaque;
129
130	UNUSED(opaqueCtx);
131
132	str->timer = timer;
133	str->flags |= EV_STR_TIMEROK;
134	return (0);
135}
136
137int
138evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
139	evStream *str = id.opaque;
140
141	UNUSED(opaqueCtx);
142
143	str->flags &= ~EV_STR_TIMEROK;
144	return (0);
145}
146
147int
148evCancelRW(evContext opaqueCtx, evStreamID id) {
149	evContext_p *ctx = opaqueCtx.opaque;
150	evStream *old = id.opaque;
151
152	/*
153	 * The streams list is doubly threaded.  First, there's ctx->streams
154	 * that's used by evDestroy() to find and cancel all streams.  Second,
155	 * there's ctx->strDone (head) and ctx->strLast (tail) which thread
156	 * through the potentially smaller number of "IO completed" streams,
157	 * used in evGetNext() to avoid scanning the entire list.
158	 */
159
160	/* Unlink from ctx->streams. */
161	if (old->prev != NULL)
162		old->prev->next = old->next;
163	else
164		ctx->streams = old->next;
165	if (old->next != NULL)
166		old->next->prev = old->prev;
167
168	/*
169	 * If 'old' is on the ctx->strDone list, remove it.  Update
170	 * ctx->strLast if necessary.
171	 */
172	if (old->prevDone == NULL && old->nextDone == NULL) {
173		/*
174		 * Either 'old' is the only item on the done list, or it's
175		 * not on the done list.  If the former, then we unlink it
176		 * from the list.  If the latter, we leave the list alone.
177		 */
178		if (ctx->strDone == old) {
179			ctx->strDone = NULL;
180			ctx->strLast = NULL;
181		}
182	} else {
183		if (old->prevDone != NULL)
184			old->prevDone->nextDone = old->nextDone;
185		else
186			ctx->strDone = old->nextDone;
187		if (old->nextDone != NULL)
188			old->nextDone->prevDone = old->prevDone;
189		else
190			ctx->strLast = old->prevDone;
191	}
192
193	/* Deallocate the stream. */
194	if (old->file.opaque)
195		evDeselectFD(opaqueCtx, old->file);
196	memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount);
197	FREE(old);
198	return (0);
199}
200
201/* Copy a scatter/gather vector and initialize a stream handler's IO. */
202static int
203copyvec(evStream *str, const struct iovec *iov, int iocnt) {
204	int i;
205
206	str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt);
207	if (str->iovOrig == NULL) {
208		errno = ENOMEM;
209		return (-1);
210	}
211	str->ioTotal = 0;
212	for (i = 0; i < iocnt; i++) {
213		str->iovOrig[i] = iov[i];
214		str->ioTotal += iov[i].iov_len;
215	}
216	str->iovOrigCount = iocnt;
217	str->iovCur = str->iovOrig;
218	str->iovCurCount = str->iovOrigCount;
219	str->ioDone = 0;
220	return (0);
221}
222
223/* Pull off or truncate lead iovec(s). */
224static void
225consume(evStream *str, size_t bytes) {
226	while (bytes > 0U) {
227		if (bytes < (size_t)str->iovCur->iov_len) {
228			str->iovCur->iov_len -= bytes;
229			str->iovCur->iov_base = (void *)
230				((u_char *)str->iovCur->iov_base + bytes);
231			str->ioDone += bytes;
232			bytes = 0;
233		} else {
234			bytes -= str->iovCur->iov_len;
235			str->ioDone += str->iovCur->iov_len;
236			str->iovCur++;
237			str->iovCurCount--;
238		}
239	}
240}
241
242/* Add a stream to Done list and deselect the FD. */
243static void
244done(evContext opaqueCtx, evStream *str) {
245	evContext_p *ctx = opaqueCtx.opaque;
246
247	if (ctx->strLast != NULL) {
248		str->prevDone = ctx->strLast;
249		ctx->strLast->nextDone = str;
250		ctx->strLast = str;
251	} else {
252		INSIST(ctx->strDone == NULL);
253		ctx->strDone = ctx->strLast = str;
254	}
255	evDeselectFD(opaqueCtx, str->file);
256	str->file.opaque = NULL;
257	/* evDrop() will call evCancelRW() on us. */
258}
259
260/* Dribble out some bytes on the stream.  (Called by evDispatch().) */
261static void
262writable(evContext opaqueCtx, void *uap, int fd, int evmask) {
263	evStream *str = uap;
264	int bytes;
265
266	UNUSED(evmask);
267
268	bytes = writev(fd, str->iovCur, str->iovCurCount);
269	if (bytes > 0) {
270		if ((str->flags & EV_STR_TIMEROK) != 0)
271			evTouchIdleTimer(opaqueCtx, str->timer);
272		consume(str, bytes);
273	} else {
274		if (bytes < 0 && errno != EINTR) {
275			str->ioDone = -1;
276			str->ioErrno = errno;
277		}
278	}
279	if (str->ioDone == -1 || str->ioDone == str->ioTotal)
280		done(opaqueCtx, str);
281}
282
283/* Scoop up some bytes from the stream.  (Called by evDispatch().) */
284static void
285readable(evContext opaqueCtx, void *uap, int fd, int evmask) {
286	evStream *str = uap;
287	int bytes;
288
289	UNUSED(evmask);
290
291	bytes = readv(fd, str->iovCur, str->iovCurCount);
292	if (bytes > 0) {
293		if ((str->flags & EV_STR_TIMEROK) != 0)
294			evTouchIdleTimer(opaqueCtx, str->timer);
295		consume(str, bytes);
296	} else {
297		if (bytes == 0)
298			str->ioDone = 0;
299		else {
300			if (errno != EINTR) {
301				str->ioDone = -1;
302				str->ioErrno = errno;
303			}
304		}
305	}
306	if (str->ioDone <= 0 || str->ioDone == str->ioTotal)
307		done(opaqueCtx, str);
308}
309
310/*! \file */
311