Annotation of src/lib/libc/isc/ev_streams.c, Revision 1.5
1.5 ! christos 1: /* $NetBSD: ev_streams.c,v 1.4 2007/03/30 20:23:03 ghen Exp $ */
1.1 christos 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:
1.2 christos 24: #include <sys/cdefs.h>
25: #if !defined(LINT) && !defined(CODECENTER) && !defined(lint)
26: #ifdef notdef
1.5 ! christos 27: static const char rcsid[] = "Id: ev_streams.c,v 1.5 2005/04/27 04:56:36 sra Exp";
1.2 christos 28: #else
1.5 ! christos 29: __RCSID("$NetBSD: ev_streams.c,v 1.4 2007/03/30 20:23:03 ghen Exp $");
1.2 christos 30: #endif
1.1 christos 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:
1.2 christos 47: #ifndef _LIBC
1.1 christos 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);
1.2 christos 53: #endif
1.1 christos 54:
55: struct iovec
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:
1.2 christos 65: #ifndef _LIBC
1.1 christos 66: int
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
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
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
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
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
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
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
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
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
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: }
1.2 christos 317: #endif
1.3 christos 318:
319: /*! \file */
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