source: branches/samba-3.3.x/source/lib/events.c@ 635

Last change on this file since 635 was 578, checked in by Herwig Bauernfeind, 14 years ago

Update Samba 3.3 to 3.3.15 (security update)
File size: 9.2 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Timed event library.
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Volker Lendecke 2005
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22
23struct timed_event {
24 struct timed_event *next, *prev;
25 struct event_context *event_ctx;
26 struct timeval when;
27 const char *event_name;
28 void (*handler)(struct event_context *event_ctx,
29 struct timed_event *te,
30 struct timeval now,
31 void *private_data);
32 void *private_data;
33};
34
35struct fd_event {
36 struct fd_event *prev, *next;
37 struct event_context *event_ctx;
38 int fd;
39 uint16_t flags; /* see EVENT_FD_* flags */
40 void (*handler)(struct event_context *event_ctx,
41 struct fd_event *event,
42 uint16 flags,
43 void *private_data);
44 void *private_data;
45};
46
47struct event_context {
48 struct timed_event *timed_events;
49 struct fd_event *fd_events;
50};
51
52static int timed_event_destructor(struct timed_event *te)
53{
54 DEBUG(10, ("Destroying timed event %lx \"%s\"\n", (unsigned long)te,
55 te->event_name));
56 if (te->event_ctx != NULL) {
57 DLIST_REMOVE(te->event_ctx->timed_events, te);
58 }
59 return 0;
60}
61
62/****************************************************************************
63 Add te by time.
64****************************************************************************/
65
66static void add_event_by_time(struct timed_event *te)
67{
68 struct event_context *ctx = te->event_ctx;
69 struct timed_event *last_te, *cur_te;
70
71 /* Keep the list ordered by time. We must preserve this. */
72 last_te = NULL;
73 for (cur_te = ctx->timed_events; cur_te; cur_te = cur_te->next) {
74 /* if the new event comes before the current one break */
75 if (!timeval_is_zero(&cur_te->when) &&
76 timeval_compare(&te->when, &cur_te->when) < 0) {
77 break;
78 }
79 last_te = cur_te;
80 }
81
82 DLIST_ADD_AFTER(ctx->timed_events, te, last_te);
83}
84
85/****************************************************************************
86 Schedule a function for future calling, cancel with TALLOC_FREE().
87 It's the responsibility of the handler to call TALLOC_FREE() on the event
88 handed to it.
89****************************************************************************/
90
91struct timed_event *_event_add_timed(struct event_context *event_ctx,
92 TALLOC_CTX *mem_ctx,
93 struct timeval when,
94 const char *event_name,
95 void (*handler)(struct event_context *event_ctx,
96 struct timed_event *te,
97 struct timeval now,
98 void *private_data),
99 void *private_data)
100{
101 struct timed_event *te;
102
103 te = TALLOC_P(mem_ctx, struct timed_event);
104 if (te == NULL) {
105 DEBUG(0, ("talloc failed\n"));
106 return NULL;
107 }
108
109 te->event_ctx = event_ctx;
110 te->when = when;
111 te->event_name = event_name;
112 te->handler = handler;
113 te->private_data = private_data;
114
115 add_event_by_time(te);
116
117 talloc_set_destructor(te, timed_event_destructor);
118
119 DEBUG(10, ("Added timed event \"%s\": %lx\n", event_name,
120 (unsigned long)te));
121 return te;
122}
123
124static int fd_event_destructor(struct fd_event *fde)
125{
126 if (fde->event_ctx != NULL) {
127 DLIST_REMOVE(fde->event_ctx->fd_events, fde);
128 }
129 return 0;
130}
131
132struct fd_event *event_add_fd(struct event_context *event_ctx,
133 TALLOC_CTX *mem_ctx,
134 int fd, uint16_t flags,
135 void (*handler)(struct event_context *event_ctx,
136 struct fd_event *event,
137 uint16 flags,
138 void *private_data),
139 void *private_data)
140{
141 struct fd_event *fde;
142
143 if (fd < 0 || fd >= FD_SETSIZE) {
144 errno = EBADF;
145 return NULL;
146 }
147
148 if (!(fde = TALLOC_P(mem_ctx, struct fd_event))) {
149 return NULL;
150 }
151
152 fde->event_ctx = event_ctx;
153 fde->fd = fd;
154 fde->flags = flags;
155 fde->handler = handler;
156 fde->private_data = private_data;
157
158 DLIST_ADD(event_ctx->fd_events, fde);
159
160 talloc_set_destructor(fde, fd_event_destructor);
161 return fde;
162}
163
164void event_fd_set_writeable(struct fd_event *fde)
165{
166 fde->flags |= EVENT_FD_WRITE;
167}
168
169void event_fd_set_not_writeable(struct fd_event *fde)
170{
171 fde->flags &= ~EVENT_FD_WRITE;
172}
173
174void event_fd_set_readable(struct fd_event *fde)
175{
176 fde->flags |= EVENT_FD_READ;
177}
178
179void event_fd_set_not_readable(struct fd_event *fde)
180{
181 fde->flags &= ~EVENT_FD_READ;
182}
183
184/*
185 * Return if there's something in the queue
186 */
187
188bool event_add_to_select_args(struct event_context *event_ctx,
189 const struct timeval *now,
190 fd_set *read_fds, fd_set *write_fds,
191 struct timeval *timeout, int *maxfd)
192{
193 struct fd_event *fde;
194 struct timeval diff;
195 bool ret = False;
196
197 for (fde = event_ctx->fd_events; fde; fde = fde->next) {
198 if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
199 /* We ignore here, as it shouldn't be
200 possible to add an invalid fde->fd
201 but we don't want FD_SET to see an
202 invalid fd. */
203 continue;
204 }
205
206 if (fde->flags & EVENT_FD_READ) {
207 FD_SET(fde->fd, read_fds);
208 ret = True;
209 }
210 if (fde->flags & EVENT_FD_WRITE) {
211 FD_SET(fde->fd, write_fds);
212 ret = True;
213 }
214
215 if ((fde->flags & (EVENT_FD_READ|EVENT_FD_WRITE))
216 && (fde->fd > *maxfd)) {
217 *maxfd = fde->fd;
218 }
219 }
220
221 if (event_ctx->timed_events == NULL) {
222 return ret;
223 }
224
225 diff = timeval_until(now, &event_ctx->timed_events->when);
226 *timeout = timeval_min(timeout, &diff);
227
228 return True;
229}
230
231bool run_events(struct event_context *event_ctx,
232 int selrtn, fd_set *read_fds, fd_set *write_fds)
233{
234 struct fd_event *fde;
235 struct timeval now;
236
237 GetTimeOfDay(&now);
238
239 if ((event_ctx->timed_events != NULL)
240 && (timeval_compare(&now, &event_ctx->timed_events->when) >= 0)) {
241
242 DEBUG(10, ("Running event \"%s\" %lx\n",
243 event_ctx->timed_events->event_name,
244 (unsigned long)event_ctx->timed_events));
245
246 event_ctx->timed_events->handler(
247 event_ctx,
248 event_ctx->timed_events, now,
249 event_ctx->timed_events->private_data);
250
251 return true;
252 }
253
254 if (selrtn == 0) {
255 /*
256 * No fd ready
257 */
258 return false;
259 }
260
261 for (fde = event_ctx->fd_events; fde; fde = fde->next) {
262 uint16 flags = 0;
263
264 if (FD_ISSET(fde->fd, read_fds)) flags |= EVENT_FD_READ;
265 if (FD_ISSET(fde->fd, write_fds)) flags |= EVENT_FD_WRITE;
266
267 if (flags & fde->flags) {
268 fde->handler(event_ctx, fde, flags, fde->private_data);
269 return true;
270 }
271 }
272
273 return false;
274}
275
276
277struct timeval *get_timed_events_timeout(struct event_context *event_ctx,
278 struct timeval *to_ret)
279{
280 struct timeval now;
281
282 if (event_ctx->timed_events == NULL) {
283 return NULL;
284 }
285
286 now = timeval_current();
287 *to_ret = timeval_until(&now, &event_ctx->timed_events->when);
288
289 DEBUG(10, ("timed_events_timeout: %d/%d\n", (int)to_ret->tv_sec,
290 (int)to_ret->tv_usec));
291
292 return to_ret;
293}
294
295int event_loop_once(struct event_context *ev)
296{
297 struct timeval now, to;
298 fd_set r_fds, w_fds;
299 int maxfd = 0;
300 int ret;
301
302 FD_ZERO(&r_fds);
303 FD_ZERO(&w_fds);
304
305 to.tv_sec = 9999; /* Max timeout */
306 to.tv_usec = 0;
307
308 GetTimeOfDay(&now);
309
310 if (!event_add_to_select_args(ev, &now, &r_fds, &w_fds, &to, &maxfd)) {
311 return -1;
312 }
313
314 if (timeval_is_zero(&to)) {
315 run_events(ev, 0, NULL, NULL);
316 return 0;
317 }
318
319 ret = sys_select(maxfd+1, &r_fds, &w_fds, NULL, &to);
320
321 if (ret == -1 && errno != EINTR) {
322 return -1;
323 }
324
325 run_events(ev, ret, &r_fds, &w_fds);
326 return 0;
327}
328
329static int event_context_destructor(struct event_context *ev)
330{
331 while (ev->fd_events != NULL) {
332 ev->fd_events->event_ctx = NULL;
333 DLIST_REMOVE(ev->fd_events, ev->fd_events);
334 }
335 while (ev->timed_events != NULL) {
336 ev->timed_events->event_ctx = NULL;
337 DLIST_REMOVE(ev->timed_events, ev->timed_events);
338 }
339 return 0;
340}
341
342void event_context_reinit(struct event_context *ev)
343{
344 event_context_destructor(ev);
345 return;
346}
347
348struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
349{
350 struct event_context *result;
351
352 result = TALLOC_ZERO_P(mem_ctx, struct event_context);
353 if (result == NULL) {
354 return NULL;
355 }
356
357 talloc_set_destructor(result, event_context_destructor);
358 return result;
359}
360
361void dump_event_list(struct event_context *event_ctx)
362{
363 struct timed_event *te;
364 struct fd_event *fe;
365 struct timeval evt, now;
366
367 if (!event_ctx) {
368 return;
369 }
370
371 now = timeval_current();
372
373 DEBUG(10,("dump_event_list:\n"));
374
375 for (te = event_ctx->timed_events; te; te = te->next) {
376
377 evt = timeval_until(&now, &te->when);
378
379 DEBUGADD(10,("Timed Event \"%s\" %lx handled in %d seconds (at %s)\n",
380 te->event_name,
381 (unsigned long)te,
382 (int)evt.tv_sec,
383 http_timestring(te->when.tv_sec)));
384 }
385
386 for (fe = event_ctx->fd_events; fe; fe = fe->next) {
387
388 DEBUGADD(10,("FD Event %d %lx, flags: 0x%04x\n",
389 fe->fd,
390 (unsigned long)fe,
391 fe->flags));
392 }
393}
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