Annotation of src/usr.bin/sndiod/file.c, Revision 1.25
1.25 ! ratchov 1: /* $OpenBSD: file.c,v 1.24 2019/06/28 13:35:03 deraadt Exp $ */
1.1 ratchov 2: /*
3: * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17: /*
18: * non-blocking file i/o module: each file can be read or written (or
19: * both). To achieve non-blocking io, we simply use the poll() syscall
20: * in an event loop and dispatch events to sub-modules.
21: *
22: * the module also provides trivial timeout implementation,
23: * derived from:
24: *
25: * anoncvs@moule.caoua.org:/midish
26: *
27: * midish/timo.c rev 1.18
28: * midish/mdep.c rev 1.71
29: *
30: * A timeout is used to schedule the call of a routine (the callback)
31: * there is a global list of timeouts that is processed inside the
32: * event loop. Timeouts work as follows:
33: *
34: * first the timo structure must be initialized with timo_set()
35: *
36: * then the timeout is scheduled (only once) with timo_add()
37: *
38: * if the timeout expires, the call-back is called; then it can
39: * be scheduled again if needed. It's OK to reschedule it again
40: * from the callback
41: *
42: * the timeout can be aborted with timo_del(), it is OK to try to
43: * abort a timout that has expired
44: *
45: */
46:
47: #include <sys/types.h>
48:
49: #include <errno.h>
50: #include <fcntl.h>
51: #include <poll.h>
52: #include <signal.h>
53: #include <stdio.h>
54: #include <stdlib.h>
55: #include <time.h>
56:
57: #include "file.h"
58: #include "utils.h"
59:
60: #define MAXFDS 100
1.7 ratchov 61: #define TIMER_MSEC 5
1.4 ratchov 62:
63: void timo_update(unsigned int);
64: void timo_init(void);
65: void timo_done(void);
1.13 ratchov 66: void file_process(struct file *, struct pollfd *);
1.1 ratchov 67:
68: struct timespec file_ts;
69: struct file *file_list;
70: struct timo *timo_queue;
71: unsigned int timo_abstime;
72: int file_slowaccept = 0, file_nfds;
73: #ifdef DEBUG
74: long long file_wtime, file_utime;
75: #endif
76:
77: /*
78: * initialise a timeout structure, arguments are callback and argument
79: * that will be passed to the callback
80: */
81: void
82: timo_set(struct timo *o, void (*cb)(void *), void *arg)
83: {
84: o->cb = cb;
85: o->arg = arg;
86: o->set = 0;
87: }
88:
89: /*
90: * schedule the callback in 'delta' 24-th of microseconds. The timeout
91: * must not be already scheduled
92: */
93: void
94: timo_add(struct timo *o, unsigned int delta)
95: {
96: struct timo **i;
97: unsigned int val;
98: int diff;
99:
100: #ifdef DEBUG
101: if (o->set) {
102: log_puts("timo_add: already set\n");
103: panic();
104: }
105: if (delta == 0) {
106: log_puts("timo_add: zero timeout is evil\n");
107: panic();
108: }
109: #endif
110: val = timo_abstime + delta;
111: for (i = &timo_queue; *i != NULL; i = &(*i)->next) {
112: diff = (*i)->val - val;
113: if (diff > 0) {
114: break;
115: }
116: }
117: o->set = 1;
118: o->val = val;
119: o->next = *i;
120: *i = o;
121: }
122:
123: /*
124: * abort a scheduled timeout
125: */
126: void
127: timo_del(struct timo *o)
128: {
129: struct timo **i;
130:
131: for (i = &timo_queue; *i != NULL; i = &(*i)->next) {
132: if (*i == o) {
133: *i = o->next;
134: o->set = 0;
135: return;
136: }
137: }
138: #ifdef DEBUG
139: if (log_level >= 4)
140: log_puts("timo_del: not found\n");
141: #endif
142: }
143:
144: /*
145: * routine to be called by the timer when 'delta' 24-th of microsecond
146: * elapsed. This routine updates time referece used by timeouts and
147: * calls expired timeouts
148: */
149: void
150: timo_update(unsigned int delta)
151: {
152: struct timo *to;
153: int diff;
154:
155: /*
156: * update time reference
157: */
158: timo_abstime += delta;
159:
160: /*
161: * remove from the queue and run expired timeouts
162: */
163: while (timo_queue != NULL) {
164: /*
165: * there is no overflow here because + and - are
166: * modulo 2^32, they are the same for both signed and
167: * unsigned integers
168: */
169: diff = timo_queue->val - timo_abstime;
170: if (diff > 0)
171: break;
172: to = timo_queue;
173: timo_queue = to->next;
174: to->set = 0;
175: to->cb(to->arg);
176: }
177: }
178:
179: /*
180: * initialize timeout queue
181: */
182: void
183: timo_init(void)
184: {
185: timo_queue = NULL;
186: timo_abstime = 0;
187: }
188:
189: /*
190: * destroy timeout queue
191: */
192: void
193: timo_done(void)
194: {
195: #ifdef DEBUG
196: if (timo_queue != NULL) {
197: log_puts("timo_done: timo_queue not empty!\n");
198: panic();
199: }
200: #endif
201: timo_queue = (struct timo *)0xdeadbeef;
202: }
203:
204: #ifdef DEBUG
205: void
206: file_log(struct file *f)
207: {
1.5 ratchov 208: static char *states[] = { "ini", "zom" };
1.1 ratchov 209:
210: log_puts(f->ops->name);
211: if (log_level >= 3) {
212: log_puts("(");
213: log_puts(f->name);
214: log_puts("|");
215: log_puts(states[f->state]);
216: log_puts(")");
217: }
218: }
219: #endif
220:
221: struct file *
222: file_new(struct fileops *ops, void *arg, char *name, unsigned int nfds)
223: {
224: struct file *f;
225:
226: if (file_nfds + nfds > MAXFDS) {
227: #ifdef DEBUG
228: if (log_level >= 1) {
229: log_puts(name);
230: log_puts(": too many polled files\n");
231: }
232: #endif
233: return NULL;
234: }
235: f = xmalloc(sizeof(struct file));
1.10 ratchov 236: f->max_nfds = nfds;
1.25 ! ratchov 237: f->nfds = 0;
1.1 ratchov 238: f->ops = ops;
239: f->arg = arg;
240: f->name = name;
241: f->state = FILE_INIT;
242: f->next = file_list;
243: file_list = f;
244: #ifdef DEBUG
245: if (log_level >= 3) {
246: file_log(f);
247: log_puts(": created\n");
248: }
249: #endif
1.10 ratchov 250: file_nfds += f->max_nfds;
1.1 ratchov 251: return f;
252: }
253:
254: void
255: file_del(struct file *f)
256: {
257: #ifdef DEBUG
258: if (f->state == FILE_ZOMB) {
259: log_puts("bad state in file_del()\n");
260: panic();
261: }
1.19 ratchov 262: #endif
1.10 ratchov 263: file_nfds -= f->max_nfds;
1.1 ratchov 264: f->state = FILE_ZOMB;
265: #ifdef DEBUG
266: if (log_level >= 3) {
267: file_log(f);
268: log_puts(": destroyed\n");
269: }
270: #endif
271: }
272:
1.12 ratchov 273: void
274: file_process(struct file *f, struct pollfd *pfd)
275: {
276: int revents;
277: #ifdef DEBUG
278: struct timespec ts0, ts1;
279: long us;
280: #endif
281:
282: #ifdef DEBUG
283: if (log_level >= 3)
1.22 ratchov 284: clock_gettime(CLOCK_UPTIME, &ts0);
1.12 ratchov 285: #endif
1.19 ratchov 286: revents = (f->state != FILE_ZOMB) ?
1.12 ratchov 287: f->ops->revents(f->arg, pfd) : 0;
288: if ((revents & POLLHUP) && (f->state != FILE_ZOMB))
289: f->ops->hup(f->arg);
290: if ((revents & POLLIN) && (f->state != FILE_ZOMB))
291: f->ops->in(f->arg);
292: if ((revents & POLLOUT) && (f->state != FILE_ZOMB))
293: f->ops->out(f->arg);
294: #ifdef DEBUG
295: if (log_level >= 3) {
1.22 ratchov 296: clock_gettime(CLOCK_UPTIME, &ts1);
1.12 ratchov 297: us = 1000000L * (ts1.tv_sec - ts0.tv_sec);
298: us += (ts1.tv_nsec - ts0.tv_nsec) / 1000;
299: if (log_level >= 4 || us >= 5000) {
300: file_log(f);
301: log_puts(": processed in ");
302: log_putu(us);
303: log_puts("us\n");
304: }
305: }
306: #endif
307: }
308:
1.1 ratchov 309: int
310: file_poll(void)
311: {
1.11 ratchov 312: struct pollfd pfds[MAXFDS], *pfd;
1.1 ratchov 313: struct file *f, **pf;
314: struct timespec ts;
315: #ifdef DEBUG
316: struct timespec sleepts;
1.9 ratchov 317: int i;
1.1 ratchov 318: #endif
319: long long delta_nsec;
1.13 ratchov 320: int nfds, res, timo;
1.12 ratchov 321:
1.1 ratchov 322: /*
323: * cleanup zombies
324: */
325: pf = &file_list;
326: while ((f = *pf) != NULL) {
327: if (f->state == FILE_ZOMB) {
328: *pf = f->next;
329: xfree(f);
330: } else
331: pf = &f->next;
332: }
333:
334: if (file_list == NULL && timo_queue == NULL) {
335: #ifdef DEBUG
336: if (log_level >= 3)
337: log_puts("nothing to do...\n");
338: #endif
339: return 0;
340: }
341:
1.12 ratchov 342: /*
343: * fill pollfd structures
344: */
1.1 ratchov 345: nfds = 0;
346: for (f = file_list; f != NULL; f = f->next) {
1.11 ratchov 347: f->nfds = f->ops->pollfd(f->arg, pfds + nfds);
348: if (f->nfds == 0)
1.1 ratchov 349: continue;
1.11 ratchov 350: nfds += f->nfds;
1.8 ratchov 351: }
1.1 ratchov 352: #ifdef DEBUG
1.8 ratchov 353: if (log_level >= 4) {
354: log_puts("poll:");
1.11 ratchov 355: pfd = pfds;
356: for (f = file_list; f != NULL; f = f->next) {
1.8 ratchov 357: log_puts(" ");
1.11 ratchov 358: log_puts(f->ops->name);
359: log_puts(":");
360: for (i = 0; i < f->nfds; i++) {
361: log_puts(" ");
362: log_putx(pfd->events);
363: pfd++;
1.1 ratchov 364: }
365: }
1.8 ratchov 366: log_puts("\n");
1.1 ratchov 367: }
1.12 ratchov 368: #endif
369:
370: /*
371: * process files that do not rely on poll
372: */
373: for (f = file_list; f != NULL; f = f->next) {
374: if (f->nfds > 0)
375: continue;
376: file_process(f, NULL);
377: }
378:
379: /*
1.23 ratchov 380: * Sleep. Calculate the number of milliseconds poll(2) must
381: * wait before the timo_update() needs to be called. If there are
1.15 ratchov 382: * no timeouts scheduled, then call poll(2) with infinite
383: * timeout (i.e -1).
1.12 ratchov 384: */
385: #ifdef DEBUG
1.22 ratchov 386: clock_gettime(CLOCK_UPTIME, &sleepts);
1.1 ratchov 387: file_utime += 1000000000LL * (sleepts.tv_sec - file_ts.tv_sec);
388: file_utime += sleepts.tv_nsec - file_ts.tv_nsec;
389: #endif
1.13 ratchov 390: if (timo_queue != NULL) {
391: timo = ((int)timo_queue->val - (int)timo_abstime) / 1000;
392: if (timo < TIMER_MSEC)
393: timo = TIMER_MSEC;
394: } else
1.15 ratchov 395: timo = -1;
1.21 ratchov 396: log_flush();
1.13 ratchov 397: res = poll(pfds, nfds, timo);
1.24 deraadt 398: if (res == -1) {
1.18 ratchov 399: if (errno != EINTR) {
400: log_puts("poll failed");
401: panic();
402: }
1.12 ratchov 403: return 1;
404: }
405:
406: /*
407: * run timeouts
408: */
1.22 ratchov 409: clock_gettime(CLOCK_UPTIME, &ts);
1.1 ratchov 410: #ifdef DEBUG
411: file_wtime += 1000000000LL * (ts.tv_sec - sleepts.tv_sec);
412: file_wtime += ts.tv_nsec - sleepts.tv_nsec;
413: #endif
1.16 ratchov 414: if (timo_queue) {
415: delta_nsec = 1000000000LL * (ts.tv_sec - file_ts.tv_sec);
416: delta_nsec += ts.tv_nsec - file_ts.tv_nsec;
1.20 ratchov 417: if (delta_nsec >= 0 && delta_nsec < 60000000000LL)
1.16 ratchov 418: timo_update(delta_nsec / 1000);
419: else {
420: if (log_level >= 2)
421: log_puts("out-of-bounds clock delta\n");
422: }
1.1 ratchov 423: }
1.19 ratchov 424: file_ts = ts;
1.12 ratchov 425:
426: /*
427: * process files that rely on poll
428: */
1.11 ratchov 429: pfd = pfds;
1.1 ratchov 430: for (f = file_list; f != NULL; f = f->next) {
1.12 ratchov 431: if (f->nfds == 0)
1.1 ratchov 432: continue;
1.12 ratchov 433: file_process(f, pfd);
1.11 ratchov 434: pfd += f->nfds;
1.1 ratchov 435: }
436: return 1;
437: }
438:
439: void
440: filelist_init(void)
441: {
442: sigset_t set;
443:
1.24 deraadt 444: if (clock_gettime(CLOCK_UPTIME, &file_ts) == -1) {
1.22 ratchov 445: log_puts("filelist_init: CLOCK_UPTIME unsupported\n");
1.18 ratchov 446: panic();
447: }
1.1 ratchov 448: sigemptyset(&set);
1.18 ratchov 449: sigaddset(&set, SIGPIPE);
450: sigprocmask(SIG_BLOCK, &set, NULL);
1.1 ratchov 451: file_list = NULL;
452: log_sync = 0;
453: timo_init();
454: }
455:
456: void
457: filelist_done(void)
458: {
459: #ifdef DEBUG
460: struct file *f;
461:
462: if (file_list != NULL) {
463: for (f = file_list; f != NULL; f = f->next) {
464: file_log(f);
465: log_puts(" not closed\n");
466: }
467: panic();
468: }
469: log_sync = 1;
470: log_flush();
471: #endif
472: timo_done();
473: }
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