Annotation of sys/kern/kern_event.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: kern_event.c,v 1.31 2007/05/30 02:24:59 tedu Exp $ */
2:
3: /*-
4: * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26: * SUCH DAMAGE.
27: *
28: * $FreeBSD: src/sys/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $
29: */
30:
31: #include <sys/param.h>
32: #include <sys/systm.h>
33: #include <sys/kernel.h>
34: #include <sys/proc.h>
35: #include <sys/malloc.h>
36: #include <sys/unistd.h>
37: #include <sys/file.h>
38: #include <sys/filedesc.h>
39: #include <sys/fcntl.h>
40: #include <sys/selinfo.h>
41: #include <sys/queue.h>
42: #include <sys/event.h>
43: #include <sys/eventvar.h>
44: #include <sys/pool.h>
45: #include <sys/protosw.h>
46: #include <sys/socket.h>
47: #include <sys/socketvar.h>
48: #include <sys/stat.h>
49: #include <sys/uio.h>
50: #include <sys/mount.h>
51: #include <sys/poll.h>
52: #include <sys/syscallargs.h>
53: #include <sys/timeout.h>
54:
55: int kqueue_scan(struct file *fp, int maxevents,
56: struct kevent *ulistp, const struct timespec *timeout,
57: struct proc *p, int *retval);
58:
59: int kqueue_read(struct file *fp, off_t *poff, struct uio *uio,
60: struct ucred *cred);
61: int kqueue_write(struct file *fp, off_t *poff, struct uio *uio,
62: struct ucred *cred);
63: int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
64: struct proc *p);
65: int kqueue_poll(struct file *fp, int events, struct proc *p);
66: int kqueue_kqfilter(struct file *fp, struct knote *kn);
67: int kqueue_stat(struct file *fp, struct stat *st, struct proc *p);
68: int kqueue_close(struct file *fp, struct proc *p);
69: void kqueue_wakeup(struct kqueue *kq);
70:
71: struct fileops kqueueops = {
72: kqueue_read,
73: kqueue_write,
74: kqueue_ioctl,
75: kqueue_poll,
76: kqueue_kqfilter,
77: kqueue_stat,
78: kqueue_close
79: };
80:
81: void knote_attach(struct knote *kn, struct filedesc *fdp);
82: void knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp);
83: void knote_enqueue(struct knote *kn);
84: void knote_dequeue(struct knote *kn);
85: #define knote_alloc() ((struct knote *)pool_get(&knote_pool, PR_WAITOK))
86: #define knote_free(kn) pool_put(&knote_pool, (kn))
87:
88: void filt_kqdetach(struct knote *kn);
89: int filt_kqueue(struct knote *kn, long hint);
90: int filt_procattach(struct knote *kn);
91: void filt_procdetach(struct knote *kn);
92: int filt_proc(struct knote *kn, long hint);
93: int filt_fileattach(struct knote *kn);
94: void filt_timerexpire(void *knx);
95: int filt_timerattach(struct knote *kn);
96: void filt_timerdetach(struct knote *kn);
97: int filt_timer(struct knote *kn, long hint);
98:
99: struct filterops kqread_filtops =
100: { 1, NULL, filt_kqdetach, filt_kqueue };
101: struct filterops proc_filtops =
102: { 0, filt_procattach, filt_procdetach, filt_proc };
103: struct filterops file_filtops =
104: { 1, filt_fileattach, NULL, NULL };
105: struct filterops timer_filtops =
106: { 0, filt_timerattach, filt_timerdetach, filt_timer };
107:
108: struct pool knote_pool;
109: struct pool kqueue_pool;
110: int kq_ntimeouts = 0;
111: int kq_timeoutmax = (4 * 1024);
112:
113: #define KNOTE_ACTIVATE(kn) do { \
114: kn->kn_status |= KN_ACTIVE; \
115: if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
116: knote_enqueue(kn); \
117: } while(0)
118:
119: #define KN_HASHSIZE 64 /* XXX should be tunable */
120: #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
121:
122: extern struct filterops sig_filtops;
123: #ifdef notyet
124: extern struct filterops aio_filtops;
125: #endif
126:
127: /*
128: * Table for for all system-defined filters.
129: */
130: struct filterops *sysfilt_ops[] = {
131: &file_filtops, /* EVFILT_READ */
132: &file_filtops, /* EVFILT_WRITE */
133: NULL, /*&aio_filtops,*/ /* EVFILT_AIO */
134: &file_filtops, /* EVFILT_VNODE */
135: &proc_filtops, /* EVFILT_PROC */
136: &sig_filtops, /* EVFILT_SIGNAL */
137: &timer_filtops, /* EVFILT_TIMER */
138: };
139:
140: void kqueue_init(void);
141:
142: void
143: kqueue_init(void)
144: {
145:
146: pool_init(&kqueue_pool, sizeof(struct kqueue), 0, 0, 0, "kqueuepl",
147: &pool_allocator_nointr);
148: pool_init(&knote_pool, sizeof(struct knote), 0, 0, 0, "knotepl",
149: &pool_allocator_nointr);
150: }
151:
152: int
153: filt_fileattach(struct knote *kn)
154: {
155: struct file *fp = kn->kn_fp;
156:
157: return ((*fp->f_ops->fo_kqfilter)(fp, kn));
158: }
159:
160: int
161: kqueue_kqfilter(struct file *fp, struct knote *kn)
162: {
163: struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
164:
165: if (kn->kn_filter != EVFILT_READ)
166: return (1);
167:
168: kn->kn_fop = &kqread_filtops;
169: SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
170: return (0);
171: }
172:
173: void
174: filt_kqdetach(struct knote *kn)
175: {
176: struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
177:
178: SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext);
179: }
180:
181: /*ARGSUSED*/
182: int
183: filt_kqueue(struct knote *kn, long hint)
184: {
185: struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
186:
187: kn->kn_data = kq->kq_count;
188: return (kn->kn_data > 0);
189: }
190:
191: int
192: filt_procattach(struct knote *kn)
193: {
194: struct proc *p;
195:
196: p = pfind(kn->kn_id);
197: if (p == NULL)
198: return (ESRCH);
199:
200: /*
201: * Fail if it's not owned by you, or the last exec gave us
202: * setuid/setgid privs (unless you're root).
203: */
204: if ((p->p_cred->p_ruid != curproc->p_cred->p_ruid ||
205: (p->p_flag & P_SUGID)) && suser(curproc, 0) != 0)
206: return (EACCES);
207:
208: kn->kn_ptr.p_proc = p;
209: kn->kn_flags |= EV_CLEAR; /* automatically set */
210:
211: /*
212: * internal flag indicating registration done by kernel
213: */
214: if (kn->kn_flags & EV_FLAG1) {
215: kn->kn_data = kn->kn_sdata; /* ppid */
216: kn->kn_fflags = NOTE_CHILD;
217: kn->kn_flags &= ~EV_FLAG1;
218: }
219:
220: /* XXX lock the proc here while adding to the list? */
221: SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
222:
223: return (0);
224: }
225:
226: /*
227: * The knote may be attached to a different process, which may exit,
228: * leaving nothing for the knote to be attached to. So when the process
229: * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
230: * it will be deleted when read out. However, as part of the knote deletion,
231: * this routine is called, so a check is needed to avoid actually performing
232: * a detach, because the original process does not exist any more.
233: */
234: void
235: filt_procdetach(struct knote *kn)
236: {
237: struct proc *p = kn->kn_ptr.p_proc;
238:
239: if (kn->kn_status & KN_DETACHED)
240: return;
241:
242: /* XXX locking? this might modify another process. */
243: SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
244: }
245:
246: int
247: filt_proc(struct knote *kn, long hint)
248: {
249: u_int event;
250:
251: /*
252: * mask off extra data
253: */
254: event = (u_int)hint & NOTE_PCTRLMASK;
255:
256: /*
257: * if the user is interested in this event, record it.
258: */
259: if (kn->kn_sfflags & event)
260: kn->kn_fflags |= event;
261:
262: /*
263: * process is gone, so flag the event as finished.
264: */
265: if (event == NOTE_EXIT) {
266: kn->kn_status |= KN_DETACHED;
267: kn->kn_flags |= (EV_EOF | EV_ONESHOT);
268: return (1);
269: }
270:
271: /*
272: * process forked, and user wants to track the new process,
273: * so attach a new knote to it, and immediately report an
274: * event with the parent's pid.
275: */
276: if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
277: struct kevent kev;
278: int error;
279:
280: /*
281: * register knote with new process.
282: */
283: kev.ident = hint & NOTE_PDATAMASK; /* pid */
284: kev.filter = kn->kn_filter;
285: kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
286: kev.fflags = kn->kn_sfflags;
287: kev.data = kn->kn_id; /* parent */
288: kev.udata = kn->kn_kevent.udata; /* preserve udata */
289: error = kqueue_register(kn->kn_kq, &kev, NULL);
290: if (error)
291: kn->kn_fflags |= NOTE_TRACKERR;
292: }
293:
294: return (kn->kn_fflags != 0);
295: }
296:
297: void
298: filt_timerexpire(void *knx)
299: {
300: struct knote *kn = knx;
301: struct timeval tv;
302: int tticks;
303:
304: kn->kn_data++;
305: KNOTE_ACTIVATE(kn);
306:
307: if ((kn->kn_flags & EV_ONESHOT) == 0) {
308: tv.tv_sec = kn->kn_sdata / 1000;
309: tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
310: tticks = tvtohz(&tv);
311: timeout_add((struct timeout *)kn->kn_hook, tticks);
312: }
313: }
314:
315:
316: /*
317: * data contains amount of time to sleep, in milliseconds
318: */
319: int
320: filt_timerattach(struct knote *kn)
321: {
322: struct timeout *to;
323: struct timeval tv;
324: int tticks;
325:
326: if (kq_ntimeouts > kq_timeoutmax)
327: return (ENOMEM);
328: kq_ntimeouts++;
329:
330: tv.tv_sec = kn->kn_sdata / 1000;
331: tv.tv_usec = (kn->kn_sdata % 1000) * 1000;
332: tticks = tvtohz(&tv);
333:
334: kn->kn_flags |= EV_CLEAR; /* automatically set */
335: MALLOC(to, struct timeout *, sizeof(*to), M_KEVENT, 0);
336: timeout_set(to, filt_timerexpire, kn);
337: timeout_add(to, tticks);
338: kn->kn_hook = to;
339:
340: return (0);
341: }
342:
343: void
344: filt_timerdetach(struct knote *kn)
345: {
346: struct timeout *to;
347:
348: to = (struct timeout *)kn->kn_hook;
349: timeout_del(to);
350: FREE(to, M_KEVENT);
351: kq_ntimeouts--;
352: }
353:
354: int
355: filt_timer(struct knote *kn, long hint)
356: {
357: return (kn->kn_data != 0);
358: }
359:
360:
361: /*
362: * filt_seltrue:
363: *
364: * This filter "event" routine simulates seltrue().
365: */
366: int
367: filt_seltrue(struct knote *kn, long hint)
368: {
369:
370: /*
371: * We don't know how much data can be read/written,
372: * but we know that it *can* be. This is about as
373: * good as select/poll does as well.
374: */
375: kn->kn_data = 0;
376: return (1);
377: }
378:
379: int
380: sys_kqueue(struct proc *p, void *v, register_t *retval)
381: {
382: struct filedesc *fdp = p->p_fd;
383: struct kqueue *kq;
384: struct file *fp;
385: int fd, error;
386:
387: error = falloc(p, &fp, &fd);
388: if (error)
389: return (error);
390: fp->f_flag = FREAD | FWRITE;
391: fp->f_type = DTYPE_KQUEUE;
392: fp->f_ops = &kqueueops;
393: kq = pool_get(&kqueue_pool, PR_WAITOK);
394: bzero(kq, sizeof(*kq));
395: TAILQ_INIT(&kq->kq_head);
396: fp->f_data = (caddr_t)kq;
397: *retval = fd;
398: if (fdp->fd_knlistsize < 0)
399: fdp->fd_knlistsize = 0; /* this process has a kq */
400: kq->kq_fdp = fdp;
401: FILE_SET_MATURE(fp);
402: return (0);
403: }
404:
405: int
406: sys_kevent(struct proc *p, void *v, register_t *retval)
407: {
408: struct filedesc* fdp = p->p_fd;
409: struct sys_kevent_args /* {
410: syscallarg(int) fd;
411: syscallarg(const struct kevent *) changelist;
412: syscallarg(int) nchanges;
413: syscallarg(struct kevent *) eventlist;
414: syscallarg(int) nevents;
415: syscallarg(const struct timespec *) timeout;
416: } */ *uap = v;
417: struct kevent *kevp;
418: struct kqueue *kq;
419: struct file *fp;
420: struct timespec ts;
421: int i, n, nerrors, error;
422:
423: if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL ||
424: (fp->f_type != DTYPE_KQUEUE))
425: return (EBADF);
426:
427: FREF(fp);
428:
429: if (SCARG(uap, timeout) != NULL) {
430: error = copyin(SCARG(uap, timeout), &ts, sizeof(ts));
431: if (error)
432: goto done;
433: SCARG(uap, timeout) = &ts;
434: }
435:
436: kq = (struct kqueue *)fp->f_data;
437: nerrors = 0;
438:
439: while (SCARG(uap, nchanges) > 0) {
440: n = SCARG(uap, nchanges) > KQ_NEVENTS
441: ? KQ_NEVENTS : SCARG(uap, nchanges);
442: error = copyin(SCARG(uap, changelist), kq->kq_kev,
443: n * sizeof(struct kevent));
444: if (error)
445: goto done;
446: for (i = 0; i < n; i++) {
447: kevp = &kq->kq_kev[i];
448: kevp->flags &= ~EV_SYSFLAGS;
449: error = kqueue_register(kq, kevp, p);
450: if (error) {
451: if (SCARG(uap, nevents) != 0) {
452: kevp->flags = EV_ERROR;
453: kevp->data = error;
454: (void) copyout((caddr_t)kevp,
455: (caddr_t)SCARG(uap, eventlist),
456: sizeof(*kevp));
457: SCARG(uap, eventlist)++;
458: SCARG(uap, nevents)--;
459: nerrors++;
460: } else {
461: goto done;
462: }
463: }
464: }
465: SCARG(uap, nchanges) -= n;
466: SCARG(uap, changelist) += n;
467: }
468: if (nerrors) {
469: *retval = nerrors;
470: error = 0;
471: goto done;
472: }
473:
474: error = kqueue_scan(fp, SCARG(uap, nevents), SCARG(uap, eventlist),
475: SCARG(uap, timeout), p, &n);
476: *retval = n;
477: done:
478: FRELE(fp);
479: return (error);
480: }
481:
482: int
483: kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
484: {
485: struct filedesc *fdp = kq->kq_fdp;
486: struct filterops *fops = NULL;
487: struct file *fp = NULL;
488: struct knote *kn = NULL;
489: int s, error = 0;
490:
491: if (kev->filter < 0) {
492: if (kev->filter + EVFILT_SYSCOUNT < 0)
493: return (EINVAL);
494: fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
495: }
496:
497: if (fops == NULL) {
498: /*
499: * XXX
500: * filter attach routine is responsible for ensuring that
501: * the identifier can be attached to it.
502: */
503: return (EINVAL);
504: }
505:
506: if (fops->f_isfd) {
507: /* validate descriptor */
508: if ((fp = fd_getfile(fdp, kev->ident)) == NULL)
509: return (EBADF);
510: FREF(fp);
511: fp->f_count++;
512:
513: if (kev->ident < fdp->fd_knlistsize) {
514: SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
515: if (kq == kn->kn_kq &&
516: kev->filter == kn->kn_filter)
517: break;
518: }
519: } else {
520: if (fdp->fd_knhashmask != 0) {
521: struct klist *list;
522:
523: list = &fdp->fd_knhash[
524: KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
525: SLIST_FOREACH(kn, list, kn_link)
526: if (kev->ident == kn->kn_id &&
527: kq == kn->kn_kq &&
528: kev->filter == kn->kn_filter)
529: break;
530: }
531: }
532:
533: if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
534: error = ENOENT;
535: goto done;
536: }
537:
538: /*
539: * kn now contains the matching knote, or NULL if no match
540: */
541: if (kev->flags & EV_ADD) {
542:
543: if (kn == NULL) {
544: kn = knote_alloc();
545: if (kn == NULL) {
546: error = ENOMEM;
547: goto done;
548: }
549: kn->kn_fp = fp;
550: kn->kn_kq = kq;
551: kn->kn_fop = fops;
552:
553: /*
554: * apply reference count to knote structure, and
555: * do not release it at the end of this routine.
556: */
557: if (fp != NULL)
558: FRELE(fp);
559: fp = NULL;
560:
561: kn->kn_sfflags = kev->fflags;
562: kn->kn_sdata = kev->data;
563: kev->fflags = 0;
564: kev->data = 0;
565: kn->kn_kevent = *kev;
566:
567: knote_attach(kn, fdp);
568: if ((error = fops->f_attach(kn)) != 0) {
569: knote_drop(kn, p, fdp);
570: goto done;
571: }
572: } else {
573: /*
574: * The user may change some filter values after the
575: * initial EV_ADD, but doing so will not reset any
576: * filters which have already been triggered.
577: */
578: kn->kn_sfflags = kev->fflags;
579: kn->kn_sdata = kev->data;
580: kn->kn_kevent.udata = kev->udata;
581: }
582:
583: s = splhigh();
584: if (kn->kn_fop->f_event(kn, 0))
585: KNOTE_ACTIVATE(kn);
586: splx(s);
587:
588: } else if (kev->flags & EV_DELETE) {
589: kn->kn_fop->f_detach(kn);
590: knote_drop(kn, p, p->p_fd);
591: goto done;
592: }
593:
594: if ((kev->flags & EV_DISABLE) &&
595: ((kn->kn_status & KN_DISABLED) == 0)) {
596: s = splhigh();
597: kn->kn_status |= KN_DISABLED;
598: splx(s);
599: }
600:
601: if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
602: s = splhigh();
603: kn->kn_status &= ~KN_DISABLED;
604: if ((kn->kn_status & KN_ACTIVE) &&
605: ((kn->kn_status & KN_QUEUED) == 0))
606: knote_enqueue(kn);
607: splx(s);
608: }
609:
610: done:
611: if (fp != NULL)
612: closef(fp, p);
613: return (error);
614: }
615:
616: int
617: kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
618: const struct timespec *tsp, struct proc *p, int *retval)
619: {
620: struct kqueue *kq = (struct kqueue *)fp->f_data;
621: struct kevent *kevp;
622: struct timeval atv, rtv, ttv;
623: struct knote *kn, marker;
624: int s, count, timeout, nkev = 0, error = 0;
625:
626: count = maxevents;
627: if (count == 0)
628: goto done;
629:
630: if (tsp != NULL) {
631: TIMESPEC_TO_TIMEVAL(&atv, tsp);
632: if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) {
633: /* No timeout, just poll */
634: timeout = -1;
635: goto start;
636: }
637: if (itimerfix(&atv)) {
638: error = EINVAL;
639: goto done;
640: }
641:
642: timeout = atv.tv_sec > 24 * 60 * 60 ?
643: 24 * 60 * 60 * hz : tvtohz(&atv);
644:
645: getmicrouptime(&rtv);
646: timeradd(&atv, &rtv, &atv);
647: } else {
648: atv.tv_sec = 0;
649: atv.tv_usec = 0;
650: timeout = 0;
651: }
652: goto start;
653:
654: retry:
655: if (atv.tv_sec || atv.tv_usec) {
656: getmicrouptime(&rtv);
657: if (timercmp(&rtv, &atv, >=))
658: goto done;
659: ttv = atv;
660: timersub(&ttv, &rtv, &ttv);
661: timeout = ttv.tv_sec > 24 * 60 * 60 ?
662: 24 * 60 * 60 * hz : tvtohz(&ttv);
663: }
664:
665: start:
666: kevp = kq->kq_kev;
667: s = splhigh();
668: if (kq->kq_count == 0) {
669: if (timeout < 0) {
670: error = EWOULDBLOCK;
671: } else {
672: kq->kq_state |= KQ_SLEEP;
673: error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout);
674: }
675: splx(s);
676: if (error == 0)
677: goto retry;
678: /* don't restart after signals... */
679: if (error == ERESTART)
680: error = EINTR;
681: else if (error == EWOULDBLOCK)
682: error = 0;
683: goto done;
684: }
685:
686: TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
687: while (count) {
688: kn = TAILQ_FIRST(&kq->kq_head);
689: TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
690: if (kn == &marker) {
691: splx(s);
692: if (count == maxevents)
693: goto retry;
694: goto done;
695: }
696: if (kn->kn_status & KN_DISABLED) {
697: kn->kn_status &= ~KN_QUEUED;
698: kq->kq_count--;
699: continue;
700: }
701: if ((kn->kn_flags & EV_ONESHOT) == 0 &&
702: kn->kn_fop->f_event(kn, 0) == 0) {
703: kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
704: kq->kq_count--;
705: continue;
706: }
707: *kevp = kn->kn_kevent;
708: kevp++;
709: nkev++;
710: if (kn->kn_flags & EV_ONESHOT) {
711: kn->kn_status &= ~KN_QUEUED;
712: kq->kq_count--;
713: splx(s);
714: kn->kn_fop->f_detach(kn);
715: knote_drop(kn, p, p->p_fd);
716: s = splhigh();
717: } else if (kn->kn_flags & EV_CLEAR) {
718: kn->kn_data = 0;
719: kn->kn_fflags = 0;
720: kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
721: kq->kq_count--;
722: } else {
723: TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
724: }
725: count--;
726: if (nkev == KQ_NEVENTS) {
727: splx(s);
728: error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
729: sizeof(struct kevent) * nkev);
730: ulistp += nkev;
731: nkev = 0;
732: kevp = kq->kq_kev;
733: s = splhigh();
734: if (error)
735: break;
736: }
737: }
738: TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
739: splx(s);
740: done:
741: if (nkev != 0)
742: error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
743: sizeof(struct kevent) * nkev);
744: *retval = maxevents - count;
745: return (error);
746: }
747:
748: /*
749: * XXX
750: * This could be expanded to call kqueue_scan, if desired.
751: */
752: /*ARGSUSED*/
753: int
754: kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
755: {
756: return (ENXIO);
757: }
758:
759: /*ARGSUSED*/
760: int
761: kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
762:
763: {
764: return (ENXIO);
765: }
766:
767: /*ARGSUSED*/
768: int
769: kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
770: {
771: return (ENOTTY);
772: }
773:
774: /*ARGSUSED*/
775: int
776: kqueue_poll(struct file *fp, int events, struct proc *p)
777: {
778: struct kqueue *kq = (struct kqueue *)fp->f_data;
779: int revents = 0;
780: int s = splhigh();
781:
782: if (events & (POLLIN | POLLRDNORM)) {
783: if (kq->kq_count) {
784: revents |= events & (POLLIN | POLLRDNORM);
785: } else {
786: selrecord(p, &kq->kq_sel);
787: kq->kq_state |= KQ_SEL;
788: }
789: }
790: splx(s);
791: return (revents);
792: }
793:
794: /*ARGSUSED*/
795: int
796: kqueue_stat(struct file *fp, struct stat *st, struct proc *p)
797: {
798: struct kqueue *kq = (struct kqueue *)fp->f_data;
799:
800: bzero((void *)st, sizeof(*st));
801: st->st_size = kq->kq_count;
802: st->st_blksize = sizeof(struct kevent);
803: st->st_mode = S_IFIFO;
804: return (0);
805: }
806:
807: /*ARGSUSED*/
808: int
809: kqueue_close(struct file *fp, struct proc *p)
810: {
811: struct kqueue *kq = (struct kqueue *)fp->f_data;
812: struct filedesc *fdp = p->p_fd;
813: struct knote **knp, *kn, *kn0;
814: int i;
815:
816: for (i = 0; i < fdp->fd_knlistsize; i++) {
817: knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
818: kn = *knp;
819: while (kn != NULL) {
820: kn0 = SLIST_NEXT(kn, kn_link);
821: if (kq == kn->kn_kq) {
822: FREF(kn->kn_fp);
823: kn->kn_fop->f_detach(kn);
824: closef(kn->kn_fp, p);
825: knote_free(kn);
826: *knp = kn0;
827: } else {
828: knp = &SLIST_NEXT(kn, kn_link);
829: }
830: kn = kn0;
831: }
832: }
833: if (fdp->fd_knhashmask != 0) {
834: for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
835: knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
836: kn = *knp;
837: while (kn != NULL) {
838: kn0 = SLIST_NEXT(kn, kn_link);
839: if (kq == kn->kn_kq) {
840: kn->kn_fop->f_detach(kn);
841: /* XXX non-fd release of kn->kn_ptr */
842: knote_free(kn);
843: *knp = kn0;
844: } else {
845: knp = &SLIST_NEXT(kn, kn_link);
846: }
847: kn = kn0;
848: }
849: }
850: }
851: pool_put(&kqueue_pool, kq);
852: fp->f_data = NULL;
853:
854: return (0);
855: }
856:
857: void
858: kqueue_wakeup(struct kqueue *kq)
859: {
860:
861: if (kq->kq_state & KQ_SLEEP) {
862: kq->kq_state &= ~KQ_SLEEP;
863: wakeup(kq);
864: }
865: if (kq->kq_state & KQ_SEL) {
866: kq->kq_state &= ~KQ_SEL;
867: selwakeup(&kq->kq_sel);
868: }
869: KNOTE(&kq->kq_sel.si_note, 0);
870: }
871:
872: /*
873: * walk down a list of knotes, activating them if their event has triggered.
874: */
875: void
876: knote(struct klist *list, long hint)
877: {
878: struct knote *kn;
879:
880: SLIST_FOREACH(kn, list, kn_selnext)
881: if (kn->kn_fop->f_event(kn, hint))
882: KNOTE_ACTIVATE(kn);
883: }
884:
885: /*
886: * remove all knotes from a specified klist
887: */
888: void
889: knote_remove(struct proc *p, struct klist *list)
890: {
891: struct knote *kn;
892:
893: while ((kn = SLIST_FIRST(list)) != NULL) {
894: kn->kn_fop->f_detach(kn);
895: knote_drop(kn, p, p->p_fd);
896: }
897: }
898:
899: /*
900: * remove all knotes referencing a specified fd
901: */
902: void
903: knote_fdclose(struct proc *p, int fd)
904: {
905: struct filedesc *fdp = p->p_fd;
906: struct klist *list = &fdp->fd_knlist[fd];
907:
908: knote_remove(p, list);
909: }
910:
911: void
912: knote_attach(struct knote *kn, struct filedesc *fdp)
913: {
914: struct klist *list;
915: int size;
916:
917: if (! kn->kn_fop->f_isfd) {
918: if (fdp->fd_knhashmask == 0)
919: fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP,
920: M_WAITOK, &fdp->fd_knhashmask);
921: list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
922: goto done;
923: }
924:
925: if (fdp->fd_knlistsize <= kn->kn_id) {
926: size = fdp->fd_knlistsize;
927: while (size <= kn->kn_id)
928: size += KQEXTENT;
929: list = malloc(size * sizeof(struct klist *), M_TEMP, M_WAITOK);
930: bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
931: fdp->fd_knlistsize * sizeof(struct klist *));
932: bzero((caddr_t)list +
933: fdp->fd_knlistsize * sizeof(struct klist *),
934: (size - fdp->fd_knlistsize) * sizeof(struct klist *));
935: if (fdp->fd_knlist != NULL)
936: free(fdp->fd_knlist, M_TEMP);
937: fdp->fd_knlistsize = size;
938: fdp->fd_knlist = list;
939: }
940: list = &fdp->fd_knlist[kn->kn_id];
941: done:
942: SLIST_INSERT_HEAD(list, kn, kn_link);
943: kn->kn_status = 0;
944: }
945:
946: /*
947: * should be called at spl == 0, since we don't want to hold spl
948: * while calling closef and free.
949: */
950: void
951: knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp)
952: {
953: struct klist *list;
954:
955: if (kn->kn_fop->f_isfd)
956: list = &fdp->fd_knlist[kn->kn_id];
957: else
958: list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
959:
960: SLIST_REMOVE(list, kn, knote, kn_link);
961: if (kn->kn_status & KN_QUEUED)
962: knote_dequeue(kn);
963: if (kn->kn_fop->f_isfd) {
964: FREF(kn->kn_fp);
965: closef(kn->kn_fp, p);
966: }
967: knote_free(kn);
968: }
969:
970:
971: void
972: knote_enqueue(struct knote *kn)
973: {
974: struct kqueue *kq = kn->kn_kq;
975: int s = splhigh();
976:
977: KASSERT((kn->kn_status & KN_QUEUED) == 0);
978:
979: TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
980: kn->kn_status |= KN_QUEUED;
981: kq->kq_count++;
982: splx(s);
983: kqueue_wakeup(kq);
984: }
985:
986: void
987: knote_dequeue(struct knote *kn)
988: {
989: struct kqueue *kq = kn->kn_kq;
990: int s = splhigh();
991:
992: KASSERT(kn->kn_status & KN_QUEUED);
993:
994: TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
995: kn->kn_status &= ~KN_QUEUED;
996: kq->kq_count--;
997: splx(s);
998: }
999:
1000: void
1001: klist_invalidate(struct klist *list)
1002: {
1003: struct knote *kn;
1004:
1005: SLIST_FOREACH(kn, list, kn_selnext) {
1006: kn->kn_status |= KN_DETACHED;
1007: kn->kn_flags |= EV_EOF | EV_ONESHOT;
1008: }
1009: }
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