1 /*- 2 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/sys/kern/kern_event.c,v 1.2.2.9 2003/05/08 07:47:16 kbyanc Exp $ 27 * $DragonFly: src/sys/kern/kern_event.c,v 1.9 2003/07/30 00:19:14 dillon Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/proc.h> 34 #include <sys/malloc.h> 35 #include <sys/unistd.h> 36 #include <sys/file.h> 37 #include <sys/fcntl.h> 38 #include <sys/select.h> 39 #include <sys/queue.h> 40 #include <sys/event.h> 41 #include <sys/eventvar.h> 42 #include <sys/poll.h> 43 #include <sys/protosw.h> 44 #include <sys/socket.h> 45 #include <sys/socketvar.h> 46 #include <sys/stat.h> 47 #include <sys/sysctl.h> 48 #include <sys/sysproto.h> 49 #include <sys/uio.h> 50 #include <sys/file2.h> 51 52 #include <vm/vm_zone.h> 53 54 MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 55 56 static int kqueue_scan(struct file *fp, int maxevents, 57 struct kevent *ulistp, const struct timespec *timeout, 58 struct proc *p, int *res); 59 static int kqueue_read(struct file *fp, struct uio *uio, 60 struct ucred *cred, int flags, struct thread *td); 61 static int kqueue_write(struct file *fp, struct uio *uio, 62 struct ucred *cred, int flags, struct thread *td); 63 static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 64 struct thread *td); 65 static int kqueue_poll(struct file *fp, int events, struct ucred *cred, 66 struct thread *td); 67 static int kqueue_kqfilter(struct file *fp, struct knote *kn); 68 static int kqueue_stat(struct file *fp, struct stat *st, struct thread *td); 69 static int kqueue_close(struct file *fp, struct thread *td); 70 static void kqueue_wakeup(struct kqueue *kq); 71 72 static struct fileops kqueueops = { 73 NULL, /* port */ 74 0, /* autoq */ 75 kqueue_read, 76 kqueue_write, 77 kqueue_ioctl, 78 kqueue_poll, 79 kqueue_kqfilter, 80 kqueue_stat, 81 kqueue_close 82 }; 83 84 static void knote_attach(struct knote *kn, struct filedesc *fdp); 85 static void knote_drop(struct knote *kn, struct thread *td); 86 static void knote_enqueue(struct knote *kn); 87 static void knote_dequeue(struct knote *kn); 88 static void knote_init(void); 89 static struct knote *knote_alloc(void); 90 static void knote_free(struct knote *kn); 91 92 static void filt_kqdetach(struct knote *kn); 93 static int filt_kqueue(struct knote *kn, long hint); 94 static int filt_procattach(struct knote *kn); 95 static void filt_procdetach(struct knote *kn); 96 static int filt_proc(struct knote *kn, long hint); 97 static int filt_fileattach(struct knote *kn); 98 static void filt_timerexpire(void *knx); 99 static int filt_timerattach(struct knote *kn); 100 static void filt_timerdetach(struct knote *kn); 101 static int filt_timer(struct knote *kn, long hint); 102 103 static struct filterops file_filtops = 104 { 1, filt_fileattach, NULL, NULL }; 105 static struct filterops kqread_filtops = 106 { 1, NULL, filt_kqdetach, filt_kqueue }; 107 static struct filterops proc_filtops = 108 { 0, filt_procattach, filt_procdetach, filt_proc }; 109 static struct filterops timer_filtops = 110 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 111 112 static vm_zone_t knote_zone; 113 static int kq_ncallouts = 0; 114 static int kq_calloutmax = (4 * 1024); 115 SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 116 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 117 118 #define KNOTE_ACTIVATE(kn) do { \ 119 kn->kn_status |= KN_ACTIVE; \ 120 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 121 knote_enqueue(kn); \ 122 } while(0) 123 124 #define KN_HASHSIZE 64 /* XXX should be tunable */ 125 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 126 127 extern struct filterops aio_filtops; 128 extern struct filterops sig_filtops; 129 130 /* 131 * Table for for all system-defined filters. 132 */ 133 static struct filterops *sysfilt_ops[] = { 134 &file_filtops, /* EVFILT_READ */ 135 &file_filtops, /* EVFILT_WRITE */ 136 &aio_filtops, /* EVFILT_AIO */ 137 &file_filtops, /* EVFILT_VNODE */ 138 &proc_filtops, /* EVFILT_PROC */ 139 &sig_filtops, /* EVFILT_SIGNAL */ 140 &timer_filtops, /* EVFILT_TIMER */ 141 }; 142 143 static int 144 filt_fileattach(struct knote *kn) 145 { 146 return (fo_kqfilter(kn->kn_fp, kn)); 147 } 148 149 /*ARGSUSED*/ 150 static int 151 kqueue_kqfilter(struct file *fp, struct knote *kn) 152 { 153 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 154 155 if (kn->kn_filter != EVFILT_READ) 156 return (1); 157 158 kn->kn_fop = &kqread_filtops; 159 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 160 return (0); 161 } 162 163 static void 164 filt_kqdetach(struct knote *kn) 165 { 166 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 167 168 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 169 } 170 171 /*ARGSUSED*/ 172 static int 173 filt_kqueue(struct knote *kn, long hint) 174 { 175 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 176 177 kn->kn_data = kq->kq_count; 178 return (kn->kn_data > 0); 179 } 180 181 static int 182 filt_procattach(struct knote *kn) 183 { 184 struct proc *p; 185 int immediate; 186 187 immediate = 0; 188 p = pfind(kn->kn_id); 189 if (p == NULL && (kn->kn_sfflags & NOTE_EXIT)) { 190 p = zpfind(kn->kn_id); 191 immediate = 1; 192 } 193 if (p == NULL) 194 return (ESRCH); 195 if (! PRISON_CHECK(curproc->p_ucred, p->p_ucred)) 196 return (EACCES); 197 198 kn->kn_ptr.p_proc = p; 199 kn->kn_flags |= EV_CLEAR; /* automatically set */ 200 201 /* 202 * internal flag indicating registration done by kernel 203 */ 204 if (kn->kn_flags & EV_FLAG1) { 205 kn->kn_data = kn->kn_sdata; /* ppid */ 206 kn->kn_fflags = NOTE_CHILD; 207 kn->kn_flags &= ~EV_FLAG1; 208 } 209 210 /* XXX lock the proc here while adding to the list? */ 211 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 212 213 /* 214 * Immediately activate any exit notes if the target process is a 215 * zombie. This is necessary to handle the case where the target 216 * process, e.g. a child, dies before the kevent is registered. 217 */ 218 if (immediate && filt_proc(kn, NOTE_EXIT)) 219 KNOTE_ACTIVATE(kn); 220 221 return (0); 222 } 223 224 /* 225 * The knote may be attached to a different process, which may exit, 226 * leaving nothing for the knote to be attached to. So when the process 227 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 228 * it will be deleted when read out. However, as part of the knote deletion, 229 * this routine is called, so a check is needed to avoid actually performing 230 * a detach, because the original process does not exist any more. 231 */ 232 static void 233 filt_procdetach(struct knote *kn) 234 { 235 struct proc *p = kn->kn_ptr.p_proc; 236 237 if (kn->kn_status & KN_DETACHED) 238 return; 239 240 /* XXX locking? this might modify another process. */ 241 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 242 } 243 244 static int 245 filt_proc(struct knote *kn, long hint) 246 { 247 u_int event; 248 249 /* 250 * mask off extra data 251 */ 252 event = (u_int)hint & NOTE_PCTRLMASK; 253 254 /* 255 * if the user is interested in this event, record it. 256 */ 257 if (kn->kn_sfflags & event) 258 kn->kn_fflags |= event; 259 260 /* 261 * process is gone, so flag the event as finished. 262 */ 263 if (event == NOTE_EXIT) { 264 kn->kn_status |= KN_DETACHED; 265 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 266 return (1); 267 } 268 269 /* 270 * process forked, and user wants to track the new process, 271 * so attach a new knote to it, and immediately report an 272 * event with the parent's pid. 273 */ 274 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 275 struct kevent kev; 276 int error; 277 278 /* 279 * register knote with new process. 280 */ 281 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 282 kev.filter = kn->kn_filter; 283 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 284 kev.fflags = kn->kn_sfflags; 285 kev.data = kn->kn_id; /* parent */ 286 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 287 error = kqueue_register(kn->kn_kq, &kev, NULL); 288 if (error) 289 kn->kn_fflags |= NOTE_TRACKERR; 290 } 291 292 return (kn->kn_fflags != 0); 293 } 294 295 static void 296 filt_timerexpire(void *knx) 297 { 298 struct knote *kn = knx; 299 struct callout *calloutp; 300 struct timeval tv; 301 int tticks; 302 303 kn->kn_data++; 304 KNOTE_ACTIVATE(kn); 305 306 if ((kn->kn_flags & EV_ONESHOT) == 0) { 307 tv.tv_sec = kn->kn_sdata / 1000; 308 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 309 tticks = tvtohz(&tv); 310 calloutp = (struct callout *)kn->kn_hook; 311 callout_reset(calloutp, tticks, filt_timerexpire, kn); 312 } 313 } 314 315 /* 316 * data contains amount of time to sleep, in milliseconds 317 */ 318 static int 319 filt_timerattach(struct knote *kn) 320 { 321 struct callout *calloutp; 322 struct timeval tv; 323 int tticks; 324 325 if (kq_ncallouts >= kq_calloutmax) 326 return (ENOMEM); 327 kq_ncallouts++; 328 329 tv.tv_sec = kn->kn_sdata / 1000; 330 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 331 tticks = tvtohz(&tv); 332 333 kn->kn_flags |= EV_CLEAR; /* automatically set */ 334 MALLOC(calloutp, struct callout *, sizeof(*calloutp), 335 M_KQUEUE, M_WAITOK); 336 callout_init(calloutp); 337 callout_reset(calloutp, tticks, filt_timerexpire, kn); 338 kn->kn_hook = (caddr_t)calloutp; 339 340 return (0); 341 } 342 343 static void 344 filt_timerdetach(struct knote *kn) 345 { 346 struct callout *calloutp; 347 348 calloutp = (struct callout *)kn->kn_hook; 349 callout_stop(calloutp); 350 FREE(calloutp, M_KQUEUE); 351 kq_ncallouts--; 352 } 353 354 static int 355 filt_timer(struct knote *kn, long hint) 356 { 357 358 return (kn->kn_data != 0); 359 } 360 361 int 362 kqueue(struct kqueue_args *uap) 363 { 364 struct proc *p = curproc; 365 struct filedesc *fdp = p->p_fd; 366 struct kqueue *kq; 367 struct file *fp; 368 int fd, error; 369 370 error = falloc(p, &fp, &fd); 371 if (error) 372 return (error); 373 fp->f_flag = FREAD | FWRITE; 374 fp->f_type = DTYPE_KQUEUE; 375 fp->f_ops = &kqueueops; 376 kq = malloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO); 377 TAILQ_INIT(&kq->kq_head); 378 fp->f_data = (caddr_t)kq; 379 uap->sysmsg_result = fd; 380 if (fdp->fd_knlistsize < 0) 381 fdp->fd_knlistsize = 0; /* this process has a kq */ 382 kq->kq_fdp = fdp; 383 return (error); 384 } 385 386 int 387 kevent(struct kevent_args *uap) 388 { 389 struct thread *td = curthread; 390 struct proc *p = td->td_proc; 391 struct filedesc *fdp; 392 struct kevent *kevp; 393 struct kqueue *kq; 394 struct file *fp = NULL; 395 struct timespec ts; 396 int i, n, nerrors, error; 397 398 KKASSERT(p); 399 fdp = p->p_fd; 400 401 if (((u_int)uap->fd) >= fdp->fd_nfiles || 402 (fp = fdp->fd_ofiles[uap->fd]) == NULL || 403 (fp->f_type != DTYPE_KQUEUE)) 404 return (EBADF); 405 406 fhold(fp); 407 408 if (uap->timeout != NULL) { 409 error = copyin(uap->timeout, &ts, sizeof(ts)); 410 if (error) 411 goto done; 412 uap->timeout = &ts; 413 } 414 415 kq = (struct kqueue *)fp->f_data; 416 nerrors = 0; 417 418 while (uap->nchanges > 0) { 419 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges; 420 error = copyin(uap->changelist, kq->kq_kev, 421 n * sizeof(struct kevent)); 422 if (error) 423 goto done; 424 for (i = 0; i < n; i++) { 425 kevp = &kq->kq_kev[i]; 426 kevp->flags &= ~EV_SYSFLAGS; 427 error = kqueue_register(kq, kevp, td); 428 if (error) { 429 if (uap->nevents != 0) { 430 kevp->flags = EV_ERROR; 431 kevp->data = error; 432 (void) copyout((caddr_t)kevp, 433 (caddr_t)uap->eventlist, 434 sizeof(*kevp)); 435 uap->eventlist++; 436 uap->nevents--; 437 nerrors++; 438 } else { 439 goto done; 440 } 441 } 442 } 443 uap->nchanges -= n; 444 uap->changelist += n; 445 } 446 if (nerrors) { 447 uap->sysmsg_result = nerrors; 448 error = 0; 449 goto done; 450 } 451 452 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p, &uap->sysmsg_result); 453 done: 454 if (fp != NULL) 455 fdrop(fp, p->p_thread); 456 return (error); 457 } 458 459 int 460 kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td) 461 { 462 struct filedesc *fdp = kq->kq_fdp; 463 struct filterops *fops; 464 struct file *fp = NULL; 465 struct knote *kn = NULL; 466 int s, error = 0; 467 468 if (kev->filter < 0) { 469 if (kev->filter + EVFILT_SYSCOUNT < 0) 470 return (EINVAL); 471 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 472 } else { 473 /* 474 * XXX 475 * filter attach routine is responsible for insuring that 476 * the identifier can be attached to it. 477 */ 478 printf("unknown filter: %d\n", kev->filter); 479 return (EINVAL); 480 } 481 482 if (fops->f_isfd) { 483 /* validate descriptor */ 484 if ((u_int)kev->ident >= fdp->fd_nfiles || 485 (fp = fdp->fd_ofiles[kev->ident]) == NULL) 486 return (EBADF); 487 fhold(fp); 488 489 if (kev->ident < fdp->fd_knlistsize) { 490 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 491 if (kq == kn->kn_kq && 492 kev->filter == kn->kn_filter) 493 break; 494 } 495 } else { 496 if (fdp->fd_knhashmask != 0) { 497 struct klist *list; 498 499 list = &fdp->fd_knhash[ 500 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 501 SLIST_FOREACH(kn, list, kn_link) 502 if (kev->ident == kn->kn_id && 503 kq == kn->kn_kq && 504 kev->filter == kn->kn_filter) 505 break; 506 } 507 } 508 509 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 510 error = ENOENT; 511 goto done; 512 } 513 514 /* 515 * kn now contains the matching knote, or NULL if no match 516 */ 517 if (kev->flags & EV_ADD) { 518 519 if (kn == NULL) { 520 kn = knote_alloc(); 521 if (kn == NULL) { 522 error = ENOMEM; 523 goto done; 524 } 525 kn->kn_fp = fp; 526 kn->kn_kq = kq; 527 kn->kn_fop = fops; 528 529 /* 530 * apply reference count to knote structure, and 531 * do not release it at the end of this routine. 532 */ 533 fp = NULL; 534 535 kn->kn_sfflags = kev->fflags; 536 kn->kn_sdata = kev->data; 537 kev->fflags = 0; 538 kev->data = 0; 539 kn->kn_kevent = *kev; 540 541 knote_attach(kn, fdp); 542 if ((error = fops->f_attach(kn)) != 0) { 543 knote_drop(kn, td); 544 goto done; 545 } 546 } else { 547 /* 548 * The user may change some filter values after the 549 * initial EV_ADD, but doing so will not reset any 550 * filter which have already been triggered. 551 */ 552 kn->kn_sfflags = kev->fflags; 553 kn->kn_sdata = kev->data; 554 kn->kn_kevent.udata = kev->udata; 555 } 556 557 s = splhigh(); 558 if (kn->kn_fop->f_event(kn, 0)) 559 KNOTE_ACTIVATE(kn); 560 splx(s); 561 562 } else if (kev->flags & EV_DELETE) { 563 kn->kn_fop->f_detach(kn); 564 knote_drop(kn, td); 565 goto done; 566 } 567 568 if ((kev->flags & EV_DISABLE) && 569 ((kn->kn_status & KN_DISABLED) == 0)) { 570 s = splhigh(); 571 kn->kn_status |= KN_DISABLED; 572 splx(s); 573 } 574 575 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 576 s = splhigh(); 577 kn->kn_status &= ~KN_DISABLED; 578 if ((kn->kn_status & KN_ACTIVE) && 579 ((kn->kn_status & KN_QUEUED) == 0)) 580 knote_enqueue(kn); 581 splx(s); 582 } 583 584 done: 585 if (fp != NULL) 586 fdrop(fp, td); 587 return (error); 588 } 589 590 static int 591 kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, 592 const struct timespec *tsp, struct proc *p, int *res) 593 { 594 struct thread *td = p->p_thread; 595 struct kqueue *kq = (struct kqueue *)fp->f_data; 596 struct kevent *kevp; 597 struct timeval atv, rtv, ttv; 598 struct knote *kn, marker; 599 int s, count, timeout, nkev = 0, error = 0; 600 601 count = maxevents; 602 if (count == 0) 603 goto done; 604 605 if (tsp != NULL) { 606 TIMESPEC_TO_TIMEVAL(&atv, tsp); 607 if (itimerfix(&atv)) { 608 error = EINVAL; 609 goto done; 610 } 611 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 612 timeout = -1; 613 else 614 timeout = atv.tv_sec > 24 * 60 * 60 ? 615 24 * 60 * 60 * hz : tvtohz(&atv); 616 getmicrouptime(&rtv); 617 timevaladd(&atv, &rtv); 618 } else { 619 atv.tv_sec = 0; 620 atv.tv_usec = 0; 621 timeout = 0; 622 } 623 goto start; 624 625 retry: 626 if (atv.tv_sec || atv.tv_usec) { 627 getmicrouptime(&rtv); 628 if (timevalcmp(&rtv, &atv, >=)) 629 goto done; 630 ttv = atv; 631 timevalsub(&ttv, &rtv); 632 timeout = ttv.tv_sec > 24 * 60 * 60 ? 633 24 * 60 * 60 * hz : tvtohz(&ttv); 634 } 635 636 start: 637 kevp = kq->kq_kev; 638 s = splhigh(); 639 if (kq->kq_count == 0) { 640 if (timeout < 0) { 641 error = EWOULDBLOCK; 642 } else { 643 kq->kq_state |= KQ_SLEEP; 644 error = tsleep(kq, PCATCH, "kqread", timeout); 645 } 646 splx(s); 647 if (error == 0) 648 goto retry; 649 /* don't restart after signals... */ 650 if (error == ERESTART) 651 error = EINTR; 652 else if (error == EWOULDBLOCK) 653 error = 0; 654 goto done; 655 } 656 657 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 658 while (count) { 659 kn = TAILQ_FIRST(&kq->kq_head); 660 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 661 if (kn == &marker) { 662 splx(s); 663 if (count == maxevents) 664 goto retry; 665 goto done; 666 } 667 if (kn->kn_status & KN_DISABLED) { 668 kn->kn_status &= ~KN_QUEUED; 669 kq->kq_count--; 670 continue; 671 } 672 if ((kn->kn_flags & EV_ONESHOT) == 0 && 673 kn->kn_fop->f_event(kn, 0) == 0) { 674 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 675 kq->kq_count--; 676 continue; 677 } 678 *kevp = kn->kn_kevent; 679 kevp++; 680 nkev++; 681 if (kn->kn_flags & EV_ONESHOT) { 682 kn->kn_status &= ~KN_QUEUED; 683 kq->kq_count--; 684 splx(s); 685 kn->kn_fop->f_detach(kn); 686 knote_drop(kn, td); 687 s = splhigh(); 688 } else if (kn->kn_flags & EV_CLEAR) { 689 kn->kn_data = 0; 690 kn->kn_fflags = 0; 691 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 692 kq->kq_count--; 693 } else { 694 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 695 } 696 count--; 697 if (nkev == KQ_NEVENTS) { 698 splx(s); 699 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 700 sizeof(struct kevent) * nkev); 701 ulistp += nkev; 702 nkev = 0; 703 kevp = kq->kq_kev; 704 s = splhigh(); 705 if (error) 706 break; 707 } 708 } 709 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 710 splx(s); 711 done: 712 if (nkev != 0) 713 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 714 sizeof(struct kevent) * nkev); 715 *res = maxevents - count; 716 return (error); 717 } 718 719 /* 720 * XXX 721 * This could be expanded to call kqueue_scan, if desired. 722 */ 723 /*ARGSUSED*/ 724 static int 725 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, 726 int flags, struct thread *td) 727 { 728 return (ENXIO); 729 } 730 731 /*ARGSUSED*/ 732 static int 733 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, 734 int flags, struct thread *td) 735 { 736 return (ENXIO); 737 } 738 739 /*ARGSUSED*/ 740 static int 741 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td) 742 { 743 return (ENOTTY); 744 } 745 746 /*ARGSUSED*/ 747 static int 748 kqueue_poll(struct file *fp, int events, struct ucred *cred, struct thread *td) 749 { 750 struct kqueue *kq = (struct kqueue *)fp->f_data; 751 int revents = 0; 752 int s = splnet(); 753 754 if (events & (POLLIN | POLLRDNORM)) { 755 if (kq->kq_count) { 756 revents |= events & (POLLIN | POLLRDNORM); 757 } else { 758 selrecord(td, &kq->kq_sel); 759 kq->kq_state |= KQ_SEL; 760 } 761 } 762 splx(s); 763 return (revents); 764 } 765 766 /*ARGSUSED*/ 767 static int 768 kqueue_stat(struct file *fp, struct stat *st, struct thread *td) 769 { 770 struct kqueue *kq = (struct kqueue *)fp->f_data; 771 772 bzero((void *)st, sizeof(*st)); 773 st->st_size = kq->kq_count; 774 st->st_blksize = sizeof(struct kevent); 775 st->st_mode = S_IFIFO; 776 return (0); 777 } 778 779 /*ARGSUSED*/ 780 static int 781 kqueue_close(struct file *fp, struct thread *td) 782 { 783 struct proc *p = td->td_proc; 784 struct kqueue *kq = (struct kqueue *)fp->f_data; 785 struct filedesc *fdp; 786 struct knote **knp, *kn, *kn0; 787 int i; 788 789 KKASSERT(p); 790 fdp = p->p_fd; 791 for (i = 0; i < fdp->fd_knlistsize; i++) { 792 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 793 kn = *knp; 794 while (kn != NULL) { 795 kn0 = SLIST_NEXT(kn, kn_link); 796 if (kq == kn->kn_kq) { 797 kn->kn_fop->f_detach(kn); 798 fdrop(kn->kn_fp, td); 799 knote_free(kn); 800 *knp = kn0; 801 } else { 802 knp = &SLIST_NEXT(kn, kn_link); 803 } 804 kn = kn0; 805 } 806 } 807 if (fdp->fd_knhashmask != 0) { 808 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 809 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 810 kn = *knp; 811 while (kn != NULL) { 812 kn0 = SLIST_NEXT(kn, kn_link); 813 if (kq == kn->kn_kq) { 814 kn->kn_fop->f_detach(kn); 815 /* XXX non-fd release of kn->kn_ptr */ 816 knote_free(kn); 817 *knp = kn0; 818 } else { 819 knp = &SLIST_NEXT(kn, kn_link); 820 } 821 kn = kn0; 822 } 823 } 824 } 825 free(kq, M_KQUEUE); 826 fp->f_data = NULL; 827 828 return (0); 829 } 830 831 static void 832 kqueue_wakeup(struct kqueue *kq) 833 { 834 835 if (kq->kq_state & KQ_SLEEP) { 836 kq->kq_state &= ~KQ_SLEEP; 837 wakeup(kq); 838 } 839 if (kq->kq_state & KQ_SEL) { 840 kq->kq_state &= ~KQ_SEL; 841 selwakeup(&kq->kq_sel); 842 } 843 KNOTE(&kq->kq_sel.si_note, 0); 844 } 845 846 /* 847 * walk down a list of knotes, activating them if their event has triggered. 848 */ 849 void 850 knote(struct klist *list, long hint) 851 { 852 struct knote *kn; 853 854 SLIST_FOREACH(kn, list, kn_selnext) 855 if (kn->kn_fop->f_event(kn, hint)) 856 KNOTE_ACTIVATE(kn); 857 } 858 859 /* 860 * remove all knotes from a specified klist 861 */ 862 void 863 knote_remove(struct thread *td, struct klist *list) 864 { 865 struct knote *kn; 866 867 while ((kn = SLIST_FIRST(list)) != NULL) { 868 kn->kn_fop->f_detach(kn); 869 knote_drop(kn, td); 870 } 871 } 872 873 /* 874 * remove all knotes referencing a specified fd 875 */ 876 void 877 knote_fdclose(struct proc *p, int fd) 878 { 879 struct filedesc *fdp = p->p_fd; 880 struct klist *list = &fdp->fd_knlist[fd]; 881 882 knote_remove(p->p_thread, list); 883 } 884 885 static void 886 knote_attach(struct knote *kn, struct filedesc *fdp) 887 { 888 struct klist *list; 889 int size; 890 891 if (! kn->kn_fop->f_isfd) { 892 if (fdp->fd_knhashmask == 0) 893 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 894 &fdp->fd_knhashmask); 895 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 896 goto done; 897 } 898 899 if (fdp->fd_knlistsize <= kn->kn_id) { 900 size = fdp->fd_knlistsize; 901 while (size <= kn->kn_id) 902 size += KQEXTENT; 903 MALLOC(list, struct klist *, 904 size * sizeof(struct klist *), M_KQUEUE, M_WAITOK); 905 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, 906 fdp->fd_knlistsize * sizeof(struct klist *)); 907 bzero((caddr_t)list + 908 fdp->fd_knlistsize * sizeof(struct klist *), 909 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 910 if (fdp->fd_knlist != NULL) 911 FREE(fdp->fd_knlist, M_KQUEUE); 912 fdp->fd_knlistsize = size; 913 fdp->fd_knlist = list; 914 } 915 list = &fdp->fd_knlist[kn->kn_id]; 916 done: 917 SLIST_INSERT_HEAD(list, kn, kn_link); 918 kn->kn_status = 0; 919 } 920 921 /* 922 * should be called at spl == 0, since we don't want to hold spl 923 * while calling fdrop and free. 924 */ 925 static void 926 knote_drop(struct knote *kn, struct thread *td) 927 { 928 struct filedesc *fdp; 929 struct klist *list; 930 931 KKASSERT(td->td_proc); 932 fdp = td->td_proc->p_fd; 933 if (kn->kn_fop->f_isfd) 934 list = &fdp->fd_knlist[kn->kn_id]; 935 else 936 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 937 938 SLIST_REMOVE(list, kn, knote, kn_link); 939 if (kn->kn_status & KN_QUEUED) 940 knote_dequeue(kn); 941 if (kn->kn_fop->f_isfd) 942 fdrop(kn->kn_fp, td); 943 knote_free(kn); 944 } 945 946 947 static void 948 knote_enqueue(struct knote *kn) 949 { 950 struct kqueue *kq = kn->kn_kq; 951 int s = splhigh(); 952 953 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 954 955 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 956 kn->kn_status |= KN_QUEUED; 957 kq->kq_count++; 958 splx(s); 959 kqueue_wakeup(kq); 960 } 961 962 static void 963 knote_dequeue(struct knote *kn) 964 { 965 struct kqueue *kq = kn->kn_kq; 966 int s = splhigh(); 967 968 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 969 970 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 971 kn->kn_status &= ~KN_QUEUED; 972 kq->kq_count--; 973 splx(s); 974 } 975 976 static void 977 knote_init(void) 978 { 979 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); 980 } 981 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) 982 983 static struct knote * 984 knote_alloc(void) 985 { 986 return ((struct knote *)zalloc(knote_zone)); 987 } 988 989 static void 990 knote_free(struct knote *kn) 991 { 992 zfree(knote_zone, kn); 993 } 994