kern_event.c revision 84138
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: head/sys/kern/kern_event.c 84138 2001-09-29 17:48:39Z jlemon $ 27 */ 28 29#include <sys/param.h> 30#include <sys/systm.h> 31#include <sys/kernel.h> 32#include <sys/lock.h> 33#include <sys/mutex.h> 34#include <sys/proc.h> 35#include <sys/malloc.h> 36#include <sys/unistd.h> 37#include <sys/file.h> 38#include <sys/fcntl.h> 39#include <sys/selinfo.h> 40#include <sys/queue.h> 41#include <sys/event.h> 42#include <sys/eventvar.h> 43#include <sys/poll.h> 44#include <sys/protosw.h> 45#include <sys/socket.h> 46#include <sys/socketvar.h> 47#include <sys/stat.h> 48#include <sys/sysctl.h> 49#include <sys/sysproto.h> 50#include <sys/uio.h> 51 52#include <vm/vm_zone.h> 53 54MALLOC_DEFINE(M_KQUEUE, "kqueue", "memory for kqueue system"); 55 56static int kqueue_scan(struct file *fp, int maxevents, 57 struct kevent *ulistp, const struct timespec *timeout, 58 struct thread *td); 59static int kqueue_read(struct file *fp, struct uio *uio, 60 struct ucred *cred, int flags, struct thread *td); 61static int kqueue_write(struct file *fp, struct uio *uio, 62 struct ucred *cred, int flags, struct thread *td); 63static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 64 struct thread *td); 65static int kqueue_poll(struct file *fp, int events, struct ucred *cred, 66 struct thread *td); 67static int kqueue_kqfilter(struct file *fp, struct knote *kn); 68static int kqueue_stat(struct file *fp, struct stat *st, struct thread *td); 69static int kqueue_close(struct file *fp, struct thread *td); 70static void kqueue_wakeup(struct kqueue *kq); 71 72static struct fileops kqueueops = { 73 kqueue_read, 74 kqueue_write, 75 kqueue_ioctl, 76 kqueue_poll, 77 kqueue_kqfilter, 78 kqueue_stat, 79 kqueue_close 80}; 81 82static void knote_attach(struct knote *kn, struct filedesc *fdp); 83static void knote_drop(struct knote *kn, struct thread *td); 84static void knote_enqueue(struct knote *kn); 85static void knote_dequeue(struct knote *kn); 86static void knote_init(void); 87static struct knote *knote_alloc(void); 88static void knote_free(struct knote *kn); 89 90static void filt_kqdetach(struct knote *kn); 91static int filt_kqueue(struct knote *kn, long hint); 92static int filt_procattach(struct knote *kn); 93static void filt_procdetach(struct knote *kn); 94static int filt_proc(struct knote *kn, long hint); 95static int filt_fileattach(struct knote *kn); 96static void filt_timerexpire(void *knx); 97static int filt_timerattach(struct knote *kn); 98static void filt_timerdetach(struct knote *kn); 99static int filt_timer(struct knote *kn, long hint); 100 101static struct filterops file_filtops = 102 { 1, filt_fileattach, NULL, NULL }; 103static struct filterops kqread_filtops = 104 { 1, NULL, filt_kqdetach, filt_kqueue }; 105static struct filterops proc_filtops = 106 { 0, filt_procattach, filt_procdetach, filt_proc }; 107static struct filterops timer_filtops = 108 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 109 110static vm_zone_t knote_zone; 111static int kq_ncallouts = 0; 112static int kq_calloutmax = (4 * 1024); 113SYSCTL_INT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW, 114 &kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue"); 115 116#define KNOTE_ACTIVATE(kn) do { \ 117 kn->kn_status |= KN_ACTIVE; \ 118 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 119 knote_enqueue(kn); \ 120} while(0) 121 122#define KN_HASHSIZE 64 /* XXX should be tunable */ 123#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 124 125extern struct filterops aio_filtops; 126extern struct filterops sig_filtops; 127 128/* 129 * Table for for all system-defined filters. 130 */ 131static struct filterops *sysfilt_ops[] = { 132 &file_filtops, /* EVFILT_READ */ 133 &file_filtops, /* EVFILT_WRITE */ 134 &aio_filtops, /* EVFILT_AIO */ 135 &file_filtops, /* EVFILT_VNODE */ 136 &proc_filtops, /* EVFILT_PROC */ 137 &sig_filtops, /* EVFILT_SIGNAL */ 138 &timer_filtops, /* EVFILT_TIMER */ 139}; 140 141static int 142filt_fileattach(struct knote *kn) 143{ 144 145 return (fo_kqfilter(kn->kn_fp, kn)); 146} 147 148/*ARGSUSED*/ 149static int 150kqueue_kqfilter(struct file *fp, struct knote *kn) 151{ 152 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 153 154 if (kn->kn_filter != EVFILT_READ) 155 return (1); 156 157 kn->kn_fop = &kqread_filtops; 158 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 159 return (0); 160} 161 162static void 163filt_kqdetach(struct knote *kn) 164{ 165 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 166 167 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 168} 169 170/*ARGSUSED*/ 171static int 172filt_kqueue(struct knote *kn, long hint) 173{ 174 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 175 176 kn->kn_data = kq->kq_count; 177 return (kn->kn_data > 0); 178} 179 180static int 181filt_procattach(struct knote *kn) 182{ 183 struct proc *p; 184 int error; 185 186 p = pfind(kn->kn_id); 187 if (p == NULL) 188 return (ESRCH); 189 if ((error = p_cansee(curproc, p))) { 190 PROC_UNLOCK(p); 191 return (error); 192 } 193 194 kn->kn_ptr.p_proc = p; 195 kn->kn_flags |= EV_CLEAR; /* automatically set */ 196 197 /* 198 * internal flag indicating registration done by kernel 199 */ 200 if (kn->kn_flags & EV_FLAG1) { 201 kn->kn_data = kn->kn_sdata; /* ppid */ 202 kn->kn_fflags = NOTE_CHILD; 203 kn->kn_flags &= ~EV_FLAG1; 204 } 205 206 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 207 PROC_UNLOCK(p); 208 209 return (0); 210} 211 212/* 213 * The knote may be attached to a different process, which may exit, 214 * leaving nothing for the knote to be attached to. So when the process 215 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 216 * it will be deleted when read out. However, as part of the knote deletion, 217 * this routine is called, so a check is needed to avoid actually performing 218 * a detach, because the original process does not exist any more. 219 */ 220static void 221filt_procdetach(struct knote *kn) 222{ 223 struct proc *p = kn->kn_ptr.p_proc; 224 225 if (kn->kn_status & KN_DETACHED) 226 return; 227 228 PROC_LOCK(p); 229 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 230 PROC_UNLOCK(p); 231} 232 233static int 234filt_proc(struct knote *kn, long hint) 235{ 236 u_int event; 237 238 /* 239 * mask off extra data 240 */ 241 event = (u_int)hint & NOTE_PCTRLMASK; 242 243 /* 244 * if the user is interested in this event, record it. 245 */ 246 if (kn->kn_sfflags & event) 247 kn->kn_fflags |= event; 248 249 /* 250 * process is gone, so flag the event as finished. 251 */ 252 if (event == NOTE_EXIT) { 253 kn->kn_status |= KN_DETACHED; 254 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 255 return (1); 256 } 257 258 /* 259 * process forked, and user wants to track the new process, 260 * so attach a new knote to it, and immediately report an 261 * event with the parent's pid. 262 */ 263 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 264 struct kevent kev; 265 int error; 266 267 /* 268 * register knote with new process. 269 */ 270 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 271 kev.filter = kn->kn_filter; 272 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 273 kev.fflags = kn->kn_sfflags; 274 kev.data = kn->kn_id; /* parent */ 275 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 276 error = kqueue_register(kn->kn_kq, &kev, NULL); 277 if (error) 278 kn->kn_fflags |= NOTE_TRACKERR; 279 } 280 281 return (kn->kn_fflags != 0); 282} 283 284static void 285filt_timerexpire(void *knx) 286{ 287 struct knote *kn = knx; 288 struct callout *calloutp; 289 struct timeval tv; 290 int tticks; 291 292 kn->kn_data++; 293 KNOTE_ACTIVATE(kn); 294 295 if ((kn->kn_flags & EV_ONESHOT) == 0) { 296 tv.tv_sec = kn->kn_sdata / 1000; 297 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 298 tticks = tvtohz(&tv); 299 calloutp = (struct callout *)kn->kn_hook; 300 callout_reset(calloutp, tticks, filt_timerexpire, kn); 301 } 302} 303 304/* 305 * data contains amount of time to sleep, in milliseconds 306 */ 307static int 308filt_timerattach(struct knote *kn) 309{ 310 struct callout *calloutp; 311 struct timeval tv; 312 int tticks; 313 314 if (kq_ncallouts >= kq_calloutmax) 315 return (ENOMEM); 316 kq_ncallouts++; 317 318 tv.tv_sec = kn->kn_sdata / 1000; 319 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 320 tticks = tvtohz(&tv); 321 322 kn->kn_flags |= EV_CLEAR; /* automatically set */ 323 MALLOC(calloutp, struct callout *, sizeof(*calloutp), 324 M_KQUEUE, M_WAITOK); 325 callout_init(calloutp, 0); 326 callout_reset(calloutp, tticks, filt_timerexpire, kn); 327 kn->kn_hook = (caddr_t)calloutp; 328 329 return (0); 330} 331 332static void 333filt_timerdetach(struct knote *kn) 334{ 335 struct callout *calloutp; 336 337 calloutp = (struct callout *)kn->kn_hook; 338 callout_stop(calloutp); 339 FREE(calloutp, M_KQUEUE); 340 kq_ncallouts--; 341} 342 343static int 344filt_timer(struct knote *kn, long hint) 345{ 346 347 return (kn->kn_data != 0); 348} 349 350/* 351 * MPSAFE 352 */ 353int 354kqueue(struct thread *td, struct kqueue_args *uap) 355{ 356 struct filedesc *fdp; 357 struct kqueue *kq; 358 struct file *fp; 359 int fd, error; 360 361 mtx_lock(&Giant); 362 fdp = td->td_proc->p_fd; 363 error = falloc(td, &fp, &fd); 364 if (error) 365 goto done2; 366 fp->f_flag = FREAD | FWRITE; 367 fp->f_type = DTYPE_KQUEUE; 368 fp->f_ops = &kqueueops; 369 kq = malloc(sizeof(struct kqueue), M_KQUEUE, M_WAITOK | M_ZERO); 370 TAILQ_INIT(&kq->kq_head); 371 fp->f_data = (caddr_t)kq; 372 td->td_retval[0] = fd; 373 if (fdp->fd_knlistsize < 0) 374 fdp->fd_knlistsize = 0; /* this process has a kq */ 375 kq->kq_fdp = fdp; 376done2: 377 mtx_unlock(&Giant); 378 return (error); 379} 380 381#ifndef _SYS_SYSPROTO_H_ 382struct kevent_args { 383 int fd; 384 const struct kevent *changelist; 385 int nchanges; 386 struct kevent *eventlist; 387 int nevents; 388 const struct timespec *timeout; 389}; 390#endif 391/* 392 * MPSAFE 393 */ 394int 395kevent(struct thread *td, struct kevent_args *uap) 396{ 397 struct filedesc *fdp; 398 struct kevent *kevp; 399 struct kqueue *kq; 400 struct file *fp = NULL; 401 struct timespec ts; 402 int i, n, nerrors, error; 403 404 mtx_lock(&Giant); 405 fdp = td->td_proc->p_fd; 406 if (((u_int)uap->fd) >= fdp->fd_nfiles || 407 (fp = fdp->fd_ofiles[uap->fd]) == NULL || 408 (fp->f_type != DTYPE_KQUEUE)) { 409 error = EBADF; 410 goto done; 411 } 412 fhold(fp); 413 414 if (uap->timeout != NULL) { 415 error = copyin(uap->timeout, &ts, sizeof(ts)); 416 if (error) 417 goto done; 418 uap->timeout = &ts; 419 } 420 421 kq = (struct kqueue *)fp->f_data; 422 nerrors = 0; 423 424 while (uap->nchanges > 0) { 425 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges; 426 error = copyin(uap->changelist, kq->kq_kev, 427 n * sizeof(struct kevent)); 428 if (error) 429 goto done; 430 for (i = 0; i < n; i++) { 431 kevp = &kq->kq_kev[i]; 432 kevp->flags &= ~EV_SYSFLAGS; 433 error = kqueue_register(kq, kevp, td); 434 if (error) { 435 if (uap->nevents != 0) { 436 kevp->flags = EV_ERROR; 437 kevp->data = error; 438 (void) copyout((caddr_t)kevp, 439 (caddr_t)uap->eventlist, 440 sizeof(*kevp)); 441 uap->eventlist++; 442 uap->nevents--; 443 nerrors++; 444 } else { 445 goto done; 446 } 447 } 448 } 449 uap->nchanges -= n; 450 uap->changelist += n; 451 } 452 if (nerrors) { 453 td->td_retval[0] = nerrors; 454 error = 0; 455 goto done; 456 } 457 458 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, td); 459done: 460 if (fp != NULL) 461 fdrop(fp, td); 462 mtx_unlock(&Giant); 463 return (error); 464} 465 466int 467kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td) 468{ 469 struct filedesc *fdp = kq->kq_fdp; 470 struct filterops *fops; 471 struct file *fp = NULL; 472 struct knote *kn = NULL; 473 int s, error = 0; 474 475 if (kev->filter < 0) { 476 if (kev->filter + EVFILT_SYSCOUNT < 0) 477 return (EINVAL); 478 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 479 } else { 480 /* 481 * XXX 482 * filter attach routine is responsible for insuring that 483 * the identifier can be attached to it. 484 */ 485 printf("unknown filter: %d\n", kev->filter); 486 return (EINVAL); 487 } 488 489 if (fops->f_isfd) { 490 /* validate descriptor */ 491 if ((u_int)kev->ident >= fdp->fd_nfiles || 492 (fp = fdp->fd_ofiles[kev->ident]) == NULL) 493 return (EBADF); 494 fhold(fp); 495 496 if (kev->ident < fdp->fd_knlistsize) { 497 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 498 if (kq == kn->kn_kq && 499 kev->filter == kn->kn_filter) 500 break; 501 } 502 } else { 503 if (fdp->fd_knhashmask != 0) { 504 struct klist *list; 505 506 list = &fdp->fd_knhash[ 507 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 508 SLIST_FOREACH(kn, list, kn_link) 509 if (kev->ident == kn->kn_id && 510 kq == kn->kn_kq && 511 kev->filter == kn->kn_filter) 512 break; 513 } 514 } 515 516 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 517 error = ENOENT; 518 goto done; 519 } 520 521 /* 522 * kn now contains the matching knote, or NULL if no match 523 */ 524 if (kev->flags & EV_ADD) { 525 526 if (kn == NULL) { 527 kn = knote_alloc(); 528 if (kn == NULL) { 529 error = ENOMEM; 530 goto done; 531 } 532 kn->kn_fp = fp; 533 kn->kn_kq = kq; 534 kn->kn_fop = fops; 535 536 /* 537 * apply reference count to knote structure, and 538 * do not release it at the end of this routine. 539 */ 540 fp = NULL; 541 542 kn->kn_sfflags = kev->fflags; 543 kn->kn_sdata = kev->data; 544 kev->fflags = 0; 545 kev->data = 0; 546 kn->kn_kevent = *kev; 547 548 knote_attach(kn, fdp); 549 if ((error = fops->f_attach(kn)) != 0) { 550 knote_drop(kn, td); 551 goto done; 552 } 553 } else { 554 /* 555 * The user may change some filter values after the 556 * initial EV_ADD, but doing so will not reset any 557 * filter which have already been triggered. 558 */ 559 kn->kn_sfflags = kev->fflags; 560 kn->kn_sdata = kev->data; 561 kn->kn_kevent.udata = kev->udata; 562 } 563 564 s = splhigh(); 565 if (kn->kn_fop->f_event(kn, 0)) 566 KNOTE_ACTIVATE(kn); 567 splx(s); 568 569 } else if (kev->flags & EV_DELETE) { 570 kn->kn_fop->f_detach(kn); 571 knote_drop(kn, td); 572 goto done; 573 } 574 575 if ((kev->flags & EV_DISABLE) && 576 ((kn->kn_status & KN_DISABLED) == 0)) { 577 s = splhigh(); 578 kn->kn_status |= KN_DISABLED; 579 splx(s); 580 } 581 582 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 583 s = splhigh(); 584 kn->kn_status &= ~KN_DISABLED; 585 if ((kn->kn_status & KN_ACTIVE) && 586 ((kn->kn_status & KN_QUEUED) == 0)) 587 knote_enqueue(kn); 588 splx(s); 589 } 590 591done: 592 if (fp != NULL) 593 fdrop(fp, td); 594 return (error); 595} 596 597static int 598kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, 599 const struct timespec *tsp, struct thread *td) 600{ 601 struct kqueue *kq = (struct kqueue *)fp->f_data; 602 struct kevent *kevp; 603 struct timeval atv, rtv, ttv; 604 struct knote *kn, marker; 605 int s, count, timeout, nkev = 0, error = 0; 606 607 count = maxevents; 608 if (count == 0) 609 goto done; 610 611 if (tsp != NULL) { 612 TIMESPEC_TO_TIMEVAL(&atv, tsp); 613 if (itimerfix(&atv)) { 614 error = EINVAL; 615 goto done; 616 } 617 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 618 timeout = -1; 619 else 620 timeout = atv.tv_sec > 24 * 60 * 60 ? 621 24 * 60 * 60 * hz : tvtohz(&atv); 622 getmicrouptime(&rtv); 623 timevaladd(&atv, &rtv); 624 } else { 625 atv.tv_sec = 0; 626 atv.tv_usec = 0; 627 timeout = 0; 628 } 629 goto start; 630 631retry: 632 if (atv.tv_sec || atv.tv_usec) { 633 getmicrouptime(&rtv); 634 if (timevalcmp(&rtv, &atv, >=)) 635 goto done; 636 ttv = atv; 637 timevalsub(&ttv, &rtv); 638 timeout = ttv.tv_sec > 24 * 60 * 60 ? 639 24 * 60 * 60 * hz : tvtohz(&ttv); 640 } 641 642start: 643 kevp = kq->kq_kev; 644 s = splhigh(); 645 if (kq->kq_count == 0) { 646 if (timeout < 0) { 647 error = EWOULDBLOCK; 648 } else { 649 kq->kq_state |= KQ_SLEEP; 650 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 651 } 652 splx(s); 653 if (error == 0) 654 goto retry; 655 /* don't restart after signals... */ 656 if (error == ERESTART) 657 error = EINTR; 658 else if (error == EWOULDBLOCK) 659 error = 0; 660 goto done; 661 } 662 663 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 664 while (count) { 665 kn = TAILQ_FIRST(&kq->kq_head); 666 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 667 if (kn == &marker) { 668 splx(s); 669 if (count == maxevents) 670 goto retry; 671 goto done; 672 } 673 if (kn->kn_status & KN_DISABLED) { 674 kn->kn_status &= ~KN_QUEUED; 675 kq->kq_count--; 676 continue; 677 } 678 if ((kn->kn_flags & EV_ONESHOT) == 0 && 679 kn->kn_fop->f_event(kn, 0) == 0) { 680 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 681 kq->kq_count--; 682 continue; 683 } 684 *kevp = kn->kn_kevent; 685 kevp++; 686 nkev++; 687 if (kn->kn_flags & EV_ONESHOT) { 688 kn->kn_status &= ~KN_QUEUED; 689 kq->kq_count--; 690 splx(s); 691 kn->kn_fop->f_detach(kn); 692 knote_drop(kn, td); 693 s = splhigh(); 694 } else if (kn->kn_flags & EV_CLEAR) { 695 kn->kn_data = 0; 696 kn->kn_fflags = 0; 697 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 698 kq->kq_count--; 699 } else { 700 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 701 } 702 count--; 703 if (nkev == KQ_NEVENTS) { 704 splx(s); 705 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 706 sizeof(struct kevent) * nkev); 707 ulistp += nkev; 708 nkev = 0; 709 kevp = kq->kq_kev; 710 s = splhigh(); 711 if (error) 712 break; 713 } 714 } 715 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 716 splx(s); 717done: 718 if (nkev != 0) 719 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 720 sizeof(struct kevent) * nkev); 721 td->td_retval[0] = maxevents - count; 722 return (error); 723} 724 725/* 726 * XXX 727 * This could be expanded to call kqueue_scan, if desired. 728 */ 729/*ARGSUSED*/ 730static int 731kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, 732 int flags, struct thread *td) 733{ 734 return (ENXIO); 735} 736 737/*ARGSUSED*/ 738static int 739kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, 740 int flags, struct thread *td) 741{ 742 return (ENXIO); 743} 744 745/*ARGSUSED*/ 746static int 747kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td) 748{ 749 return (ENOTTY); 750} 751 752/*ARGSUSED*/ 753static int 754kqueue_poll(struct file *fp, int events, struct ucred *cred, struct thread *td) 755{ 756 struct kqueue *kq = (struct kqueue *)fp->f_data; 757 int revents = 0; 758 int s = splnet(); 759 760 if (events & (POLLIN | POLLRDNORM)) { 761 if (kq->kq_count) { 762 revents |= events & (POLLIN | POLLRDNORM); 763 } else { 764 selrecord(td, &kq->kq_sel); 765 kq->kq_state |= KQ_SEL; 766 } 767 } 768 splx(s); 769 return (revents); 770} 771 772/*ARGSUSED*/ 773static int 774kqueue_stat(struct file *fp, struct stat *st, struct thread *td) 775{ 776 struct kqueue *kq = (struct kqueue *)fp->f_data; 777 778 bzero((void *)st, sizeof(*st)); 779 st->st_size = kq->kq_count; 780 st->st_blksize = sizeof(struct kevent); 781 st->st_mode = S_IFIFO; 782 return (0); 783} 784 785/*ARGSUSED*/ 786static int 787kqueue_close(struct file *fp, struct thread *td) 788{ 789 struct kqueue *kq = (struct kqueue *)fp->f_data; 790 struct filedesc *fdp = td->td_proc->p_fd; 791 struct knote **knp, *kn, *kn0; 792 int i; 793 794 for (i = 0; i < fdp->fd_knlistsize; i++) { 795 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 796 kn = *knp; 797 while (kn != NULL) { 798 kn0 = SLIST_NEXT(kn, kn_link); 799 if (kq == kn->kn_kq) { 800 kn->kn_fop->f_detach(kn); 801 fdrop(kn->kn_fp, td); 802 knote_free(kn); 803 *knp = kn0; 804 } else { 805 knp = &SLIST_NEXT(kn, kn_link); 806 } 807 kn = kn0; 808 } 809 } 810 if (fdp->fd_knhashmask != 0) { 811 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 812 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 813 kn = *knp; 814 while (kn != NULL) { 815 kn0 = SLIST_NEXT(kn, kn_link); 816 if (kq == kn->kn_kq) { 817 kn->kn_fop->f_detach(kn); 818 /* XXX non-fd release of kn->kn_ptr */ 819 knote_free(kn); 820 *knp = kn0; 821 } else { 822 knp = &SLIST_NEXT(kn, kn_link); 823 } 824 kn = kn0; 825 } 826 } 827 } 828 free(kq, M_KQUEUE); 829 fp->f_data = NULL; 830 831 return (0); 832} 833 834static void 835kqueue_wakeup(struct kqueue *kq) 836{ 837 838 if (kq->kq_state & KQ_SLEEP) { 839 kq->kq_state &= ~KQ_SLEEP; 840 wakeup(kq); 841 } 842 if (kq->kq_state & KQ_SEL) { 843 kq->kq_state &= ~KQ_SEL; 844 selwakeup(&kq->kq_sel); 845 } 846 KNOTE(&kq->kq_sel.si_note, 0); 847} 848 849/* 850 * walk down a list of knotes, activating them if their event has triggered. 851 */ 852void 853knote(struct klist *list, long hint) 854{ 855 struct knote *kn; 856 857 SLIST_FOREACH(kn, list, kn_selnext) 858 if (kn->kn_fop->f_event(kn, hint)) 859 KNOTE_ACTIVATE(kn); 860} 861 862/* 863 * remove all knotes from a specified klist 864 */ 865void 866knote_remove(struct thread *td, struct klist *list) 867{ 868 struct knote *kn; 869 870 while ((kn = SLIST_FIRST(list)) != NULL) { 871 kn->kn_fop->f_detach(kn); 872 knote_drop(kn, td); 873 } 874} 875 876/* 877 * remove all knotes referencing a specified fd 878 */ 879void 880knote_fdclose(struct thread *td, int fd) 881{ 882 struct filedesc *fdp = td->td_proc->p_fd; 883 struct klist *list = &fdp->fd_knlist[fd]; 884 885 knote_remove(td, list); 886} 887 888static void 889knote_attach(struct knote *kn, struct filedesc *fdp) 890{ 891 struct klist *list; 892 int size; 893 894 if (! kn->kn_fop->f_isfd) { 895 if (fdp->fd_knhashmask == 0) 896 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_KQUEUE, 897 &fdp->fd_knhashmask); 898 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 899 goto done; 900 } 901 902 if (fdp->fd_knlistsize <= kn->kn_id) { 903 size = fdp->fd_knlistsize; 904 while (size <= kn->kn_id) 905 size += KQEXTENT; 906 MALLOC(list, struct klist *, 907 size * sizeof(struct klist *), M_KQUEUE, M_WAITOK); 908 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, 909 fdp->fd_knlistsize * sizeof(struct klist *)); 910 bzero((caddr_t)list + 911 fdp->fd_knlistsize * sizeof(struct klist *), 912 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 913 if (fdp->fd_knlist != NULL) 914 FREE(fdp->fd_knlist, M_KQUEUE); 915 fdp->fd_knlistsize = size; 916 fdp->fd_knlist = list; 917 } 918 list = &fdp->fd_knlist[kn->kn_id]; 919done: 920 SLIST_INSERT_HEAD(list, kn, kn_link); 921 kn->kn_status = 0; 922} 923 924/* 925 * should be called at spl == 0, since we don't want to hold spl 926 * while calling fdrop and free. 927 */ 928static void 929knote_drop(struct knote *kn, struct thread *td) 930{ 931 struct filedesc *fdp = td->td_proc->p_fd; 932 struct klist *list; 933 934 if (kn->kn_fop->f_isfd) 935 list = &fdp->fd_knlist[kn->kn_id]; 936 else 937 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 938 939 SLIST_REMOVE(list, kn, knote, kn_link); 940 if (kn->kn_status & KN_QUEUED) 941 knote_dequeue(kn); 942 if (kn->kn_fop->f_isfd) 943 fdrop(kn->kn_fp, td); 944 knote_free(kn); 945} 946 947 948static void 949knote_enqueue(struct knote *kn) 950{ 951 struct kqueue *kq = kn->kn_kq; 952 int s = splhigh(); 953 954 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 955 956 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 957 kn->kn_status |= KN_QUEUED; 958 kq->kq_count++; 959 splx(s); 960 kqueue_wakeup(kq); 961} 962 963static void 964knote_dequeue(struct knote *kn) 965{ 966 struct kqueue *kq = kn->kn_kq; 967 int s = splhigh(); 968 969 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 970 971 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 972 kn->kn_status &= ~KN_QUEUED; 973 kq->kq_count--; 974 splx(s); 975} 976 977static void 978knote_init(void) 979{ 980 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); 981} 982SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) 983 984static struct knote * 985knote_alloc(void) 986{ 987 return ((struct knote *)zalloc(knote_zone)); 988} 989 990static void 991knote_free(struct knote *kn) 992{ 993 zfree(knote_zone, kn); 994} 995