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