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Comparing libev/ev.c (file contents):
Revision 1.372 by root, Wed Feb 16 08:02:50 2011 UTC vs.
Revision 1.378 by root, Mon Jun 13 09:52:36 2011 UTC

… …
43# include EV_CONFIG_H 43# include EV_CONFIG_H
44# else 44# else
45# include "config.h" 45# include "config.h"
46# endif 46# endif
47 47
48#if HAVE_FLOOR
49# ifndef EV_USE_FLOOR
50# define EV_USE_FLOOR 1
51# endif
52#endif
53
48# if HAVE_CLOCK_SYSCALL 54# if HAVE_CLOCK_SYSCALL
49# ifndef EV_USE_CLOCK_SYSCALL 55# ifndef EV_USE_CLOCK_SYSCALL
50# define EV_USE_CLOCK_SYSCALL 1 56# define EV_USE_CLOCK_SYSCALL 1
51# ifndef EV_USE_REALTIME 57# ifndef EV_USE_REALTIME
52# define EV_USE_REALTIME 0 58# define EV_USE_REALTIME 0
… …
156# define EV_USE_EVENTFD 0 162# define EV_USE_EVENTFD 0
157# endif 163# endif
158 164
159#endif 165#endif
160 166
161#include <math.h>
162#include <stdlib.h> 167#include <stdlib.h>
163#include <string.h> 168#include <string.h>
164#include <fcntl.h> 169#include <fcntl.h>
165#include <stddef.h> 170#include <stddef.h>
166 171
… …
232/* to make it compile regardless, just remove the above line, */ 237/* to make it compile regardless, just remove the above line, */
233/* but consider reporting it, too! :) */ 238/* but consider reporting it, too! :) */
234# define EV_NSIG 65 239# define EV_NSIG 65
235#endif 240#endif
236 241
242#ifndef EV_USE_FLOOR
243# define EV_USE_FLOOR 0
244#endif
245
237#ifndef EV_USE_CLOCK_SYSCALL 246#ifndef EV_USE_CLOCK_SYSCALL
238# if __linux && __GLIBC__ >= 2 247# if __linux && __GLIBC__ >= 2
239# define EV_USE_CLOCK_SYSCALL EV_FEATURE_OS 248# define EV_USE_CLOCK_SYSCALL EV_FEATURE_OS
240# else 249# else
241# define EV_USE_CLOCK_SYSCALL 0 250# define EV_USE_CLOCK_SYSCALL 0
… …
443#else 452#else
444# define EV_FREQUENT_CHECK do { } while (0) 453# define EV_FREQUENT_CHECK do { } while (0)
445#endif 454#endif
446 455
447/* 456/*
448 * This is used to avoid floating point rounding problems. 457 * This is used to work around floating point rounding problems.
449 * It is added to ev_rt_now when scheduling periodics
450 * to ensure progress, time-wise, even when rounding
451 * errors are against us.
452 * This value is good at least till the year 4000. 458 * This value is good at least till the year 4000.
453 * Better solutions welcome.
454 */ 459 */
455#define TIME_EPSILON 0.0001220703125 /* 1/8192 */ 460#define MIN_INTERVAL 0.0001220703125 /* 1/2**13, good till 4000 */
461/*#define MIN_INTERVAL 0.00000095367431640625 /* 1/2**20, good till 2200 */
456 462
457#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */ 463#define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */
458#define MAX_BLOCKTIME 59.743 /* never wait longer than this time (to detect time jumps) */ 464#define MAX_BLOCKTIME 59.743 /* never wait longer than this time (to detect time jumps) */
459 465
460#define EV_TV_SET(tv,t) do { tv.tv_sec = (long)t; tv.tv_usec = (long)((t - tv.tv_sec) * 1e6); } while (0) 466#define EV_TV_SET(tv,t) do { tv.tv_sec = (long)t; tv.tv_usec = (long)((t - tv.tv_sec) * 1e6); } while (0)
… …
519# define EV_WIN32_CLOSE_FD(fd) close (fd) 525# define EV_WIN32_CLOSE_FD(fd) close (fd)
520#endif 526#endif
521 527
522#ifdef _WIN32 528#ifdef _WIN32
523# include "ev_win32.c" 529# include "ev_win32.c"
530#endif
531
532/*****************************************************************************/
533
534/* define a suitable floor function (only used by periodics atm) */
535
536#if EV_USE_FLOOR
537# include <math.h>
538# define ev_floor(v) floor (v)
539#else
540
541#include <float.h>
542
543/* a floor() replacement function, should be independent of ev_tstamp type */
544static ev_tstamp noinline
545ev_floor (ev_tstamp v)
546{
547 /* the choice of shift factor is not terribly important */
548#if FLT_RADIX != 2 /* assume FLT_RADIX == 10 */
549 const ev_tstamp shift = sizeof (unsigned long) >= 8 ? 10000000000000000000. : 1000000000.;
550#else
551 const ev_tstamp shift = sizeof (unsigned long) >= 8 ? 18446744073709551616. : 4294967296.;
552#endif
553
554 /* argument too large for an unsigned long? */
555 if (expect_false (v >= shift))
556 {
557 ev_tstamp f;
558
559 if (v == v - 1.)
560 return v; /* very large number */
561
562 f = shift * ev_floor (v * (1. / shift));
563 return f + ev_floor (v - f);
564 }
565
566 /* special treatment for negative args? */
567 if (expect_false (v < 0.))
568 {
569 ev_tstamp f = -ev_floor (-v);
570
571 return f - (f == v ? 0 : 1);
572 }
573
574 /* fits into an unsigned long */
575 return (unsigned long)v;
576}
577
524#endif 578#endif
525 579
526/*****************************************************************************/ 580/*****************************************************************************/
527 581
528#ifdef __linux 582#ifdef __linux
… …
816 select (0, 0, 0, 0, &tv); 870 select (0, 0, 0, 0, &tv);
817#endif 871#endif
818 } 872 }
819} 873}
820 874
821inline_speed int
822ev_timeout_to_ms (ev_tstamp timeout)
823{
824 int ms = timeout * 1000. + .999999;
825
826 return expect_true (ms) ? ms : timeout < 1e-6 ? 0 : 1;
827}
828
829/*****************************************************************************/ 875/*****************************************************************************/
830 876
831#define MALLOC_ROUND 4096 /* prefer to allocate in chunks of this size, must be 2**n and >> 4 longs */ 877#define MALLOC_ROUND 4096 /* prefer to allocate in chunks of this size, must be 2**n and >> 4 longs */
832 878
833/* find a suitable new size for the given array, */ 879/* find a suitable new size for the given array, */
… …
980 for (i = 0; i < fdchangecnt; ++i) 1026 for (i = 0; i < fdchangecnt; ++i)
981 { 1027 {
982 int fd = fdchanges [i]; 1028 int fd = fdchanges [i];
983 ANFD *anfd = anfds + fd; 1029 ANFD *anfd = anfds + fd;
984 1030
985 if (anfd->reify & EV__IOFDSET) 1031 if (anfd->reify & EV__IOFDSET && anfd->head)
986 { 1032 {
987 SOCKET handle = EV_FD_TO_WIN32_HANDLE (fd); 1033 SOCKET handle = EV_FD_TO_WIN32_HANDLE (fd);
988 1034
989 if (handle != anfd->handle) 1035 if (handle != anfd->handle)
990 { 1036 {
… …
1322inline_size void 1368inline_size void
1323evpipe_write (EV_P_ EV_ATOMIC_T *flag) 1369evpipe_write (EV_P_ EV_ATOMIC_T *flag)
1324{ 1370{
1325 if (!*flag) 1371 if (!*flag)
1326 { 1372 {
1327 int old_errno = errno; /* save errno because write might clobber it */
1328 char dummy;
1329
1330 *flag = 1; 1373 *flag = 1;
1331 1374
1375 pipe_write_skipped = 1;
1376
1377 if (pipe_write_wanted)
1378 {
1379 int old_errno = errno; /* save errno because write will clobber it */
1380 char dummy;
1381
1382 pipe_write_skipped = 0;
1383
1332#if EV_USE_EVENTFD 1384#if EV_USE_EVENTFD
1333 if (evfd >= 0) 1385 if (evfd >= 0)
1334 { 1386 {
1335 uint64_t counter = 1; 1387 uint64_t counter = 1;
1336 write (evfd, &counter, sizeof (uint64_t)); 1388 write (evfd, &counter, sizeof (uint64_t));
1389 }
1390 else
1391#endif
1392 {
1393 /* win32 people keep sending patches that change this write() to send() */
1394 /* and then run away. but send() is wrong, it wants a socket handle on win32 */
1395 /* so when you think this write should be a send instead, please find out */
1396 /* where your send() is from - it's definitely not the microsoft send, and */
1397 /* tell me. thank you. */
1398 write (evpipe [1], &dummy, 1);
1399 }
1400
1401 errno = old_errno;
1337 } 1402 }
1338 else
1339#endif
1340 /* win32 people keep sending patches that change this write() to send() */
1341 /* and then run away. but send() is wrong, it wants a socket handle on win32 */
1342 /* so when you think this write should be a send instead, please find out */
1343 /* where your send() is from - it's definitely not the microsoft send, and */
1344 /* tell me. thank you. */
1345 write (evpipe [1], &dummy, 1);
1346
1347 errno = old_errno;
1348 } 1403 }
1349} 1404}
1350 1405
1351/* called whenever the libev signal pipe */ 1406/* called whenever the libev signal pipe */
1352/* got some events (signal, async) */ 1407/* got some events (signal, async) */
1353static void 1408static void
1354pipecb (EV_P_ ev_io *iow, int revents) 1409pipecb (EV_P_ ev_io *iow, int revents)
1355{ 1410{
1356 int i; 1411 int i;
1357 1412
1413 if (revents & EV_READ)
1414 {
1358#if EV_USE_EVENTFD 1415#if EV_USE_EVENTFD
1359 if (evfd >= 0) 1416 if (evfd >= 0)
1360 { 1417 {
1361 uint64_t counter; 1418 uint64_t counter;
1362 read (evfd, &counter, sizeof (uint64_t)); 1419 read (evfd, &counter, sizeof (uint64_t));
1363 } 1420 }
1364 else 1421 else
1365#endif 1422#endif
1366 { 1423 {
1367 char dummy; 1424 char dummy;
1368 /* see discussion in evpipe_write when you think this read should be recv in win32 */ 1425 /* see discussion in evpipe_write when you think this read should be recv in win32 */
1369 read (evpipe [0], &dummy, 1); 1426 read (evpipe [0], &dummy, 1);
1427 }
1370 } 1428 }
1429
1430 pipe_write_skipped = 0;
1371 1431
1372#if EV_SIGNAL_ENABLE 1432#if EV_SIGNAL_ENABLE
1373 if (sig_pending) 1433 if (sig_pending)
1374 { 1434 {
1375 sig_pending = 0; 1435 sig_pending = 0;
… …
1404 EV_P = signals [signum - 1].loop; 1464 EV_P = signals [signum - 1].loop;
1405 1465
1406 if (!EV_A) 1466 if (!EV_A)
1407 return; 1467 return;
1408#endif 1468#endif
1469
1470 evpipe_init (EV_A);
1409 1471
1410 signals [signum - 1].pending = 1; 1472 signals [signum - 1].pending = 1;
1411 evpipe_write (EV_A_ &sig_pending); 1473 evpipe_write (EV_A_ &sig_pending);
1412} 1474}
1413 1475
… …
1711 if (!(flags & EVFLAG_NOENV) 1773 if (!(flags & EVFLAG_NOENV)
1712 && !enable_secure () 1774 && !enable_secure ()
1713 && getenv ("LIBEV_FLAGS")) 1775 && getenv ("LIBEV_FLAGS"))
1714 flags = atoi (getenv ("LIBEV_FLAGS")); 1776 flags = atoi (getenv ("LIBEV_FLAGS"));
1715 1777
1716 ev_rt_now = ev_time (); 1778 ev_rt_now = ev_time ();
1717 mn_now = get_clock (); 1779 mn_now = get_clock ();
1718 now_floor = mn_now; 1780 now_floor = mn_now;
1719 rtmn_diff = ev_rt_now - mn_now; 1781 rtmn_diff = ev_rt_now - mn_now;
1720#if EV_FEATURE_API 1782#if EV_FEATURE_API
1721 invoke_cb = ev_invoke_pending; 1783 invoke_cb = ev_invoke_pending;
1722#endif 1784#endif
1723 1785
1724 io_blocktime = 0.; 1786 io_blocktime = 0.;
1725 timeout_blocktime = 0.; 1787 timeout_blocktime = 0.;
1726 backend = 0; 1788 backend = 0;
1727 backend_fd = -1; 1789 backend_fd = -1;
1728 sig_pending = 0; 1790 sig_pending = 0;
1729#if EV_ASYNC_ENABLE 1791#if EV_ASYNC_ENABLE
1730 async_pending = 0; 1792 async_pending = 0;
1731#endif 1793#endif
1794 pipe_write_skipped = 0;
1795 pipe_write_wanted = 0;
1732#if EV_USE_INOTIFY 1796#if EV_USE_INOTIFY
1733 fs_fd = flags & EVFLAG_NOINOTIFY ? -1 : -2; 1797 fs_fd = flags & EVFLAG_NOINOTIFY ? -1 : -2;
1734#endif 1798#endif
1735#if EV_USE_SIGNALFD 1799#if EV_USE_SIGNALFD
1736 sigfd = flags & EVFLAG_SIGNALFD ? -2 : -1; 1800 sigfd = flags & EVFLAG_SIGNALFD ? -2 : -1;
1737#endif 1801#endif
1738 1802
1739 if (!(flags & EVBACKEND_MASK)) 1803 if (!(flags & EVBACKEND_MASK))
1740 flags |= ev_recommended_backends (); 1804 flags |= ev_recommended_backends ();
1741 1805
… …
1906 infy_fork (EV_A); 1970 infy_fork (EV_A);
1907#endif 1971#endif
1908 1972
1909 if (ev_is_active (&pipe_w)) 1973 if (ev_is_active (&pipe_w))
1910 { 1974 {
1911 /* this "locks" the handlers against writing to the pipe */ 1975 /* pipe_write_wanted must be false now, so modifying fd vars should be safe */
1912 /* while we modify the fd vars */
1913 sig_pending = 1;
1914#if EV_ASYNC_ENABLE
1915 async_pending = 1;
1916#endif
1917 1976
1918 ev_ref (EV_A); 1977 ev_ref (EV_A);
1919 ev_io_stop (EV_A_ &pipe_w); 1978 ev_io_stop (EV_A_ &pipe_w);
1920 1979
1921#if EV_USE_EVENTFD 1980#if EV_USE_EVENTFD
… …
2208 } 2267 }
2209} 2268}
2210 2269
2211#if EV_PERIODIC_ENABLE 2270#if EV_PERIODIC_ENABLE
2212 2271
2213inline_speed void 2272static void noinline
2214periodic_recalc (EV_P_ ev_periodic *w) 2273periodic_recalc (EV_P_ ev_periodic *w)
2215{ 2274{
2216 /* TODO: use slow but potentially more correct incremental algo, */ 2275 ev_tstamp interval = w->interval > MIN_INTERVAL ? w->interval : MIN_INTERVAL;
2217 /* also do not rely on ceil */ 2276 ev_tstamp at = w->offset + interval * ev_floor ((ev_rt_now - w->offset) / interval);
2218 ev_at (w) = w->offset + ceil ((ev_rt_now - w->offset) / w->interval) * w->interval; 2277
2278 /* the above almost always errs on the low side */
2279 while (at <= ev_rt_now)
2280 {
2281 ev_tstamp nat = at + w->interval;
2282
2283 /* when resolution fails us, we use ev_rt_now */
2284 if (expect_false (nat == at))
2285 {
2286 at = ev_rt_now;
2287 break;
2288 }
2289
2290 at = nat;
2291 }
2292
2293 ev_at (w) = at;
2219} 2294}
2220 2295
2221/* make periodics pending */ 2296/* make periodics pending */
2222inline_size void 2297inline_size void
2223periodics_reify (EV_P) 2298periodics_reify (EV_P)
… …
2245 downheap (periodics, periodiccnt, HEAP0); 2320 downheap (periodics, periodiccnt, HEAP0);
2246 } 2321 }
2247 else if (w->interval) 2322 else if (w->interval)
2248 { 2323 {
2249 periodic_recalc (EV_A_ w); 2324 periodic_recalc (EV_A_ w);
2250
2251 /* if next trigger time is not sufficiently in the future, put it there */
2252 /* this might happen because of floating point inexactness */
2253 if (ev_at (w) - ev_rt_now < TIME_EPSILON)
2254 {
2255 ev_at (w) += w->interval;
2256
2257 /* if interval is unreasonably low we might still have a time in the past */
2258 /* so correct this. this will make the periodic very inexact, but the user */
2259 /* has effectively asked to get triggered more often than possible */
2260 if (ev_at (w) < ev_rt_now)
2261 ev_at (w) = ev_rt_now;
2262 }
2263
2264 ANHE_at_cache (periodics [HEAP0]); 2325 ANHE_at_cache (periodics [HEAP0]);
2265 downheap (periodics, periodiccnt, HEAP0); 2326 downheap (periodics, periodiccnt, HEAP0);
2266 } 2327 }
2267 else 2328 else
2268 ev_periodic_stop (EV_A_ w); /* nonrepeating: stop timer */ 2329 ev_periodic_stop (EV_A_ w); /* nonrepeating: stop timer */
… …
2346 * doesn't hurt either as we only do this on time-jumps or 2407 * doesn't hurt either as we only do this on time-jumps or
2347 * in the unlikely event of having been preempted here. 2408 * in the unlikely event of having been preempted here.
2348 */ 2409 */
2349 for (i = 4; --i; ) 2410 for (i = 4; --i; )
2350 { 2411 {
2412 ev_tstamp diff;
2351 rtmn_diff = ev_rt_now - mn_now; 2413 rtmn_diff = ev_rt_now - mn_now;
2352 2414
2415 diff = odiff - rtmn_diff;
2416
2353 if (expect_true (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)) 2417 if (expect_true ((diff < 0. ? -diff : diff) < MIN_TIMEJUMP))
2354 return; /* all is well */ 2418 return; /* all is well */
2355 2419
2356 ev_rt_now = ev_time (); 2420 ev_rt_now = ev_time ();
2357 mn_now = get_clock (); 2421 mn_now = get_clock ();
2358 now_floor = mn_now; 2422 now_floor = mn_now;
… …
2448 ev_tstamp prev_mn_now = mn_now; 2512 ev_tstamp prev_mn_now = mn_now;
2449 2513
2450 /* update time to cancel out callback processing overhead */ 2514 /* update time to cancel out callback processing overhead */
2451 time_update (EV_A_ 1e100); 2515 time_update (EV_A_ 1e100);
2452 2516
2517 /* from now on, we want a pipe-wake-up */
2518 pipe_write_wanted = 1;
2519
2453 if (expect_true (!(flags & EVRUN_NOWAIT || idleall || !activecnt))) 2520 if (expect_true (!(flags & EVRUN_NOWAIT || idleall || !activecnt || pipe_write_skipped)))
2454 { 2521 {
2455 waittime = MAX_BLOCKTIME; 2522 waittime = MAX_BLOCKTIME;
2456 2523
2457 if (timercnt) 2524 if (timercnt)
2458 { 2525 {
2459 ev_tstamp to = ANHE_at (timers [HEAP0]) - mn_now + backend_fudge; 2526 ev_tstamp to = ANHE_at (timers [HEAP0]) - mn_now;
2460 if (waittime > to) waittime = to; 2527 if (waittime > to) waittime = to;
2461 } 2528 }
2462 2529
2463#if EV_PERIODIC_ENABLE 2530#if EV_PERIODIC_ENABLE
2464 if (periodiccnt) 2531 if (periodiccnt)
2465 { 2532 {
2466 ev_tstamp to = ANHE_at (periodics [HEAP0]) - ev_rt_now + backend_fudge; 2533 ev_tstamp to = ANHE_at (periodics [HEAP0]) - ev_rt_now;
2467 if (waittime > to) waittime = to; 2534 if (waittime > to) waittime = to;
2468 } 2535 }
2469#endif 2536#endif
2470 2537
2471 /* don't let timeouts decrease the waittime below timeout_blocktime */ 2538 /* don't let timeouts decrease the waittime below timeout_blocktime */
2472 if (expect_false (waittime < timeout_blocktime)) 2539 if (expect_false (waittime < timeout_blocktime))
2473 waittime = timeout_blocktime; 2540 waittime = timeout_blocktime;
2541
2542 /* at this point, we NEED to wait, so we have to ensure */
2543 /* to pass a minimum nonzero value to the backend */
2544 if (expect_false (waittime < backend_mintime))
2545 waittime = backend_mintime;
2474 2546
2475 /* extra check because io_blocktime is commonly 0 */ 2547 /* extra check because io_blocktime is commonly 0 */
2476 if (expect_false (io_blocktime)) 2548 if (expect_false (io_blocktime))
2477 { 2549 {
2478 sleeptime = io_blocktime - (mn_now - prev_mn_now); 2550 sleeptime = io_blocktime - (mn_now - prev_mn_now);
2479 2551
2480 if (sleeptime > waittime - backend_fudge) 2552 if (sleeptime > waittime - backend_mintime)
2481 sleeptime = waittime - backend_fudge; 2553 sleeptime = waittime - backend_mintime;
2482 2554
2483 if (expect_true (sleeptime > 0.)) 2555 if (expect_true (sleeptime > 0.))
2484 { 2556 {
2485 ev_sleep (sleeptime); 2557 ev_sleep (sleeptime);
2486 waittime -= sleeptime; 2558 waittime -= sleeptime;
… …
2492 ++loop_count; 2564 ++loop_count;
2493#endif 2565#endif
2494 assert ((loop_done = EVBREAK_RECURSE, 1)); /* assert for side effect */ 2566 assert ((loop_done = EVBREAK_RECURSE, 1)); /* assert for side effect */
2495 backend_poll (EV_A_ waittime); 2567 backend_poll (EV_A_ waittime);
2496 assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */ 2568 assert ((loop_done = EVBREAK_CANCEL, 1)); /* assert for side effect */
2569
2570 pipe_write_wanted = 0;
2571
2572 if (pipe_write_skipped)
2573 {
2574 assert (("libev: pipe_w not active, but pipe not written", ev_is_active (&pipe_w)));
2575 ev_feed_event (EV_A_ &pipe_w, EV_CUSTOM);
2576 }
2577
2497 2578
2498 /* update ev_rt_now, do magic */ 2579 /* update ev_rt_now, do magic */
2499 time_update (EV_A_ waittime + sleeptime); 2580 time_update (EV_A_ waittime + sleeptime);
2500 } 2581 }
2501 2582

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