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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 1.373 by root, Sun Feb 20 02:56:23 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
… …
2208 } 2262 }
2209} 2263}
2210 2264
2211#if EV_PERIODIC_ENABLE 2265#if EV_PERIODIC_ENABLE
2212 2266
2213inline_speed void 2267static void noinline
2214periodic_recalc (EV_P_ ev_periodic *w) 2268periodic_recalc (EV_P_ ev_periodic *w)
2215{ 2269{
2216 /* TODO: use slow but potentially more correct incremental algo, */ 2270 ev_tstamp interval = w->interval > MIN_INTERVAL ? w->interval : MIN_INTERVAL;
2217 /* also do not rely on ceil */ 2271 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; 2272
2273 /* the above almost always errs on the low side */
2274 while (at <= ev_rt_now)
2275 {
2276 ev_tstamp nat = at + w->interval;
2277
2278 /* when resolution fails us, we use ev_rt_now */
2279 if (expect_false (nat == at))
2280 {
2281 at = ev_rt_now;
2282 break;
2283 }
2284
2285 at = nat;
2286 }
2287
2288 ev_at (w) = at;
2219} 2289}
2220 2290
2221/* make periodics pending */ 2291/* make periodics pending */
2222inline_size void 2292inline_size void
2223periodics_reify (EV_P) 2293periodics_reify (EV_P)
… …
2245 downheap (periodics, periodiccnt, HEAP0); 2315 downheap (periodics, periodiccnt, HEAP0);
2246 } 2316 }
2247 else if (w->interval) 2317 else if (w->interval)
2248 { 2318 {
2249 periodic_recalc (EV_A_ w); 2319 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]); 2320 ANHE_at_cache (periodics [HEAP0]);
2265 downheap (periodics, periodiccnt, HEAP0); 2321 downheap (periodics, periodiccnt, HEAP0);
2266 } 2322 }
2267 else 2323 else
2268 ev_periodic_stop (EV_A_ w); /* nonrepeating: stop timer */ 2324 ev_periodic_stop (EV_A_ w); /* nonrepeating: stop timer */
… …
2346 * doesn't hurt either as we only do this on time-jumps or 2402 * doesn't hurt either as we only do this on time-jumps or
2347 * in the unlikely event of having been preempted here. 2403 * in the unlikely event of having been preempted here.
2348 */ 2404 */
2349 for (i = 4; --i; ) 2405 for (i = 4; --i; )
2350 { 2406 {
2407 ev_tstamp diff;
2351 rtmn_diff = ev_rt_now - mn_now; 2408 rtmn_diff = ev_rt_now - mn_now;
2352 2409
2410 diff = odiff - rtmn_diff;
2411
2353 if (expect_true (fabs (odiff - rtmn_diff) < MIN_TIMEJUMP)) 2412 if (expect_true ((diff < 0. ? -diff : diff) < MIN_TIMEJUMP))
2354 return; /* all is well */ 2413 return; /* all is well */
2355 2414
2356 ev_rt_now = ev_time (); 2415 ev_rt_now = ev_time ();
2357 mn_now = get_clock (); 2416 mn_now = get_clock ();
2358 now_floor = mn_now; 2417 now_floor = mn_now;

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