--- libev/ev.c 2007/12/11 04:08:54 1.175 +++ libev/ev.c 2007/12/11 04:31:55 1.176 @@ -218,9 +218,20 @@ /**/ +/* + * This is used to avoid floating point rounding problems. + * It is added to ev_rt_now when scheduling periodics + * to ensure progress, time-wise, even when rounding + * errors are against us. + * This value is good at least till the year 4000 + * and intervals up to 20 years. + * Better solutions welcome. + */ +#define TIME_EPSILON 0.0001220703125 /* 1/8192 */ + #define MIN_TIMEJUMP 1. /* minimum timejump that gets detected (if monotonic clock available) */ #define MAX_BLOCKTIME 59.743 /* never wait longer than this time (to detect time jumps) */ -/*#define CLEANUP_INTERVAL (MAX_BLOCKTIME * 5.) /* how often to try to free memory and re-check fds */ +/*#define CLEANUP_INTERVAL (MAX_BLOCKTIME * 5.) /* how often to try to free memory and re-check fds, TODO */ #if __GNUC__ >= 3 # define expect(expr,value) __builtin_expect ((expr),(value)) @@ -1233,13 +1244,13 @@ /* first reschedule or stop timer */ if (w->reschedule_cb) { - ((WT)w)->at = w->reschedule_cb (w, ev_rt_now + 0.0001220703125 /* 1/8192 */); + ((WT)w)->at = w->reschedule_cb (w, ev_rt_now + TIME_EPSILON); assert (("ev_periodic reschedule callback returned time in the past", ((WT)w)->at > ev_rt_now)); downheap ((WT *)periodics, periodiccnt, 0); } else if (w->interval) { - ((WT)w)->at = w->offset + (floor ((ev_rt_now - w->offset) / w->interval) + 1.) * w->interval; + ((WT)w)->at = w->offset + floor ((ev_rt_now + TIME_EPSILON - w->offset) / w->interval + 1.) * w->interval; assert (("ev_periodic timeout in the past detected while processing timers, negative interval?", ((WT)w)->at > ev_rt_now)); downheap ((WT *)periodics, periodiccnt, 0); }