X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxnanosleep.c;h=3b2b43baaf84b6e594fb3eae15d841bd5e017f4a;hb=cd56634a4a8179fd5a4419fbb3e27211b042ab1c;hp=64bc7d29a5411270a543458d3ef7cd1391437fb3;hpb=441aa3044f43e5572f58c354f01e6bc070acd5c7;p=gnulib.git diff --git a/lib/xnanosleep.c b/lib/xnanosleep.c index 64bc7d29a..3b2b43baa 100644 --- a/lib/xnanosleep.c +++ b/lib/xnanosleep.c @@ -1,7 +1,6 @@ /* xnanosleep.c -- a more convenient interface to nanosleep - Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software - Foundation, Inc. + Copyright (C) 2002-2007, 2009-2014 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -23,85 +22,25 @@ #include "xnanosleep.h" -#include -#include -#include -#include +#include + #include -#include #include -#include "intprops.h" - -#ifndef TIME_T_MAX -# define TIME_T_MAX TYPE_MAXIMUM (time_t) -#endif - /* Sleep until the time (call it WAKE_UP_TIME) specified as SECONDS seconds after the time this function is called. SECONDS must be non-negative. If SECONDS is so large that - it is not representable as a `struct timespec', then use + it is not representable as a 'struct timespec', then use the maximum value for that interval. Return -1 on failure (setting errno), 0 on success. */ int xnanosleep (double seconds) { - enum { BILLION = 1000000000 }; - - /* For overflow checking, use naive comparison if possible, widening - to long double if double is not wide enough. Otherwise, use <=, - not <, to avoid problems when TIME_T_MAX is less than SECONDS but - compares equal to SECONDS after loss of precision when coercing - from time_t to long double. This mishandles near-maximal values - in some rare (perhaps theoretical) cases but that is better than - undefined behavior. */ - bool overflow = ((time_t) ((double) TIME_T_MAX / 2) == TIME_T_MAX / 2 - ? TIME_T_MAX < seconds - : (time_t) ((long double) TIME_T_MAX / 2) == TIME_T_MAX / 2 - ? TIME_T_MAX < (long double) seconds - : TIME_T_MAX <= (long double) seconds); - - struct timespec ts_sleep; - - assert (0 <= seconds); - - /* Separate whole seconds from nanoseconds. */ - if (! overflow) - { - time_t floor_seconds = seconds; - double ns = BILLION * (seconds - floor_seconds); - ts_sleep.tv_sec = floor_seconds; - - /* Round up to the next whole number, if necessary, so that we - always sleep for at least the requested amount of time. Assuming - the default rounding mode, we don't have to worry about the - rounding error when computing 'ns' above, since the error won't - cause 'ns' to drop below an integer boundary. */ - ts_sleep.tv_nsec = ns; - ts_sleep.tv_nsec += (ts_sleep.tv_nsec < ns); - - /* Normalize the interval length. nanosleep requires this. */ - if (BILLION <= ts_sleep.tv_nsec) - { - if (ts_sleep.tv_sec == TIME_T_MAX) - overflow = true; - else - { - ts_sleep.tv_sec++; - ts_sleep.tv_nsec -= BILLION; - } - } - } + struct timespec ts_sleep = dtotimespec (seconds); for (;;) { - if (overflow) - { - ts_sleep.tv_sec = TIME_T_MAX; - ts_sleep.tv_nsec = BILLION - 1; - } - /* Linux-2.6.8.1's nanosleep returns -1, but doesn't set errno when resumed after being suspended. Earlier versions would set errno to EINTR. nanosleep from linux-2.6.10, as well as