X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fnanosleep.c;h=fe22a97cabac69e955e2c10c6575e71e571f4716;hb=b566a1cae5310716bad3151cee69f943915b2d31;hp=c5451ffc4f5992d4089751f192b7e70b4065bb56;hpb=c6beac9fc4202f59840b4b1e774ff803b43ec044;p=gnulib.git diff --git a/lib/nanosleep.c b/lib/nanosleep.c index c5451ffc4..fe22a97ca 100644 --- a/lib/nanosleep.c +++ b/lib/nanosleep.c @@ -1,5 +1,7 @@ /* Provide a replacement for the POSIX nanosleep function. - Copyright (C) 1999, 2000, 2002, 2004 Free Software Foundation, Inc. + + Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006 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 @@ -13,7 +15,7 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, - Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ /* written by Jim Meyering */ @@ -23,27 +25,99 @@ prototype for rpl_nanosleep. (they'd conflict e.g., on alpha-dec-osf3.2) */ #undef nanosleep +#include #include #include +#if HAVE_SYS_SELECT_H +# include +#endif #include -#include -#ifndef errno -extern int errno; +#if TIME_WITH_SYS_TIME +# include +# include +#else +# if HAVE_SYS_TIME_H +# include +# else +# include +# endif #endif -#if HAVE_UNISTD_H -# include -#endif +#include + +#include + +#include "timespec.h" + +enum { BILLION = 1000 * 1000 * 1000 }; + +#if HAVE_BUG_BIG_NANOSLEEP + +void +getnow (struct timespec *t) +{ +# if defined CLOCK_MONOTONIC && HAVE_CLOCK_GETTIME + if (clock_gettime (CLOCK_MONOTONIC, t) == 0) + return; +# endif + gettime (t); +} + +int +rpl_nanosleep (const struct timespec *requested_delay, + struct timespec *remaining_delay) +{ + /* nanosleep mishandles large sleeps due to internal overflow + problems, so check that the proper amount of time has actually + elapsed. */ + + struct timespec delay = *requested_delay; + struct timespec t0; + getnow (&t0); + + for (;;) + { + int r = nanosleep (&delay, remaining_delay); + if (r == 0) + { + time_t secs_sofar; + struct timespec now; + getnow (&now); + + secs_sofar = now.tv_sec - t0.tv_sec; + if (requested_delay->tv_sec < secs_sofar) + return 0; + delay.tv_sec = requested_delay->tv_sec - secs_sofar; + delay.tv_nsec = requested_delay->tv_nsec - (now.tv_nsec - t0.tv_nsec); + if (delay.tv_nsec < 0) + { + if (delay.tv_sec == 0) + return 0; + delay.tv_nsec += BILLION; + delay.tv_sec--; + } + else if (BILLION <= delay.tv_nsec) + { + delay.tv_nsec -= BILLION; + delay.tv_sec++; + } + } + } +} + +#else /* Some systems (MSDOS) don't have SIGCONT. Using SIGTERM here turns the signal-handling code below into a no-op on such systems. */ -#ifndef SIGCONT -# define SIGCONT SIGTERM -#endif +# ifndef SIGCONT +# define SIGCONT SIGTERM +# endif -#include "timespec.h" +# if ! HAVE_SIGINTERRUPT +# define siginterrupt(sig, flag) /* empty */ +# endif static sig_atomic_t volatile suspended; @@ -55,7 +129,7 @@ sighandler (int sig) suspended = 1; } -/* FIXME: comment */ +/* Suspend execution for at least *TS_DELAY seconds. */ static void my_usleep (const struct timespec *ts_delay) @@ -65,30 +139,32 @@ my_usleep (const struct timespec *ts_delay) tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000; if (tv_delay.tv_usec == 1000000) { - tv_delay.tv_sec++; - tv_delay.tv_usec = 0; + time_t t1 = tv_delay.tv_sec + 1; + if (t1 < tv_delay.tv_sec) + tv_delay.tv_usec = 1000000 - 1; /* close enough */ + else + { + tv_delay.tv_sec = t1; + tv_delay.tv_usec = 0; + } } - select (0, (void *) 0, (void *) 0, (void *) 0, &tv_delay); + select (0, NULL, NULL, NULL, &tv_delay); } -/* FIXME: comment */ +/* Suspend execution for at least *REQUESTED_DELAY seconds. The + *REMAINING_DELAY part isn't implemented yet. */ int rpl_nanosleep (const struct timespec *requested_delay, struct timespec *remaining_delay) { - static int initialized; - -#ifdef SA_NOCLDSTOP - struct sigaction oldact, newact; -#endif - - suspended = 0; + static bool initialized; /* set up sig handler */ if (! initialized) { -#ifdef SA_NOCLDSTOP +# ifdef SA_NOCLDSTOP + struct sigaction oldact, newact; newact.sa_handler = sighandler; sigemptyset (&newact.sa_mask); newact.sa_flags = 0; @@ -96,13 +172,18 @@ rpl_nanosleep (const struct timespec *requested_delay, sigaction (SIGCONT, NULL, &oldact); if (oldact.sa_handler != SIG_IGN) sigaction (SIGCONT, &newact, NULL); -#else +# else if (signal (SIGCONT, SIG_IGN) != SIG_IGN) - signal (SIGCONT, sighandler); -#endif - initialized = 1; + { + signal (SIGCONT, sighandler); + siginterrupt (SIGCONT, 1); + } +# endif + initialized = true; } + suspended = 0; + my_usleep (requested_delay); if (suspended) @@ -118,3 +199,4 @@ rpl_nanosleep (const struct timespec *requested_delay, return suspended; } +#endif