X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fnanosleep.c;h=e413c5db01d7da19b5e90c32edc14f9969db98c2;hb=0600c3a06dc7495a7649234fe6e1ff813abeac02;hp=126a02622031f4eb2e2132bbcf39553fe5b7af43;hpb=840d60f5784edf31db3c78667f42b4b6659b5430;p=gnulib.git diff --git a/lib/nanosleep.c b/lib/nanosleep.c index 126a02622..e413c5db0 100644 --- a/lib/nanosleep.c +++ b/lib/nanosleep.c @@ -1,10 +1,12 @@ /* Provide a replacement for the POSIX nanosleep function. - Copyright (C) 1999 Free Software Foundation, Inc. - This program is free software; you can redistribute it and/or modify + Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008 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 - the Free Software Foundation; either version 2, or (at your option) - any later version. + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -12,85 +14,155 @@ GNU General Public License for more details. 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. */ + along with this program. If not, see . */ /* written by Jim Meyering */ #include + +#include + +#include "sig-handler.h" +#include "timespec.h" + +#include #include #include +#include #include +#include #include -#ifndef errno -extern int errno; -#endif -#if HAVE_UNISTD_H -# include -#endif +#include -#include -/* FIXME: is including both like this kosher? */ -#include +#undef nanosleep -static int suspended; +enum { BILLION = 1000 * 1000 * 1000 }; -/* Handle SIGCONT. */ +#if HAVE_BUG_BIG_NANOSLEEP -static void -sighandler (int sig) +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) { -#ifdef SA_INTERRUPT - struct sigaction sigact; + /* 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++; + } + } + } +} - sigact.sa_handler = SIG_DFL; - sigemptyset (&sigact.sa_mask); - sigact.sa_flags = 0; - sigaction (sig, &sigact, NULL); #else - signal (sig, SIG_DFL); -#endif +/* 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 + +static sig_atomic_t volatile suspended; + +/* Handle SIGCONT. */ + +static void +sighandler (int sig) +{ suspended = 1; - kill (getpid (), sig); } -/* Sleep for USEC microseconds. */ +/* Suspend execution for at least *TS_DELAY seconds. */ static void my_usleep (const struct timespec *ts_delay) { struct timeval tv_delay; tv_delay.tv_sec = ts_delay->tv_sec; - tv_delay.tv_usec = 1000 * ts_delay->tv_nsec; - select (0, (void *) 0, (void *) 0, (void *) 0, &tv_delay); + tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000; + if (tv_delay.tv_usec == 1000000) + { + 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, NULL, NULL, NULL, &tv_delay); } +/* Suspend execution for at least *REQUESTED_DELAY seconds. The + *REMAINING_DELAY part isn't implemented yet. */ + int -nanosleep (const struct timespec *requested_delay, - struct timespec *remaining_delay) +rpl_nanosleep (const struct timespec *requested_delay, + struct timespec *remaining_delay) { -#ifdef SA_INTERRUPT - struct sigaction oldact, newact; -#endif - - suspended = 0; + static bool initialized; - /* set up sig handler -- but maybe only do this the first time? */ -#ifdef SA_INTERRUPT - newact.sa_handler = sighandler; - sigemptyset (&newact.sa_mask); - newact.sa_flags = 0; + /* set up sig handler */ + if (! initialized) + { + struct sigaction oldact; + + sigaction (SIGCONT, NULL, &oldact); + if (get_handler (&oldact) != SIG_IGN) + { + struct sigaction newact; + + newact.sa_handler = sighandler; + sigemptyset (&newact.sa_mask); + newact.sa_flags = 0; + sigaction (SIGCONT, &newact, NULL); + } + initialized = true; + } - sigaction (SIGCONT, NULL, &oldact); - if (oldact.sa_handler != SIG_IGN) - sigaction (SIGCONT, &newact, NULL); -#else - if (signal (SIGCONT, SIG_IGN) != SIG_IGN) - signal (SIGCONT, sighandler); -#endif + suspended = 0; my_usleep (requested_delay); @@ -99,11 +171,12 @@ nanosleep (const struct timespec *requested_delay, /* Calculate time remaining. */ /* FIXME: the code in sleep doesn't use this, so there's no rush to implement it. */ + + errno = EINTR; } /* FIXME: Restore sig handler? */ - errno = EINTR; - return suspended; } +#endif