diff options
Diffstat (limited to 'lib/sh/timers.c')
| -rw-r--r-- | lib/sh/timers.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/lib/sh/timers.c b/lib/sh/timers.c new file mode 100644 index 0000000..69b754c --- /dev/null +++ b/lib/sh/timers.c @@ -0,0 +1,262 @@ +/* timers - functions to manage shell timers */ + +/* Copyright (C) 2021 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + Bash 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 3 of the License, or + (at your option) any later version. + + Bash is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "config.h" + +#include "bashtypes.h" +#include "posixtime.h" + +#if defined (HAVE_UNISTD_H) +#include <unistd.h> +#endif + +#if defined (HAVE_SELECT) +# include "posixselect.h" +# include "stat-time.h" +#endif + +#include "sig.h" +#include "bashjmp.h" +#include "xmalloc.h" + +#include "timer.h" + +#include <errno.h> +#if !defined (errno) +extern int errno; +#endif /* !errno */ + +#ifndef FREE +#define FREE(s) do { if (s) free (s); } while (0) +#endif + +extern unsigned int falarm (unsigned int, unsigned int); + +static void shtimer_zero (sh_timer *); + +static void +shtimer_zero (sh_timer *t) +{ + t->tmout.tv_sec = 0; + t->tmout.tv_usec = 0; + + t->fd = -1; + t->flags = t->alrmflag = 0; + + t->alrm_handler = t->old_handler = 0; + + memset (t->jmpenv, '\0', sizeof (t->jmpenv)); + + t->tm_handler = 0; + t->data = 0; +} + +sh_timer * +shtimer_alloc (void) +{ + sh_timer *t; + + t = (sh_timer *)xmalloc (sizeof (sh_timer)); + shtimer_zero (t); + return t; +} + +void +shtimer_flush (sh_timer *t) +{ + /* The caller can manage t->data arbitrarily as long as it frees and sets + t->data to 0 before calling this function. Otherwise, we do what we can + to avoid memleaks. */ + FREE (t->data); + shtimer_zero (t); +} + +void +shtimer_dispose (sh_timer *t) +{ + free (t); +} + +/* We keep the timer as an offset into the future from the time it's set. */ +void +shtimer_set (sh_timer *t, time_t sec, long usec) +{ + struct timeval now; + + if (t->flags & SHTIMER_ALARM) + { + t->alrmflag = 0; /* just paranoia */ + t->old_handler = set_signal_handler (SIGALRM, t->alrm_handler); + t->flags |= SHTIMER_SIGSET; + falarm (t->tmout.tv_sec = sec, t->tmout.tv_usec = usec); + t->flags |= SHTIMER_ALRMSET; + return; + } + + if (gettimeofday (&now, 0) < 0) + timerclear (&now); + + t->tmout.tv_sec = now.tv_sec + sec; + t->tmout.tv_usec = now.tv_usec + usec; + if (t->tmout.tv_usec > USEC_PER_SEC) + { + t->tmout.tv_sec++; + t->tmout.tv_usec -= USEC_PER_SEC; + } +} + +void +shtimer_unset (sh_timer *t) +{ + t->tmout.tv_sec = 0; + t->tmout.tv_usec = 0; + + if (t->flags & SHTIMER_ALARM) + { + t->alrmflag = 0; + if (t->flags & SHTIMER_ALRMSET) + falarm (0, 0); + if (t->old_handler && (t->flags & SHTIMER_SIGSET)) + { + set_signal_handler (SIGALRM, t->old_handler); + t->flags &= ~SHTIMER_SIGSET; + t->old_handler = 0; + } + } +} + +void +shtimer_cleanup (sh_timer *t) +{ + shtimer_unset (t); +} + +void +shtimer_clear (sh_timer *t) +{ + shtimer_unset (t); + shtimer_dispose (t); +} + +int +shtimer_chktimeout (sh_timer *t) +{ + struct timeval now; + int r; + + /* Use the flag to avoid returning sigalrm_seen here */ + if (t->flags & SHTIMER_ALARM) + return t->alrmflag; + + /* Could check a flag for this */ + if (t->tmout.tv_sec == 0 && t->tmout.tv_usec == 0) + return 0; + + if (gettimeofday (&now, 0) < 0) + return 0; + r = ((now.tv_sec > t->tmout.tv_sec) || + (now.tv_sec == t->tmout.tv_sec && now.tv_usec >= t->tmout.tv_usec)); + + return r; +} + +#if defined (HAVE_SELECT) || defined (HAVE_PSELECT) +int +shtimer_select (sh_timer *t) +{ + int r, nfd; + sigset_t blocked_sigs, prevmask; + struct timeval now, tv; + fd_set readfds; +#if defined (HAVE_PSELECT) + struct timespec ts; +#endif + + /* We don't want a SIGCHLD to interrupt this */ + sigemptyset (&blocked_sigs); +# if defined (SIGCHLD) + sigaddset (&blocked_sigs, SIGCHLD); +# endif + + if (gettimeofday (&now, 0) < 0) + { + if (t->flags & SHTIMER_LONGJMP) + sh_longjmp (t->jmpenv, 1); + else + return -1; + } + + /* If the timer has already expired, return immediately */ + if ((now.tv_sec > t->tmout.tv_sec) || + (now.tv_sec == t->tmout.tv_sec && now.tv_usec >= t->tmout.tv_usec)) + { + if (t->flags & SHTIMER_LONGJMP) + sh_longjmp (t->jmpenv, 1); + else if (t->tm_handler) + return ((*t->tm_handler) (t)); + else + return 0; + } + + /* compute timeout */ + tv.tv_sec = t->tmout.tv_sec - now.tv_sec; + tv.tv_usec = t->tmout.tv_usec - now.tv_usec; + if (tv.tv_usec < 0) + { + tv.tv_sec--; + tv.tv_usec += USEC_PER_SEC; + } + +#if defined (HAVE_PSELECT) + ts.tv_sec = tv.tv_sec; + ts.tv_nsec = tv.tv_usec * 1000; +#else + sigemptyset (&prevmask); +#endif /* !HAVE_PSELECT */ + + nfd = (t->fd >= 0) ? t->fd + 1 : 0; + FD_ZERO (&readfds); + if (t->fd >= 0) + FD_SET (t->fd, &readfds); + +#if defined (HAVE_PSELECT) + r = pselect(nfd, &readfds, (fd_set *)0, (fd_set *)0, &ts, &blocked_sigs); +#else + sigprocmask (SIG_SETMASK, &blocked_sigs, &prevmask); + r = select(nfd, &readfds, (fd_set *)0, (fd_set *)0, &tv); + sigprocmask (SIG_SETMASK, &prevmask, NULL); +#endif + + if (r < 0) + return r; /* caller will handle */ + else if (r == 0 && (t->flags & SHTIMER_LONGJMP)) + sh_longjmp (t->jmpenv, 1); + else if (r == 0 && t->tm_handler) + return ((*t->tm_handler) (t)); + else + return r; +} +#endif /* !HAVE_TIMEVAL || !HAVE_SELECT */ + +int +shtimer_alrm (sh_timer *t) +{ + return 0; +} |