@ -13,6 +13,7 @@
# include <utime.h>
# ifndef WIN32
# include <sys/stat.h> /* for stat() */
# include <sys/time.h> /* for setitimer() */
# include <fcntl.h> /* open() flags */
# include <unistd.h> /* for geteuid(), getpid(), stat() */
# else
@ -4894,8 +4895,17 @@ do_watch(PQExpBuffer query_buf, double sleep)
const char * strftime_fmt ;
const char * user_title ;
char * title ;
const char * pagerprog = NULL ;
FILE * pagerpipe = NULL ;
int title_len ;
int res = 0 ;
# ifndef WIN32
sigset_t sigalrm_sigchld_sigint ;
sigset_t sigalrm_sigchld ;
sigset_t sigint ;
struct itimerval interval ;
bool done = false ;
# endif
if ( ! query_buf | | query_buf - > len < = 0 )
{
@ -4903,6 +4913,58 @@ do_watch(PQExpBuffer query_buf, double sleep)
return false ;
}
# ifndef WIN32
sigemptyset ( & sigalrm_sigchld_sigint ) ;
sigaddset ( & sigalrm_sigchld_sigint , SIGCHLD ) ;
sigaddset ( & sigalrm_sigchld_sigint , SIGALRM ) ;
sigaddset ( & sigalrm_sigchld_sigint , SIGINT ) ;
sigemptyset ( & sigalrm_sigchld ) ;
sigaddset ( & sigalrm_sigchld , SIGCHLD ) ;
sigaddset ( & sigalrm_sigchld , SIGALRM ) ;
sigemptyset ( & sigint ) ;
sigaddset ( & sigint , SIGINT ) ;
/*
* Block SIGALRM and SIGCHLD before we start the timer and the pager ( if
* configured ) , to avoid races . sigwait ( ) will receive them .
*/
sigprocmask ( SIG_BLOCK , & sigalrm_sigchld , NULL ) ;
/*
* Set a timer to interrupt sigwait ( ) so we can run the query at the
* requested intervals .
*/
interval . it_value . tv_sec = sleep_ms / 1000 ;
interval . it_value . tv_usec = ( sleep_ms % 1000 ) * 1000 ;
interval . it_interval = interval . it_value ;
if ( setitimer ( ITIMER_REAL , & interval , NULL ) < 0 )
{
pg_log_error ( " could not set timer: %m " ) ;
done = true ;
}
# endif
/*
* For \ watch , we ignore the size of the result and always use the pager
* if PSQL_WATCH_PAGER is set . We also ignore the regular PSQL_PAGER or
* PAGER environment variables , because traditional pagers probably won ' t
* be very useful for showing a stream of results .
*/
# ifndef WIN32
pagerprog = getenv ( " PSQL_WATCH_PAGER " ) ;
# endif
if ( pagerprog & & myopt . topt . pager )
{
disable_sigpipe_trap ( ) ;
pagerpipe = popen ( pagerprog , " w " ) ;
if ( ! pagerpipe )
/* silently proceed without pager */
restore_sigpipe_trap ( ) ;
}
/*
* Choose format for timestamps . We might eventually make this a \ pset
* option . In the meantime , using a variable for the format suppresses
@ -4911,10 +4973,12 @@ do_watch(PQExpBuffer query_buf, double sleep)
strftime_fmt = " %c " ;
/*
* Set up rendering options , in particular , disable the pager , because
* nobody wants to be prompted while watching the output of ' watch ' .
* Set up rendering options , in particular , disable the pager unless
* PSQL_WATCH_PAGER was successfully launched .
*/
myopt . topt . pager = 0 ;
if ( ! pagerpipe )
myopt . topt . pager = 0 ;
/*
* If there ' s a title in the user configuration , make sure we have room
@ -4929,7 +4993,6 @@ do_watch(PQExpBuffer query_buf, double sleep)
{
time_t timer ;
char timebuf [ 128 ] ;
long i ;
/*
* Prepare title for output . Note that we intentionally include a
@ -4948,7 +5011,7 @@ do_watch(PQExpBuffer query_buf, double sleep)
myopt . title = title ;
/* Run the query and print out the results */
res = PSQLexecWatch ( query_buf - > data , & myopt ) ;
res = PSQLexecWatch ( query_buf - > data , & myopt , pagerpipe ) ;
/*
* PSQLexecWatch handles the case where we can no longer repeat the
@ -4957,6 +5020,11 @@ do_watch(PQExpBuffer query_buf, double sleep)
if ( res < = 0 )
break ;
if ( pagerpipe & & ferror ( pagerpipe ) )
break ;
# ifdef WIN32
/*
* Set up cancellation of ' watch ' via SIGINT . We redo this each time
* through the loop since it ' s conceivable something inside
@ -4967,12 +5035,10 @@ do_watch(PQExpBuffer query_buf, double sleep)
/*
* Enable ' watch ' cancellations and wait a while before running the
* query again . Break the sleep into short intervals ( at most 1 s )
* since pg_usleep isn ' t interruptible on some platforms .
* query again . Break the sleep into short intervals ( at most 1 s ) .
*/
sigint_interrupt_enabled = true ;
i = sleep_ms ;
while ( i > 0 )
for ( long i = sleep_ms ; i > 0 ; )
{
long s = Min ( i , 1000L ) ;
@ -4982,8 +5048,57 @@ do_watch(PQExpBuffer query_buf, double sleep)
i - = s ;
}
sigint_interrupt_enabled = false ;
# else
/* sigwait() will handle SIGINT. */
sigprocmask ( SIG_BLOCK , & sigint , NULL ) ;
if ( cancel_pressed )
done = true ;
/* Wait for SIGINT, SIGCHLD or SIGALRM. */
while ( ! done )
{
int signal_received ;
if ( sigwait ( & sigalrm_sigchld_sigint , & signal_received ) < 0 )
{
/* Some other signal arrived? */
if ( errno = = EINTR )
continue ;
else
{
pg_log_error ( " could not wait for signals: %m " ) ;
done = true ;
break ;
}
}
/* On ^C or pager exit, it's time to stop running the query. */
if ( signal_received = = SIGINT | | signal_received = = SIGCHLD )
done = true ;
/* Otherwise, we must have SIGALRM. Time to run the query again. */
break ;
}
/* Unblock SIGINT so that slow queries can be interrupted. */
sigprocmask ( SIG_UNBLOCK , & sigint , NULL ) ;
if ( done )
break ;
# endif
}
if ( pagerpipe )
{
pclose ( pagerpipe ) ;
restore_sigpipe_trap ( ) ;
}
# ifndef WIN32
/* Disable the interval timer. */
memset ( & interval , 0 , sizeof ( interval ) ) ;
setitimer ( ITIMER_REAL , & interval , NULL ) ;
/* Unblock SIGINT, SIGCHLD and SIGALRM. */
sigprocmask ( SIG_UNBLOCK , & sigalrm_sigchld_sigint , NULL ) ;
# endif
pg_free ( title ) ;
return ( res > = 0 ) ;
}
Thomas Munro
4 years ago