src/wd_keepalive.c - manifest_repos/watchdog - Git at Google

 /**********************************************************
  * Copyright:   Appliance Studio Ltd
  * License:	GPL
  *
  * Filename:    $Id: wd_keepalive.c,v 1.6 2007/08/17 09:24:54 meskes Exp $
  * Author:      Marcel Jansen, 22 February 2001
  * 		Michael Meskes, since then
  * Purpose:     This program can be run during critical periods
  *              when the normal watcdog shouldn't be run. It will
  *              read from the same configuration file, it will do
  *              no checks but will keep writing to the device
  *
 ***********************************************************/
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <errno.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <limits.h>
 #include <sched.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/mman.h>
 #include <sys/ioctl.h>
 #include <sys/wait.h>
 #include <linux/watchdog.h>
 #include <libgen.h>
 #include <string.h>
 #include <syslog.h>

 #include <unistd.h>

 #if USE_SYSLOG
 #include <syslog.h>
 #endif

 #define TRUE  1
 #define FALSE 0

 #define DEVICE		"watchdog-device"
 #define INTERVAL	"interval"
 #define PRIORITY        "priority"
 #define REALTIME        "realtime"

 int watchdog = -1, tint = 10, schedprio = 1;
 char *devname = NULL, *progname = NULL;
 volatile sig_atomic_t _running = 1;

 #if defined(_POSIX_MEMLOCK)
 int mlocked = FALSE, realtime = FALSE;
 #endif

 static void usage(void)
 {
     fprintf(stderr, "%s version %d.%d, usage:\n", progname, MAJOR_VERSION, MINOR_VERSION);
     fprintf(stderr, "%s \n", progname);
     exit(1);
 }

 /* write a log entry on exit */
 static void log_end()
 {
 #if USE_SYSLOG
     /* Log the closing message */
     syslog(LOG_INFO, "stopping watchdog keepalive daemon (%d.%d)", MAJOR_VERSION, MINOR_VERSION);
     closelog();
     sleep(5);           /* make sure log is written */
 #endif                          /* USE_SYSLOG */
     return;
 }

 /* close the device and check for error */
 static void close_all()
 {
 	if (watchdog != -1) {
 		if (write(watchdog, "V", 1) < 0 ) {
 			int err = errno;
 #if USE_SYSLOG
 	                syslog(LOG_ERR, "write watchdog device gave error %d = '%m'!", err);
 #else                           /* USE_SYSLOG */
 	                perror(progname);
 #endif                          /* USE_SYSLOG */
 	        }
 		if (close(watchdog) == -1) {
 #if USE_SYSLOG
 		        syslog(LOG_ALERT, "cannot close %s (errno = %d)", devname, errno);
 #else                           /* USE_SYSLOG */
 			perror(progname);
 #endif                          /* USE_SYSLOG */
 		}
         }
 }

 void sigterm_handler(int arg) {
     _running = 0;
 }

 /* on exit we close the device and log that we stop */
 void terminate(void) {
 #if defined(_POSIX_MEMLOCK)
     if ( realtime == TRUE && mlocked == TRUE ) {
         /* unlock all locked pages */
         if ( munlockall() != 0 ) {
 #if USE_SYSLOG
 	    syslog(LOG_ERR, "cannot unlock realtime memory (errno = %d)", errno);
 #else                           /* USE_SYSLOG */
             perror(progname);
 #endif                          /* USE_SYSLOG */
 	}
     }
 #endif    	/* _POSIX_MEMLOCK */
     close_all();
     log_end();
     exit(0);
 }

 static int spool(char *line, int *i, int offset)
 {
     for ( (*i) += offset; line[*i] == ' ' || line[*i] == '\t'; (*i)++ );
     if ( line[*i] == '=' )
         (*i)++;
     for ( ; line[*i] == ' ' || line[*i] == '\t'; (*i)++ );
     if ( line[*i] == '\0' )
         return(1);
     else
         return(0);
 }

 static void read_config(char *configfile, char *progname)
 {
     FILE *wc;

     if ( (wc = fopen(configfile, "r")) == NULL ) {
         perror(progname);
         exit(1);
     }

     while ( !feof(wc) ) {
 	char *line = NULL;
 	size_t n;

 	if (getline(&line, &n, wc) == -1) {
             if ( !ferror(wc) )
                 break;
             else {
                 perror(progname);
                 exit(1);
             }
         }
         else {
             int i, j;

             /* scan the actual line for an option */
             /* first remove the leading blanks */
             for ( i = 0; line[i] == ' ' || line[i] == '\t'; i++ );

             /* if the next sign is a '#' we have a comment */
             if ( line[i] == '#' )
                 continue;

             /* also remove the trailing blanks and the \n */
             for ( j = strlen(line) - 1; line[j] == ' ' || line[j] == '\t' || line[j] == '\n'; j-- );
             line[j + 1] = '\0';

             /* if the line is empty now, we don't have to parse it */
             if ( strlen(line + i) == 0 )
                 continue;

             /* now check for an option */
             if ( strncmp(line + i, INTERVAL, strlen(INTERVAL)) == 0 ) {
                 if ( spool(line, &i, strlen(INTERVAL)) )
                     fprintf(stderr, "Ignoring invalid line in config file:\n%s\n", line);
                 else
                     tint = atol(line + i);
             }
             else if ( strncmp(line + i, DEVICE, strlen(DEVICE)) == 0 ) {
                 if ( spool(line, &i, strlen(DEVICE)) )
                     devname = NULL;
                 else
                     devname = strdup(line + i);
 	    } else if (strncmp(line + i, REALTIME, strlen(REALTIME)) == 0) {
                 (void)spool(line, &i, strlen(REALTIME));
 	        realtime = (strncmp(line + i, "yes", 3) == 0) ? TRUE : FALSE;
 	    } else if (strncmp(line + i, PRIORITY, strlen(PRIORITY)) == 0) {
 	        if (spool(line, &i, strlen(PRIORITY)))
 			fprintf(stderr, "Ignoring invalid line in config file:\n%s\n", line);
 		else
 		        schedprio = atol(line + i);
 	    }
             else {
                 /*
 		 * do not print an error message here because we usually use
 		 * watchdog's config file which may contain far more valid
 		 * options than we understand
 		 */
 		/* fprintf(stderr, "Ignoring config line: %s\n", line); */
             }
         }
     }

     if ( fclose(wc) != 0 ) {
         perror(progname);
         exit(1);
     }
 }


 int main(int argc, char *const argv[])
 {
     FILE *fp;
     char *configfile = CONFIG_FILENAME;
     pid_t child_pid;
     int count = 0;
     int c;
     int oom_adjusted = 0;
     struct stat s;

     /* allow all options watchdog understands too */
 #if USE_SYSLOG
     char *opts = "d:i:n:fsvbql:p:t:c:r:m:a:";
     struct option long_options[] =
     {
 	{"config-file", required_argument, NULL, 'c'},
 	{"force", no_argument, NULL, 'f'},
 	{"sync", no_argument, NULL, 's'},
 	{"no-action", no_argument, NULL, 'q'},
 	{"verbose", no_argument, NULL, 'v'},
 	{"softboot", no_argument, NULL, 'b'},
 	{NULL, 0, NULL, 0}
     };
     struct watchdog_info ident;
 #else				/* USE_SYSLOG */
     char *opts = "d:i:n:fsbql:p:t:c:r:m:a:";
     struct option long_options[] =
     {
 	{"config-file", required_argument, NULL, 'c'},
 	{"force", no_argument, NULL, 'f'},
 	{"sync", no_argument, NULL, 's'},
 	{"no-action", no_argument, NULL, 'q'},
 	{"softboot", no_argument, NULL, 'b'},
 	{NULL, 0, NULL, 0}
     };
 #endif				/* USE_SYSLOG */

     progname = basename(argv[0]);

     /* check for the one option we understand */
     while ((c = getopt_long(argc, argv, opts, long_options, NULL)) != EOF) {
 	if (c == -1)
 	    break;
 	switch (c) {
 	case 'c':
 	    configfile = optarg;
 	    break;
 	case 'n':
 	case 'p':
 	case 'a':
 	case 'r':
 	case 'd':
 	case 't':
 	case 'l':
 	case 'm':
 	case 'i':
 	case 'f':
 	case 's':
 	case 'b':
 	case 'q':
 #if USE_SYSLOG
 	case 'v':
 #endif				/* USE_SYSLOG */
 	     break;
 	default:
 	    usage();
 	}
     }

     read_config(configfile, progname);

     /* make sure we're on the root partition */
     if ( chdir("/") < 0 ) {
         perror(progname);
         exit(1);
     }

 #if !defined(DEBUG)
     /* fork to go into the background */
     if ( (child_pid = fork()) < 0 ) {
         perror(progname);
         exit(1);
     }
     else if ( child_pid > 0 ) {
         /* fork was okay          */
         /* wait for child to exit */
         if ( waitpid(child_pid, NULL, 0) != child_pid ) {
             perror(progname);
             exit(1);
         }
         /* and exit myself */
         exit(0);
     }
     /* and fork again to make sure we inherit all rights from init */
     if ( (child_pid = fork()) < 0 ) {
         perror(progname);
         exit(1);
     }
     else if ( child_pid > 0 )
         exit(0);
 #endif				/* !DEBUG */

     /* now we're free */
 #if USE_SYSLOG
 #if !defined(DEBUG)
     /* Okay, we're a daemon     */
     /* but we're still attached to the tty */
     /* create our own session */
     setsid();
     /* with USE_SYSLOG we don't do any console IO */
     close(0);
     close(1);
     close(2);
 #endif				/* !DEBUG */

     /* Log the starting message */
     openlog(progname, LOG_PID, LOG_DAEMON);
     syslog(LOG_INFO, "starting watchdog keepalive daemon (%d.%d):", MAJOR_VERSION, MINOR_VERSION);
     if (devname == NULL)
 	syslog(LOG_INFO, " no watchdog device configured, aborting");
     else
     	syslog(LOG_INFO, " int=%d alive=%s realtime=%s", tint, devname, realtime ? "yes" : "no");
 #endif                          /* USE_SYSLOG */

     /* this daemon has no other function than writing to this device
      * i.e. if there is no device given we better punt */
     if ( devname == NULL )
 	terminate();

     /* open the device */
     watchdog = open(devname, O_WRONLY);
     if ( watchdog == -1 ) {
 #if USE_SYSLOG
             syslog(LOG_ERR, "cannot open %s (errno = %d = '%m')", devname, errno);
 #else                           /* USE_SYSLOG */
             perror(progname);
 #endif                          /* USE_SYSLOG */

             exit(1);
     }

 #if USE_SYSLOG
     /* Also log watchdog identity */
     if (ioctl(watchdog, WDIOC_GETSUPPORT, &ident) < 0) {
 	syslog(LOG_ERR, "cannot get watchdog identity (errno = %d = '%m')", errno);
     }
     else {
 	ident.identity[sizeof(ident.identity) - 1] = '\0'; /* Be sure */
 	syslog(LOG_INFO, "hardware wartchdog identity: %s", ident.identity);
     }
 #endif

     /* tuck my process id away */
     fp = fopen(KA_PIDFILE, "w");
     if ( fp != NULL ) {
         fprintf(fp, "%d\n", getpid());
         (void) fclose(fp);
     }

     /* set signal term to call sigterm_handler() */
     /* to make sure watchdog device is closed */
     signal(SIGTERM, sigterm_handler);

 #if defined(_POSIX_MEMLOCK)
     if ( realtime == TRUE ) {
         /* lock all actual and future pages into memory */
         if ( mlockall(MCL_CURRENT | MCL_FUTURE) != 0 ) {
 #if USE_SYSLOG
 		syslog(LOG_ERR, "cannot lock realtime memory (errno = %d = '%m')", errno);
 #else                           /* USE_SYSLOG */
                 perror(progname);
 #endif                           /* USE_SYSLOG */

         }
         else {
             struct sched_param sp;

             /* now set the scheduler */
             sp.sched_priority = schedprio;
             if ( sched_setscheduler(0, SCHED_RR, &sp) != 0 ) {
 #if USE_SYSLOG
 		syslog(LOG_ERR, "cannot set scheduler (errno = %d = '%m')", errno);
 #else                           /* USE_SYSLOG */
                 perror(progname);
 #endif                           /* USE_SYSLOG */
             }
             else
                 mlocked = TRUE;
         }
     }
 #endif

     /* tell oom killer to not kill this process */
 #ifdef OOM_SCORE_ADJ_MIN
    if ( ! stat("/proc/self/oom_score_adj", &s) ) {
 	fp = fopen("/proc/self/oom_score_adj", "w");
 	if (fp) {
 		fprintf(fp, "%d\n", OOM_SCORE_ADJ_MIN);
 		(void) fclose(fp);
 		oom_adjusted = 1;
 	}
    }
 #endif
 #ifdef OOM_DISABLE
    if ( ! oom_adjusted ) {
 	if ( ! stat("/proc/self/oom_adj", &s) ) {
 		fp = fopen("/proc/self/oom_adj", "w");
 		if (fp) {
 			fprintf(fp, "%d\n", OOM_DISABLE);
 			(void) fclose(fp);
 			oom_adjusted = 1;
 		}
 	}
    }
 #endif
 #if USE_SYSLOG
    if ( ! oom_adjusted ) {
 	syslog(LOG_WARNING, "unable to disable oom handling!");
    }
 #endif				/* USE_SYSLOG */

     /* main loop: update after <tint> seconds */
     while ( _running ) {
         if ( write(watchdog, "\0", 1) < 0 ) {
             int err = errno;
 #if USE_SYSLOG
 	    syslog(LOG_ERR, "write watchdog device gave error %d = '%m'!", err);
 #else                   /* USE_SYSLOG */
             perror(progname);
 #endif                  /* USE_SYSLOG */
         }

         /* finally sleep some seconds */
         sleep(tint);

         count++;
     }

     terminate();
     /* not reached */
     return 0;
 }
	/**********************************************************
	* Copyright: Appliance Studio Ltd
	* License: GPL
	*
	* Filename: $Id: wd_keepalive.c,v 1.6 2007/08/17 09:24:54 meskes Exp $
	* Author: Marcel Jansen, 22 February 2001
	* Michael Meskes, since then
	* Purpose: This program can be run during critical periods
	* when the normal watcdog shouldn't be run. It will
	* read from the same configuration file, it will do
	* no checks but will keep writing to the device
	*
	***********************************************************/
	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <errno.h>
	#include <fcntl.h>
	#include <getopt.h>
	#include <limits.h>
	#include <sched.h>
	#include <signal.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/mman.h>
	#include <sys/ioctl.h>
	#include <sys/wait.h>
	#include <linux/watchdog.h>
	#include <libgen.h>
	#include <string.h>
	#include <syslog.h>

	#include <unistd.h>

	#if USE_SYSLOG
	#include <syslog.h>
	#endif

	#define TRUE 1
	#define FALSE 0

	#define DEVICE "watchdog-device"
	#define INTERVAL "interval"
	#define PRIORITY "priority"
	#define REALTIME "realtime"

	int watchdog = -1, tint = 10, schedprio = 1;
	char devname = NULL, progname = NULL;
	volatile sig_atomic_t _running = 1;

	#if defined(_POSIX_MEMLOCK)
	int mlocked = FALSE, realtime = FALSE;
	#endif

	static void usage(void)
	{
	fprintf(stderr, "%s version %d.%d, usage:\n", progname, MAJOR_VERSION, MINOR_VERSION);
	fprintf(stderr, "%s \n", progname);
	exit(1);
	}

	/* write a log entry on exit */
	static void log_end()
	{
	#if USE_SYSLOG
	/* Log the closing message */
	syslog(LOG_INFO, "stopping watchdog keepalive daemon (%d.%d)", MAJOR_VERSION, MINOR_VERSION);
	closelog();
	sleep(5); /* make sure log is written */
	#endif /* USE_SYSLOG */
	return;
	}

	/* close the device and check for error */
	static void close_all()
	{
	if (watchdog != -1) {
	if (write(watchdog, "V", 1) < 0 ) {
	int err = errno;
	#if USE_SYSLOG
	syslog(LOG_ERR, "write watchdog device gave error %d = '%m'!", err);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */
	}
	if (close(watchdog) == -1) {
	#if USE_SYSLOG
	syslog(LOG_ALERT, "cannot close %s (errno = %d)", devname, errno);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */
	}
	}
	}

	void sigterm_handler(int arg) {
	_running = 0;
	}

	/* on exit we close the device and log that we stop */
	void terminate(void) {
	#if defined(_POSIX_MEMLOCK)
	if ( realtime == TRUE && mlocked == TRUE ) {
	/* unlock all locked pages */
	if ( munlockall() != 0 ) {
	#if USE_SYSLOG
	syslog(LOG_ERR, "cannot unlock realtime memory (errno = %d)", errno);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */
	}
	}
	#endif /* _POSIX_MEMLOCK */
	close_all();
	log_end();
	exit(0);
	}

	static int spool(char line, int i, int offset)
	{
	for ( (i) += offset; line[i] == ' ' \|\| line[i] == '\t'; (i)++ );
	if ( line[*i] == '=' )
	(*i)++;
	for ( ; line[i] == ' ' \|\| line[i] == '\t'; (*i)++ );
	if ( line[*i] == '\0' )
	return(1);
	else
	return(0);
	}

	static void read_config(char configfile, char progname)
	{
	FILE *wc;

	if ( (wc = fopen(configfile, "r")) == NULL ) {
	perror(progname);
	exit(1);
	}

	while ( !feof(wc) ) {
	char *line = NULL;
	size_t n;

	if (getline(&line, &n, wc) == -1) {
	if ( !ferror(wc) )
	break;
	else {
	perror(progname);
	exit(1);
	}
	}
	else {
	int i, j;

	/* scan the actual line for an option */
	/* first remove the leading blanks */
	for ( i = 0; line[i] == ' ' \|\| line[i] == '\t'; i++ );

	/* if the next sign is a '#' we have a comment */
	if ( line[i] == '#' )
	continue;

	/* also remove the trailing blanks and the \n */
	for ( j = strlen(line) - 1; line[j] == ' ' \|\| line[j] == '\t' \|\| line[j] == '\n'; j-- );
	line[j + 1] = '\0';

	/* if the line is empty now, we don't have to parse it */
	if ( strlen(line + i) == 0 )
	continue;

	/* now check for an option */
	if ( strncmp(line + i, INTERVAL, strlen(INTERVAL)) == 0 ) {
	if ( spool(line, &i, strlen(INTERVAL)) )
	fprintf(stderr, "Ignoring invalid line in config file:\n%s\n", line);
	else
	tint = atol(line + i);
	}
	else if ( strncmp(line + i, DEVICE, strlen(DEVICE)) == 0 ) {
	if ( spool(line, &i, strlen(DEVICE)) )
	devname = NULL;
	else
	devname = strdup(line + i);
	} else if (strncmp(line + i, REALTIME, strlen(REALTIME)) == 0) {
	(void)spool(line, &i, strlen(REALTIME));
	realtime = (strncmp(line + i, "yes", 3) == 0) ? TRUE : FALSE;
	} else if (strncmp(line + i, PRIORITY, strlen(PRIORITY)) == 0) {
	if (spool(line, &i, strlen(PRIORITY)))
	fprintf(stderr, "Ignoring invalid line in config file:\n%s\n", line);
	else
	schedprio = atol(line + i);
	}
	else {
	/*
	* do not print an error message here because we usually use
	* watchdog's config file which may contain far more valid
	* options than we understand
	*/
	/* fprintf(stderr, "Ignoring config line: %s\n", line); */
	}
	}
	}

	if ( fclose(wc) != 0 ) {
	perror(progname);
	exit(1);
	}
	}


	int main(int argc, char *const argv[])
	{
	FILE *fp;
	char *configfile = CONFIG_FILENAME;
	pid_t child_pid;
	int count = 0;
	int c;
	int oom_adjusted = 0;
	struct stat s;

	/* allow all options watchdog understands too */
	#if USE_SYSLOG
	char *opts = "d:i:n:fsvbql:p:t:c:r:m:a:";
	struct option long_options[] =
	{
	{"config-file", required_argument, NULL, 'c'},
	{"force", no_argument, NULL, 'f'},
	{"sync", no_argument, NULL, 's'},
	{"no-action", no_argument, NULL, 'q'},
	{"verbose", no_argument, NULL, 'v'},
	{"softboot", no_argument, NULL, 'b'},
	{NULL, 0, NULL, 0}
	};
	struct watchdog_info ident;
	#else /* USE_SYSLOG */
	char *opts = "d:i:n:fsbql:p:t:c:r:m:a:";
	struct option long_options[] =
	{
	{"config-file", required_argument, NULL, 'c'},
	{"force", no_argument, NULL, 'f'},
	{"sync", no_argument, NULL, 's'},
	{"no-action", no_argument, NULL, 'q'},
	{"softboot", no_argument, NULL, 'b'},
	{NULL, 0, NULL, 0}
	};
	#endif /* USE_SYSLOG */

	progname = basename(argv[0]);

	/* check for the one option we understand */
	while ((c = getopt_long(argc, argv, opts, long_options, NULL)) != EOF) {
	if (c == -1)
	break;
	switch (c) {
	case 'c':
	configfile = optarg;
	break;
	case 'n':
	case 'p':
	case 'a':
	case 'r':
	case 'd':
	case 't':
	case 'l':
	case 'm':
	case 'i':
	case 'f':
	case 's':
	case 'b':
	case 'q':
	#if USE_SYSLOG
	case 'v':
	#endif /* USE_SYSLOG */
	break;
	default:
	usage();
	}
	}

	read_config(configfile, progname);

	/* make sure we're on the root partition */
	if ( chdir("/") < 0 ) {
	perror(progname);
	exit(1);
	}

	#if !defined(DEBUG)
	/* fork to go into the background */
	if ( (child_pid = fork()) < 0 ) {
	perror(progname);
	exit(1);
	}
	else if ( child_pid > 0 ) {
	/* fork was okay */
	/* wait for child to exit */
	if ( waitpid(child_pid, NULL, 0) != child_pid ) {
	perror(progname);
	exit(1);
	}
	/* and exit myself */
	exit(0);
	}
	/* and fork again to make sure we inherit all rights from init */
	if ( (child_pid = fork()) < 0 ) {
	perror(progname);
	exit(1);
	}
	else if ( child_pid > 0 )
	exit(0);
	#endif /* !DEBUG */

	/* now we're free */
	#if USE_SYSLOG
	#if !defined(DEBUG)
	/* Okay, we're a daemon */
	/* but we're still attached to the tty */
	/* create our own session */
	setsid();
	/* with USE_SYSLOG we don't do any console IO */
	close(0);
	close(1);
	close(2);
	#endif /* !DEBUG */

	/* Log the starting message */
	openlog(progname, LOG_PID, LOG_DAEMON);
	syslog(LOG_INFO, "starting watchdog keepalive daemon (%d.%d):", MAJOR_VERSION, MINOR_VERSION);
	if (devname == NULL)
	syslog(LOG_INFO, " no watchdog device configured, aborting");
	else
	syslog(LOG_INFO, " int=%d alive=%s realtime=%s", tint, devname, realtime ? "yes" : "no");
	#endif /* USE_SYSLOG */

	/* this daemon has no other function than writing to this device
	* i.e. if there is no device given we better punt */
	if ( devname == NULL )
	terminate();

	/* open the device */
	watchdog = open(devname, O_WRONLY);
	if ( watchdog == -1 ) {
	#if USE_SYSLOG
	syslog(LOG_ERR, "cannot open %s (errno = %d = '%m')", devname, errno);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */

	exit(1);
	}

	#if USE_SYSLOG
	/* Also log watchdog identity */
	if (ioctl(watchdog, WDIOC_GETSUPPORT, &ident) < 0) {
	syslog(LOG_ERR, "cannot get watchdog identity (errno = %d = '%m')", errno);
	}
	else {
	ident.identity[sizeof(ident.identity) - 1] = '\0'; /* Be sure */
	syslog(LOG_INFO, "hardware wartchdog identity: %s", ident.identity);
	}
	#endif

	/* tuck my process id away */
	fp = fopen(KA_PIDFILE, "w");
	if ( fp != NULL ) {
	fprintf(fp, "%d\n", getpid());
	(void) fclose(fp);
	}

	/* set signal term to call sigterm_handler() */
	/* to make sure watchdog device is closed */
	signal(SIGTERM, sigterm_handler);

	#if defined(_POSIX_MEMLOCK)
	if ( realtime == TRUE ) {
	/* lock all actual and future pages into memory */
	if ( mlockall(MCL_CURRENT \| MCL_FUTURE) != 0 ) {
	#if USE_SYSLOG
	syslog(LOG_ERR, "cannot lock realtime memory (errno = %d = '%m')", errno);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */

	}
	else {
	struct sched_param sp;

	/* now set the scheduler */
	sp.sched_priority = schedprio;
	if ( sched_setscheduler(0, SCHED_RR, &sp) != 0 ) {
	#if USE_SYSLOG
	syslog(LOG_ERR, "cannot set scheduler (errno = %d = '%m')", errno);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */
	}
	else
	mlocked = TRUE;
	}
	}
	#endif

	/* tell oom killer to not kill this process */
	#ifdef OOM_SCORE_ADJ_MIN
	if ( ! stat("/proc/self/oom_score_adj", &s) ) {
	fp = fopen("/proc/self/oom_score_adj", "w");
	if (fp) {
	fprintf(fp, "%d\n", OOM_SCORE_ADJ_MIN);
	(void) fclose(fp);
	oom_adjusted = 1;
	}
	}
	#endif
	#ifdef OOM_DISABLE
	if ( ! oom_adjusted ) {
	if ( ! stat("/proc/self/oom_adj", &s) ) {
	fp = fopen("/proc/self/oom_adj", "w");
	if (fp) {
	fprintf(fp, "%d\n", OOM_DISABLE);
	(void) fclose(fp);
	oom_adjusted = 1;
	}
	}
	}
	#endif
	#if USE_SYSLOG
	if ( ! oom_adjusted ) {
	syslog(LOG_WARNING, "unable to disable oom handling!");
	}
	#endif /* USE_SYSLOG */

	/* main loop: update after <tint> seconds */
	while ( _running ) {
	if ( write(watchdog, "\0", 1) < 0 ) {
	int err = errno;
	#if USE_SYSLOG
	syslog(LOG_ERR, "write watchdog device gave error %d = '%m'!", err);
	#else /* USE_SYSLOG */
	perror(progname);
	#endif /* USE_SYSLOG */
	}

	/* finally sleep some seconds */
	sleep(tint);

	count++;
	}

	terminate();
	/* not reached */
	return 0;
	}