# HG changeset patch
# User Michiel Broek <mbroek@mbse.eu>
# Date 1399916711 -7200
# Node ID 38e3e3a49320e4c8e329dfa6aa367cd6b7f6b8e0
# Parent  2357e8636a6077aae203dbcd5220fb094be05e88
Added lock/pid file

diff -r 2357e8636a60 -r 38e3e3a49320 coolers/coolers.c
--- a/coolers/coolers.c	Fri May 09 22:29:42 2014 +0200
+++ b/coolers/coolers.c	Mon May 12 19:45:11 2014 +0200
@@ -241,6 +241,11 @@
     rc_switch		*tmp2, *old2;
     int			rc, run = 0, temp;
 
+    if (lockprog((char *)"coolers")) {
+	syslog(LOG_NOTICE, "Can't lock");
+	return 1;
+    }
+
     my_mosquitto_init();
 
     rc = piThreadCreate(my_sensors_loop);
@@ -323,6 +328,8 @@
     stopLCD();
     disableTransmit();
 
+    ulockprog((char *)"coolers");
+
     if (debug)
 	fprintf(stdout, "Goodbye\n");
 
diff -r 2357e8636a60 -r 38e3e3a49320 lib/Makefile
--- a/lib/Makefile	Fri May 09 22:29:42 2014 +0200
+++ b/lib/Makefile	Mon May 12 19:45:11 2014 +0200
@@ -3,9 +3,9 @@
 include ../Makefile.global
 
 SRCS		= xutil.c rdconfig.c lcd-pcf8574.c rc-switch.c dht11.c \
-		  logger.c
+		  logger.c lock.c
 OBJS		= xutil.o rdconfig.o lcd-pcf8574.o rc-switch.o dht11.o \
-		  logger.o
+		  logger.o lock.o
 HDRS		= mbselib.h
 TARGET		= libmbse.a
 
@@ -52,4 +52,5 @@
 rc-switch.o: ../config.h mbselib.h
 dht11.o: ../config.h mbselib.h
 logger.o: ../config.h mbselib.h
+lock.o: ../config.h mbselib.h
 # End of generated dependencies
diff -r 2357e8636a60 -r 38e3e3a49320 lib/lock.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/lock.c	Mon May 12 19:45:11 2014 +0200
@@ -0,0 +1,133 @@
+/*****************************************************************************
+ * Copyright (C) 2014
+ *   
+ * Michiel Broek <mbroek at mbse dot eu>
+ *
+ * This file is part of the mbsePi-apps
+ *
+ * This 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.
+ *
+ * mbsePi-apps 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 EC-65K; see the file COPYING.  If not, write to the Free
+ * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *****************************************************************************/
+
+#include "../config.h"
+#include "mbselib.h"
+
+/*
+ *  Put a lock on this program.
+ */
+int lockprog(char *name)
+{
+    char    *tempfile, *lockfile;
+    FILE    *fp;
+    pid_t   oldpid;
+
+    tempfile = calloc(PATH_MAX, sizeof(char));
+    lockfile = calloc(PATH_MAX, sizeof(char));
+
+    snprintf(tempfile, PATH_MAX, "/var/run/%s.tmp", name);
+    snprintf(lockfile, PATH_MAX, "/var/run/%s.pid", name);
+
+    if ((fp = fopen(tempfile, "w")) == NULL) {
+	perror(name);
+	printf("Can't create lockfile \"%s\"\n", tempfile);
+	free(tempfile);
+	free(lockfile);
+	return 1;
+    }
+    fprintf(fp, "%10u\n", getpid());
+    fclose(fp);
+
+    while (TRUE) {
+	if (link(tempfile, lockfile) == 0) {
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 0;
+	}
+	if ((fp = fopen(lockfile, "r")) == NULL) {
+	    perror(name);
+	    printf("Can't open lockfile \"%s\"\n", tempfile);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+	if (fscanf(fp, "%u", &oldpid) != 1) {
+	    perror(name);
+	    printf("Can't read old pid from \"%s\"\n", tempfile);
+	    fclose(fp);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+	fclose(fp);
+	if (kill(oldpid,0) == -1) {
+	    if (errno == ESRCH) {
+		printf("Stale lock found for pid %u\n", oldpid);
+		unlink(lockfile);
+		/* no return, try lock again */  
+	    } else {
+		perror(name);
+		printf("Kill for %u failed\n",oldpid);
+		unlink(tempfile);
+		free(tempfile);
+		free(lockfile);
+		return 1;
+	    }
+	} else {
+	    printf("Another %s is already running, pid=%u\n", name, oldpid);
+	    unlink(tempfile);
+	    free(tempfile);
+	    free(lockfile);
+	    return 1;
+	}
+    }
+}
+
+
+
+void ulockprog(char *name)
+{
+    char	    *lockfile;
+    pid_t	    oldpid;
+    FILE	    *fp;
+
+    lockfile = calloc(PATH_MAX, sizeof(char));
+    snprintf(lockfile, PATH_MAX, "/var/run/%s.pid", name);
+
+    if ((fp = fopen(lockfile, "r")) == NULL) {
+	syslog(LOG_NOTICE, "Can't open lockfile \"%s\"", lockfile);
+	free(lockfile);
+	return;
+    }
+
+    if (fscanf(fp, "%u", &oldpid) != 1) {
+	syslog(LOG_NOTICE, "Can't read old pid from \"%s\"", lockfile);
+	fclose(fp);
+	unlink(lockfile);
+	free(lockfile);
+	return;
+    }
+
+    fclose(fp);
+
+    if (oldpid == getpid()) {
+	(void)unlink(lockfile);
+    }
+
+    free(lockfile);
+}
+
+
diff -r 2357e8636a60 -r 38e3e3a49320 lib/mbselib.h
--- a/lib/mbselib.h	Fri May 09 22:29:42 2014 +0200
+++ b/lib/mbselib.h	Mon May 12 19:45:11 2014 +0200
@@ -18,6 +18,8 @@
 #include <errno.h>
 #include <signal.h>
 #include <getopt.h>
+#include <limits.h>
+
 
 /* mosquitto */
 #include <mosquitto.h>
@@ -74,11 +76,15 @@
 } sys_config;
 
 
-
 void killconfig(void);
 int  rdconfig(char *);
 
 
+/* lock.c */
+int  lockprog(char *);
+void ulockprog(char *);
+
+
 /* xutil.c */
 char *xmalloc(size_t);
 char *xstrcpy(char *);
@@ -109,7 +115,6 @@
 
 
 /* rc-switch.c */
-
 int  toggleSwitch(char *);
 int  toggleTypeA(char *, char *, bool);
 int  toggleTypeB(int, int, bool);