From a32d9e41a440a043e19d20e3b91a45f626297472 Mon Sep 17 00:00:00 2001
From: Nikolas Garofil <nikolas@garofil.be>
Date: Wed, 5 May 2010 18:46:04 +0200
Subject: [PATCH] Bugfix: memory and thread-deleting problems

For example the following config had a problem:
TEXT
$i8k_cpu_temp

I could fix it shorter, but then valgrind would still show memleaks
---
 src/apcupsd.cc     |  4 +--
 src/apcupsd.h      |  2 +-
 src/common.cc      | 22 ++++++++++++----
 src/common.h       | 22 ++++++++--------
 src/conky.cc       | 14 +++++++---
 src/diskio.h       |  2 +-
 src/entropy.cc     |  3 ++-
 src/entropy.h      |  2 +-
 src/fs.cc          |  5 ++--
 src/fs.h           |  2 +-
 src/hddtemp.cc     |  9 ++++---
 src/hddtemp.h      |  2 +-
 src/i8k.cc         | 12 ++++++---
 src/i8k.h          |  2 +-
 src/ibm.cc         |  3 ++-
 src/ibm.h          |  2 +-
 src/linux.cc       | 65 +++++++++++++++++++++++++++-------------------
 src/linux.h        |  4 +--
 src/logging.h      |  4 +++
 src/moc.cc         |  3 ++-
 src/moc.h          |  2 +-
 src/mpd.cc         |  7 ++---
 src/mpd.h          |  2 +-
 src/net_stat.cc    |  7 ++---
 src/net_stat.h     |  2 +-
 src/tcp-portmon.cc |  3 ++-
 src/tcp-portmon.h  |  2 +-
 src/users.cc       |  3 ++-
 src/users.h        |  2 +-
 29 files changed, 132 insertions(+), 82 deletions(-)

diff --git a/src/apcupsd.cc b/src/apcupsd.cc
index 2e3564d1..8f7fad6b 100644
--- a/src/apcupsd.cc
+++ b/src/apcupsd.cc
@@ -180,7 +180,7 @@ static int fill_items(int sock, PAPCUPSD_S apc)
 //
 // Conky update function for apcupsd data
 //
-void update_apcupsd(void)
+int update_apcupsd(void)
 {
 	int i;
 	APCUPSD_S apc;
@@ -251,7 +251,7 @@ void update_apcupsd(void)
 	// "atomically" copy the data into working set
 	//
 	memcpy(apcupsd.items, apc.items, sizeof(apcupsd.items));
-	return;
+	return 0;
 }
 
 int apcupsd_scan_arg(const char *arg)
diff --git a/src/apcupsd.h b/src/apcupsd.h
index 25562698..67862b44 100644
--- a/src/apcupsd.h
+++ b/src/apcupsd.h
@@ -28,7 +28,7 @@
 int apcupsd_scan_arg(const char *);
 
 /* Service routine for the conky main thread */
-void update_apcupsd(void);
+int update_apcupsd(void);
 
 double apcupsd_loadbarval(struct text_object *);
 
diff --git a/src/common.cc b/src/common.cc
index e3125e16..ca7ed564 100644
--- a/src/common.cc
+++ b/src/common.cc
@@ -87,9 +87,10 @@ char *strndup(const char *s, size_t n)
 }
 #endif /* HAVE_STRNDUP */
 
-void update_uname(void)
+int update_uname(void)
 {
 	uname(&info.uname_s);
+	return 0;
 }
 
 double get_time(void)
@@ -261,7 +262,7 @@ void format_seconds_short(char *buf, unsigned int n, long seconds)
  * Populated while initialising text objects in construct_text_object(). */
 struct update_cb {
 	struct update_cb *next;
-	void (*func)(void);
+	int (*func)(void);
 	pthread_t thread;
 	sem_t start_wait, end_wait;
 	update_cb() : next(NULL), func(NULL) {}
@@ -279,7 +280,7 @@ static int threading_started = 0;
 
 /* Register an update callback. Don't allow duplicates, to minimise side
  * effects and overhead. */
-void add_update_callback(void (*func)(void))
+void add_update_callback(int (*func)(void))
 {
 	struct update_cb *uc = &update_cb_head;
 
@@ -369,7 +370,12 @@ static void *run_update_callback(void *data)
 	while (1) {
 		if (sem_wait(&ucb->start_wait)) return(NULL);
 		if (ucb->running == 0) return(NULL);
-		(*ucb->func)();
+		if((*ucb->func)()) {
+			ucb->next = ucb;	//this is normally not be possible, so we use it to show that there was a critical error
+			sem_post(&ucb->end_wait);
+			sem_post(&ucb->end_wait);
+			pthread_exit(NULL);
+		}
 		if (sem_post(&ucb->end_wait)) return(NULL);
 	}
 }
@@ -404,8 +410,14 @@ void update_stuff(void)
 	}
 	/* need to synchronise here, otherwise locking is needed (as data
 	 * would be printed with some update callbacks still running) */
-	for (uc = update_cb_head.next; uc; uc = uc->next)
+	for (uc = update_cb_head.next; uc; uc = uc->next) {
 		sem_wait(&uc->end_wait);
+		if(uc == uc->next) {
+			pthread_join(uc->thread, NULL);
+			delete uc;
+			exit(EXIT_FAILURE);
+		}
+	}
 
 	/* XXX: move the following into the update_meminfo() functions? */
 	if (no_buffers) {
diff --git a/src/common.h b/src/common.h
index d543a3c2..fc3e921d 100644
--- a/src/common.h
+++ b/src/common.h
@@ -37,27 +37,27 @@ char* readfile(const char* filename, int* total_read, char showerror);
 
 void print_to_bytes(struct text_object *, char *, int);
 
-void add_update_callback(void (*func)(void));
+void add_update_callback(int (*func)(void));
 void free_update_callbacks(void);
 void start_update_threading(void);
 
 void strfold(char *start, int count);
 int check_mount(struct text_object *);
 void prepare_update(void);
-void update_uptime(void);
-void update_meminfo(void);
-void update_net_stats(void);
-void update_cpu_usage(void);
-void update_total_processes(void);
-void update_uname(void);
-void update_threads(void);
-void update_running_processes(void);
+int update_uptime(void);
+int update_meminfo(void);
+int update_net_stats(void);
+int update_cpu_usage(void);
+int update_total_processes(void);
+int update_uname(void);
+int update_threads(void);
+int update_running_processes(void);
 void update_stuff(void);
 char get_freq(char *, size_t, const char *, int, unsigned int);
 void print_voltage_mv(struct text_object *, char *, int);
 void print_voltage_v(struct text_object *, char *, int);
-void update_load_average(void);
-void update_top(void);
+int update_load_average(void);
+int update_top(void);
 void free_all_processes(void);
 struct process *get_first_process(void);
 void get_cpu_count(void);
diff --git a/src/conky.cc b/src/conky.cc
index 50baf8d4..787eb3b8 100644
--- a/src/conky.cc
+++ b/src/conky.cc
@@ -490,6 +490,7 @@ static inline void for_each_line(char *b, int f(char *, int))
 	char *ps, *pe;
 	int special_index = 0; /* specials index */
 
+	if(! b) return;
 	for (ps = b, pe = b; *pe; pe++) {
 		if (*pe == '\n') {
 			*pe = '\0';
@@ -748,6 +749,9 @@ void generate_text_internal(char *p, int p_max_size, struct text_object root)
 {
 	struct text_object *obj;
 	size_t a;
+
+	if(! p) return;
+
 #ifdef BUILD_ICONV
 	char *buff_in;
 
@@ -2427,9 +2431,7 @@ void free_specials(special_t *current) {
 	}
 }
 
-void clean_up(void *memtofree1, void* memtofree2)
-{
-	free_update_callbacks();
+void clean_up_without_threads(void *memtofree1, void* memtofree2) {
 
 #ifdef BUILD_NCURSES
 	if(output_methods & TO_NCURSES) {
@@ -2501,6 +2503,12 @@ void clean_up(void *memtofree1, void* memtofree2)
 	free_and_zero(global_cpu);
 }
 
+void clean_up(void *memtofree1, void* memtofree2)
+{
+	free_update_callbacks();
+	clean_up_without_threads(memtofree1, memtofree2);
+}
+
 static bool string_to_bool(const char *s)
 {
 	if (!s) {
diff --git a/src/diskio.h b/src/diskio.h
index f8bbd3ed..15009214 100644
--- a/src/diskio.h
+++ b/src/diskio.h
@@ -63,7 +63,7 @@ struct diskio_stat {
 extern struct diskio_stat stats;
 
 struct diskio_stat *prepare_diskio_stat(const char *);
-void update_diskio(void);
+int update_diskio(void);
 void clear_diskio_stats(void);
 void update_diskio_values(struct diskio_stat *, unsigned int, unsigned int);
 
diff --git a/src/entropy.cc b/src/entropy.cc
index 86fdadea..a8200c85 100644
--- a/src/entropy.cc
+++ b/src/entropy.cc
@@ -49,10 +49,11 @@ struct _entropy {
 
 static _entropy entropy;
 
-void update_entropy(void)
+int update_entropy(void)
 {
 	get_entropy_avail(&entropy.avail);
 	get_entropy_poolsize(&entropy.poolsize);
+	return 0;
 }
 
 void print_entropy_avail(struct text_object *obj, char *p, int p_max_size)
diff --git a/src/entropy.h b/src/entropy.h
index d508a042..765d2d18 100644
--- a/src/entropy.h
+++ b/src/entropy.h
@@ -31,7 +31,7 @@
 #ifndef _ENTROPY_H
 #define _ENTROPY_H
 
-void update_entropy(void);
+int update_entropy(void);
 
 void print_entropy_avail(struct text_object *, char *, int);
 uint8_t entropy_percentage(struct text_object *);
diff --git a/src/fs.cc b/src/fs.cc
index 1ace9c36..7fdddcd8 100644
--- a/src/fs.cc
+++ b/src/fs.cc
@@ -69,13 +69,13 @@ static void update_fs_stat(struct fs_stat *fs);
 
 void get_fs_type(const char *path, char *result);
 
-void update_fs_stats(void)
+int update_fs_stats(void)
 {
 	unsigned i;
 	static double last_fs_update = 0.0;
 
 	if (current_update_time - last_fs_update < 13)
-		return;
+		return 0;
 
 	for (i = 0; i < MAX_FS_STATS; ++i) {
 		if (fs_stats[i].set) {
@@ -83,6 +83,7 @@ void update_fs_stats(void)
 		}
 	}
 	last_fs_update = current_update_time;
+	return 0;
 }
 
 void clear_fs_stats(void)
diff --git a/src/fs.h b/src/fs.h
index 64ac11d8..19285d96 100644
--- a/src/fs.h
+++ b/src/fs.h
@@ -58,7 +58,7 @@ void print_fs_size(struct text_object *, char *, int);
 void print_fs_used(struct text_object *, char *, int);
 void print_fs_type(struct text_object *, char *, int);
 
-void update_fs_stats(void);
+int update_fs_stats(void);
 struct fs_stat *prepare_fs_stat(const char *path);
 void clear_fs_stats(void);
 
diff --git a/src/hddtemp.cc b/src/hddtemp.cc
index 68173240..7238b0ce 100644
--- a/src/hddtemp.cc
+++ b/src/hddtemp.cc
@@ -207,29 +207,30 @@ out_fail:
 	return 1;
 }
 
-void update_hddtemp(void) {
+int update_hddtemp(void) {
 	char *data, *dev, unit, *saveptr;
 	short val;
 	static double last_hddtemp_update = 0.0;
 
 	/* limit tcp connection overhead */
 	if (current_update_time - last_hddtemp_update < 5)
-		return;
+		return 0;
 	last_hddtemp_update = current_update_time;
 
 	free_hddtemp_info();
 
 	if (!(data = fetch_hddtemp_output()))
-		return;
+		return 0;
 
 	if (read_hdd_val(data, &dev, &val, &unit, &saveptr)) {
 		free(data);
-		return;
+		return 0;
 	}
 	do {
 		add_hddtemp_info(dev, val, unit);
 	} while (!read_hdd_val(NULL, &dev, &val, &unit, &saveptr));
 	free(data);
+	return 0;
 }
 
 void free_hddtemp(struct text_object *obj)
diff --git a/src/hddtemp.h b/src/hddtemp.h
index f84df705..b4c1cdf5 100644
--- a/src/hddtemp.h
+++ b/src/hddtemp.h
@@ -29,7 +29,7 @@
 
 void set_hddtemp_host(const char *);
 void set_hddtemp_port(const char *);
-void update_hddtemp(void);
+int update_hddtemp(void);
 void free_hddtemp(struct text_object *);
 void print_hddtemp(struct text_object *, char *, int);
 
diff --git a/src/i8k.cc b/src/i8k.cc
index f9aac854..fc7f9089 100644
--- a/src/i8k.cc
+++ b/src/i8k.cc
@@ -53,7 +53,7 @@ struct _i8k {
 #define PROC_I8K "/proc/i8k"
 #define I8K_DELIM " "
 static char *i8k_procbuf = NULL;
-void update_i8k(void)
+int update_i8k(void)
 {
 	FILE *fp;
 
@@ -61,8 +61,13 @@ void update_i8k(void)
 		i8k_procbuf = (char *) malloc(128 * sizeof(char));
 	}
 	if ((fp = fopen(PROC_I8K, "r")) == NULL) {
-		CRIT_ERR(NULL, NULL, "/proc/i8k doesn't exist! use insmod to make sure the kernel "
-			"driver is loaded...");
+		free_and_zero(i8k_procbuf);
+		/*THREAD_CRIT_ERR(NULL, NULL, "/proc/i8k doesn't exist! use insmod to make sure the kernel "
+			"driver is loaded...");*/
+		NORM_ERR("/proc/i8k doesn't exist! use insmod to make sure the kernel driver is loaded...");
+		clean_up_without_threads(NULL, NULL);
+		free(current_mail_spool);
+		return 1;
 	}
 
 	memset(&i8k_procbuf[0], 0, 128);
@@ -82,6 +87,7 @@ void update_i8k(void)
 	i8k.right_fan_rpm = strtok(NULL, I8K_DELIM);
 	i8k.ac_status = strtok(NULL, I8K_DELIM);
 	i8k.buttons_status = strtok(NULL, I8K_DELIM);
+	return 0;
 }
 
 static const char *fan_status_to_string(int status)
diff --git a/src/i8k.h b/src/i8k.h
index 88da9df8..5606118a 100644
--- a/src/i8k.h
+++ b/src/i8k.h
@@ -32,7 +32,7 @@
 #ifndef _I8K_H
 #define _I8K_H
 
-void update_i8k(void);
+int update_i8k(void);
 void print_i8k_left_fan_status(struct text_object *, char *, int);
 void print_i8k_cpu_temp(struct text_object *, char *, int);
 void print_i8k_right_fan_status(struct text_object *, char *, int);
diff --git a/src/ibm.cc b/src/ibm.cc
index 534db16e..a72b3660 100644
--- a/src/ibm.cc
+++ b/src/ibm.cc
@@ -129,7 +129,7 @@ void get_ibm_acpi_fan(struct text_object *obj, char *p, int p_max_size)
 temperatures:   41 43 31 46 33 -128 29 -128
  * Peter Tarjan (ptarjan@citromail.hu) */
 
-void get_ibm_acpi_temps(void)
+int get_ibm_acpi_temps(void)
 {
 
 	FILE *fp;
@@ -158,6 +158,7 @@ void get_ibm_acpi_temps(void)
 	}
 
 	fclose(fp);
+	return 0;
 }
 
 /* get volume (0-14) on IBM/Lenovo laptops running the ibm acpi.
diff --git a/src/ibm.h b/src/ibm.h
index cc84d4f9..e7fbe4e0 100644
--- a/src/ibm.h
+++ b/src/ibm.h
@@ -27,7 +27,7 @@
 #define _IBM_H
 
 void get_ibm_acpi_fan(struct text_object *, char *, int);
-void get_ibm_acpi_temps(void);
+int get_ibm_acpi_temps(void);
 void get_ibm_acpi_volume(struct text_object *, char *, int);
 void get_ibm_acpi_brightness(struct text_object *, char *, int);
 
diff --git a/src/linux.cc b/src/linux.cc
index 39ee545d..5b3a7e9b 100644
--- a/src/linux.cc
+++ b/src/linux.cc
@@ -101,7 +101,7 @@ void prepare_update(void)
 {
 }
 
-void update_uptime(void)
+int update_uptime(void)
 {
 #ifdef HAVE_SYSINFO
 	if (!prefer_proc) {
@@ -117,12 +117,13 @@ void update_uptime(void)
 
 		if (!(fp = open_file("/proc/uptime", &rep))) {
 			info.uptime = 0.0;
-			return;
+			return 0;
 		}
 		if (fscanf(fp, "%lf", &info.uptime) <= 0)
 			info.uptime = 0;
 		fclose(fp);
 	}
+	return 0;
 }
 
 int check_mount(struct text_object *obj)
@@ -153,7 +154,7 @@ int check_mount(struct text_object *obj)
 /* these things are also in sysinfo except Buffers:
  * (that's why I'm reading them from proc) */
 
-void update_meminfo(void)
+int update_meminfo(void)
 {
 	FILE *meminfo_fp;
 	static int rep = 0;
@@ -165,7 +166,7 @@ void update_meminfo(void)
         info.bufmem = info.buffers = info.cached = info.memfree = info.memeasyfree = 0;
 
 	if (!(meminfo_fp = open_file("/proc/meminfo", &rep))) {
-		return;
+		return 0;
 	}
 
 	while (!feof(meminfo_fp)) {
@@ -195,6 +196,7 @@ void update_meminfo(void)
 	info.bufmem = info.cached + info.buffers;
 
 	fclose(meminfo_fp);
+	return 0;
 }
 
 void print_laptop_mode(struct text_object *obj, char *p, int p_max_size)
@@ -270,7 +272,7 @@ void update_gateway_info_failure(const char *reason)
 /* Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT */
 #define RT_ENTRY_FORMAT "%63s %lx %lx %x %*d %*d %*d %lx %*d %*d %*d\n"
 
-void update_gateway_info(void)
+int update_gateway_info(void)
 {
 	FILE *fp;
 	struct in_addr ina;
@@ -284,13 +286,13 @@ void update_gateway_info(void)
 
 	if ((fp = fopen("/proc/net/route", "r")) == NULL) {
 		update_gateway_info_failure("fopen()");
-		return;
+		return 0;
 	}
 
 	/* skip over the table header line, which is always present */
 	if (fscanf(fp, "%*[^\n]\n") < 0) {
 		fclose(fp);
-		return;
+		return 0;
 	}
 
 	while (!feof(fp)) {
@@ -307,7 +309,7 @@ void update_gateway_info(void)
 		}
 	}
 	fclose(fp);
-	return;
+	return 0;
 }
 
 void free_gateway_info(struct text_object *obj)
@@ -339,7 +341,7 @@ void print_gateway_ip(struct text_object *obj, char *p, int p_max_size)
 	snprintf(p, p_max_size, "%s", gw_info.ip);
 }
 
-void update_net_stats(void)
+int update_net_stats(void)
 {
 	FILE *net_dev_fp;
 	static int rep = 0;
@@ -363,19 +365,19 @@ void update_net_stats(void)
 	/* get delta */
 	delta = current_update_time - last_update_time;
 	if (delta <= 0.0001) {
-		return;
+		return 0;
 	}
 
 	/* open file and ignore first two lines */
 	if (!(net_dev_fp = open_file("/proc/net/dev", &rep))) {
 		clear_net_stats();
-		return;
+		return 0;
 	}
 
 	if (!fgets(buf, 255, net_dev_fp) ||  /* garbage */
 	    !fgets(buf, 255, net_dev_fp)) {  /* garbage (field names) */
 		fclose(net_dev_fp);
-		return;
+		return 0;
 	}
 
 	/* read each interface */
@@ -554,11 +556,12 @@ void update_net_stats(void)
 	first = 0;
 
 	fclose(net_dev_fp);
+	return 0;
 }
 
 int result;
 
-void update_total_processes(void)
+int update_total_processes(void)
 {
 	DIR *dir;
 	struct dirent *entry;
@@ -567,23 +570,24 @@ void update_total_processes(void)
 
 	info.procs = 0;
 	if (!(dir = opendir("/proc"))) {
-		return;
+		return 0;
 	}
 	while ((entry = readdir(dir))) {
 		if (!entry) {
 			/* Problem reading list of processes */
 			closedir(dir);
 			info.procs = 0;
-			return;
+			return 0;
 		}
 		if (sscanf(entry->d_name, "%d%c", &ignore1, &ignore2) == 1) {
 			info.procs++;
 		}
 	}
 	closedir(dir);
+	return 0;
 }
 
-void update_threads(void)
+int update_threads(void)
 {
 #ifdef HAVE_SYSINFO
 	if (!prefer_proc) {
@@ -599,12 +603,13 @@ void update_threads(void)
 
 		if (!(fp = open_file("/proc/loadavg", &rep))) {
 			info.threads = 0;
-			return;
+			return 0;
 		}
 		if (fscanf(fp, "%*f %*f %*f %*d/%hu", &info.threads) <= 0)
 			info.threads = 0;
 		fclose(fp);
 	}
+	return 0;
 }
 
 #define CPU_SAMPLE_COUNT 15
@@ -678,7 +683,7 @@ void get_cpu_count(void)
 #define TMPL_LONGSTAT "%*s %llu %llu %llu %llu %llu %llu %llu %llu"
 #define TMPL_SHORTSTAT "%*s %llu %llu %llu %llu"
 
-void update_stat(void)
+int update_stat(void)
 {
 	FILE *stat_fp;
 	static int rep = 0;
@@ -700,7 +705,7 @@ void update_stat(void)
 	pthread_mutex_lock(&last_stat_update_mutex);
 	if (last_stat_update == current_update_time) {
 		pthread_mutex_unlock(&last_stat_update_mutex);
-		return;
+		return 0;
 	}
 	last_stat_update = current_update_time;
 	pthread_mutex_unlock(&last_stat_update_mutex);
@@ -728,7 +733,7 @@ void update_stat(void)
 		if (info.cpu_usage) {
 			memset(info.cpu_usage, 0, info.cpu_count * sizeof(float));
 		}
-		return;
+		return 0;
 	}
 
 	idx = 0;
@@ -799,19 +804,22 @@ void update_stat(void)
 		}
 	}
 	fclose(stat_fp);
+	return 0;
 }
 
-void update_running_processes(void)
+int update_running_processes(void)
 {
 	update_stat();
+	return 0;
 }
 
-void update_cpu_usage(void)
+int update_cpu_usage(void)
 {
 	update_stat();
+	return 0;
 }
 
-void update_load_average(void)
+int update_load_average(void)
 {
 #ifdef HAVE_GETLOADAVG
 	if (!prefer_proc) {
@@ -829,13 +837,14 @@ void update_load_average(void)
 
 		if (!(fp = open_file("/proc/loadavg", &rep))) {
 			info.loadavg[0] = info.loadavg[1] = info.loadavg[2] = 0.0;
-			return;
+			return 0;
 		}
 		if (fscanf(fp, "%f %f %f", &info.loadavg[0], &info.loadavg[1],
 		           &info.loadavg[2]) < 0)
 			info.loadavg[0] = info.loadavg[1] = info.loadavg[2] = 0.0;
 		fclose(fp);
 	}
+	return 0;
 }
 
 /***********************************************************/
@@ -2209,7 +2218,7 @@ void get_powerbook_batt_info(struct text_object *obj, char *buffer, int n)
 	snprintf(buffer, n, "%s", pb_battery_info[obj->data.i]);
 }
 
-void update_top(void)
+int update_top(void)
 {
 	process_find_top(info.cpu, info.memu, info.time
 #ifdef BUILD_IOSTATS
@@ -2217,6 +2226,7 @@ void update_top(void)
 #endif
                 );
 	info.first_process = get_first_process();
+	return 0;
 }
 
 #define ENTROPY_AVAIL_PATH "/proc/sys/kernel/random/entropy_avail"
@@ -2319,7 +2329,7 @@ int is_disk(char *dev)
 	return dev_cur->memoized;
 }
 
-void update_diskio(void)
+int update_diskio(void)
 {
 	FILE *fp;
 	static int rep = 0;
@@ -2335,7 +2345,7 @@ void update_diskio(void)
 	stats.current_write = 0;
 
 	if (!(fp = open_file("/proc/diskstats", &rep))) {
-		return;
+		return 0;
 	}
 
 	/* read reads and writes from all disks (minor = 0), including cd-roms
@@ -2370,6 +2380,7 @@ void update_diskio(void)
 	}
 	update_diskio_values(&stats, total_reads, total_writes);
 	fclose(fp);
+	return 0;
 }
 
 void print_distribution(struct text_object *obj, char *p, int p_max_size)
diff --git a/src/linux.h b/src/linux.h
index 71697821..982647ac 100644
--- a/src/linux.h
+++ b/src/linux.h
@@ -33,7 +33,7 @@ void print_disk_protect_queue(struct text_object *, char *, int);
 void print_ioscheduler(struct text_object *, char *, int);
 void print_laptop_mode(struct text_object *, char *, int);
 
-void update_gateway_info(void);
+int update_gateway_info(void);
 void free_gateway_info(struct text_object *obj);
 int gateway_exists(struct text_object *);
 void print_gateway_iface(struct text_object *, char *, int);
@@ -51,7 +51,7 @@ void free_sysfs_sensor(struct text_object *);
 int get_entropy_avail(unsigned int *);
 int get_entropy_poolsize(unsigned int *);
 
-void update_stat(void);
+int update_stat(void);
 
 void print_distribution(struct text_object *, char *, int);
 
diff --git a/src/logging.h b/src/logging.h
index ccb075fc..211ea18b 100644
--- a/src/logging.h
+++ b/src/logging.h
@@ -34,6 +34,7 @@
 #include "mail.h"
 
 void clean_up(void *memtofree1, void* memtofree2);
+void clean_up_without_threads(void *memtofree1, void* memtofree2);
 
 #define NORM_ERR(...) { \
 	fprintf(stderr, PACKAGE_NAME": "); \
@@ -45,6 +46,9 @@ void clean_up(void *memtofree1, void* memtofree2);
 #define CRIT_ERR(memtofree1, memtofree2, ...) \
 	{ NORM_ERR(__VA_ARGS__); clean_up(memtofree1, memtofree2); free(current_mail_spool); exit(EXIT_FAILURE); }
 
+#define THREAD_CRIT_ERR(memtofree1, memtofree2, ...) \
+	{ NORM_ERR(__VA_ARGS__); clean_up_without_threads(memtofree1, memtofree2); free(current_mail_spool); return; }
+
 /* debugging output */
 extern int global_debug_level;
 #define __DBGP(level, ...) \
diff --git a/src/moc.cc b/src/moc.cc
index 157d67ba..0965823e 100644
--- a/src/moc.cc
+++ b/src/moc.cc
@@ -139,9 +139,10 @@ static int run_moc_thread(double interval)
 	return 0;
 }
 
-void update_moc(void)
+int update_moc(void)
 {
 	run_moc_thread(info.music_player_interval * 100000);
+	return 0;
 }
 
 #define MOC_PRINT_GENERATOR(type, alt) \
diff --git a/src/moc.h b/src/moc.h
index 7433e1d8..5cc53050 100644
--- a/src/moc.h
+++ b/src/moc.h
@@ -24,7 +24,7 @@
 #ifndef MOC_H_
 #define MOC_H_
 
-void update_moc(void);
+int update_moc(void);
 void free_moc(struct text_object *);
 
 void print_moc_state(struct text_object *, char *, int);
diff --git a/src/mpd.cc b/src/mpd.cc
index c3dbddca..e2bf93b2 100644
--- a/src/mpd.cc
+++ b/src/mpd.cc
@@ -125,20 +125,21 @@ void free_mpd(struct text_object *obj)
 
 static void update_mpd_thread(thread_handle &handle);
 
-void update_mpd(void)
+int update_mpd(void)
 {
 	int interval;
 	static timed_thread_ptr thread;
 
 	if (thread)
-		return;
+		return 0;
 
 	interval = info.music_player_interval * 1000000;
 	thread = timed_thread::create(std::bind(update_mpd_thread, std::placeholders::_1), interval);
 	if (!thread) {
 		NORM_ERR("Failed to create MPD timed thread");
-		return;
+		return 0;
 	}
+	return 0;
 }
 
 /* stringMAXdup dups at most text_buffer_size bytes */
diff --git a/src/mpd.h b/src/mpd.h
index 80c38e4c..c2506a84 100644
--- a/src/mpd.h
+++ b/src/mpd.h
@@ -35,7 +35,7 @@ int mpd_set_port(const char *);
 /* text object functions */
 void init_mpd(void);
 void free_mpd(struct text_object *);
-void update_mpd(void);
+int update_mpd(void);
 
 void print_mpd_elapsed(struct text_object *, char *, int);
 void print_mpd_length(struct text_object *, char *, int);
diff --git a/src/net_stat.cc b/src/net_stat.cc
index 28308886..a1963850 100644
--- a/src/net_stat.cc
+++ b/src/net_stat.cc
@@ -396,7 +396,7 @@ void free_dns_data(struct text_object *obj)
 	memset(&dns_data, 0, sizeof(dns_data));
 }
 
-void update_dns_data(void)
+int update_dns_data(void)
 {
 	FILE *fp;
 	char line[256];
@@ -404,7 +404,7 @@ void update_dns_data(void)
 
 	/* maybe updating too often causes higher load because of /etc lying on a real FS
 	if (current_update_time - last_dns_update < 10.0)
-		return;
+		return 0;
 
 	last_dns_update = current_update_time;
 	*/
@@ -412,7 +412,7 @@ void update_dns_data(void)
 	free_dns_data(NULL);
 
 	if ((fp = fopen("/etc/resolv.conf", "r")) == NULL)
-		return;
+		return 0;
 	while(!feof(fp)) {
 		if (fgets(line, 255, fp) == NULL) {
 			break;
@@ -425,6 +425,7 @@ void update_dns_data(void)
 		}
 	}
 	fclose(fp);
+	return 0;
 }
 
 void parse_nameserver_arg(struct text_object *obj, const char *arg)
diff --git a/src/net_stat.h b/src/net_stat.h
index 0ebd54b2..52e638a0 100644
--- a/src/net_stat.h
+++ b/src/net_stat.h
@@ -92,7 +92,7 @@ int interface_up(struct text_object *);
 void free_if_up(struct text_object *);
 
 void free_dns_data(struct text_object *);
-void update_dns_data(void);
+int update_dns_data(void);
 void parse_nameserver_arg(struct text_object *, const char *);
 void print_nameserver(struct text_object *, char *, int);
 
diff --git a/src/tcp-portmon.cc b/src/tcp-portmon.cc
index 433e37b3..a2cb6b70 100644
--- a/src/tcp-portmon.cc
+++ b/src/tcp-portmon.cc
@@ -131,9 +131,10 @@ void tcp_portmon_action(struct text_object *obj, char *p, int p_max_size)
 	}
 }
 
-void tcp_portmon_update(void)
+int tcp_portmon_update(void)
 {
 	update_tcp_port_monitor_collection(pmc);
+	return 0;
 }
 
 int tcp_portmon_clear(void)
diff --git a/src/tcp-portmon.h b/src/tcp-portmon.h
index 992a97c4..db3699a5 100644
--- a/src/tcp-portmon.h
+++ b/src/tcp-portmon.h
@@ -39,7 +39,7 @@ struct text_object;
 
 int tcp_portmon_init(struct text_object *, const char *);
 void tcp_portmon_action(struct text_object *, char *, int);
-void tcp_portmon_update(void);
+int tcp_portmon_update(void);
 int tcp_portmon_clear(void);
 int tcp_portmon_set_max_connections(int);
 void tcp_portmon_free(struct text_object *);
diff --git a/src/users.cc b/src/users.cc
index ac36dab8..599f3228 100644
--- a/src/users.cc
+++ b/src/users.cc
@@ -151,7 +151,7 @@ static void update_user_time(char *tty)
 	}
 }
 
-void update_users(void)
+int update_users(void)
 {
 	struct information *current_info = &info;
 	char temp[BUFLEN] = "";
@@ -197,6 +197,7 @@ void update_users(void)
 		current_info->users.times = (char*)malloc(text_buffer_size);
 		strncpy(current_info->users.times, "broken", text_buffer_size);
 	}
+	return 0;
 }
 
 void print_user_names(struct text_object *obj, char *p, int p_max_size)
diff --git a/src/users.h b/src/users.h
index 49e7bfd4..dd5e7ece 100644
--- a/src/users.h
+++ b/src/users.h
@@ -31,7 +31,7 @@
 #ifndef _USERS_H
 #define _USERS_H
 
-void update_users(void);
+int update_users(void);
 
 void print_user_names(struct text_object *, char *, int);
 void print_user_terms(struct text_object *, char *, int);