4 files changed, 46 insertions, 39 deletions

diff --git a/src/fb.c b/src/fb.c
index 03a04ac..f24e4fe 100644
--- a/src/fb.c
+++ b/src/fb.c
@@ -239,22 +239,26 @@ void fb_get_put_pages_count(fb_t *fb, unsigned *count)
 
 
 /* free the fb and associated resources */
-void fb_free(fb_t *fb)
+fb_t * fb_free(fb_t *fb)
 {
-	if (fb->active_page)
-		fb_release(fb);
+	if (fb) {
+		if (fb->active_page)
+			fb_release(fb);
 
-	/* TODO: free all the pages */
+		/* TODO: free all the pages */
 
-	if (fb->ops->shutdown && fb->ops_context)
-		fb->ops->shutdown(fb, fb->ops_context);
+		if (fb->ops->shutdown && fb->ops_context)
+			fb->ops->shutdown(fb, fb->ops_context);
 
-	pthread_mutex_destroy(&fb->ready_mutex);
-	pthread_cond_destroy(&fb->ready_cond);
-	pthread_mutex_destroy(&fb->inactive_mutex);
-	pthread_cond_destroy(&fb->inactive_cond);
+		pthread_mutex_destroy(&fb->ready_mutex);
+		pthread_cond_destroy(&fb->ready_cond);
+		pthread_mutex_destroy(&fb->inactive_mutex);
+		pthread_cond_destroy(&fb->inactive_cond);
 
-	free(fb);
+		free(fb);
+	}
+
+	return NULL;
 }
 
 
diff --git a/src/fb.h b/src/fb.h
index 3a3646a..5e1331e 100644
--- a/src/fb.h
+++ b/src/fb.h
@@ -47,7 +47,7 @@ typedef struct fb_ops_t {
 
 fb_page_t * fb_page_get(fb_t *fb);
 void fb_page_put(fb_t *fb, fb_page_t *page);
-void fb_free(fb_t *fb);
+fb_t * fb_free(fb_t *fb);
 void fb_get_put_pages_count(fb_t *fb, unsigned *count);
 int fb_new(const fb_ops_t *ops, settings_t *settings, int n_pages, fb_t **res_fb);
 void * fb_context(fb_t *fb);
diff --git a/src/settings.c b/src/settings.c
index 3ba4f15..e54a690 100644
--- a/src/settings.c
+++ b/src/settings.c
@@ -119,20 +119,21 @@ settings_t * settings_new(const char *settings_string)
 
 
 /* free structure attained via settings_new() */
-void settings_free(settings_t *settings)
+settings_t * settings_free(settings_t *settings)
 {
-	unsigned	i;
 
-	assert(settings);
+	if (settings) {
+		for (unsigned i = 0; i < settings->num; i++) {
+			free((void *)settings->keys[i]);
+			free((void *)settings->values[i]);
+		}
 
-	for (i = 0; i < settings->num; i++) {
-		free((void *)settings->keys[i]);
-		free((void *)settings->values[i]);
+		free((void *)settings->keys);
+		free((void *)settings->values);
+		free(settings);
 	}
 
-	free((void *)settings->keys);
-	free((void *)settings->values);
-	free(settings);
+	return NULL;
 }
 
 
@@ -282,28 +283,30 @@ int setting_desc_clone(const setting_desc_t *desc, setting_desc_t **res_desc)
 }
 
 
-void setting_desc_free(setting_desc_t *desc)
+setting_desc_t * setting_desc_free(setting_desc_t *desc)
 {
-	free((void *)desc->name);
-	free((void *)desc->key);
-	free((void *)desc->regex);
-	free((void *)desc->preferred);
-
-	if (desc->values) {
-		unsigned	i;
-
-		for (i = 0; desc->values[i]; i++) {
-			free((void *)desc->values[i]);
+	if (desc) {
+		free((void *)desc->name);
+		free((void *)desc->key);
+		free((void *)desc->regex);
+		free((void *)desc->preferred);
+
+		if (desc->values) {
+			for (unsigned i = 0; desc->values[i]; i++) {
+				free((void *)desc->values[i]);
+
+				if (desc->annotations)
+					free((void *)desc->annotations[i]);
+			}
 
-			if (desc->annotations)
-				free((void *)desc->annotations[i]);
+			free((void *)desc->values);
+			free((void *)desc->annotations);
 		}
 
-		free((void *)desc->values);
-		free((void *)desc->annotations);
+		free(desc);
 	}
 
-	free(desc);
+	return NULL;
 }
 
 
diff --git a/src/settings.h b/src/settings.h
index c538531..9916ebb 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -24,7 +24,7 @@ typedef struct setting_desc_generator_t {
 typedef struct settings_t settings_t;
 
 settings_t * settings_new(const char *settings);
-void settings_free(settings_t *settings);
+settings_t * settings_free(settings_t *settings);
 const char * settings_get_value(const settings_t *settings, const char *key);
 const char * settings_get_key(const settings_t *settings, unsigned pos);
 int settings_add_value(settings_t *settings, const char *key, const char *value);
@@ -32,7 +32,7 @@ char * settings_as_arg(const settings_t *settings);
 int settings_apply_desc_generators(const settings_t *settings, const setting_desc_generator_t generators[], unsigned n_generators, void *setup_context, setting_desc_t **next_setting);
 
 int setting_desc_clone(const setting_desc_t *desc, setting_desc_t **res_desc);
-void setting_desc_free(setting_desc_t *desc);
+setting_desc_t * setting_desc_free(setting_desc_t *desc);
 int setting_desc_check(const setting_desc_t *desc, const char *value);
 
 #ifndef SETTINGS_STR