[nrf fromlist] settings: Only use mutexes when multithreading is enabled

Allows usage of settings when multithreading is disabled

Upstream PR #: 92886

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

subsys/settings/src/settings.c

@@ -23,8 +23,9 @@ LOG_MODULE_REGISTER(settings, CONFIG_SETTINGS_LOG_LEVEL);
 sys_slist_t settings_handlers;
 #endif /* CONFIG_SETTINGS_DYNAMIC_HANDLERS */
 
-K_MUTEX_DEFINE(settings_lock);
-
+#ifdef CONFIG_MULTITHREADING
+static K_MUTEX_DEFINE(settings_lock);
+#endif
 
 void settings_store_init(void);
 
@@ -47,7 +48,7 @@ int settings_register_with_cprio(struct settings_handler *handler, int cprio)
 		}
 	}
 
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 
 	struct settings_handler *ch;
 	SYS_SLIST_FOR_EACH_CONTAINER(&settings_handlers, ch, node) {
@@ -61,7 +62,7 @@ int settings_register_with_cprio(struct settings_handler *handler, int cprio)
 	sys_slist_append(&settings_handlers, &handler->node);
 
 end:
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 	return rc;
 }
 
@@ -319,3 +320,17 @@ int settings_commit_subtree(const char *subtree)
 
 	return rc;
 }
+
+void settings_lock_take(void)
+{
+#ifdef CONFIG_MULTITHREADING
+	k_mutex_lock(&settings_lock, K_FOREVER);
+#endif
+}
+
+void settings_lock_release(void)
+{
+#ifdef CONFIG_MULTITHREADING
+	k_mutex_unlock(&settings_lock);
+#endif
+}

subsys/settings/src/settings_init.c

@@ -14,8 +14,7 @@
 #include <zephyr/settings/settings.h>
 #include "settings/settings_file.h"
 #include <zephyr/kernel.h>
-
-extern struct k_mutex settings_lock;
+#include "settings_priv.h"
 
 bool settings_subsys_initialized;
 
@@ -28,7 +27,7 @@ int settings_subsys_init(void)
 
 	int err = 0;
 
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 
 	if (!settings_subsys_initialized) {
 		settings_init();
@@ -40,7 +39,7 @@ int settings_subsys_init(void)
 		}
 	}
 
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 
 	return err;
 }

subsys/settings/src/settings_priv.h

@@ -111,6 +111,12 @@ extern sys_slist_t settings_load_srcs;
 extern sys_slist_t settings_handlers;
 extern struct settings_store *settings_save_dst;
 
+/** Takes the settings mutex lock (if multithreading is enabled) */
+void settings_lock_take(void);
+
+/** Releases the settings mutex lock (if multithreading is enabled) */
+void settings_lock_release(void);
+
 #ifdef __cplusplus
 }
 #endif

subsys/settings/src/settings_store.c

@@ -22,7 +22,6 @@ LOG_MODULE_DECLARE(settings, CONFIG_SETTINGS_LOG_LEVEL);
 
 sys_slist_t settings_load_srcs;
 struct settings_store *settings_save_dst;
-extern struct k_mutex settings_lock;
 
 void settings_src_register(struct settings_store *cs)
 {
@@ -53,12 +52,12 @@ int settings_load_subtree(const char *subtree)
 	 *    apply config
 	 *    commit all
 	 */
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 	SYS_SLIST_FOR_EACH_CONTAINER(&settings_load_srcs, cs, cs_next) {
 		cs->cs_itf->csi_load(cs, &arg);
 	}
 	rc = settings_commit_subtree(subtree);
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 	return rc;
 }
 
@@ -80,11 +79,11 @@ int settings_load_subtree_direct(
 	 *    apply config
 	 *    commit all
 	 */
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 	SYS_SLIST_FOR_EACH_CONTAINER(&settings_load_srcs, cs, cs_next) {
 		cs->cs_itf->csi_load(cs, &arg);
 	}
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 	return 0;
 }
 
@@ -144,7 +143,7 @@ ssize_t settings_get_val_len(const char *name)
 	 * for every config store that supports this function
 	 * get the value's length.
 	 */
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 	SYS_SLIST_FOR_EACH_CONTAINER(&settings_load_srcs, cs, cs_next) {
 		if (cs->cs_itf->csi_get_val_len) {
 			val_len = cs->cs_itf->csi_get_val_len(cs, name);
@@ -157,7 +156,7 @@ ssize_t settings_get_val_len(const char *name)
 			rc = cs->cs_itf->csi_load(cs, &arg);
 		}
 	}
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 
 	if (rc >= 0) {
 		return val_len;
@@ -177,7 +176,7 @@ ssize_t settings_load_one(const char *name, void *buf, size_t buf_len)
 	 * For every config store that defines csi_load_one() function use it.
 	 * Otherwise, use the csi_load() function to load the key/value pair
 	 */
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 	SYS_SLIST_FOR_EACH_CONTAINER(&settings_load_srcs, cs, cs_next) {
 		if (cs->cs_itf->csi_load_one) {
 			rc = cs->cs_itf->csi_load_one(cs, name, (char *)buf, buf_len);
@@ -196,7 +195,7 @@ ssize_t settings_load_one(const char *name, void *buf, size_t buf_len)
 			rc = cs->cs_itf->csi_load(cs, &arg);
 		}
 	}
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 
 	if (rc >= 0) {
 		return val_len;
@@ -217,11 +216,11 @@ int settings_save_one(const char *name, const void *value, size_t val_len)
 		return -ENOENT;
 	}
 
-	k_mutex_lock(&settings_lock, K_FOREVER);
+	settings_lock_take();
 
 	rc = cs->cs_itf->csi_save(cs, name, (char *)value, val_len);
 
-	k_mutex_unlock(&settings_lock);
+	settings_lock_release();
 
 	return rc;
 }