settings: introduce priority for commit

A priority is introduced to allow scheduling of commit routines.

Signed-off-by: Laczen JMS <[email protected]>

include/zephyr/settings/settings.h

@@ -45,6 +45,17 @@ extern "C" {
  */
 #define SETTINGS_EXTRA_LEN ((SETTINGS_MAX_DIR_DEPTH - 1) + 2)
 
+enum settings_commit_prio_level {
+	SETTINGS_COMMIT_PRIO_DEFAULT,
+	SETTINGS_COMMIT_PRIO_LEVEL1,
+	SETTINGS_COMMIT_PRIO_LEVEL2,
+	SETTINGS_COMMIT_PRIO_LEVEL3,
+	SETTINGS_COMMIT_PRIO_LEVEL4,
+	SETTINGS_COMMIT_PRIO_LEVEL5,
+	SETTINGS_COMMIT_PRIO_LEVEL6,
+	SETTINGS_COMMIT_PRIO_LEVEL7,
+};
+
 /**
  * Function used to read the data from the settings storage in
  * h_set handler implementations.
@@ -70,6 +81,9 @@ struct settings_handler {
 	const char *name;
 	/**< Name of subtree. */
 
+	int cprio;
+	/**< Priority of commit */
+
 	int (*h_get)(const char *key, char *val, int val_len_max);
 	/**< Get values handler of settings items identified by keyword names.
 	 *
@@ -136,6 +150,9 @@ struct settings_handler_static {
 	const char *name;
 	/**< Name of subtree. */
 
+	int cprio;
+	/**< Priority of commit */
+
 	int (*h_get)(const char *key, char *val, int val_len_max);
 	/**< Get values handler of settings items identified by keyword names.
 	 *
@@ -201,17 +218,23 @@ struct settings_handler_static {
  *
  */
 
-#define SETTINGS_STATIC_HANDLER_DEFINE(_hname, _tree, _get, _set, _commit,   \
-				       _export)				     \
+#define SETTINGS_STATIC_HANDLER_DEFINE_WITH_CPRIO(_hname, _tree, _get, _set, \
+						  _commit, _export, _cprio)  \
 	const STRUCT_SECTION_ITERABLE(settings_handler_static,		     \
 				      settings_handler_ ## _hname) = {       \
 		.name = _tree,						     \
+		.cprio = _cprio,					     \
 		.h_get = _get,						     \
 		.h_set = _set,						     \
 		.h_commit = _commit,					     \
 		.h_export = _export,					     \
 	}
 
+#define SETTINGS_STATIC_HANDLER_DEFINE(_hname, _tree, _get, _set, _commit,   \
+				       _export)				     \
+	SETTINGS_STATIC_HANDLER_DEFINE_WITH_CPRIO(_hname, _tree, _get, _set, \
+		_commit, _export, CONFIG_SETTINGS_COMMIT_PRIO_MINIMUM)
+
 /**
  * Initialization of settings and backend
  *
@@ -224,7 +247,20 @@ struct settings_handler_static {
 int settings_subsys_init(void);
 
 /**
- * Register a handler for settings items stored in RAM.
+ * Register a handler for settings items stored in RAM with
+ * commit priority.
+ *
+ * @param cf   Structure containing registration info.
+ * @param cprio Commit priority level
+ *
+ * @return 0 on success, non-zero on failure.
+ */
+int settings_register_with_cprio(struct settings_handler *cf,
+				 int cprio);
+
+/**
+ * Register a handler for settings items stored in RAM with
+ * commit priority set to default.
  *
  * @param cf Structure containing registration info.
  *

subsys/settings/Kconfig

@@ -26,6 +26,14 @@ config SETTINGS_DYNAMIC_HANDLERS
 	help
 	  Enables the use of dynamic settings handlers
 
+config SETTINGS_COMMIT_PRIO_MINIMUM
+	int "minimum commit priority level"
+	default 0
+	help
+	  Minimum commit priority level. All h_commit from
+	  handlers with commit prio below this level are
+	  executed at the this minimum priority level.
+
 # Hidden option to enable encoding length into settings entry
 config SETTINGS_ENCODE_LEN
 	bool

subsys/settings/src/settings.c

@@ -36,7 +36,7 @@ void settings_init(void)
 }
 
 #if defined(CONFIG_SETTINGS_DYNAMIC_HANDLERS)
-int settings_register(struct settings_handler *handler)
+int settings_register_with_cprio(struct settings_handler *handler, int cprio)
 {
 	int rc = 0;
 
@@ -55,12 +55,19 @@ int settings_register(struct settings_handler *handler)
 			goto end;
 		}
 	}
+
+	handler->cprio = cprio;
 	sys_slist_append(&settings_handlers, &handler->node);
 
 end:
 	k_mutex_unlock(&settings_lock);
 	return rc;
 }
+
+int settings_register(struct settings_handler *handler)
+{
+	return settings_register_with_cprio(handler, CONFIG_SETTINGS_COMMIT_PRIO_MINIMUM);
+}
 #endif /* CONFIG_SETTINGS_DYNAMIC_HANDLERS */
 
 int settings_name_steq(const char *name, const char *key, const char **next)
@@ -234,39 +241,75 @@ int settings_commit(void)
 	return settings_commit_subtree(NULL);
 }
 
+static bool skip_commit(int ch_cprio, int cprio, int *nprio)
+{
+	if (ch_cprio > cprio) {
+		*nprio = (*nprio == cprio) ? ch_cprio : MIN(*nprio, ch_cprio);
+		return true;
+	}
+
+	if ((ch_cprio < cprio) && (cprio != CONFIG_SETTINGS_COMMIT_PRIO_MINIMUM)) {
+		return true;
+	}
+
+	return false;
+}
+
 int settings_commit_subtree(const char *subtree)
 {
 	int rc;
 	int rc2;
+	int cprio = CONFIG_SETTINGS_COMMIT_PRIO_MINIMUM;
 
 	rc = 0;
 
-	STRUCT_SECTION_FOREACH(settings_handler_static, ch) {
-		if (subtree && !settings_name_steq(ch->name, subtree, NULL)) {
-			continue;
-		}
-		if (ch->h_commit) {
-			rc2 = ch->h_commit();
-			if (!rc) {
-				rc = rc2;
+	while (true) {
+		int nprio = cprio;
+
+		STRUCT_SECTION_FOREACH(settings_handler_static, ch) {
+			if (subtree && !settings_name_steq(ch->name, subtree, NULL)) {
+				continue;
 			}
-		}
-	}
 
-#if defined(CONFIG_SETTINGS_DYNAMIC_HANDLERS)
-	struct settings_handler *ch;
-	SYS_SLIST_FOR_EACH_CONTAINER(&settings_handlers, ch, node) {
-		if (subtree && !settings_name_steq(ch->name, subtree, NULL)) {
-			continue;
+			if (ch->h_commit) {
+				if (skip_commit(ch->cprio, cprio, &nprio)) {
+					continue;
+				}
+
+				rc2 = ch->h_commit();
+				if (!rc) {
+					rc = rc2;
+				}
+			}
 		}
-		if (ch->h_commit) {
-			rc2 = ch->h_commit();
-			if (!rc) {
-				rc = rc2;
+
+		if (IS_ENABLED(CONFIG_SETTINGS_DYNAMIC_HANDLERS)) {
+			struct settings_handler *ch;
+
+			SYS_SLIST_FOR_EACH_CONTAINER(&settings_handlers, ch, node) {
+				if (subtree && !settings_name_steq(ch->name, subtree, NULL)) {
+					continue;
+				}
+
+				if (ch->h_commit) {
+					if (skip_commit(ch->cprio, cprio, &nprio)) {
+						continue;
+					}
+
+					rc2 = ch->h_commit();
+					if (!rc) {
+						rc = rc2;
+					}
+				}
 			}
 		}
+
+		if (nprio == cprio) {
+			break;
+		}
+
+		cprio = nprio;
 	}
-#endif /* CONFIG_SETTINGS_DYNAMIC_HANDLERS */
 
 	return rc;
 }