plugin commands: add numeric priority to enforce execution order

tuned/plugins/base.py

@@ -227,7 +227,7 @@ class Plugin(object):
 		"""
 		Initialize commands.
 		"""
-		self._commands = {}
+		self._commands = collections.OrderedDict()
 		self._autoregister_commands()
 		self._check_commands()
 
@@ -249,14 +249,19 @@ class Plugin(object):
 				info["custom"] = None
 				info["set"] = member
 				info["per_device"] = member._command["per_device"]
+				info["priority"] = member._command["priority"]
 			elif "get" in member._command:
 				info["get"] = member
 			elif "custom" in member._command:
 				info["custom"] = member
 				info["per_device"] = member._command["per_device"]
+				info["priority"] = member._command["priority"]
 
 			self._commands[command_name] = info
 
+		# sort commands by priority
+		self._commands = collections.OrderedDict(sorted(self._commands.iteritems(), key=lambda (name, info): info["priority"]))
+
 	def _check_commands(self):
 		"""
 		Check if all commands are defined correctly.

tuned/plugins/decorators.py

@@ -17,12 +17,13 @@ __all__ = ["command_set", "command_get", "command_custom"]
 #		return current_foo
 #
 
-def command_set(name, per_device=False):
+def command_set(name, per_device=False, priority=0):
 	def wrapper(method):
 		method._command = {
 			"set": True,
 			"name": name,
 			"per_device": per_device,
+			"priority": priority,
 		}
 		return method
 
@@ -37,12 +38,13 @@ def command_get(name):
 		return method
 	return wrapper
 
-def command_custom(name, per_device=False):
+def command_custom(name, per_device=False, priority=0):
 	def wrapper(method):
 		method._command = {
 			"custom": True,
 			"name": name,
 			"per_device": per_device,
+			"priority": priority,
 		}
 		return method
 	return wrapper