libctrl: Add support for 'deferred control commands'
Sometimes a control interface command cannot be processed
and responded immediately, but we need to process it asynchronously.
In order to support this, we introduce the 'ctrl_cmd_def', which
represents such a deferred command. It is created by the service
implementing the command using ctrl_cmd_def_make(), and a response is
later sent using ctrl_cmd_def_send().
ctrl_cmd_def_is_zombie() must be called to handle the case where
the control connection has disconnected/died between receiving the
command and sending the response.
diff --git a/include/osmocom/ctrl/control_cmd.h b/include/osmocom/ctrl/control_cmd.h
index 9e94963..8f2eaa2 100644
--- a/include/osmocom/ctrl/control_cmd.h
+++ b/include/osmocom/ctrl/control_cmd.h
@@ -45,6 +45,9 @@
/* Pending commands for this connection */
struct llist_head cmds;
+
+ /* Pending deferred commands for this connection */
+ struct llist_head def_cmds;
};
struct ctrl_cmd {
@@ -75,6 +78,18 @@
enum ctrl_type type;
};
+/* deferred control command, i.e. responded asynchronously */
+struct ctrl_cmd_def {
+ struct llist_head list; /* ctrl_connection.def_cmds */
+ struct ctrl_cmd *cmd;
+ void *data; /* opaque user data */
+};
+
+struct ctrl_cmd_def *
+ctrl_cmd_def_make(const void *ctx, struct ctrl_cmd *cmd, void *data, unsigned int secs);
+int ctrl_cmd_def_is_zombie(struct ctrl_cmd_def *cd);
+int ctrl_cmd_def_send(struct ctrl_cmd_def *cd);
+
int ctrl_cmd_exec(vector vline, struct ctrl_cmd *command, vector node, void *data);
int ctrl_cmd_install(enum ctrl_node_type node, struct ctrl_cmd_element *cmd);
int ctrl_cmd_send(struct osmo_wqueue *queue, struct ctrl_cmd *cmd);