State object

SMF uses a data structure of type struct smf_ctx to track the current state of the state machine. In the Asset Tracker Template, this structure is embedded within a larger structure called the state object that holds the following:

• SMF's context structure.
• The zbus channel of the latest message received.
• The contents of the latest message received.
• Any extended state variables needed by the module.

For example, the Network module defines its state object structure:

struct network_state_object {
        /* This must be first */
        struct smf_ctx ctx;

        /* Last channel type that a message was received on */
        const struct zbus_channel *chan;

        /* Buffer for last ZBus message */
        uint8_t msg_buf[MAX_MSG_SIZE];

        /* Any extended state variables */
};

The structure is allocated in the module's thread as network_state and passed to all SMF functions.