xref: /btstack/src/btstack_fsm.h (revision bb8a927b64a2bed4835a6cf12ebf71eb29487bd9)

/*
 * Copyright (C) 2024 BlueKitchen GmbH
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 *    documentation and/or other materials provided with the distribution.
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 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 * 4. Any redistribution, use, or modification is done solely for
 *    personal benefit and not for any commercial purpose or for
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 *
 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
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 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
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/**
 * @title Finite State Machine (FSM)
 *
 */

#ifndef BTSTACK_FSM_H
#define BTSTACK_FSM_H

#if defined __cplusplus
extern "C" {
#endif

#include <stdint.h>

typedef uint16_t btstack_fsm_signal_t;
enum btstack_fsm_reserved_signals_e {
    BTSTACK_FSM_EMPTY_SIG,
    BTSTACK_FSM_INIT_SIG,
    BTSTACK_FSM_ENTRY_SIG,
    BTSTACK_FSM_EXIT_SIG,
    BTSTACK_FSM_USER_SIG
};

typedef struct {
    btstack_fsm_signal_t sig;
} btstack_fsm_event_t;

typedef struct btstack_fsm_s btstack_fsm_t;

typedef enum {
    BTSTACK_FSM_TRAN_STATUS,
    BTSTACK_FSM_SUPER_STATUS,
    BTSTACK_FSM_HANDLED_STATUS,
    BTSTACK_FSM_UNHANDLED_STATUS,
    BTSTACK_FSM_IGNORED_STATUS
} btstack_fsm_state_t;

typedef btstack_fsm_state_t (*btstack_fsm_state_handler_t)(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);

struct btstack_fsm_s {
    btstack_fsm_state_handler_t state;
};

/* API_START */

/*
 * @brief Request the transition from the current state to the given new state
 * @param me the current state machine
 * @param target the new state to transit to
 * @result transition status
 */
btstack_fsm_state_t btstack_fsm_transit(btstack_fsm_t * const me, btstack_fsm_state_handler_t target);

/*
 * @brief Constructs a new state hierarchical machine machine, with storage for maximum hierarchy depth.
 * @param me the current state machine
 * @param initial the initial state
 */
void btstack_fsm_constructor(btstack_fsm_t * const me, btstack_fsm_state_handler_t initial);

/*
 * @brief Takes the initial transition of the state machine and sending it a BTSTACK_HSM_INIT_SIG
 * @param me the current state machine
 * @param e event
 */
void btstack_fsm_init(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);

/*
 * @brief Dispatches the given event to the state machine, if a transition is requested, leave the old states and enter the new on.
 *        Handling entering/exiting all states on the way.
 * @param me the current state machine
 * @param e event
 */
btstack_fsm_state_t btstack_fsm_dispatch(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);

/*
 * @brief Dispatches the given event to the state machine until it was handled.
 * @param me the current state machine
 * @param e event
 */
void btstack_fsm_dispatch_until(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);

/* API_END */

#if defined __cplusplus
}
#endif

#endif