1 /* 2 * Copyright (C) 2024 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN 24 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 /** 39 * @title Hierarchical State Machine (HSM) 40 * 41 */ 42 43 #ifndef BTSTACK_HSM_H 44 #define BTSTACK_HSM_H 45 46 #if defined __cplusplus 47 extern "C" { 48 #endif 49 50 #include <stdint.h> 51 52 typedef uint16_t btstack_hsm_signal_t; 53 enum btstack_hsm_reserved_signals_e { 54 BTSTACK_HSM_EMPTY_SIG, 55 BTSTACK_HSM_INIT_SIG, 56 BTSTACK_HSM_ENTRY_SIG, 57 BTSTACK_HSM_EXIT_SIG, 58 BTSTACK_HSM_USER_SIG 59 }; 60 61 typedef struct { 62 btstack_hsm_signal_t sig; 63 } btstack_hsm_event_t; 64 typedef struct btstack_hsm_s btstack_hsm_t; 65 typedef enum { 66 BTSTACK_HSM_TRAN_STATUS, 67 BTSTACK_HSM_SUPER_STATUS, 68 BTSTACK_HSM_HANDLED_STATUS, 69 BTSTACK_HSM_UNHANDLED_STATUS, 70 BTSTACK_HSM_IGNORED_STATUS 71 } btstack_hsm_state_t; 72 73 typedef btstack_hsm_state_t (*btstack_hsm_state_handler_t)(btstack_hsm_t * const me, btstack_hsm_event_t const * const e); 74 75 struct btstack_hsm_s { 76 btstack_hsm_state_handler_t state; 77 btstack_hsm_state_handler_t temp; 78 btstack_hsm_state_handler_t *path; 79 int_fast8_t depth; 80 }; 81 82 /* API_START */ 83 84 /* 85 * @brief Request the transition from the current state to the given new state 86 * @param me the current state machine 87 * @param target the new state to transit to 88 * @result transition status 89 */ 90 btstack_hsm_state_t btstack_hsm_transit(btstack_hsm_t * const me, btstack_hsm_state_handler_t const target); 91 92 /* 93 * @brief Specifies the upper state in a state hierarchy 94 * @param me the current state machine 95 * @param target the next parent state in the hierarchy 96 * @result transition status 97 */ 98 btstack_hsm_state_t btstack_hsm_super(btstack_hsm_t * const me, btstack_hsm_state_handler_t const target); 99 100 /* 101 * @brief Placeholder state to mark the top most state in a state hierarchy, the root state. Ignores all events. 102 * @param me the current state machine 103 * @param e event 104 * @result ignored status 105 */ 106 btstack_hsm_state_t btstack_hsm_top(btstack_hsm_t * const me, btstack_hsm_event_t const * const e); 107 108 /* 109 * @brief Constructs a new state hierarchical machine machine, with storage for maximum hierarchy depth. 110 * @param me the current state machine 111 * @param initial the initial state 112 * @param array of btstack_hsm_state_handler_t elements with the same number of elements as the maximum number of nested state machines. 113 * @param The number of nested state machines. 114 */ 115 void btstack_hsm_constructor(btstack_hsm_t * const me, btstack_hsm_state_handler_t initial, btstack_hsm_state_handler_t path[], int8_t depth); 116 117 /* 118 * @brief Takes the initial transition of the state machine and sending it a BTSTACK_HSM_INIT_SIG 119 * @param me the current state machine 120 * @param e event 121 */ 122 void btstack_hsm_init(btstack_hsm_t * const me, btstack_hsm_event_t const * const e); 123 124 /* 125 * @brief Dispatches the given event to the state machine, if a transition is requested, leave the old states and enter the new on. 126 * Honoring the hierarchy and handling entering/exiting all states on the way. 127 * @param me the current state machine 128 * @param e event 129 */ 130 btstack_hsm_state_t btstack_hsm_dispatch(btstack_hsm_t * const me, btstack_hsm_event_t const * const e); 131 132 /* API_END */ 133 134 #if defined __cplusplus 135 } 136 #endif 137 138 #endif 139