xref: /btstack/src/btstack_fsm.h (revision 47f34e0cffc2da3ae0dfdf6cba95f7f9d992eb2f)
1 /*
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37 
38 /**
39  * @title Finite State Machine (FSM)
40  *
41  */
42 
43 #ifndef BTSTACK_FSM_H
44 #define BTSTACK_FSM_H
45 
46 #if defined __cplusplus
47 extern "C" {
48 #endif
49 
50 #include <stdint.h>
51 
52 typedef uint16_t btstack_fsm_signal_t;
53 enum btstack_fsm_reserved_signals_e {
54     BTSTACK_FSM_EMPTY_SIG,
55     BTSTACK_FSM_INIT_SIG,
56     BTSTACK_FSM_ENTRY_SIG,
57     BTSTACK_FSM_EXIT_SIG,
58     BTSTACK_FSM_USER_SIG
59 };
60 
61 typedef struct {
62     btstack_fsm_signal_t sig;
63 } btstack_fsm_event_t;
64 
65 typedef struct btstack_fsm_s btstack_fsm_t;
66 
67 typedef enum {
68     BTSTACK_FSM_TRAN_STATUS,
69     BTSTACK_FSM_SUPER_STATUS,
70     BTSTACK_FSM_HANDLED_STATUS,
71     BTSTACK_FSM_UNHANDLED_STATUS,
72     BTSTACK_FSM_IGNORED_STATUS
73 } btstack_fsm_state_t;
74 
75 typedef btstack_fsm_state_t (*btstack_fsm_state_handler_t)(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);
76 
77 struct btstack_fsm_s {
78     btstack_fsm_state_handler_t state;
79 };
80 
81 /* API_START */
82 
83 /*
84  * @brief Request the transition from the current state to the given new state
85  * @param me the current state machine
86  * @param target the new state to transit to
87  * @result transition status
88  */
89 btstack_fsm_state_t btstack_fsm_transit(btstack_fsm_t * const me, btstack_fsm_state_handler_t target);
90 
91 /*
92  * @brief Constructs a new state hierarchical machine machine, with storage for maximum hierarchy depth.
93  * @param me the current state machine
94  * @param initial the initial state
95  */
96 void btstack_fsm_constructor(btstack_fsm_t * const me, btstack_fsm_state_handler_t initial);
97 
98 /*
99  * @brief Takes the initial transition of the state machine and sending it a BTSTACK_HSM_INIT_SIG
100  * @param me the current state machine
101  * @param e event
102  */
103 void btstack_fsm_init(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);
104 
105 /*
106  * @brief Dispatches the given event to the state machine, if a transition is requested, leave the old states and enter the new on.
107  *        Handling entering/exiting all states on the way.
108  * @param me the current state machine
109  * @param e event
110  */
111 btstack_fsm_state_t btstack_fsm_dispatch(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);
112 
113 /*
114  * @brief Dispatches the given event to the state machine until it was handled.
115  * @param me the current state machine
116  * @param e event
117  */
118 void btstack_fsm_dispatch_until(btstack_fsm_t * const me, btstack_fsm_event_t const * const e);
119 
120 /* API_END */
121 
122 #if defined __cplusplus
123 }
124 #endif
125 
126 #endif
127 
128