summaryrefslogtreecommitdiffstats
path: root/include/osmocom/core/fsm.h
blob: a2c20b7887f90ed575a279f317d376e23a6b27c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
#pragma once

#include <stdint.h>
#include <stdbool.h>

#include <osmocom/core/linuxlist.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/utils.h>

/*! \defgroup fsm Finite State Machine abstraction
 *  @{
 */

/*! \file fsm.h
 *  \brief Finite State Machine
 */

struct osmo_fsm_inst;

enum osmo_fsm_term_cause {
	/*! \brief terminate because parent terminated */
	OSMO_FSM_TERM_PARENT,
	/*! \brief terminate on explicit user request */
	OSMO_FSM_TERM_REQUEST,
	/*! \brief regular termination of process */
	OSMO_FSM_TERM_REGULAR,
	/*! \brief erroneous termination of process */
	OSMO_FSM_TERM_ERROR,
	/*! \brief termination due to time-out */
	OSMO_FSM_TERM_TIMEOUT,
};

extern const struct value_string osmo_fsm_term_cause_names[];
static inline const char *osmo_fsm_term_cause_name(enum osmo_fsm_term_cause cause)
{
	return get_value_string(osmo_fsm_term_cause_names, cause);
}


/*! \brief description of a rule in the FSM */
struct osmo_fsm_state {
	/*! \brief bit-mask of permitted input events for this state */
	uint32_t in_event_mask;
	/*! \brief bit-mask to which other states this state may transiton */
	uint32_t out_state_mask;
	/*! \brief human-readable name of this state */
	const char *name;
	/*! \brief function to be called for events arriving in this state */
	void (*action)(struct osmo_fsm_inst *fi, uint32_t event, void *data);
	/*! \brief function to be called just after entering the state */
	void (*onenter)(struct osmo_fsm_inst *fi, uint32_t prev_state);
	/*! \brief function to be called just before leaving the state */
	void (*onleave)(struct osmo_fsm_inst *fi, uint32_t next_state);
};

/*! \brief a description of an osmocom finite state machine */
struct osmo_fsm {
	/*! \brief global list */
	struct llist_head list;
	/*! \brief list of instances of this FSM */
	struct llist_head instances;
	/*! \brief human readable name */
	const char *name;
	/*! \brief table of state transition rules */
	const struct osmo_fsm_state *states;
	/*! \brief number of entries in \ref states */
	unsigned int num_states;
	/*! \brief bit-mask of events permitted in all states */
	uint32_t allstate_event_mask;
	/*! \brief function pointer to be called for allstate events */
	void (*allstate_action)(struct osmo_fsm_inst *fi, uint32_t event, void *data);
	/*! \brief clean-up function, called during termination */
	void (*cleanup)(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause);
	/*! \brief timer call-back for states with time-out.
	 * \returns 1 to request termination, 0 to keep running. */
	int (*timer_cb)(struct osmo_fsm_inst *fi);
	/*! \brief logging sub-system for this FSM */
	int log_subsys;
	/*! \brief human-readable names of events */
	const struct value_string *event_names;
};

/*! \brief a single instanceof an osmocom finite state machine */
struct osmo_fsm_inst {
	/*! \brief member in the fsm->instances list */
	struct llist_head list;
	/*! \brief back-pointer to the FSM of which we are an instance */
	struct osmo_fsm *fsm;
	/*! \brief human readable identifier */
	const char *id;
	/*! \brief human readable fully-qualified name */
	const char *name;
	/*! \brief some private data of this instance */
	void *priv;
	/*! \brief logging level for this FSM */
	int log_level;
	/*! \brief current state of the FSM */
	uint32_t state;

	/*! \brief timer number for states with time-out */
	int T;
	/*! \brief timer back-end for states with time-out */
	struct osmo_timer_list timer;

	/*! \brief support for fsm-based procedures */
	struct {
		/*! \brief the parent FSM that has created us */
		struct osmo_fsm_inst *parent;
		/*! \brief the event we should send upon termination */
		uint32_t parent_term_event;
		/*! \brief a list of children processes */
		struct llist_head children;
		/*! \brief \ref llist_head linked to parent->proc.children */
		struct llist_head child;
	} proc;
};

void osmo_fsm_log_addr(bool log_addr);

#define LOGPFSML(fi, level, fmt, args...) \
		LOGP((fi)->fsm->log_subsys, level, "%s{%s}: " fmt, \
			osmo_fsm_inst_name(fi),				    \
			osmo_fsm_state_name((fi)->fsm, (fi)->state), ## args)

#define LOGPFSM(fi, fmt, args...) \
		LOGPFSML(fi, (fi)->log_level, fmt, ## args)

#define LOGPFSMLSRC(fi, level, caller_file, caller_line, fmt, args...) \
		LOGPSRC((fi)->fsm->log_subsys, level, \
			caller_file, caller_line, \
			"%s{%s}: " fmt, \
			osmo_fsm_inst_name(fi), \
			osmo_fsm_state_name((fi)->fsm, (fi)->state), \
			## args)

#define LOGPFSMSRC(fi, caller_file, caller_line, fmt, args...) \
		LOGPFSMLSRC(fi, (fi)->log_level, \
			    caller_file, caller_line, \
			    fmt, ## args)

int osmo_fsm_register(struct osmo_fsm *fsm);
void osmo_fsm_unregister(struct osmo_fsm *fsm);
struct osmo_fsm_inst *osmo_fsm_inst_alloc(struct osmo_fsm *fsm, void *ctx, void *priv,
					  int log_level, const char *id);
struct osmo_fsm_inst *osmo_fsm_inst_alloc_child(struct osmo_fsm *fsm,
						struct osmo_fsm_inst *parent,
						uint32_t parent_term_event);
void osmo_fsm_inst_free(struct osmo_fsm_inst *fi);

const char *osmo_fsm_event_name(struct osmo_fsm *fsm, uint32_t event);
const char *osmo_fsm_inst_name(struct osmo_fsm_inst *fi);
const char *osmo_fsm_state_name(struct osmo_fsm *fsm, uint32_t state);

/*! \brief perform a state change of the given FSM instance
 *
 *  This is a macro that calls _osmo_fsm_inst_state_chg() with the given
 *  parameters as well as the caller's source file and line number for logging
 *  purposes. See there for documentation.
 */
#define osmo_fsm_inst_state_chg(fi, new_state, timeout_secs, T) \
	_osmo_fsm_inst_state_chg(fi, new_state, timeout_secs, T, \
				 __BASE_FILE__, __LINE__)
int _osmo_fsm_inst_state_chg(struct osmo_fsm_inst *fi, uint32_t new_state,
			     unsigned long timeout_secs, int T,
			     const char *file, int line);

/*! \brief dispatch an event to an osmocom finite state machine instance
 *
 *  This is a macro that calls _osmo_fsm_inst_dispatch() with the given
 *  parameters as well as the caller's source file and line number for logging
 *  purposes. See there for documentation.
 */
#define osmo_fsm_inst_dispatch(fi, event, data) \
	_osmo_fsm_inst_dispatch(fi, event, data, __BASE_FILE__, __LINE__)
int _osmo_fsm_inst_dispatch(struct osmo_fsm_inst *fi, uint32_t event, void *data,
			    const char *file, int line);

/*! \brief Terminate FSM instance with given cause
 *
 *  This is a macro that calls _osmo_fsm_inst_term() with the given parameters
 *  as well as the caller's source file and line number for logging purposes.
 *  See there for documentation.
 */
#define osmo_fsm_inst_term(fi, cause, data) \
	_osmo_fsm_inst_term(fi, cause, data, __BASE_FILE__, __LINE__)
void _osmo_fsm_inst_term(struct osmo_fsm_inst *fi,
			 enum osmo_fsm_term_cause cause, void *data,
			 const char *file, int line);

/*! \brief Terminate all child FSM instances of an FSM instance.
 *
 *  This is a macro that calls _osmo_fsm_inst_term_children() with the given
 *  parameters as well as the caller's source file and line number for logging
 *  purposes. See there for documentation.
 */
#define osmo_fsm_inst_term_children(fi, cause, data) \
	_osmo_fsm_inst_term_children(fi, cause, data, __BASE_FILE__, __LINE__)
void _osmo_fsm_inst_term_children(struct osmo_fsm_inst *fi,
				  enum osmo_fsm_term_cause cause,
				  void *data,
				  const char *file, int line);

/*! @} */