summaryrefslogtreecommitdiffstats
path: root/include/osmocom/core/fsm.h
blob: 2c2a99611bfc13bd405fd4f87500446510fef639 (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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/*! \file fsm.h
 *  Finite State Machine
 */

#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 */

struct osmo_fsm_inst;

enum osmo_fsm_term_cause {
	/*! terminate because parent terminated */
	OSMO_FSM_TERM_PARENT,
	/*! terminate on explicit user request */
	OSMO_FSM_TERM_REQUEST,
	/*! regular termination of process */
	OSMO_FSM_TERM_REGULAR,
	/*! erroneous termination of process */
	OSMO_FSM_TERM_ERROR,
	/*! 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);
}


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

/*! a description of an osmocom finite state machine */
struct osmo_fsm {
	/*! global list */
	struct llist_head list;
	/*! list of instances of this FSM */
	struct llist_head instances;
	/*! human readable name */
	const char *name;
	/*! table of state transition rules */
	const struct osmo_fsm_state *states;
	/*! number of entries in \ref states */
	unsigned int num_states;
	/*! bit-mask of events permitted in all states */
	uint32_t allstate_event_mask;
	/*! function pointer to be called for allstate events */
	void (*allstate_action)(struct osmo_fsm_inst *fi, uint32_t event, void *data);
	/*! clean-up function, called during termination */
	void (*cleanup)(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause);
	/*! 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);
	/*! logging sub-system for this FSM */
	int log_subsys;
	/*! human-readable names of events */
	const struct value_string *event_names;
	/*! graceful exit function, called at the beginning of termination */
	void (*pre_term)(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause);
};

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

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

	/*! support for fsm-based procedures */
	struct {
		/*! the parent FSM that has created us */
		struct osmo_fsm_inst *parent;
		/*! the event we should send upon termination */
		uint32_t parent_term_event;
		/*! a list of children processes */
		struct llist_head children;
		/*! \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 *osmo_fsm_find_by_name(const char *name);
struct osmo_fsm_inst *osmo_fsm_inst_find_by_name(const struct osmo_fsm *fsm,
						 const char *name);
struct osmo_fsm_inst *osmo_fsm_inst_find_by_id(const struct osmo_fsm *fsm,
						const char *id);
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_unlink_parent(struct osmo_fsm_inst *fi, void *ctx);
void osmo_fsm_inst_change_parent(struct osmo_fsm_inst *fi,
				 struct osmo_fsm_inst *new_parent,
				 uint32_t new_parent_term_event);
void osmo_fsm_inst_free(struct osmo_fsm_inst *fi);

int osmo_fsm_inst_update_id(struct osmo_fsm_inst *fi, const char *id);

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);

/*! return the name of the state the FSM instance is currently in. */
static inline const char *osmo_fsm_inst_state_name(struct osmo_fsm_inst *fi)
{ return osmo_fsm_state_name(fi->fsm, fi->state); }

/*! 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);

/*! 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);

/*! 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);

/*! 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);

/*! @} */