Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
[qemu.git] / trace / control.h
1 /*
2 * Interface for configuring and controlling the state of tracing events.
3 *
4 * Copyright (C) 2011-2012 LluĂ­s Vilanova <vilanova@ac.upc.edu>
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 */
9
10 #ifndef TRACE__CONTROL_H
11 #define TRACE__CONTROL_H
12
13 #include "qemu-common.h"
14 #include "trace/generated-events.h"
15
16
17 /**
18 * TraceEventID:
19 *
20 * Unique tracing event identifier.
21 *
22 * These are named as 'TRACE_${EVENT_NAME}'.
23 *
24 * See also: "trace/generated-events.h"
25 */
26 enum TraceEventID;
27
28 /**
29 * trace_event_id:
30 * @id: Event identifier.
31 *
32 * Get an event by its identifier.
33 *
34 * This routine has a constant cost, as opposed to trace_event_name and
35 * trace_event_pattern.
36 *
37 * Pre-conditions: The identifier is valid.
38 *
39 * Returns: pointer to #TraceEvent.
40 *
41 */
42 static TraceEvent *trace_event_id(TraceEventID id);
43
44 /**
45 * trace_event_name:
46 * @id: Event name.
47 *
48 * Search an event by its name.
49 *
50 * Returns: pointer to #TraceEvent or NULL if not found.
51 */
52 TraceEvent *trace_event_name(const char *name);
53
54 /**
55 * trace_event_pattern:
56 * @pat: Event name pattern.
57 * @ev: Event to start searching from (not included).
58 *
59 * Get all events with a given name pattern.
60 *
61 * Returns: pointer to #TraceEvent or NULL if not found.
62 */
63 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev);
64
65 /**
66 * trace_event_is_pattern:
67 *
68 * Whether the given string is an event name pattern.
69 */
70 static bool trace_event_is_pattern(const char *str);
71
72 /**
73 * trace_event_count:
74 *
75 * Return the number of events.
76 */
77 static TraceEventID trace_event_count(void);
78
79
80
81 /**
82 * trace_event_get_id:
83 *
84 * Get the identifier of an event.
85 */
86 static TraceEventID trace_event_get_id(TraceEvent *ev);
87
88 /**
89 * trace_event_get_name:
90 *
91 * Get the name of an event.
92 */
93 static const char * trace_event_get_name(TraceEvent *ev);
94
95 /**
96 * trace_event_get_state:
97 * @id: Event identifier.
98 *
99 * Get the tracing state of an event (both static and dynamic).
100 *
101 * If the event has the disabled property, the check will have no performance
102 * impact.
103 *
104 * As a down side, you must always use an immediate #TraceEventID value.
105 */
106 #define trace_event_get_state(id) \
107 ((id ##_ENABLED) && trace_event_get_state_dynamic(trace_event_id(id)))
108
109 /**
110 * trace_event_get_state_static:
111 * @id: Event identifier.
112 *
113 * Get the static tracing state of an event.
114 *
115 * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
116 * be set to 1 or 0 according to the presence of the disabled property).
117 */
118 static bool trace_event_get_state_static(TraceEvent *ev);
119
120 /**
121 * trace_event_get_state_dynamic:
122 *
123 * Get the dynamic tracing state of an event.
124 */
125 static bool trace_event_get_state_dynamic(TraceEvent *ev);
126
127 /**
128 * trace_event_set_state:
129 *
130 * Set the tracing state of an event (only if possible).
131 */
132 #define trace_event_set_state(id, state) \
133 do { \
134 if ((id ##_ENABLED)) { \
135 TraceEvent *_e = trace_event_id(id); \
136 trace_event_set_state_dynamic(_e, state); \
137 } \
138 } while (0)
139
140 /**
141 * trace_event_set_state_dynamic:
142 *
143 * Set the dynamic tracing state of an event.
144 *
145 * Pre-condition: trace_event_get_state_static(ev) == true
146 */
147 static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
148
149 /**
150 * trace_event_set_state_dynamic_backend:
151 *
152 * Warning: This function must be implemented by each tracing backend.
153 */
154 void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state);
155
156
157
158 /**
159 * trace_print_events:
160 *
161 * Print the state of all events.
162 *
163 * Warning: This function must be implemented by each tracing backend.
164 */
165 void trace_print_events(FILE *stream, fprintf_function stream_printf);
166
167 /**
168 * trace_backend_init:
169 * @events: Name of file with events to be enabled at startup; may be NULL.
170 * Corresponds to commandline option "-trace events=...".
171 * @file: Name of trace output file; may be NULL.
172 * Corresponds to commandline option "-trace file=...".
173 *
174 * Initialize the tracing backend.
175 *
176 * Warning: This function must be implemented by each tracing backend.
177 *
178 * Returns: Whether the backend could be successfully initialized.
179 */
180 bool trace_backend_init(const char *events, const char *file);
181
182 /**
183 * trace_backend_init_events:
184 * @fname: Name of file with events to enable; may be NULL.
185 *
186 * Generic function to initialize the state of events.
187 */
188 void trace_backend_init_events(const char *fname);
189
190
191 #include "trace/control-internal.h"
192
193 #endif /* TRACE__CONTROL_H */