aboutsummaryrefslogtreecommitdiff
path: root/trace/control.h
blob: a2dd3eaedf14d9eec599b649f1d04696037d4446 (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
/*
 * Interface for configuring and controlling the state of tracing events.
 *
 * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#ifndef TRACE__CONTROL_H
#define TRACE__CONTROL_H

#include "qemu-common.h"
#include "trace/generated-events.h"


/**
 * TraceEventID:
 *
 * Unique tracing event identifier.
 *
 * These are named as 'TRACE_${EVENT_NAME}'.
 *
 * See also: "trace/generated-events.h"
 */
enum TraceEventID;

/**
 * trace_event_id:
 * @id: Event identifier.
 *
 * Get an event by its identifier.
 *
 * This routine has a constant cost, as opposed to trace_event_name and
 * trace_event_pattern.
 *
 * Pre-conditions: The identifier is valid.
 *
 * Returns: pointer to #TraceEvent.
 *
 */
static TraceEvent *trace_event_id(TraceEventID id);

/**
 * trace_event_name:
 * @id: Event name.
 *
 * Search an event by its name.
 *
 * Returns: pointer to #TraceEvent or NULL if not found.
 */
TraceEvent *trace_event_name(const char *name);

/**
 * trace_event_pattern:
 * @pat: Event name pattern.
 * @ev: Event to start searching from (not included).
 *
 * Get all events with a given name pattern.
 *
 * Returns: pointer to #TraceEvent or NULL if not found.
 */
TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev);

/**
 * trace_event_is_pattern:
 *
 * Whether the given string is an event name pattern.
 */
static bool trace_event_is_pattern(const char *str);

/**
 * trace_event_count:
 *
 * Return the number of events.
 */
static TraceEventID trace_event_count(void);



/**
 * trace_event_get_id:
 *
 * Get the identifier of an event.
 */
static TraceEventID trace_event_get_id(TraceEvent *ev);

/**
 * trace_event_get_name:
 *
 * Get the name of an event.
 */
static const char * trace_event_get_name(TraceEvent *ev);

/**
 * trace_event_get_state:
 * @id: Event identifier.
 *
 * Get the tracing state of an event (both static and dynamic).
 *
 * If the event has the disabled property, the check will have no performance
 * impact.
 *
 * As a down side, you must always use an immediate #TraceEventID value.
 */
#define trace_event_get_state(id)                       \
    ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))

/**
 * trace_event_get_state_static:
 * @id: Event identifier.
 *
 * Get the static tracing state of an event.
 *
 * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
 * be set to 1 or 0 according to the presence of the disabled property).
 */
static bool trace_event_get_state_static(TraceEvent *ev);

/**
 * trace_event_get_state_dynamic:
 *
 * Get the dynamic tracing state of an event.
 */
static bool trace_event_get_state_dynamic(TraceEvent *ev);

/**
 * trace_event_set_state:
 *
 * Set the tracing state of an event (only if possible).
 */
#define trace_event_set_state(id, state)                \
    do {                                                \
        if ((id ##_ENABLED)) {                          \
            TraceEvent *_e = trace_event_id(id);        \
            trace_event_set_state_dynamic(_e, state);   \
        }                                               \
    } while (0)

/**
 * trace_event_set_state_dynamic:
 *
 * Set the dynamic tracing state of an event.
 *
 * Pre-condition: trace_event_get_state_static(ev) == true
 */
static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);



/**
 * trace_init_backends:
 * @file:   Name of trace output file; may be NULL.
 *          Corresponds to commandline option "-trace file=...".
 *
 * Initialize the tracing backend.
 *
 * Returns: Whether the backends could be successfully initialized.
 */
bool trace_init_backends(void);

/**
 * trace_init_file:
 * @file:   Name of trace output file; may be NULL.
 *          Corresponds to commandline option "-trace file=...".
 *
 * Record the name of the output file for the tracing backend.
 * Exits if no selected backend does not support specifying the
 * output file, and a non-NULL file was passed.
 */
void trace_init_file(const char *file);

/**
 * trace_list_events:
 *
 * List all available events.
 */
void trace_list_events(void);

/**
 * trace_enable_events:
 * @line_buf: A string with a glob pattern of events to be enabled or,
 *            if the string starts with '-', disabled.
 *
 * Enable or disable matching events.
 */
void trace_enable_events(const char *line_buf);

/**
 * Definition of QEMU options describing trace subsystem configuration
 */
extern QemuOptsList qemu_trace_opts;

/**
 * trace_opt_parse:
 * @optarg: A string argument of --trace command line argument
 *
 * Initialize tracing subsystem.
 *
 * Returns the filename to save trace to.  It must be freed with g_free().
 */
char *trace_opt_parse(const char *optarg);

#include "trace/control-internal.h"

#endif  /* TRACE__CONTROL_H */