trace/control.h

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2011-2016 Lluís 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 "event-internal.h"
  14
  15 typedef struct TraceEventIter {
  16     /* iter state */
  17     size_t event;
  18     size_t group;
  19     /* filter conditions */
  20     size_t group_id;
  21     const char *pattern;
  22 } TraceEventIter;
  23
  24
  25 /**
  26  * trace_event_iter_init_all:
  27  * @iter: the event iterator struct
  28  *
  29  * Initialize the event iterator struct @iter,
  30  * for all events.
  31  */
  32 void trace_event_iter_init_all(TraceEventIter *iter);
  33
  34 /**
  35  * trace_event_iter_init_pattern:
  36  * @iter: the event iterator struct
  37  * @pattern: pattern to filter events on name
  38  *
  39  * Initialize the event iterator struct @iter,
  40  * using @pattern to filter out events
  41  * with non-matching names.
  42  */
  43 void trace_event_iter_init_pattern(TraceEventIter *iter, const char *pattern);
  44
  45 /**
  46  * trace_event_iter_init_group:
  47  * @iter: the event iterator struct
  48  * @group_id: group_id to filter events by group.
  49  *
  50  * Initialize the event iterator struct @iter,
  51  * using @group_id to filter for events in the group.
  52  */
  53 void trace_event_iter_init_group(TraceEventIter *iter, size_t group_id);
  54
  55 /**
  56  * trace_event_iter_next:
  57  * @iter: the event iterator struct
  58  *
  59  * Get the next event, if any. When this returns NULL,
  60  * the iterator should no longer be used.
  61  *
  62  * Returns: the next event, or NULL if no more events exist
  63  */
  64 TraceEvent *trace_event_iter_next(TraceEventIter *iter);
  65
  66
  67 /**
  68  * trace_event_name:
  69  * @id: Event name.
  70  *
  71  * Search an event by its name.
  72  *
  73  * Returns: pointer to #TraceEvent or NULL if not found.
  74  */
  75 TraceEvent *trace_event_name(const char *name);
  76
  77 /**
  78  * trace_event_is_pattern:
  79  *
  80  * Whether the given string is an event name pattern.
  81  */
  82 static bool trace_event_is_pattern(const char *str);
  83
  84
  85 /**
  86  * trace_event_get_id:
  87  *
  88  * Get the identifier of an event.
  89  */
  90 static uint32_t trace_event_get_id(TraceEvent *ev);
  91
  92 /**
  93  * trace_event_get_name:
  94  *
  95  * Get the name of an event.
  96  */
  97 static const char * trace_event_get_name(TraceEvent *ev);
  98
  99 /**
 100  * trace_event_get_state:
 101  * @id: Event identifier name.
 102  *
 103  * Get the tracing state of an event, both static and the QEMU dynamic state.
 104  *
 105  * If the event has the disabled property, the check will have no performance
 106  * impact.
 107  */
 108 #define trace_event_get_state(id)                       \
 109     ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))
 110
 111 /**
 112  * trace_event_get_state_backends:
 113  * @id: Event identifier name.
 114  *
 115  * Get the tracing state of an event, both static and dynamic state from all
 116  * compiled-in backends.
 117  *
 118  * If the event has the disabled property, the check will have no performance
 119  * impact.
 120  *
 121  * Returns: true if at least one backend has the event enabled and the event
 122  * does not have the disabled property.
 123  */
 124 #define trace_event_get_state_backends(id)              \
 125     ((id ##_ENABLED) && id ##_BACKEND_DSTATE())
 126
 127 /**
 128  * trace_event_get_state_static:
 129  * @id: Event identifier.
 130  *
 131  * Get the static tracing state of an event.
 132  *
 133  * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
 134  * be set to 1 or 0 according to the presence of the disabled property).
 135  */
 136 static bool trace_event_get_state_static(TraceEvent *ev);
 137
 138 /**
 139  * trace_event_get_state_dynamic:
 140  *
 141  * Get the dynamic tracing state of an event.
 142  *
 143  * If the event has the 'vcpu' property, gets the OR'ed state of all vCPUs.
 144  */
 145 static bool trace_event_get_state_dynamic(TraceEvent *ev);
 146
 147 /**
 148  * trace_event_set_state_dynamic:
 149  *
 150  * Set the dynamic tracing state of an event.
 151  *
 152  * If the event has the 'vcpu' property, sets the state on all vCPUs.
 153  *
 154  * Pre-condition: trace_event_get_state_static(ev) == true
 155  */
 156 void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 157
 158 /**
 159  * trace_init_backends:
 160  *
 161  * Initialize the tracing backend.
 162  *
 163  * Returns: Whether the backends could be successfully initialized.
 164  */
 165 bool trace_init_backends(void);
 166
 167 /**
 168  * trace_init_file:
 169  *
 170  * Record the name of the output file for the tracing backend.
 171  * Exits if no selected backend does not support specifying the
 172  * output file, and a file was specified with "-trace file=...".
 173  */
 174 void trace_init_file(void);
 175
 176 /**
 177  * trace_list_events:
 178  * @f: Where to send output.
 179  *
 180  * List all available events.
 181  */
 182 void trace_list_events(FILE *f);
 183
 184 /**
 185  * trace_enable_events:
 186  * @line_buf: A string with a glob pattern of events to be enabled or,
 187  *            if the string starts with '-', disabled.
 188  *
 189  * Enable or disable matching events.
 190  */
 191 void trace_enable_events(const char *line_buf);
 192
 193 /**
 194  * Definition of QEMU options describing trace subsystem configuration
 195  */
 196 extern QemuOptsList qemu_trace_opts;
 197
 198 /**
 199  * trace_opt_parse:
 200  * @optarg: A string argument of --trace command line argument
 201  *
 202  * Initialize tracing subsystem.
 203  */
 204 void trace_opt_parse(const char *optarg);
 205
 206 /**
 207  * trace_get_vcpu_event_count:
 208  *
 209  * Return the number of known vcpu-specific events
 210  */
 211 uint32_t trace_get_vcpu_event_count(void);
 212
 213
 214 #include "control-internal.h"
 215
 216 #endif /* TRACE__CONTROL_H */