tools/perf/util/trace-event.c

   1
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <errno.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <linux/kernel.h>
  10 #include <traceevent/event-parse.h>
  11 #include "trace-event.h"
  12 #include "machine.h"
  13 #include "util.h"
  14
  15 /*
  16  * global trace_event object used by trace_event__tp_format
  17  *
  18  * TODO There's no cleanup call for this. Add some sort of
  19  * __exit function support and call trace_event__cleanup
  20  * there.
  21  */
  22 static struct trace_event tevent;
  23 static bool tevent_initialized;
  24
  25 int trace_event__init(struct trace_event *t)
  26 {
  27         struct pevent *pevent = pevent_alloc();
  28
  29         if (pevent) {
  30                 t->plugin_list = traceevent_load_plugins(pevent);
  31                 t->pevent  = pevent;
  32         }
  33
  34         return pevent ? 0 : -1;
  35 }
  36
  37 static int trace_event__init2(void)
  38 {
  39         int be = traceevent_host_bigendian();
  40         struct pevent *pevent;
  41
  42         if (trace_event__init(&tevent))
  43                 return -1;
  44
  45         pevent = tevent.pevent;
  46         pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
  47         pevent_set_file_bigendian(pevent, be);
  48         pevent_set_host_bigendian(pevent, be);
  49         tevent_initialized = true;
  50         return 0;
  51 }
  52
  53 int trace_event__register_resolver(struct machine *machine,
  54                                    pevent_func_resolver_t *func)
  55 {
  56         if (!tevent_initialized && trace_event__init2())
  57                 return -1;
  58
  59         return pevent_set_function_resolver(tevent.pevent, func, machine);
  60 }
  61
  62 void trace_event__cleanup(struct trace_event *t)
  63 {
  64         traceevent_unload_plugins(t->plugin_list, t->pevent);
  65         pevent_free(t->pevent);
  66 }
  67
  68 static struct event_format*
  69 tp_format(const char *sys, const char *name)
  70 {
  71         struct pevent *pevent = tevent.pevent;
  72         struct event_format *event = NULL;
  73         char path[PATH_MAX];
  74         size_t size;
  75         char *data;
  76
  77         scnprintf(path, PATH_MAX, "%s/%s/%s/format",
  78                   tracing_events_path, sys, name);
  79
  80         if (filename__read_str(path, &data, &size))
  81                 return NULL;
  82
  83         pevent_parse_format(pevent, &event, data, size, sys);
  84
  85         free(data);
  86         return event;
  87 }
  88
  89 struct event_format*
  90 trace_event__tp_format(const char *sys, const char *name)
  91 {
  92         if (!tevent_initialized && trace_event__init2())
  93                 return NULL;
  94
  95         return tp_format(sys, name);
  96 }