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 "util.h"
  13
  14 /*
  15  * global trace_event object used by trace_event__tp_format
  16  *
  17  * TODO There's no cleanup call for this. Add some sort of
  18  * __exit function support and call trace_event__cleanup
  19  * there.
  20  */
  21 static struct trace_event tevent;
  22
  23 int trace_event__init(struct trace_event *t)
  24 {
  25         struct pevent *pevent = pevent_alloc();
  26
  27         if (pevent) {
  28                 t->plugin_list = traceevent_load_plugins(pevent);
  29                 t->pevent  = pevent;
  30         }
  31
  32         return pevent ? 0 : -1;
  33 }
  34
  35 void trace_event__cleanup(struct trace_event *t)
  36 {
  37         traceevent_unload_plugins(t->plugin_list, t->pevent);
  38         pevent_free(t->pevent);
  39 }
  40
  41 static struct event_format*
  42 tp_format(const char *sys, const char *name)
  43 {
  44         struct pevent *pevent = tevent.pevent;
  45         struct event_format *event = NULL;
  46         char path[PATH_MAX];
  47         size_t size;
  48         char *data;
  49
  50         scnprintf(path, PATH_MAX, "%s/%s/%s/format",
  51                   tracing_events_path, sys, name);
  52
  53         if (filename__read_str(path, &data, &size))
  54                 return NULL;
  55
  56         pevent_parse_format(pevent, &event, data, size, sys);
  57
  58         free(data);
  59         return event;
  60 }
  61
  62 struct event_format*
  63 trace_event__tp_format(const char *sys, const char *name)
  64 {
  65         static bool initialized;
  66
  67         if (!initialized) {
  68                 int be = traceevent_host_bigendian();
  69                 struct pevent *pevent;
  70
  71                 if (trace_event__init(&tevent))
  72                         return NULL;
  73
  74                 pevent = tevent.pevent;
  75                 pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
  76                 pevent_set_file_bigendian(pevent, be);
  77                 pevent_set_host_bigendian(pevent, be);
  78                 initialized = true;
  79         }
  80
  81         return tp_format(sys, name);
  82 }