tools lib traceevent: Implement a new API, tep_list_events_copy()

Existing API tep_list_events() is not thread safe, it uses the internal
array sort_events to keep cache of the sorted events and reuses it. This
patch implements a new API, tep_list_events_copy(), which allocates new
sorted array each time it is called. It could be used when a sorted
events functionality is needed in thread safe use cases. It is up to the
caller to free the array.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/linux-trace-devel/20181218133013.31094-1-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190401164343.117437443@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index aec48f2aea8a..41159358abc2 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -544,7 +544,10 @@ void tep_event_info(struct trace_seq *s, struct tep_event *event,
 int tep_strerror(struct tep_handle *pevent, enum tep_errno errnum,
 		 char *buf, size_t buflen);
 
-struct tep_event **tep_list_events(struct tep_handle *pevent, enum tep_event_sort_type);
+struct tep_event **tep_list_events(struct tep_handle *tep,
+				   enum tep_event_sort_type);
+struct tep_event **tep_list_events_copy(struct tep_handle *tep,
+					enum tep_event_sort_type);
 struct tep_format_field **tep_event_common_fields(struct tep_event *event);
 struct tep_format_field **tep_event_fields(struct tep_event *event);