lib/tevent: Add trace point callback

Set/get a single callback function to be invoked at various trace
points.  Define "before wait" and "after wait" trace points - more
trace points can be added later if required.

CTDB wants this to log long waits and events.

Pair-programmed-with: Amitay Isaacs <amitay@gmail.com>
Signed-off-by: Martin Schwenke <martin@meltin.net>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/tevent/tevent_debug.c b/lib/tevent/tevent_debug.c
index 3f4112831a..31da7b9683 100644
--- a/lib/tevent/tevent_debug.c
+++ b/lib/tevent/tevent_debug.c
@@ -94,3 +94,26 @@ void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level,
 	va_end(ap);
 }
 
+void tevent_set_trace_callback(struct tevent_context *ev,
+			       tevent_trace_callback_t cb,
+			       void *private_data)
+{
+	ev->tracing.callback = cb;
+	ev->tracing.private_data = private_data;
+}
+
+void tevent_get_trace_callback(struct tevent_context *ev,
+			       tevent_trace_callback_t *cb,
+			       void *private_data)
+{
+	*cb = ev->tracing.callback;
+	*(void**)private_data = ev->tracing.private_data;
+}
+
+void tevent_trace_point_callback(struct tevent_context *ev,
+				 enum tevent_trace_point tp)
+{
+	if (ev->tracing.callback != NULL) {
+		ev->tracing.callback(tp, ev->tracing.private_data);
+	}
+}