Cycles: add time statistics to scene update

Gathers information for time spent in the various managers or object (Film, Camera, etc.) being updated in Scene::device_update.

The stats include the total time spent in the device_update methods as well as time spent in subroutines (e.g. bvh build, displacement, etc.).

This does not qualify as a full blown profiler, but is useful to identify potential bottleneck areas.

The stats can be enabled and printed by passing `--cycles-print-stats` on the command line to Cycles, or `-- --cycles-print-stats` to Blender.

Reviewed By: brecht

Maniphest Tasks: T79174

Differential Revision: https://developer.blender.org/D8596

1 files changed, 21 insertions, 0 deletions

diff --git a/intern/cycles/util/util_time.h b/intern/cycles/util/util_time.h
index bc9a7414312..a82d400a0d7 100644
--- a/intern/cycles/util/util_time.h
+++ b/intern/cycles/util/util_time.h
@@ -17,6 +17,7 @@
 #ifndef __UTIL_TIME_H__
 #define __UTIL_TIME_H__
 
+#include "util/util_function.h"
 #include "util/util_string.h"
 
 CCL_NAMESPACE_BEGIN
@@ -60,6 +61,26 @@ class scoped_timer {
   double time_start_;
 };
 
+class scoped_callback_timer {
+ public:
+  using callback_type = function<void(double)>;
+
+  explicit scoped_callback_timer(callback_type cb) : cb(cb)
+  {
+  }
+
+  ~scoped_callback_timer()
+  {
+    if (cb) {
+      cb(timer.get_time());
+    }
+  }
+
+ protected:
+  scoped_timer timer;
+  callback_type cb;
+};
+
 /* Make human readable string from time, compatible with Blender metadata. */
 
 string time_human_readable_from_seconds(const double seconds);