Fix #129596: Cycles oneAPI crash with interactive BVH updates

There is a bug in Embree that makes BVH updates crash. Disabling multithreaded
BVH updates after the initial BVH build appears to work around it, at the cost
of some performance.

This will not affect performance of the initial BVH build, transforming objects
or editing a single mesh. It will only affect performance when multiple smaller
meshes are edited together, as those can no longer have their BVH updated in
parallel or benefit from parallellization over many primitives.

Pull Request: https://projects.blender.org/blender/blender/pulls/134747

intern/cycles/device/device.cpp

@@ -816,4 +816,17 @@ bool GPUDevice::is_shared(const void *shared_pointer,
 
 /* DeviceInfo */
 
+bool DeviceInfo::contains_device_type(const DeviceType type) const
+{
+  if (this->type == type) {
+    return true;
+  }
+  for (const DeviceInfo &info : multi_devices) {
+    if (info.contains_device_type(type)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 CCL_NAMESPACE_END

intern/cycles/device/device.h

@@ -130,6 +130,8 @@ class DeviceInfo {
   {
     return !(*this == info);
   }
+
+  bool contains_device_type(const DeviceType type) const;
 };
 
 /* Device */

intern/cycles/scene/geometry.cpp

@@ -943,13 +943,23 @@ void GeometryManager::device_update(Device *device,
     });
     TaskPool pool;
 
+    /* Work around Embree/oneAPI bug #129596 with BVH updates. */
+    const bool use_multithreaded_build = first_bvh_build ||
+                                         !device->info.contains_device_type(DEVICE_ONEAPI);
+    first_bvh_build = false;
+
     size_t i = 0;
     for (Geometry *geom : scene->geometry) {
       if (geom->is_modified() || geom->need_update_bvh_for_offset) {
         need_update_scene_bvh = true;
-        pool.push([geom, device, dscene, scene, &progress, i, num_bvh] {
+        if (use_multithreaded_build) {
+          pool.push([geom, device, dscene, scene, &progress, i, num_bvh] {
+            geom->compute_bvh(device, dscene, &scene->params, &progress, i, num_bvh);
+          });
+        }
+        else {
           geom->compute_bvh(device, dscene, &scene->params, &progress, i, num_bvh);
-        });
+        }
         if (geom->need_build_bvh(bvh_layout)) {
           i++;
         }

intern/cycles/scene/geometry.h

@@ -225,6 +225,7 @@ class GeometryManager {
 
   /* Update Flags */
   bool need_flags_update;
+  bool first_bvh_build = true;
 
   /* Constructor/Destructor */
   GeometryManager();