Fix T81426: Infinite loop building VSE relations
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Authored by Richard Antalik (ISS) on Oct 19 2020, 9:14 AM.

Details

Reviewers

Sergey Sharybin (sergey)

Maniphest Tasks

T81426: Crash VSE - Circular dependence of scenes as strip

Commits

rB3deb4f4cb8ba: Fix T81426: Infinite loop building VSE relations

Summary

It is possible to create scene strips pointing to each other. This is
sanitized when rendering, but in dependency graph such setup will cause
infinite loop.

This patch fixes loop in dependency graph, but same problem exists in
audaspace

Diff Detail

Repository

rB Blender

Branch

T81426 (branched from master)

Build Status

Buildable 10792
Build 10792: arc lint + arc unit

Event Timeline

Richard Antalik (ISS) requested review of this revision.Oct 19 2020, 9:14 AM

Richard Antalik (ISS) created this revision.

Harbormaster completed remote builds in B10792: Diff 30096.Oct 19 2020, 9:15 AM

First of all, the relations builder should be doing same tag as in nodes builder:

if (built_map_.checkIsBuiltAndTag(scene, BuilderMap::TAG_SCENE_SEQUENCER)) {
  return;
}

See the beginning of DepsgraphNodeBuilder::build_scene_sequencer. Basically, the nodes and relations builders are to be symmetrical.
This is an obvious oversight. If fixing it will not solve the recursion bug you're fixing here I'd need to think harder :)

This revision now requires changes to proceed.Oct 19 2020, 10:49 AM

Use BuilderMap to check for recursivity

Harbormaster completed remote builds in B10793: Diff 30099.Oct 19 2020, 11:09 AM

In D9262#228930, @Sergey Sharybin (sergey) wrote:
First of all, the relations builder should be doing same tag as in nodes builder:
if (built_map_.checkIsBuiltAndTag(scene, BuilderMap::TAG_SCENE_SEQUENCER)) {
  return;
}
See the beginning of DepsgraphNodeBuilder::build_scene_sequencer. Basically, the nodes and relations builders are to be symmetrical.
This is an obvious oversight. If fixing it will not solve the recursion bug you're fixing here I'd need to think harder :)

Indeed this worked. Thanks for suggestion.

I will need to implement original solution for rendering though, because it isn't properly sanitized now when I checked.

This part seems fine. Please commit it.

If fix in rendering is needed, make it a separate commit.

This revision is now accepted and ready to land.Oct 19 2020, 11:14 AM

Closed by commit rB3deb4f4cb8ba: Fix T81426: Infinite loop building VSE relations (authored by Richard Antalik (ISS)). · Explain WhyOct 26 2020, 12:35 AM

This revision was automatically updated to reflect the committed changes.

Richard Antalik (ISS) added a commit: rB3deb4f4cb8ba: Fix T81426: Infinite loop building VSE relations.