[dds/dap] Fix breakpoint resolution races when there are multiple isolates

When there are multiple isolates, we may get breakpoint responses/events like this:

- Request/Response to add breakpoint to Isolate 1
- Request/Response to add breakpoint to Isolate 2
- BreakpointAdded for Isolate 1
- BreakpointResolved for Isolate 1
- BreakpointAdded for Isolate 2

Because Isolate 2 did not load the script, the last breakpoint was never resolved. However because the breakpoint ID matched, we would forward this event to the client and un-resolve the previously resolved breakpoint. This would result in odd behaviour in VS Code.

Additionally, the VM may return the same BM breakpoint ID for what the client thinks are two breakpoints (they are on different lines, but resolve to the same location) so when we get a resolved breakpoint, we need to handle both:

- Client breakpoints that have already been transmitted
- Future client breakpoints that may resolve to this same VM breakpoint

The previous code assumed that a BreakpointResolved event could be handled just once. Either for an existing breakpoint, or a future one.

This change swaps from storing queued events to storing the resolution information for each breakpoint, and it does this even if there was an existing breakpoint (in case the breakpoint is reused in future).

Fixes at least some of https://github.com/Dart-Code/Dart-Code/issues/4598

Change-Id: I53b92debfaa0c8f538dc8d67966854bb89634708
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/311480
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
5 files changed
tree: 302d5e83064822211ce45af703cff71bdae69bd9
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. .vpython
  22. AUTHORS
  23. BUILD.gn
  24. CHANGELOG.md
  25. codereview.settings
  26. CONTRIBUTING.md
  27. DEPS
  28. LICENSE
  29. OWNERS
  30. PATENT_GRANT
  31. PRESUBMIT.py
  32. README.dart-sdk
  33. README.md
  34. sdk.code-workspace
  35. sdk_args.gni
  36. SECURITY.md
  37. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app.

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

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See LICENSE and PATENT_GRANT.

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Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

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There are more documents on our wiki.

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