Support "Suspend VM" and "Suspend Thread" Breakpoint Modes

[tsmaeder]

I propose we support the Java breakpoint suspend modes by adding the "breakpointModes" capability and honoring when breakpoints are set.

[tsmaeder]

As I read the VS Code UI code, this should then just show up in the UI, as well.

[github-actions]

Hi Thomas Mäder (@tsmaeder), I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

Suggestions

• Review the Debug Adapter Protocol (DAP) specification for SetBreakpointsRequest to understand how capabilities are declared and how breakpoint payloads are structured:

  • https://microsoft.github.io/debug-adapter-protocol/specification#setbreakpointsrequest

• In the vscode-java-debug extension:

  1. Add a new capability in the initialize response (e.g. breakpointModes) in javaDebugProtocol.ts.
  2. Extend your client-side UI to allow users to choose between VM and Thread suspend modes when setting a breakpoint.
  3. In JavaBreakpointManager.ts, inspect the incoming breakpoint payload for the chosen mode and call the corresponding JDI API:
     • BreakpointRequest.setSuspendPolicy(EventRequest.SUSPEND_ALL) for “Suspend VM”
     • BreakpointRequest.setSuspendPolicy(EventRequest.SUSPEND_EVENT_THREAD) for “Suspend Thread”
  4. Test that the adapter honors the selected mode by verifying whether all threads suspend or only the breakpoint’s thread suspends.

Labels

• enhancement

Duplicates

None

Other references with low confidence

• Java remote attach to debug not hitting breakpoints: discusses use of suspend=y vs suspend=n when launching the JVM, but not per-breakpoint suspend modes.
  • Java remote attach to debug not hitting breakpoints. vscode-java-debug#755 (comment)

The team will respond to your issue shortly. I hope these suggestions are helpful in the meantime. If this comment helped you, please give it a 👍. If the suggestion was not helpful or incorrect, please give it a 👎. Your feedback helps us improve!

[tsmaeder]

I'm working on an PR for this. Should be landing next week.