ExitedEvent versus TerminatedEvent

[rkeithhill]

When should a debugger use the ExitedEvent vs the TerminatedEvent? The PowerShell debugger is launched (it doesn't support attach yet) but we are sending a TerminatedEvent at the end which apparently causes the client to send us a disconnectRequest which is a bit odd. We don't respond to this message because we are in the middle of shutting the debug host down. This results (sometimes) in a Error Canceled popup. It seems to happen when we pause/resume the debugger.

If I switch that to use the ExitedEvent we don't get the disconnectRequest message but the client pops a new error Error Debug adapter process has terminated unexpectedly. And if the program was paused and resumed it also pops up Error Canceled.

[tromey]

This came up when writing the gdb DAP implementation. See https://sourceware.org/bugzilla/show_bug.cgi?id=30681. That bug came from https://sourceware.org/bugzilla/show_bug.cgi?id=30678#c1, where there's a video showing that VSCode thought the debug session was still active even after an exited event.

We're changing gdb to send both the exited event and the terminated event, but it's unclear why both are needed, and it's also unclear to me whether the terminated event ought to be sent in response to client actions like disconnect or terminate.