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• JDI ThreadReference.stop
• JDI ThreadReference.popFrame
• JDI ThreadReference.forceEarlyReturn
• JDI StackFrame.setValue() has limitted support. It can be used on the topmost frame when suspended due to certain events, such as breakpoint and single step. Details are still being refined.

JDWP agent options

As a temporary solution to allow existing debuggers work with virtual threads, the JDWP agent will track virtual threads so they can be enumerated for debuggers that want to enumerate all virtual threads. The options that control this behavior are:

• enumeratevthreads control whether or not virtual threads are included in the list of threads returned by JDWP VirtualThread.GetAllThreads and ThreadGroupReference.Children commands. This flag can be turned on for compatibility purposes. This flag will eventually go away and the debug agent will operate as if it was set to 'n'.
• [notifyvthreads has been removed. To disable THREAD_START and THREAD_END events for vthreads, use the PlatformThreadsOnly filter as described in this section] notifyvthreads controls whether or not THREAD_START and THREAD_END events are sent for virtual threads. The default is to send them. The purpose is to allow debugger writers to use notifyvthreads=n to see how the debugger works without getting these events. This is meant as a short term convenience flag rather than having to set the PlatformThreadsOnly filter as described above. Once support for notifyvthreads=n is gone, if debuggers don't want THREAD_START and THREAD_END events for virtual threads, they will need to set the PlatformThreadsOnly filter. When using the PlatformThreadsOnly filter, the debugger can learn about virtual threads when events are delivered for them, such as a BreakpointEvent. Since no THREAD_END event will be sent for the virtual thread, the debugger will then need to figure out how to "forget" about the virtual threads it is tracking when they have terminated. This could possibly be done with a ThreadDeathRequest that filters on the virtual thread. This would need to be done for each virtual thread being tracked by the debugger. Please note that notifyvthreads=y will not override any PlatformThreadsOnly filter that is in place.

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