RFR: JDK-8218754: JDK-8068225 regression in JDIBreakpointTest

[David Holmes]

Hi Gary,

On 12/02/2019 8:08 pm, gary.adams at oracle.com wrote:
> The recent change to JDK-8068225 changed the order of operations
> in Debugee.endDebugee() to wait for the debugee to exit before
> disposing of the vm on the debugger side of the connection.
> For the tests based on JDIBreakpointTest the debuggee exit
> status is not used and the tests relied on the
> debugger side dispose operation to end the test.
> 
> Since JDIBreakpointTest already includes a call to wait for
> the debugee, if does not need to use endDebuggee()
> to dispose and wait for the debugee to finish.

I agree that potentially calling waitFor twice seems pointless. But how 
did the reordering of vm.dispose() and waitFor() cause all these tests 
to hang if they were waiting anyway? Does vm.dispose() have an effect on 
destroying the process?

Also what concerns me is that dispose() is not resilient the way that 
endDebuggee is:

  public void dispose() {
     vm.dispose();
  }

versus

     public int endDebugee() {
         if (vm != null) {
             try {
                 vm.dispose();
             } catch (VMDisconnectedException ignore) {
             }
             vm = null;
         }

Do we need to be concerned with a null VM or getting 
VMDisconnectedException?

Thanks,
David

> Testing in progress. The vm/mlvm tests are included in tiers 2, 3 and 6.
> 
> diff --git 
> a/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/jdi/JDIBreakpointTest.java 
> b/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/jdi/JDIBreakpointTest.java
> --- 
> a/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/jdi/JDIBreakpointTest.java
> +++ 
> b/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/jdi/JDIBreakpointTest.java
> @@ -1,5 +1,5 @@
>   /*
> - * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights 
> reserved.
> + * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights 
> reserved.
>    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>    *
>    * This code is free software; you can redistribute it and/or modify it
> @@ -359,7 +359,7 @@
>           }.go();
> 
>           if (!debuggee.terminated())
> -            debuggee.endDebugee();
> +            debuggee.dispose();
> 
>           debuggee.waitFor();
>           return true;
>