8268433: serviceability/dcmd/framework/VMVersionTest.java fails with Unable to...

8268433: serviceability/dcmd/framework/VMVersionTest.java fails with Unable to send object throw not established PipeIO Listener Thread connection

Backport-of: 280f2d57d1f78b3d15dd98e726267a100eb0b5db

test/hotspot/jtreg/ProblemList-zgc.txt

@@ -44,7 +44,3 @@ serviceability/sa/TestJmapCoreMetaspace.java                  8268722,8268636
 serviceability/sa/TestJhsdbJstackMixed.java                   8248912   generic-all
 serviceability/sa/ClhsdbPstack.java#id0                       8248912   generic-all
 serviceability/sa/ClhsdbPstack.java#id1                       8248912   generic-all
-
-serviceability/dcmd/framework/HelpTest.java                   8268433 windows-x64
-serviceability/dcmd/framework/InvalidCommandTest.java         8268433 windows-x64
-serviceability/dcmd/framework/VMVersionTest.java              8268433 windows-x64

test/hotspot/jtreg/serviceability/dcmd/framework/TestProcessLauncher.java

@@ -77,7 +77,11 @@ public class TestProcessLauncher {
 
     public void quit() {
         if (pipe != null) {
+            if (pipe.isConnected()) {
                 pipe.println("quit");
+            } else {
+                System.out.println("WARNING: IOPipe is not connected");
+            }
         }
     }