test/hotspot/jtreg/vmTestbase/nsk/jdwp/ReferenceType/Instances/instances001/instances001.java
--- a/test/hotspot/jtreg/vmTestbase/nsk/jdwp/ReferenceType/Instances/instances001/instances001.java Tue Jun 12 07:52:30 2018 -0700
+++ b/test/hotspot/jtreg/vmTestbase/nsk/jdwp/ReferenceType/Instances/instances001/instances001.java Tue Jun 12 17:40:28 2018 +0200
@@ -60,6 +60,7 @@
* Finally, debugger sends debuggee signal to quit, waits for it exits
* and exits too with the proper exit code.
*
+ * @requires vm.gc != "Z"
* @library /vmTestbase /test/hotspot/jtreg/vmTestbase
* /test/lib
* @run driver jdk.test.lib.FileInstaller . .
@@ -156,6 +157,10 @@
long typeID = debuggee.getReferenceTypeID(createTypeSignature(testClassName));
+ // Note! This test is broken, in the sense that it incorrectly assumes
+ // that no GC can happen before it walks the heap. In practice, it seems
+ // to only affect this test when using ZGC. However, this test will also
+ // fail when using other GCs if an explicit GC is done here.
// create command with maxInstances=1, only 1 instance should be returned
testClass(typeID, 1, 1, false, 0);