test/hotspot/jtreg/vmTestbase/nsk/jdwp/VirtualMachine/InstanceCounts/instanceCounts001/instanceCounts001.java

@@ -59,10 +59,11 @@
  *         Also, test performs check for case when incorrect data is sent in command:
  *                 - create command with refTypesCount < 0, expect ILLEGAL_ARGUMENT error
  *     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 . .
  * @build nsk.jdwp.VirtualMachine.InstanceCounts.instanceCounts001.instanceCounts001
  *        nsk.jdwp.VirtualMachine.InstanceCounts.instanceCounts001.instanceCounts001a

@@ -162,10 +163,15 @@
         pipe.println(instanceCounts001a.COMMAND_CREATE_TEST_INSTANCES);
 
         if (!isDebuggeeReady())
             return;
 
+        // 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.
+
         int expectedCount = instanceCounts001a.expectedCount;
 
         String classNames[];
 
         classNames = new String[] { createTypeSignature(testClass1) };