8261666: [mlvm] Remove WhiteBoxHelper

Reviewed-by: iignatyev

Author: Evgeny Nikitin

test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/stress/gc/lotsOfCallSites/Test.java

@@ -62,11 +62,12 @@
 import java.lang.management.MemoryUsage;
 import java.util.HashSet;
 
+import sun.hotspot.WhiteBox;
+
 import nsk.share.test.Stresser;
 import vm.mlvm.share.CustomClassLoaders;
 import vm.mlvm.share.Env;
 import vm.mlvm.share.MlvmTest;
-import vm.mlvm.share.WhiteBoxHelper;
 import vm.share.FileUtils;
 import vm.share.options.Option;
 
@@ -87,6 +88,7 @@ public class Test extends MlvmTest {
     @Option(name = "iterations", default_value = "100000", description = "Iterations: each iteration loads one new class")
     private int iterations = 100_000;
 
+    private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
     private static final int GC_COUNT = 6;
     private static final boolean TERMINATE_ON_FULL_METASPACE = false;
 
@@ -133,15 +135,6 @@ private MemoryPoolMXBean getClassMetadataMemoryPoolMXBean() {
         return null;
     }
 
-    private MethodHandle getFullGCMethod() throws NoSuchMethodException, IllegalAccessException {
-        try {
-            return WhiteBoxHelper.getMethod("fullGC", MethodType.methodType(void.class));
-        } catch (NoSuchMethodException | ClassNotFoundException | InvocationTargetException e) {
-            Env.traceDebug(e, "No WhiteBox API. Will use System.gc() instead of WhiteBox.fullGC()");
-            return MethodHandles.lookup().findStatic(System.class, "gc", MethodType.methodType(void.class));
-        }
-    }
-
     @Override
     public boolean run() throws Throwable {
         setHeapDumpAfter(heapDumpOpt);
@@ -150,8 +143,6 @@ public boolean run() throws Throwable {
         final MemoryPoolMXBean classMetadataPoolMXB = getClassMetadataMemoryPoolMXBean();
         final String memPoolName = classMetadataPoolMXB == null ? "" : classMetadataPoolMXB.getName();
 
-        MethodHandle mhCollectHeap = getFullGCMethod();
-
         int removedEntries = 0;
 
         Stresser stresser = createStresser();
@@ -183,7 +174,7 @@ public boolean run() throws Throwable {
         }
 
         for (int i = 0; i < GC_COUNT; ++i) {
-            mhCollectHeap.invoke();
+            WHITE_BOX.fullGC();
             Thread.sleep(500);
             removedEntries += removeQueuedReferences();
         }