diff --git a/src/share/vm/prims/whitebox.cpp b/src/share/vm/prims/whitebox.cpp
index 9028a85398372d8113209aa8f76466981e30dc5e..ef5cd01d85fc3659992d853183c59371d1a09e7c 100644
--- a/src/share/vm/prims/whitebox.cpp
+++ b/src/share/vm/prims/whitebox.cpp
@@ -695,6 +695,12 @@ WB_END
 WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o))
   Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(true);
   Universe::heap()->collect(GCCause::_last_ditch_collection);
+#if INCLUDE_ALL_GCS
+  if (UseG1GC) {
+    // Needs to be cleared explicitly for G1
+    Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(false);
+  }
+#endif // INCLUDE_ALL_GCS
 WB_END
 
 WB_ENTRY(void, WB_YoungGC(JNIEnv* env, jobject o))
@@ -838,6 +844,36 @@ bool WhiteBox::lookup_bool(const char* field_name, oop object) {
   return ret;
 }
 
+void WhiteBox::register_methods(JNIEnv* env, jclass wbclass, JavaThread* thread, JNINativeMethod* method_array, int method_count) {
+  ResourceMark rm;
+  ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
+
+  //  one by one registration natives for exception catching
+  jclass no_such_method_error_klass = env->FindClass(vmSymbols::java_lang_NoSuchMethodError()->as_C_string());
+  CHECK_JNI_EXCEPTION(env);
+  for (int i = 0, n = method_count; i < n; ++i) {
+    // Skip dummy entries
+    if (method_array[i].fnPtr == NULL) continue;
+    if (env->RegisterNatives(wbclass, &method_array[i], 1) != 0) {
+      jthrowable throwable_obj = env->ExceptionOccurred();
+      if (throwable_obj != NULL) {
+        env->ExceptionClear();
+        if (env->IsInstanceOf(throwable_obj, no_such_method_error_klass)) {
+          // NoSuchMethodError is thrown when a method can't be found or a method is not native.
+          // Ignoring the exception since it is not preventing use of other WhiteBox methods.
+          tty->print_cr("Warning: 'NoSuchMethodError' on register of sun.hotspot.WhiteBox::%s%s",
+              method_array[i].name, method_array[i].signature);
+        }
+      } else {
+        // Registration failed unexpectedly.
+        tty->print_cr("Warning: unexpected error on register of sun.hotspot.WhiteBox::%s%s. All methods will be unregistered",
+            method_array[i].name, method_array[i].signature);
+        env->UnregisterNatives(wbclass);
+        break;
+      }
+    }
+  }
+}
 
 #define CC (char*)
 
@@ -940,35 +976,9 @@ JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass))
       instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass());
       Handle loader(ikh->class_loader());
       if (loader.is_null()) {
-        ResourceMark rm;
-        ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI
-        bool result = true;
-        //  one by one registration natives for exception catching
-        jclass exceptionKlass = env->FindClass(vmSymbols::java_lang_NoSuchMethodError()->as_C_string());
-        CHECK_JNI_EXCEPTION(env);
-        for (int i = 0, n = sizeof(methods) / sizeof(methods[0]); i < n; ++i) {
-          if (env->RegisterNatives(wbclass, methods + i, 1) != 0) {
-            result = false;
-            jthrowable throwable_obj = env->ExceptionOccurred();
-            if (throwable_obj != NULL) {
-              env->ExceptionClear();
-              if (env->IsInstanceOf(throwable_obj, exceptionKlass)) {
-                // j.l.NoSuchMethodError is thrown when a method can't be found or a method is not native
-                // ignoring the exception
-                tty->print_cr("Warning: 'NoSuchMethodError' on register of sun.hotspot.WhiteBox::%s%s", methods[i].name, methods[i].signature);
-              }
-            } else {
-              // register is failed w/o exception or w/ unexpected exception
-              tty->print_cr("Warning: unexpected error on register of sun.hotspot.WhiteBox::%s%s. All methods will be unregistered", methods[i].name, methods[i].signature);
-              env->UnregisterNatives(wbclass);
-              break;
-            }
-          }
-        }
-
-        if (result) {
-          WhiteBox::set_used();
-        }
+        WhiteBox::register_methods(env, wbclass, thread, methods, sizeof(methods) / sizeof(methods[0]));
+        WhiteBox::register_extended(env, wbclass, thread);
+        WhiteBox::set_used();
       }
     }
   }
diff --git a/src/share/vm/prims/whitebox.hpp b/src/share/vm/prims/whitebox.hpp
index 9ab406fc67261994e4123b5008fee1e0e8091f42..6461d1eb812445c2b9adc317118317c21540ffe3 100644
--- a/src/share/vm/prims/whitebox.hpp
+++ b/src/share/vm/prims/whitebox.hpp
@@ -29,6 +29,8 @@
 
 #include "memory/allocation.hpp"
 #include "oops/oopsHierarchy.hpp"
+#include "oops/symbol.hpp"
+#include "runtime/interfaceSupport.hpp"
 
 // Entry macro to transition from JNI to VM state.
 
@@ -64,6 +66,9 @@ class WhiteBox : public AllStatic {
   static bool lookup_bool(const char* field_name, oop object);
 
   static int array_bytes_to_length(size_t bytes);
+  static void register_methods(JNIEnv* env, jclass wbclass, JavaThread* thread,
+    JNINativeMethod* method_array, int method_count);
+  static void register_extended(JNIEnv* env, jclass wbclass, JavaThread* thread);
 };
 
 
diff --git a/src/share/vm/prims/whitebox_ext.cpp b/src/share/vm/prims/whitebox_ext.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..34f191cbdb7df1c6a434a67c70d9af970ddf20e2
--- /dev/null
+++ b/src/share/vm/prims/whitebox_ext.cpp
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2012, 2014, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+
+#include "prims/whitebox.hpp"
+
+void WhiteBox::register_extended(JNIEnv* env, jclass wbclass, JavaThread* thread) { }
diff --git a/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java b/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java
index 360d702c2792ae8ba3d12b714f3793335d9bbea0..2dfaa05fac382f5f5864988b2a83dedc4d54baba 100644
--- a/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java
+++ b/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java
@@ -30,6 +30,7 @@ import java.util.List;
 import java.util.function.Function;
 import java.util.stream.Stream;
 import java.security.BasicPermission;
+
 import sun.hotspot.parser.DiagnosticCommand;
 
 public class WhiteBox {
@@ -168,6 +169,12 @@ public class WhiteBox {
   // CPU features
   public native String getCPUFeatures();
 
+  // Native extensions
+  public native long getHeapUsageForContext(int context);
+  public native long getHeapRegionCountForContext(int context);
+  public native int getContextForObject(Object obj);
+  public native void printRegionInfo(int context);
+
   // VM flags
   public native void    setBooleanVMFlag(String name, boolean value);
   public native void    setIntxVMFlag(String name, long value);