8078644: CDS needs to support JVMTI CFLH
authorjiangli
Sun, 18 Sep 2016 21:10:48 -0400
changeset 41182 dbd59c1da636
parent 41181 2ce2f1c582ca
child 41183 207b92e69457
child 41184 9d76828a29ae
child 41284 b4276ec89d0d
8078644: CDS needs to support JVMTI CFLH Summary: Support posting CLFH for shared classes. Tests are contributed by Misha Seledtsov. Reviewed-by: iklam, coleenp, acorn, dcubed, sspitsyn
hotspot/src/share/vm/classfile/klassFactory.cpp
hotspot/src/share/vm/classfile/klassFactory.hpp
hotspot/src/share/vm/classfile/systemDictionary.cpp
hotspot/src/share/vm/memory/filemap.cpp
hotspot/src/share/vm/memory/filemap.hpp
hotspot/src/share/vm/memory/metaspace.cpp
hotspot/src/share/vm/memory/metaspaceShared.cpp
hotspot/src/share/vm/memory/metaspaceShared.hpp
hotspot/src/share/vm/oops/instanceKlass.cpp
hotspot/src/share/vm/oops/instanceKlass.hpp
hotspot/src/share/vm/utilities/debug.cpp
hotspot/src/share/vm/utilities/debug.hpp
hotspot/test/runtime/SharedArchiveFile/CDSTestUtils.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/Implementor.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/Interface.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/SubClass.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/SuperClazz.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TestEntry.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformInterfaceAndImplementor.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformRelatedClasses.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformSuperAndSubClasses.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformSuperSubTwoPckgs.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformTestCommon.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/myPkg1/SuperClazz.java
hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/myPkg2/SubClass.java
hotspot/test/testlibrary/jvmti/TransformUtil.java
hotspot/test/testlibrary/jvmti/TransformerAgent.java
hotspot/test/testlibrary/jvmti/TransformerAgent.mf
--- a/hotspot/src/share/vm/classfile/klassFactory.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/classfile/klassFactory.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -25,12 +25,85 @@
 #include "precompiled.hpp"
 #include "classfile/classFileParser.hpp"
 #include "classfile/classFileStream.hpp"
+#include "classfile/classLoader.hpp"
 #include "classfile/classLoaderData.hpp"
+#include "classfile/classLoaderData.inline.hpp"
 #include "classfile/klassFactory.hpp"
+#include "classfile/sharedClassUtil.hpp"
+#include "memory/metaspaceShared.hpp"
 #include "memory/resourceArea.hpp"
 #include "prims/jvmtiEnvBase.hpp"
+#include "prims/jvmtiRedefineClasses.hpp"
 #include "trace/traceMacros.hpp"
 
+// called during initial loading of a shared class
+instanceKlassHandle KlassFactory::check_shared_class_file_load_hook(
+                                          instanceKlassHandle ik,
+                                          Symbol* class_name,
+                                          Handle class_loader,
+                                          Handle protection_domain, TRAPS) {
+#if INCLUDE_CDS && INCLUDE_JVMTI
+  assert(ik.not_null(), "sanity");
+  assert(ik()->is_shared(), "expecting a shared class");
+
+  if (JvmtiExport::should_post_class_file_load_hook()) {
+    assert(THREAD->is_Java_thread(), "must be JavaThread");
+
+    // Post the CFLH
+    JvmtiCachedClassFileData* cached_class_file = NULL;
+    JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data();
+    assert(archived_class_data != NULL, "shared class has no archived class data");
+    unsigned char* ptr =
+        VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data);
+    unsigned char* end_ptr =
+        ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data);
+    unsigned char* old_ptr = ptr;
+    JvmtiExport::post_class_file_load_hook(class_name,
+                                           class_loader,
+                                           protection_domain,
+                                           &ptr,
+                                           &end_ptr,
+                                           &cached_class_file);
+    if (old_ptr != ptr) {
+      // JVMTI agent has modified class file data.
+      // Set new class file stream using JVMTI agent modified class file data.
+      ClassLoaderData* loader_data =
+        ClassLoaderData::class_loader_data(class_loader());
+      int path_index = ik->shared_classpath_index();
+      SharedClassPathEntry* ent =
+        (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
+      ClassFileStream* stream = new ClassFileStream(ptr,
+                                                    end_ptr - ptr,
+                                                    ent->_name,
+                                                    ClassFileStream::verify);
+      ClassFileParser parser(stream,
+                             class_name,
+                             loader_data,
+                             protection_domain,
+                             NULL,
+                             NULL,
+                             ClassFileParser::BROADCAST, // publicity level
+                             CHECK_NULL);
+      instanceKlassHandle new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
+                                                                CHECK_NULL);
+      if (cached_class_file != NULL) {
+        new_ik->set_cached_class_file(cached_class_file);
+      }
+
+      if (class_loader.is_null()) {
+        ResourceMark rm;
+        ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
+      }
+
+      return new_ik;
+    }
+  }
+#endif
+
+  return NULL;
+}
+
+
 static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
                                                    Symbol* name,
                                                    ClassLoaderData* loader_data,
@@ -97,7 +170,6 @@
                                                      const InstanceKlass* host_klass,
                                                      GrowableArray<Handle>* cp_patches,
                                                      TRAPS) {
-
   assert(stream != NULL, "invariant");
   assert(loader_data != NULL, "invariant");
   assert(THREAD->is_Java_thread(), "must be a JavaThread");
@@ -142,5 +214,27 @@
 
   TRACE_KLASS_CREATION(result, parser, THREAD);
 
+#if INCLUDE_CDS && INCLUDE_JVMTI
+  if (DumpSharedSpaces) {
+    assert(cached_class_file == NULL, "Sanity");
+    // Archive the class stream data into the optional data section
+    JvmtiCachedClassFileData *p;
+    int len;
+    const unsigned char *bytes;
+    // event based tracing might set cached_class_file
+    if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
+      len = result->get_cached_class_file_len();
+    } else {
+      len = stream->length();
+      bytes = stream->buffer();
+    }
+    p = (JvmtiCachedClassFileData*)MetaspaceShared::optional_data_space_alloc(
+                    offset_of(JvmtiCachedClassFileData, data) + len);
+    p->length = len;
+    memcpy(p->data, bytes, len);
+    result->set_archived_class_data(p);
+  }
+#endif
+
   return result;
 }
--- a/hotspot/src/share/vm/classfile/klassFactory.hpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/classfile/klassFactory.hpp	Sun Sep 18 21:10:48 2016 -0400
@@ -75,6 +75,12 @@
                                                 const InstanceKlass* host_klass,
                                                 GrowableArray<Handle>* cp_patches,
                                                 TRAPS);
+ public:
+  static instanceKlassHandle check_shared_class_file_load_hook(
+                                          instanceKlassHandle ik,
+                                          Symbol* class_name,
+                                          Handle class_loader,
+                                          Handle protection_domain, TRAPS);
 };
 
 #endif // SHARE_VM_CLASSFILE_KLASSFACTORY_HPP
--- a/hotspot/src/share/vm/classfile/systemDictionary.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/classfile/systemDictionary.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -1210,16 +1210,12 @@
 
 instanceKlassHandle SystemDictionary::load_shared_class(
                  Symbol* class_name, Handle class_loader, TRAPS) {
-  // Don't load shared class when JvmtiExport::should_post_class_file_load_hook()
-  // is enabled since posting CFLH is not supported when loading shared class.
-  if (!JvmtiExport::should_post_class_file_load_hook()) {
-    instanceKlassHandle ik (THREAD, find_shared_class(class_name));
-    // Make sure we only return the boot class for the NULL classloader.
-    if (ik.not_null() &&
-        ik->is_shared_boot_class() && class_loader.is_null()) {
-      Handle protection_domain;
-      return load_shared_class(ik, class_loader, protection_domain, THREAD);
-    }
+  instanceKlassHandle ik (THREAD, find_shared_class(class_name));
+  // Make sure we only return the boot class for the NULL classloader.
+  if (ik.not_null() &&
+      ik->is_shared_boot_class() && class_loader.is_null()) {
+    Handle protection_domain;
+    return load_shared_class(ik, class_loader, protection_domain, THREAD);
   }
   return instanceKlassHandle();
 }
@@ -1303,11 +1299,6 @@
                                                         Handle class_loader,
                                                         Handle protection_domain, TRAPS) {
   instanceKlassHandle nh = instanceKlassHandle(); // null Handle
-  if (JvmtiExport::should_post_class_file_load_hook()) {
-    // Don't load shared class when JvmtiExport::should_post_class_file_load_hook()
-    // is enabled since posting CFLH is not supported when loading shared class.
-    return nh;
-  }
 
   if (ik.not_null()) {
     Symbol* class_name = ik->name();
@@ -1358,6 +1349,14 @@
       }
     }
 
+    instanceKlassHandle new_ik = KlassFactory::check_shared_class_file_load_hook(
+        ik, class_name, class_loader, protection_domain, CHECK_(nh));
+    if (new_ik.not_null()) {
+      // The class is changed by CFLH. Return the new class. The shared class is
+      // not used.
+      return new_ik;
+    }
+
     // Adjust methods to recover missing data.  They need addresses for
     // interpreter entry points and their default native method address
     // must be reset.
--- a/hotspot/src/share/vm/memory/filemap.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/memory/filemap.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -649,7 +649,7 @@
 
 // Memory map a region in the address space.
 static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode",
-                                            "String1", "String2" };
+                                            "String1", "String2", "OptionalData" };
 
 char* FileMapInfo::map_region(int i) {
   assert(!MetaspaceShared::is_string_region(i), "sanity");
--- a/hotspot/src/share/vm/memory/filemap.hpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/memory/filemap.hpp	Sun Sep 18 21:10:48 2016 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2016, 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
@@ -252,10 +252,27 @@
   bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false);
   void print_shared_spaces() NOT_CDS_RETURN;
 
+  // The ro+rw+md+mc spaces size
+  static size_t core_spaces_size() {
+    return align_size_up((SharedReadOnlySize + SharedReadWriteSize +
+                          SharedMiscDataSize + SharedMiscCodeSize),
+                          os::vm_allocation_granularity());
+  }
+
+  // The estimated optional space size.
+  //
+  // Currently the optional space only has archived class bytes.
+  // The core_spaces_size is the size of all class metadata, which is a good
+  // estimate of the total class bytes to be archived. Only the portion
+  // containing data is written out to the archive and mapped at runtime.
+  // There is no memory waste due to unused portion in optional space.
+  static size_t optional_space_size() {
+    return core_spaces_size();
+  }
+
+  // Total shared_spaces size includes the ro, rw, md, mc and od spaces
   static size_t shared_spaces_size() {
-    return align_size_up(SharedReadOnlySize + SharedReadWriteSize +
-                         SharedMiscDataSize + SharedMiscCodeSize,
-                         os::vm_allocation_granularity());
+    return core_spaces_size() + optional_space_size();
   }
 
   // Stop CDS sharing and unmap CDS regions.
--- a/hotspot/src/share/vm/memory/metaspace.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/memory/metaspace.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -3172,36 +3172,28 @@
       address cds_address = NULL;
       FileMapInfo* mapinfo = new FileMapInfo();
 
-      if (JvmtiExport::should_post_class_file_load_hook()) {
-        // Currently CDS does not support JVMTI CFLH when loading shared class.
-        // If JvmtiExport::should_post_class_file_load_hook is already enabled,
-        // just disable UseSharedSpaces.
-        FileMapInfo::fail_continue("Tool agent requires sharing to be disabled.");
-        delete mapinfo;
-      } else {
-        // Open the shared archive file, read and validate the header. If
-        // initialization fails, shared spaces [UseSharedSpaces] are
-        // disabled and the file is closed.
-        // Map in spaces now also
-        if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
-          cds_total = FileMapInfo::shared_spaces_size();
-          cds_address = (address)mapinfo->header()->region_addr(0);
+      // Open the shared archive file, read and validate the header. If
+      // initialization fails, shared spaces [UseSharedSpaces] are
+      // disabled and the file is closed.
+      // Map in spaces now also
+      if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
+        cds_total = FileMapInfo::shared_spaces_size();
+        cds_address = (address)mapinfo->header()->region_addr(0);
 #ifdef _LP64
-          if (using_class_space()) {
-            char* cds_end = (char*)(cds_address + cds_total);
-            cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
-            // If UseCompressedClassPointers is set then allocate the metaspace area
-            // above the heap and above the CDS area (if it exists).
-            allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
-            // Map the shared string space after compressed pointers
-            // because it relies on compressed class pointers setting to work
-            mapinfo->map_string_regions();
-          }
+        if (using_class_space()) {
+          char* cds_end = (char*)(cds_address + cds_total);
+          cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
+          // If UseCompressedClassPointers is set then allocate the metaspace area
+          // above the heap and above the CDS area (if it exists).
+          allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
+          // Map the shared string space after compressed pointers
+          // because it relies on compressed class pointers setting to work
+          mapinfo->map_string_regions();
+        }
 #endif // _LP64
-        } else {
-          assert(!mapinfo->is_open() && !UseSharedSpaces,
-                 "archive file not closed or shared spaces not disabled.");
-        }
+      } else {
+        assert(!mapinfo->is_open() && !UseSharedSpaces,
+               "archive file not closed or shared spaces not disabled.");
       }
     }
 #endif // INCLUDE_CDS
--- a/hotspot/src/share/vm/memory/metaspaceShared.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/memory/metaspaceShared.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -65,6 +65,7 @@
 size_t MetaspaceShared::_cds_i2i_entry_code_buffers_size = 0;
 SharedMiscRegion MetaspaceShared::_mc;
 SharedMiscRegion MetaspaceShared::_md;
+SharedMiscRegion MetaspaceShared::_od;
 
 void SharedMiscRegion::initialize(ReservedSpace rs, size_t committed_byte_size,  SharedSpaceType space_type) {
   _vs.initialize(rs, committed_byte_size);
@@ -93,16 +94,24 @@
   assert(DumpSharedSpaces, "dump time only");
   _shared_rs = rs;
 
-  // Split up and initialize the misc code and data spaces
+  size_t core_spaces_size = FileMapInfo::core_spaces_size();
   size_t metadata_size = SharedReadOnlySize + SharedReadWriteSize;
-  ReservedSpace shared_ro_rw = _shared_rs->first_part(metadata_size);
-  ReservedSpace misc_section = _shared_rs->last_part(metadata_size);
+
+  // Split into the core and optional sections
+  ReservedSpace core_data = _shared_rs->first_part(core_spaces_size);
+  ReservedSpace optional_data = _shared_rs->last_part(core_spaces_size);
 
-  // Now split into misc sections.
+  // The RO/RW and the misc sections
+  ReservedSpace shared_ro_rw = core_data.first_part(metadata_size);
+  ReservedSpace misc_section = core_data.last_part(metadata_size);
+
+  // Now split the misc code and misc data sections.
   ReservedSpace md_rs   = misc_section.first_part(SharedMiscDataSize);
   ReservedSpace mc_rs   = misc_section.last_part(SharedMiscDataSize);
+
   _md.initialize(md_rs, SharedMiscDataSize, SharedMiscData);
-  _mc.initialize(mc_rs, SharedMiscCodeSize, SharedMiscData);
+  _mc.initialize(mc_rs, SharedMiscCodeSize, SharedMiscCode);
+  _od.initialize(optional_data, metadata_size, SharedOptional);
 }
 
 // Read/write a data stream for restoring/preserving metadata pointers and
@@ -521,6 +530,7 @@
   GrowableArray<Klass*> *_class_promote_order;
   VirtualSpace _md_vs;
   VirtualSpace _mc_vs;
+  VirtualSpace _od_vs;
   GrowableArray<MemRegion> *_string_regions;
 
 public:
@@ -598,15 +608,19 @@
   remove_unshareable_in_classes();
   tty->print_cr("done. ");
 
-  // Set up the share data and shared code segments.
+  // Set up the misc data, misc code and optional data segments.
   _md_vs = *MetaspaceShared::misc_data_region()->virtual_space();
   _mc_vs = *MetaspaceShared::misc_code_region()->virtual_space();
+  _od_vs = *MetaspaceShared::optional_data_region()->virtual_space();
   char* md_low = _md_vs.low();
   char* md_top = MetaspaceShared::misc_data_region()->alloc_top();
   char* md_end = _md_vs.high();
   char* mc_low = _mc_vs.low();
   char* mc_top = MetaspaceShared::misc_code_region()->alloc_top();
   char* mc_end = _mc_vs.high();
+  char* od_low = _od_vs.low();
+  char* od_top = MetaspaceShared::optional_data_region()->alloc_top();
+  char* od_end = _od_vs.high();
 
   // Reserve space for the list of Klass*s whose vtables are used
   // for patching others as needed.
@@ -661,28 +675,32 @@
   const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
   const size_t md_alloced = md_end-md_low;
   const size_t mc_alloced = mc_end-mc_low;
+  const size_t od_alloced = od_end-od_low;
   const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced
-                             + ss_bytes;
+                             + ss_bytes + od_alloced;
 
   // Occupied size of each space.
   const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
   const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
   const size_t md_bytes = size_t(md_top - md_low);
   const size_t mc_bytes = size_t(mc_top - mc_low);
+  const size_t od_bytes = size_t(od_top - od_low);
 
   // Percent of total size
-  const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes + ss_bytes;
+  const size_t total_bytes = ro_bytes + rw_bytes + md_bytes + mc_bytes + ss_bytes + od_bytes;
   const double ro_t_perc = ro_bytes / double(total_bytes) * 100.0;
   const double rw_t_perc = rw_bytes / double(total_bytes) * 100.0;
   const double md_t_perc = md_bytes / double(total_bytes) * 100.0;
   const double mc_t_perc = mc_bytes / double(total_bytes) * 100.0;
   const double ss_t_perc = ss_bytes / double(total_bytes) * 100.0;
+  const double od_t_perc = od_bytes / double(total_bytes) * 100.0;
 
   // Percent of fullness of each space
   const double ro_u_perc = ro_bytes / double(ro_alloced) * 100.0;
   const double rw_u_perc = rw_bytes / double(rw_alloced) * 100.0;
   const double md_u_perc = md_bytes / double(md_alloced) * 100.0;
   const double mc_u_perc = mc_bytes / double(mc_alloced) * 100.0;
+  const double od_u_perc = od_bytes / double(od_alloced) * 100.0;
   const double total_u_perc = total_bytes / double(total_alloced) * 100.0;
 
 #define fmt_space "%s space: " SIZE_FORMAT_W(9) " [ %4.1f%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used] at " INTPTR_FORMAT
@@ -691,6 +709,7 @@
   tty->print_cr(fmt_space, "md", md_bytes, md_t_perc, md_alloced, md_u_perc, p2i(md_low));
   tty->print_cr(fmt_space, "mc", mc_bytes, mc_t_perc, mc_alloced, mc_u_perc, p2i(mc_low));
   tty->print_cr(fmt_space, "st", ss_bytes, ss_t_perc, ss_bytes,   100.0,     p2i(ss_low));
+  tty->print_cr(fmt_space, "od", od_bytes, od_t_perc, od_alloced, od_u_perc, p2i(od_low));
   tty->print_cr("total   : " SIZE_FORMAT_W(9) " [100.0%% of total] out of " SIZE_FORMAT_W(9) " bytes [%5.1f%% used]",
                  total_bytes, total_alloced, total_u_perc);
 
@@ -734,6 +753,10 @@
                           SharedMiscCodeSize,
                           true, true);
     mapinfo->write_string_regions(_string_regions);
+    mapinfo->write_region(MetaspaceShared::od, _od_vs.low(),
+                          pointer_delta(od_top, _od_vs.low(), sizeof(char)),
+                          pointer_delta(od_end, _od_vs.low(), sizeof(char)),
+                          true, false);
   }
 
   mapinfo->close();
@@ -1049,8 +1072,6 @@
 
 
 // Map shared spaces at requested addresses and return if succeeded.
-// Need to keep the bounds of the ro and rw space for the Metaspace::contains
-// call, or is_in_shared_space.
 bool MetaspaceShared::map_shared_spaces(FileMapInfo* mapinfo) {
   size_t image_alignment = mapinfo->alignment();
 
@@ -1068,6 +1089,7 @@
   char* _rw_base = NULL;
   char* _md_base = NULL;
   char* _mc_base = NULL;
+  char* _od_base = NULL;
 
   // Map each shared region
   if ((_ro_base = mapinfo->map_region(ro)) != NULL &&
@@ -1078,6 +1100,8 @@
       mapinfo->verify_region_checksum(md) &&
       (_mc_base = mapinfo->map_region(mc)) != NULL &&
       mapinfo->verify_region_checksum(mc) &&
+      (_od_base = mapinfo->map_region(od)) != NULL &&
+      mapinfo->verify_region_checksum(od) &&
       (image_alignment == (size_t)max_alignment()) &&
       mapinfo->validate_classpath_entry_table()) {
     // Success (no need to do anything)
@@ -1089,6 +1113,7 @@
     if (_rw_base != NULL) mapinfo->unmap_region(rw);
     if (_md_base != NULL) mapinfo->unmap_region(md);
     if (_mc_base != NULL) mapinfo->unmap_region(mc);
+    if (_od_base != NULL) mapinfo->unmap_region(od);
 #ifndef _WINDOWS
     // Release the entire mapped region
     shared_rs.release();
--- a/hotspot/src/share/vm/memory/metaspaceShared.hpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/memory/metaspaceShared.hpp	Sun Sep 18 21:10:48 2016 -0400
@@ -132,6 +132,7 @@
   // Used only during dumping.
   static SharedMiscRegion _md;
   static SharedMiscRegion _mc;
+  static SharedMiscRegion _od;
  public:
   enum {
     vtbl_list_size         = DEFAULT_VTBL_LIST_SIZE,
@@ -148,7 +149,10 @@
     max_strings = 2, // max number of string regions in string space
     num_non_strings = 4, // number of non-string regions
     first_string = num_non_strings, // index of first string region
-    n_regions = max_strings + num_non_strings // total number of regions
+    // The optional data region is the last region.
+    // Currently it only contains class file data.
+    od = max_strings + num_non_strings,
+    n_regions = od + 1 // total number of regions
   };
 
   // Accessor functions to save shared space created for metadata, which has
@@ -222,9 +226,10 @@
   static int count_class(const char* classlist_file);
   static void estimate_regions_size() NOT_CDS_RETURN;
 
-  // Allocate a block of memory from the "mc" or "md" regions.
+  // Allocate a block of memory from the "mc", "md", or "od" regions.
   static char* misc_code_space_alloc(size_t num_bytes) {  return _mc.alloc(num_bytes); }
   static char* misc_data_space_alloc(size_t num_bytes) {  return _md.alloc(num_bytes); }
+  static char* optional_data_space_alloc(size_t num_bytes) { return _od.alloc(num_bytes); }
 
   static address cds_i2i_entry_code_buffers(size_t total_size);
 
@@ -243,5 +248,9 @@
     assert(DumpSharedSpaces, "used during dumping only");
     return &_md;
   }
+  static SharedMiscRegion* optional_data_region() {
+    assert(DumpSharedSpaces, "used during dumping only");
+    return &_od;
+  }
 };
 #endif // SHARE_VM_MEMORY_METASPACESHARED_HPP
--- a/hotspot/src/share/vm/oops/instanceKlass.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/oops/instanceKlass.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -41,6 +41,7 @@
 #include "memory/heapInspection.hpp"
 #include "memory/iterator.inline.hpp"
 #include "memory/metadataFactory.hpp"
+#include "memory/metaspaceShared.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/fieldStreams.hpp"
@@ -1972,11 +1973,6 @@
     m->remove_unshareable_info();
   }
 
-  // cached_class_file might be pointing to a malloc'ed buffer allocated by
-  // event-based tracing code at CDS dump time. It's not usable at runtime
-  // so let's clear it.
-  set_cached_class_file(NULL);
-
   // do array classes also.
   array_klasses_do(remove_unshareable_in_class);
 }
@@ -2070,6 +2066,7 @@
 }
 
 void InstanceKlass::release_C_heap_structures() {
+  assert(!this->is_shared(), "should not be called for a shared class");
 
   // Can't release the constant pool here because the constant pool can be
   // deallocated separately from the InstanceKlass for default methods and
@@ -3653,6 +3650,15 @@
 }
 
 #if INCLUDE_JVMTI
+JvmtiCachedClassFileData* InstanceKlass::get_cached_class_file() {
+  if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
+    // Ignore the archived class stream data
+    return NULL;
+  } else {
+    return _cached_class_file;
+  }
+}
+
 jint InstanceKlass::get_cached_class_file_len() {
   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
 }
@@ -3660,4 +3666,15 @@
 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
 }
+
+#if INCLUDE_CDS
+JvmtiCachedClassFileData* InstanceKlass::get_archived_class_data() {
+  assert(this->is_shared(), "class should be shared");
+  if (MetaspaceShared::is_in_shared_space(_cached_class_file)) {
+    return _cached_class_file;
+  } else {
+    return NULL;
+  }
+}
 #endif
+#endif
--- a/hotspot/src/share/vm/oops/instanceKlass.hpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/oops/instanceKlass.hpp	Sun Sep 18 21:10:48 2016 -0400
@@ -783,7 +783,7 @@
   void set_cached_class_file(JvmtiCachedClassFileData *data) {
     _cached_class_file = data;
   }
-  JvmtiCachedClassFileData * get_cached_class_file() { return _cached_class_file; }
+  JvmtiCachedClassFileData * get_cached_class_file();
   jint get_cached_class_file_len();
   unsigned char * get_cached_class_file_bytes();
 
@@ -795,6 +795,13 @@
     return _jvmti_cached_class_field_map;
   }
 
+#if INCLUDE_CDS
+  void set_archived_class_data(JvmtiCachedClassFileData* data) {
+    _cached_class_file = data;
+  }
+
+  JvmtiCachedClassFileData * get_archived_class_data();
+#endif // INCLUDE_CDS
 #else // INCLUDE_JVMTI
 
   static void purge_previous_versions(InstanceKlass* ik) { return; };
--- a/hotspot/src/share/vm/utilities/debug.cpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/utilities/debug.cpp	Sun Sep 18 21:10:48 2016 -0400
@@ -282,6 +282,12 @@
 }
 
 void report_out_of_shared_space(SharedSpaceType shared_space) {
+  if (shared_space == SharedOptional) {
+    // The estimated shared_optional_space size is large enough
+    // for all class bytes.  It should not run out of space.
+    ShouldNotReachHere();
+  }
+
   static const char* name[] = {
     "shared read only space",
     "shared read write space",
--- a/hotspot/src/share/vm/utilities/debug.hpp	Tue Sep 06 13:01:27 2016 +0200
+++ b/hotspot/src/share/vm/utilities/debug.hpp	Sun Sep 18 21:10:48 2016 -0400
@@ -271,7 +271,8 @@
   SharedReadOnly,
   SharedReadWrite,
   SharedMiscData,
-  SharedMiscCode
+  SharedMiscCode,
+  SharedOptional
 };
 
 void report_out_of_shared_space(SharedSpaceType space_type);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/CDSTestUtils.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+import java.io.IOException;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.PrintStream;
+import jdk.test.lib.process.OutputAnalyzer;
+
+
+// This class contains common test utilities for CDS testing
+public class CDSTestUtils {
+
+    // check result of 'dump' operation
+    public static void checkDump(OutputAnalyzer output, String... extraMatches)
+        throws Exception {
+
+        output.shouldContain("Loading classes to share");
+        output.shouldHaveExitValue(0);
+
+        for (String match : extraMatches) {
+            output.shouldContain(match);
+        }
+    }
+
+
+    // check the output for indication that mapping of the archive failed
+    public static boolean isUnableToMap(OutputAnalyzer output) {
+        String outStr = output.getOutput();
+        if ((output.getExitValue() == 1) && (
+            outStr.contains("Unable to reserve shared space at required address") ||
+            outStr.contains("Unable to map ReadOnly shared space at required address") ||
+            outStr.contains("Unable to map ReadWrite shared space at required address") ||
+            outStr.contains("Unable to map MiscData shared space at required address") ||
+            outStr.contains("Unable to map MiscCode shared space at required address") ||
+            outStr.contains("Unable to map shared string space at required address") ||
+            outStr.contains("Could not allocate metaspace at a compatible address") ||
+            outStr.contains("Unable to allocate shared string space: range is not within java heap") ))
+        {
+            return true;
+        }
+
+        return false;
+    }
+
+    // check result of 'exec' operation, that is when JVM is run using the archive
+    public static void checkExec(OutputAnalyzer output, String... extraMatches) throws Exception {
+        if (isUnableToMap(output)) {
+            System.out.println("Unable to map shared archive: test did not complete; assumed PASS");
+            return;
+        }
+        output.shouldContain("sharing");
+        output.shouldHaveExitValue(0);
+
+        for (String match : extraMatches) {
+            output.shouldContain(match);
+        }
+    }
+
+
+    // get the file object for the test artifact
+    private static File getTestArtifactFile(String prefix, String name) {
+        File dir = new File(System.getProperty("test.classes", "."));
+        return new File(dir, prefix + name);
+    }
+
+
+    // create file containing the specified class list
+    public static File makeClassList(String testCaseName, String classes[])
+        throws Exception {
+
+        File classList = getTestArtifactFile(testCaseName, "test.classlist");
+        FileOutputStream fos = new FileOutputStream(classList);
+        PrintStream ps = new PrintStream(fos);
+
+        addToClassList(ps, classes);
+
+        ps.close();
+        fos.close();
+
+        return classList;
+    }
+
+
+    private static void addToClassList(PrintStream ps, String classes[])
+        throws IOException
+    {
+        if (classes != null) {
+            for (String s : classes) {
+                ps.println(s);
+            }
+        }
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/Implementor.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+public class Implementor implements Interface {
+    public static void main(String[] args) {
+        System.out.println("Implementor: entering main()");
+        test();
+    }
+
+    public static void test() {
+        // from interface
+        (new Implementor()).printString();
+        // from implementor
+        System.out.println(TransformUtil.ChildCheckPattern +
+                           TransformUtil.BeforePattern);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/Interface.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+public interface Interface {
+    public static final String stringToBeTransformed =
+        TransformUtil.ParentCheckPattern + TransformUtil.BeforePattern;
+
+    default void printString() {
+        System.out.println(stringToBeTransformed);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/SubClass.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+public class SubClass extends SuperClazz {
+    public static void main(String[] args) {
+        System.out.println("SubClass: entering main()");
+        test();
+    }
+
+    public static void test() {
+        // The line below will be used to check for successful class transformation
+        System.out.println(TransformUtil.ChildCheckPattern +
+                           TransformUtil.BeforePattern);
+        (new SubClass()).callParent();
+    }
+
+    private void callParent() {
+        super.testParent();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/SuperClazz.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+public class SuperClazz {
+    public static void testParent() {
+        System.out.println("SuperClazz: entering testParent()");
+
+        // The line below will be used to check for successful class transformation
+        System.out.println(TransformUtil.ParentCheckPattern + TransformUtil.BeforePattern);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TestEntry.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+// Test Entry - a single entry in a test table
+// that defines a test case
+// See TransformRelatedClasses.java for more details
+public class TestEntry {
+    int testCaseId;
+    boolean transformParent;
+    boolean transformChild;
+    boolean isParentExpectedShared;
+    boolean isChildExpectedShared;
+
+    public TestEntry(int testCaseId,
+                     boolean transformParent, boolean transformChild,
+                     boolean isParentExpectedShared, boolean isChildExpectedShared) {
+        this.testCaseId = testCaseId;
+        this.transformParent = transformParent;
+        this.transformChild = transformChild;
+        this.isParentExpectedShared = isParentExpectedShared;
+        this.isChildExpectedShared = isChildExpectedShared;
+    }
+}
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformInterfaceAndImplementor.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+/*
+ * @test
+ * @summary Exercise initial transformation (ClassFileLoadHook)
+ *  with CDS with Interface/Implementor pair
+ * @library /test/lib /runtime/SharedArchiveFile /testlibrary/jvmti
+ * @requires (vm.opt.UseCompressedOops == null) | (vm.opt.UseCompressedOops == true)
+ * @requires vm.flavor != "minimal"
+ * @modules java.base/jdk.internal.misc
+ *          jdk.jartool/sun.tools.jar
+ *          java.management
+ *          java.instrument
+ * @build TransformUtil TransformerAgent Interface Implementor
+ * @run main/othervm TransformRelatedClasses Interface Implementor
+ */
+
+// Clarification on @requires declarations:
+// CDS is not supported w/o the use of Compressed OOPs
+// JVMTI's ClassFileLoadHook is not supported under minimal VM
+
+// This test class uses TransformRelatedClasses to do its work.
+// The goal of this test is to exercise transformation of related interface
+// and its implementor in combination with CDS.
+// The transformation is done via ClassFileLoadHook mechanism.
+// Both superclass and subclass reside in the shared archive.
+// The test consists of 4 test cases where transformation is applied
+// to an interface and an implementor in a combinatorial manner.
+// Please see TransformRelatedClasses.java for details.
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformRelatedClasses.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+// This is the main test class for testing transformation of related classes
+// in combination with CDS, to ensure these features work well together.
+// The relationships that can be tested using this test class are:
+// superclass/subclass, and interface/implementor relationships.
+//
+// The test uses combinatorial approach.
+// For details on test table and test cases see main() method in this class.
+//
+// This test consists of multiple classes for better flexibility and reuse,
+// and also relies on certain common utility code.
+// Here are the details on the structure of the test
+//
+// Structure of the test:
+// TransformRelatedClasses -- common main test driver
+//     The TransformRelatedClasses is invoked from test driver classes:
+//     TransformInterfaceAndImplementor, TransformSuperAndSubClasses
+//     It is responsible for preparing test artifacts (test jar, agent jar
+//     and the shared archive), running test cases and checking the results.
+// The following test classes below are launched in a sub-process with use
+// of shared archive:
+//     SuperClazz, SubClass -- super/sub class pair under test
+//     Interface, Implementor -- classes under test
+// This test will transform these classes, based on the test case data,
+// by changing a predefined unique string in each class.
+// For more details, see the test classes' code and comments.
+//
+// Other related classes:
+//     TestEntry - a class representing a single test case, as test entry in the table
+//     TransformTestCommon - common methods for transformation test cases
+//
+// Other utility/helper classes and files used in this test:
+//     TransformerAgent - an agent that is used when JVM-under-test is executed
+//         to transform specific strings inside specified classes
+//     TransformerAgent.mf - accompanies transformer agent
+//     CDSTestUtils - Test Utilities common to all CDS tests
+
+import java.io.File;
+import java.util.ArrayList;
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+
+public class TransformRelatedClasses {
+    static final String archiveName = "./TransformRelatedClasses.jsa";
+    static String agentClasses[] = {
+        "TransformerAgent",
+        "TransformerAgent$SimpleTransformer",
+        "TransformUtil"
+    };
+
+    String parent;
+    String child;
+    String[] testClasses = new String[2];
+    String[] testNames = new String[2];
+    String testJar;
+    String agentJar;
+
+
+    private static void log(String msg) {
+        System.out.println("TransformRelatedClasses: " + msg);
+    }
+
+
+    // This class is intended to test 2 parent-child relationships:
+    // 1. Base Class (parent) and Derived Class (child)
+    // 2. Interface (parent) and Implementor (child)
+    //    Parameters to main(): parent, child
+    public static void main(String args[]) throws Exception {
+        TransformRelatedClasses test = new TransformRelatedClasses(args[0], args[1]);
+        test.prepare();
+
+        // Test Table
+        // TestEntry:  (testCaseId, transformParent, tranformChild,
+        //             isParentExpectedShared, isChildExpectedShared)
+        ArrayList<TestEntry> testTable = new ArrayList<>();
+
+        // base case - no tranformation - all expected to be shared
+        testTable.add(new TestEntry(0, false, false, true, true));
+
+        // transform parent only - both parent and child should not be shared
+        testTable.add(new TestEntry(1, true, false, false, false));
+
+        // transform parent and child - both parent and child should not be shared
+        testTable.add(new TestEntry(2, true, true, false, false));
+
+        // transform child only - parent should still be shared, but not child
+        testTable.add(new TestEntry(3, false, true, true, false));
+
+        // run the tests
+        for (TestEntry entry : testTable) {
+            test.runTest(entry);
+        }
+    }
+
+
+    public TransformRelatedClasses(String parent, String child) {
+        log("Constructor: parent = " + parent + ", child = " + child);
+        this.parent = parent;
+        this.child = child;
+        testClasses[0] = parent;
+        testClasses[1] = child;
+        testNames[0] = parent.replace('.', '/');
+        testNames[1] = child.replace('.', '/');
+    }
+
+
+    // same test jar and archive can be used for all test cases
+    private void prepare() throws Exception {
+        // create agent jar
+        // Agent is the same for all test cases
+        String pathToManifest = "../../../../testlibrary/jvmti/TransformerAgent.mf";
+        agentJar = ClassFileInstaller.writeJar("TransformerAgent.jar",
+                       ClassFileInstaller.Manifest.fromSourceFile(pathToManifest),
+                                           agentClasses);
+
+        // create a test jar
+        testJar =
+            ClassFileInstaller.writeJar(parent + "-" + child + ".jar",
+                                           testClasses);
+
+        // create an archive
+        File classList = CDSTestUtils.makeClassList("transform-" + parent,
+                                                    testNames);
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(true,
+                                        "-Xbootclasspath/a:" + testJar,
+                                        "-XX:+UnlockDiagnosticVMOptions",
+                                        "-XX:ExtraSharedClassListFile=" +
+                                        classList.getPath(),
+                                        "-XX:SharedArchiveFile=" + archiveName,
+                                        "-XX:+PrintSharedSpaces",
+                                        "-Xshare:dump");
+        OutputAnalyzer out = new OutputAnalyzer(pb.start());
+        CDSTestUtils.checkDump(out);
+    }
+
+
+    private void runTest(TestEntry entry) throws Exception {
+        log("runTest(): testCaseId = " + entry.testCaseId);
+
+        // execute with archive
+        String agentParam = "-javaagent:" + agentJar + "=" +
+            TransformTestCommon.getAgentParams(entry, parent, child);
+
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(true,
+                                        "-Xbootclasspath/a:" + testJar,
+                                        "-XX:+UnlockDiagnosticVMOptions",
+                                        "-XX:SharedArchiveFile=" + archiveName,
+                                        "-Xlog:class+load=info",
+                                        "-Xshare:on", "-showversion",
+                                        agentParam, child);
+        OutputAnalyzer out = new OutputAnalyzer(pb.start());
+
+        TransformTestCommon.checkResults(entry, out, parent, child);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformSuperAndSubClasses.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+/*
+ * @test
+ * @summary Exercise initial transformation (ClassFileLoadHook)
+ *  with CDS with SubClass and SuperClass
+ * @library /test/lib /runtime/SharedArchiveFile /testlibrary/jvmti
+ * @requires (vm.opt.UseCompressedOops == null) | (vm.opt.UseCompressedOops == true)
+ * @requires vm.flavor != "minimal"
+ * @modules java.base/jdk.internal.misc
+ *          jdk.jartool/sun.tools.jar
+ *          java.management
+ *          java.instrument
+ * @build TransformUtil TransformerAgent SubClass SuperClazz
+ * @run main/othervm TransformRelatedClasses SuperClazz SubClass
+*/
+
+// Clarification on @requires declarations:
+// CDS is not supported w/o the use of Compressed OOPs
+// JVMTI's ClassFileLoadHook is not supported under minimal VM
+
+// This test class uses TransformRelatedClasses to do its work.
+// The goal of this test is to exercise transformation of related superclass
+// and subclass in combination with CDS.
+// The transformation is done via ClassFileLoadHook mechanism.
+// Both superclass and subclass reside in the shared archive.
+// The test consists of 4 test cases where transformation is applied
+// to a parent and child in combinatorial manner.
+// Please see TransformRelatedClasses.java for details.
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformSuperSubTwoPckgs.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+/*
+ * @test
+ * @summary Exercise initial transformation (ClassFileLoadHook)
+ *  with CDS with SubClass and SuperClass, each lives in own separate package
+ * @library /test/lib /runtime/SharedArchiveFile /testlibrary/jvmti
+ * @requires (vm.opt.UseCompressedOops == null) | (vm.opt.UseCompressedOops == true)
+ * @requires vm.flavor != "minimal"
+ * @modules java.base/jdk.internal.misc
+ *          jdk.jartool/sun.tools.jar
+ *          java.management
+ *          java.instrument
+ * @build TransformUtil TransformerAgent SubClass SuperClazz
+ * @compile myPkg2/SubClass.java myPkg1/SuperClazz.java
+ * @run main/othervm TransformRelatedClasses myPkg1.SuperClazz myPkg2.SubClass
+*/
+
+// Clarification on @requires declarations:
+// CDS is not supported w/o the use of Compressed OOPs
+// JVMTI's ClassFileLoadHook is not supported under minimal VM
+
+// This test class uses TransformRelatedClasses to do its work.
+// The goal of this test is to exercise transformation of related superclass
+// and subclass in combination with CDS; each class lives in its own package.
+// The transformation is done via ClassFileLoadHook mechanism.
+// Both superclass and subclass reside in the shared archive.
+// The test consists of 4 test cases where transformation is applied
+// to a parent and child in combinatorial manner.
+// Please see TransformRelatedClasses.java for details.
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/TransformTestCommon.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+import jdk.test.lib.process.OutputAnalyzer;
+
+
+// This class contains methods common to all transformation test cases
+public class TransformTestCommon {
+
+    // get parameters to an agent depending on the test case
+    // these parameters will instruct the agent which classes should be
+    // transformed
+    public static String getAgentParams(TestEntry entry,
+                                        String parent, String child) {
+
+        if (entry.transformParent && entry.transformChild)
+            return parent + "," + child;
+        if (entry.transformParent)
+            return parent;
+        if (entry.transformChild)
+            return child;
+
+        return "";
+    }
+
+
+    private static void checkTransformationResults(TestEntry entry,
+                                                   OutputAnalyzer out)
+        throws Exception {
+
+        if (entry.transformParent)
+            out.shouldContain(TransformUtil.ParentCheckPattern +
+                              TransformUtil.AfterPattern);
+
+        if (entry.transformChild)
+            out.shouldContain(TransformUtil.ChildCheckPattern +
+                              TransformUtil.AfterPattern);
+    }
+
+
+    private static void checkSharingByClass(TestEntry entry, OutputAnalyzer out,
+                                            String parent, String child)
+        throws Exception {
+
+        String parentSharedMatch = parent + " source: shared objects file";
+        String childSharedMatch =  child +  " source: shared objects file";
+
+        if (entry.isParentExpectedShared)
+            out.shouldContain(parentSharedMatch);
+        else
+            out.shouldNotContain(parentSharedMatch);
+
+        if (entry.isChildExpectedShared)
+            out.shouldContain(childSharedMatch);
+        else
+            out.shouldNotContain(childSharedMatch);
+    }
+
+
+    // Both parent and child classes should be passed to ClassFileTransformer.transform()
+    // exactly once.
+    private static void checkTransformationCounts(TestEntry entry, OutputAnalyzer out,
+                                                  String parent, String child)
+        throws Exception {
+
+        String patternBase = "TransformerAgent: SimpleTransformer called for: ";
+
+        out.shouldContain(patternBase + child + "@1");
+        out.shouldContain(patternBase + parent + "@1");
+
+        out.shouldNotContain(patternBase + child + "@2");
+        out.shouldNotContain(patternBase + parent + "@2");
+    }
+
+
+    public static void checkResults(TestEntry entry, OutputAnalyzer out,
+                                    String parent, String child)
+        throws Exception {
+
+        // If we were not able to map an archive,
+        // then do not perform other checks, since
+        // there was no sharing at all
+        if (CDSTestUtils.isUnableToMap(out))
+            return;
+
+        String childVmName = child.replace('.', '/');
+        String parentVmName = parent.replace('.', '/');
+
+        CDSTestUtils.checkExec(out);
+        checkTransformationCounts(entry, out, parentVmName, childVmName);
+        checkTransformationResults(entry, out);
+        checkSharingByClass(entry, out, parent, child);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/myPkg1/SuperClazz.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+package myPkg1;
+
+public class SuperClazz {
+    public static void testParent() {
+        System.out.println("SuperClazz: entering testParent()");
+
+        // The line below will be used to check for successful class transformation
+        System.out.println("parent-transform-check: this-should-be-transformed");
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/SharedArchiveFile/serviceability/transformRelatedClasses/myPkg2/SubClass.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+package myPkg2;
+
+import myPkg1.SuperClazz;
+
+public class SubClass extends SuperClazz {
+    public static void main(String[] args) {
+        System.out.println("SubClass: entering main()");
+        test();
+    }
+
+    public static void test() {
+        // The line below will be used to check for successful class transformation
+        System.out.println("child-transform-check: this-should-be-transformed");
+        (new SubClass()).callParent();
+
+        // Get the system packages, which should contain myPkg1 and myPkag2
+        Package[] pkgs = Package.getPackages();
+        for (int i = 0; i < pkgs.length; i++) {
+            if (pkgs[i].getName().equals("myPkg1")) {
+                for (int j = 0; j < pkgs.length; j++) {
+                    if (pkgs[j].getName().equals("myPkg2")) {
+                        return; // found myPkg1 & myPkg1
+                    }
+                }
+            }
+        }
+        throw new RuntimeException("Missing system package");
+    }
+
+    private void callParent() {
+        super.testParent();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/jvmti/TransformUtil.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+
+public class TransformUtil {
+    public static final String BeforePattern = "this-should-be-transformed";
+    public static final String AfterPattern  = "this-has-been--transformed";
+    public static final String ParentCheckPattern = "parent-transform-check: ";
+    public static final String ChildCheckPattern = "child-transform-check: ";
+
+    /**
+     * @return the number of occurrences of the <code>from</code> string that
+     * have been replaced.
+     */
+    public static int replace(byte buff[], String from, String to) {
+        if (to.length() != from.length()) {
+            throw new RuntimeException("bad strings");
+        }
+        byte f[] = asciibytes(from);
+        byte t[] = asciibytes(to);
+        byte f0 = f[0];
+
+        int numReplaced = 0;
+        int max = buff.length - f.length;
+        for (int i = 0; i < max; ) {
+            if (buff[i] == f0 && replace(buff, f, t, i)) {
+                i += f.length;
+                numReplaced++;
+            } else {
+                i++;
+            }
+        }
+        return numReplaced;
+    }
+
+    public static boolean replace(byte buff[], byte f[], byte t[], int i) {
+        for (int x = 0; x < f.length; x++) {
+            if (buff[x+i] != f[x]) {
+                return false;
+            }
+        }
+        for (int x = 0; x < f.length; x++) {
+            buff[x+i] = t[x];
+        }
+        return true;
+    }
+
+    static byte[] asciibytes(String s) {
+        byte b[] = new byte[s.length()];
+        for (int i = 0; i < b.length; i++) {
+            b[i] = (byte)s.charAt(i);
+        }
+        return b;
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/jvmti/TransformerAgent.java	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.IllegalClassFormatException;
+import java.lang.instrument.Instrumentation;
+import java.security.ProtectionDomain;
+import java.util.HashMap;
+
+// This is a test utility class used to transform
+// specified classes via initial transformation (ClassFileLoadHook).
+// Names of classes to be transformed are supplied as arguments,
+// the phrase to be transformed is a hard-coded predefined
+// fairly unique phrase.
+
+public class TransformerAgent {
+    private static String[] classesToTransform;
+
+
+    private static void log(String msg) {
+        System.out.println("TransformerAgent: " + msg);
+    }
+
+
+    // arguments are comma-separated list of classes to transform
+    public static void premain(String agentArguments, Instrumentation instrumentation) {
+        log("premain() is called, arguments = " + agentArguments);
+        classesToTransform = agentArguments.split(",");
+        instrumentation.addTransformer(new SimpleTransformer(), /*canRetransform=*/true);
+    }
+
+
+    public static void agentmain(String args, Instrumentation inst) throws Exception {
+        log("agentmain() is called");
+        premain(args, inst);
+    }
+
+
+    static class SimpleTransformer implements ClassFileTransformer {
+       public byte[] transform(ClassLoader loader, String name, Class<?> classBeingRedefined,
+                            ProtectionDomain pd, byte[] buffer) throws IllegalClassFormatException {
+
+            log("SimpleTransformer called for: " + name + "@" + incrCounter(name));
+            if (!shouldTransform(name))
+                return null;
+
+            log("transforming: class name = " + name);
+            int nrOfReplacements = TransformUtil.replace(buffer, TransformUtil.BeforePattern,
+                                                         TransformUtil.AfterPattern);
+            log("replaced the string, nrOfReplacements = " + nrOfReplacements);
+            return buffer;
+        }
+
+        // Check class name pattern, since test should only transform certain classes
+        private static boolean shouldTransform(String name) {
+            for (String match : classesToTransform) {
+                if (name.matches(match)) {
+                    log("shouldTransform: match-found, match = " + match);
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+
+
+    static HashMap<String, Integer> counterMap = new HashMap<>();
+
+    static Integer incrCounter(String className) {
+        Integer i = counterMap.get(className);
+        if (i == null) {
+            i = new Integer(1);
+        } else {
+            i = new Integer(i.intValue() + 1);
+        }
+        counterMap.put(className, i);
+        return i;
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/testlibrary/jvmti/TransformerAgent.mf	Sun Sep 18 21:10:48 2016 -0400
@@ -0,0 +1,5 @@
+Manifest-Version: 1.0
+Premain-Class: TransformerAgent
+Agent-Class: TransformerAgent
+Can-Retransform-Classes: true
+Can-Redefine-Classes: false