8021948: Change InstanceKlass::_source_file_name and _generic_signature from...

8021948: Change InstanceKlass::_source_file_name and _generic_signature from Symbol* to constant pool indexes.
Summary: Change InstanceKlass::_source_file_name and _generic_signature to u2 fields.
Reviewed-by: coleenp, iklam

agent/src/share/classes/sun/jvm/hotspot/oops/InstanceKlass.java

@@ -75,9 +75,9 @@ public class InstanceKlass extends Klass {
     javaFieldsCount      = new CIntField(type.getCIntegerField("_java_fields_count"), 0);
     constants            = new MetadataField(type.getAddressField("_constants"), 0);
     classLoaderData      = type.getAddressField("_class_loader_data");
-    sourceFileName       = type.getAddressField("_source_file_name");
     sourceDebugExtension = type.getAddressField("_source_debug_extension");
     innerClasses         = type.getAddressField("_inner_classes");
+    sourceFileNameIndex  = new CIntField(type.getCIntegerField("_source_file_name_index"), 0);
     nonstaticFieldSize   = new CIntField(type.getCIntegerField("_nonstatic_field_size"), 0);
     staticFieldSize      = new CIntField(type.getCIntegerField("_static_field_size"), 0);
     staticOopFieldCount  = new CIntField(type.getCIntegerField("_static_oop_field_count"), 0);
@@ -87,7 +87,7 @@ public class InstanceKlass extends Klass {
     vtableLen            = new CIntField(type.getCIntegerField("_vtable_len"), 0);
     itableLen            = new CIntField(type.getCIntegerField("_itable_len"), 0);
     breakpoints          = type.getAddressField("_breakpoints");
-    genericSignature     = type.getAddressField("_generic_signature");
+    genericSignatureIndex = new CIntField(type.getCIntegerField("_generic_signature_index"), 0);
     majorVersion         = new CIntField(type.getCIntegerField("_major_version"), 0);
     minorVersion         = new CIntField(type.getCIntegerField("_minor_version"), 0);
     headerSize           = Oop.alignObjectOffset(type.getSize());
@@ -134,9 +134,9 @@ public class InstanceKlass extends Klass {
   private static CIntField javaFieldsCount;
   private static MetadataField constants;
   private static AddressField  classLoaderData;
-  private static AddressField  sourceFileName;
   private static AddressField  sourceDebugExtension;
   private static AddressField  innerClasses;
+  private static CIntField sourceFileNameIndex;
   private static CIntField nonstaticFieldSize;
   private static CIntField staticFieldSize;
   private static CIntField staticOopFieldCount;
@@ -146,7 +146,7 @@ public class InstanceKlass extends Klass {
   private static CIntField vtableLen;
   private static CIntField itableLen;
   private static AddressField breakpoints;
-  private static AddressField  genericSignature;
+  private static CIntField genericSignatureIndex;
   private static CIntField majorVersion;
   private static CIntField minorVersion;
 
@@ -346,7 +346,7 @@ public class InstanceKlass extends Klass {
   public ConstantPool getConstants()        { return (ConstantPool) constants.getValue(this); }
   public ClassLoaderData getClassLoaderData() { return                ClassLoaderData.instantiateWrapperFor(classLoaderData.getValue(getAddress())); }
   public Oop       getClassLoader()         { return                getClassLoaderData().getClassLoader(); }
-  public Symbol    getSourceFileName()      { return getSymbol(sourceFileName); }
+  public Symbol    getSourceFileName()      { return                getConstants().getSymbolAt(sourceFileNameIndex.getValue(this)); }
   public String    getSourceDebugExtension(){ return                CStringUtilities.getString(sourceDebugExtension.getValue(getAddress())); }
   public long      getNonstaticFieldSize()  { return                nonstaticFieldSize.getValue(this); }
   public long      getStaticOopFieldCount() { return                staticOopFieldCount.getValue(this); }
@@ -354,7 +354,7 @@ public class InstanceKlass extends Klass {
   public boolean   getIsMarkedDependent()   { return                isMarkedDependent.getValue(this) != 0; }
   public long      getVtableLen()           { return                vtableLen.getValue(this); }
   public long      getItableLen()           { return                itableLen.getValue(this); }
-  public Symbol    getGenericSignature()    { return getSymbol(genericSignature); }
+  public Symbol    getGenericSignature()    { return                getConstants().getSymbolAt(genericSignatureIndex.getValue(this)); }
   public long      majorVersion()           { return                majorVersion.getValue(this); }
   public long      minorVersion()           { return                minorVersion.getValue(this); }
 

src/share/vm/classfile/classFileParser.cpp

@@ -2590,7 +2590,7 @@ void ClassFileParser::parse_classfile_sourcefile_attribute(TRAPS) {
     valid_symbol_at(sourcefile_index),
     "Invalid SourceFile attribute at constant pool index %u in class file %s",
     sourcefile_index, CHECK);
-  set_class_sourcefile(_cp->symbol_at(sourcefile_index));
+  set_class_sourcefile_index(sourcefile_index);
 }
 
 
@@ -2728,7 +2728,7 @@ void ClassFileParser::parse_classfile_signature_attribute(TRAPS) {
     valid_symbol_at(signature_index),
     "Invalid constant pool index %u in Signature attribute in class file %s",
     signature_index, CHECK);
-  set_class_generic_signature(_cp->symbol_at(signature_index));
+  set_class_generic_signature_index(signature_index);
 }
 
 void ClassFileParser::parse_classfile_bootstrap_methods_attribute(u4 attribute_byte_length, TRAPS) {
@@ -2975,13 +2975,11 @@ void ClassFileParser::parse_classfile_attributes(ClassFileParser::ClassAnnotatio
 void ClassFileParser::apply_parsed_class_attributes(instanceKlassHandle k) {
   if (_synthetic_flag)
     k->set_is_synthetic();
-  if (_sourcefile != NULL) {
-    _sourcefile->increment_refcount();
-    k->set_source_file_name(_sourcefile);
+  if (_sourcefile_index != 0) {
+    k->set_source_file_name_index(_sourcefile_index);
   }
-  if (_generic_signature != NULL) {
-    _generic_signature->increment_refcount();
-    k->set_generic_signature(_generic_signature);
+  if (_generic_signature_index != 0) {
+    k->set_generic_signature_index(_generic_signature_index);
   }
   if (_sde_buffer != NULL) {
     k->set_source_debug_extension(_sde_buffer, _sde_length);

src/share/vm/classfile/classFileParser.hpp

@@ -62,8 +62,8 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
   bool       _synthetic_flag;
   int        _sde_length;
   char*      _sde_buffer;
-  Symbol*    _sourcefile;
-  Symbol*    _generic_signature;
+  u2         _sourcefile_index;
+  u2         _generic_signature_index;
 
   // Metadata created before the instance klass is created.  Must be deallocated
   // if not transferred to the InstanceKlass upon successful class loading
@@ -82,15 +82,15 @@ class ClassFileParser VALUE_OBJ_CLASS_SPEC {
   InstanceKlass*   _klass;  // InstanceKlass once created.
 
   void set_class_synthetic_flag(bool x)        { _synthetic_flag = x; }
-  void set_class_sourcefile(Symbol* x)            { _sourcefile = x; }
-  void set_class_generic_signature(Symbol* x)     { _generic_signature = x; }
+  void set_class_sourcefile_index(u2 x)        { _sourcefile_index = x; }
+  void set_class_generic_signature_index(u2 x) { _generic_signature_index = x; }
   void set_class_sde_buffer(char* x, int len)  { _sde_buffer = x; _sde_length = len; }
 
   void init_parsed_class_attributes(ClassLoaderData* loader_data) {
     _loader_data = loader_data;
     _synthetic_flag = false;
-    _sourcefile = NULL;
-    _generic_signature = NULL;
+    _sourcefile_index = 0;
+    _generic_signature_index = 0;
     _sde_buffer = NULL;
     _sde_length = 0;
     // initialize the other flags too:

src/share/vm/oops/instanceKlass.cpp

@@ -269,7 +269,7 @@ InstanceKlass::InstanceKlass(int vtable_len,
   set_fields(NULL, 0);
   set_constants(NULL);
   set_class_loader_data(NULL);
-  set_source_file_name(NULL);
+  set_source_file_name_index(0);
   set_source_debug_extension(NULL, 0);
   set_array_name(NULL);
   set_inner_classes(NULL);
@@ -284,7 +284,7 @@ InstanceKlass::InstanceKlass(int vtable_len,
   set_osr_nmethods_head(NULL);
   set_breakpoints(NULL);
   init_previous_versions();
-  set_generic_signature(NULL);
+  set_generic_signature_index(0);
   release_set_methods_jmethod_ids(NULL);
   release_set_methods_cached_itable_indices(NULL);
   set_annotations(NULL);
@@ -2368,18 +2368,12 @@ void InstanceKlass::release_C_heap_structures() {
   // unreference array name derived from this class name (arrays of an unloaded
   // class can't be referenced anymore).
   if (_array_name != NULL)  _array_name->decrement_refcount();
-  if (_source_file_name != NULL) _source_file_name->decrement_refcount();
   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
 
   assert(_total_instanceKlass_count >= 1, "Sanity check");
   Atomic::dec(&_total_instanceKlass_count);
 }
 
-void InstanceKlass::set_source_file_name(Symbol* n) {
-  _source_file_name = n;
-  if (_source_file_name != NULL) _source_file_name->increment_refcount();
-}
-
 void InstanceKlass::set_source_debug_extension(char* array, int length) {
   if (array == NULL) {
     _source_debug_extension = NULL;

src/share/vm/oops/instanceKlass.hpp

@@ -201,14 +201,10 @@ class InstanceKlass: public Klass {
   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
   Array<jushort>* _inner_classes;
 
-  // Name of source file containing this klass, NULL if not specified.
-  Symbol*         _source_file_name;
   // the source debug extension for this klass, NULL if not specified.
   // Specified as UTF-8 string without terminating zero byte in the classfile,
   // it is stored in the instanceklass as a NULL-terminated UTF-8 string
   char*           _source_debug_extension;
-  // Generic signature, or null if none.
-  Symbol*         _generic_signature;
   // Array name derived from this class which needs unreferencing
   // if this class is unloaded.
   Symbol*         _array_name;
@@ -217,6 +213,12 @@ class InstanceKlass: public Klass {
   // (including inherited fields but after header_size()).
   int             _nonstatic_field_size;
   int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass
+  // Constant pool index to the utf8 entry of the Generic signature,
+  // or 0 if none.
+  u2              _generic_signature_index;
+  // Constant pool index to the utf8 entry for the name of source file
+  // containing this klass, 0 if not specified.
+  u2              _source_file_name_index;
   u2              _static_oop_field_count;// number of static oop fields in this klass
   u2              _java_fields_count;    // The number of declared Java fields
   int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks
@@ -570,8 +572,16 @@ class InstanceKlass: public Klass {
   }
 
   // source file name
-  Symbol* source_file_name() const         { return _source_file_name; }
-  void set_source_file_name(Symbol* n);
+  Symbol* source_file_name() const               {
+    return (_source_file_name_index == 0) ?
+      (Symbol*)NULL : _constants->symbol_at(_source_file_name_index);
+  }
+  u2 source_file_name_index() const              {
+    return _source_file_name_index;
+  }
+  void set_source_file_name_index(u2 sourcefile_index) {
+    _source_file_name_index = sourcefile_index;
+  }
 
   // minor and major version numbers of class file
   u2 minor_version() const                 { return _minor_version; }
@@ -648,8 +658,16 @@ class InstanceKlass: public Klass {
   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 
   // generics support
-  Symbol* generic_signature() const                   { return _generic_signature; }
-  void set_generic_signature(Symbol* sig)             { _generic_signature = sig; }
+  Symbol* generic_signature() const                   {
+    return (_generic_signature_index == 0) ?
+      (Symbol*)NULL : _constants->symbol_at(_generic_signature_index);
+  }
+  u2 generic_signature_index() const                  {
+    return _generic_signature_index;
+  }
+  void set_generic_signature_index(u2 sig_index)      {
+    _generic_signature_index = sig_index;
+  }
 
   u2 enclosing_method_data(int offset);
   u2 enclosing_method_class_index() {

src/share/vm/prims/jvmtiRedefineClasses.cpp

@@ -1554,6 +1554,20 @@ bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
     return false;
   }
 
+  // rewrite sourc file name index:
+  u2 source_file_name_idx = scratch_class->source_file_name_index();
+  if (source_file_name_idx != 0) {
+    u2 new_source_file_name_idx = find_new_index(source_file_name_idx);
+    scratch_class->set_source_file_name_index(new_source_file_name_idx);
+  }
+
+  // rewrite class generic signature index:
+  u2 generic_signature_index = scratch_class->generic_signature_index();
+  if (generic_signature_index != 0) {
+    u2 new_generic_signature_index = find_new_index(generic_signature_index);
+    scratch_class->set_generic_signature_index(new_generic_signature_index);
+  }
+
   return true;
 } // end rewrite_cp_refs()
 
@@ -3370,7 +3384,8 @@ void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
   // Leave arrays of jmethodIDs and itable index cache unchanged
 
   // Copy the "source file name" attribute from new class version
-  the_class->set_source_file_name(scratch_class->source_file_name());
+  the_class->set_source_file_name_index(
+    scratch_class->source_file_name_index());
 
   // Copy the "source debug extension" attribute from new class version
   the_class->set_source_debug_extension(

src/share/vm/runtime/vmStructs.cpp

@@ -294,7 +294,7 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   nonstatic_field(InstanceKlass,               _java_fields_count,                            u2)                                    \
   nonstatic_field(InstanceKlass,               _constants,                                    ConstantPool*)                         \
   nonstatic_field(InstanceKlass,               _class_loader_data,                            ClassLoaderData*)                      \
-  nonstatic_field(InstanceKlass,               _source_file_name,                             Symbol*)                               \
+  nonstatic_field(InstanceKlass,               _source_file_name_index,                            u2)                               \
   nonstatic_field(InstanceKlass,               _source_debug_extension,                       char*)                                 \
   nonstatic_field(InstanceKlass,               _inner_classes,                               Array<jushort>*)                       \
   nonstatic_field(InstanceKlass,               _nonstatic_field_size,                         int)                                   \
@@ -313,7 +313,7 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   nonstatic_field(InstanceKlass,               _jni_ids,                                      JNIid*)                                \
   nonstatic_field(InstanceKlass,               _osr_nmethods_head,                            nmethod*)                              \
   nonstatic_field(InstanceKlass,               _breakpoints,                                  BreakpointInfo*)                       \
-  nonstatic_field(InstanceKlass,               _generic_signature,                            Symbol*)                               \
+  nonstatic_field(InstanceKlass,               _generic_signature_index,                           u2)                               \
   nonstatic_field(InstanceKlass,               _methods_jmethod_ids,                          jmethodID*)                            \
   nonstatic_field(InstanceKlass,               _methods_cached_itable_indices,                int*)                                  \
   volatile_nonstatic_field(InstanceKlass,      _idnum_allocated_count,                        u2)                                    \