changeset 3469:ace99a6ffc83

7181200: JVM new hashing code breaks SA in product mode Summary: Made new_hash() overloaded rather than a virtual function so SA code doesn't need to be changed. Reviewed-by: kvn, acorn, dholmes, fparain
author coleenp
date Wed, 04 Jul 2012 15:55:45 -0400
parents 65906dc96aa1
children 5a1f452f8f90 7e5976e66c62 f1f45dddb0bd 04a9b3789683
files src/share/vm/classfile/symbolTable.cpp src/share/vm/classfile/symbolTable.hpp src/share/vm/utilities/hashtable.cpp src/share/vm/utilities/hashtable.hpp
diffstat 4 files changed, 32 insertions(+), 38 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/vm/classfile/symbolTable.cpp	Tue Jul 03 17:35:00 2012 -0700
+++ b/src/share/vm/classfile/symbolTable.cpp	Wed Jul 04 15:55:45 2012 -0400
@@ -43,7 +43,6 @@
 // Static arena for symbols that are not deallocated
 Arena* SymbolTable::_arena = NULL;
 bool SymbolTable::_needs_rehashing = false;
-jint SymbolTable::_seed = 0;
 
 Symbol* SymbolTable::allocate_symbol(const u1* name, int len, bool c_heap, TRAPS) {
   assert (len <= Symbol::max_length(), "should be checked by caller");
@@ -130,12 +129,6 @@
   }
 }
 
-unsigned int SymbolTable::new_hash(Symbol* sym) {
-  ResourceMark rm;
-  // Use alternate hashing algorithm on this symbol.
-  return AltHashing::murmur3_32(seed(), (const jbyte*)sym->as_C_string(), sym->utf8_length());
-}
-
 // Create a new table and using alternate hash code, populate the new table
 // with the existing strings.   Set flag to use the alternate hash code afterwards.
 void SymbolTable::rehash_table() {
@@ -145,10 +138,6 @@
   // Create a new symbol table
   SymbolTable* new_table = new SymbolTable();
 
-  // Initialize the global seed for hashing.
-  _seed = AltHashing::compute_seed();
-  assert(seed() != 0, "shouldn't be zero");
-
   the_table()->move_to(new_table);
 
   // Delete the table and buckets (entries are reused in new table).
@@ -620,7 +609,6 @@
 StringTable* StringTable::_the_table = NULL;
 
 bool StringTable::_needs_rehashing = false;
-jint StringTable::_seed = 0;
 
 // Pick hashing algorithm
 unsigned int StringTable::hash_string(const jchar* s, int len) {
@@ -837,14 +825,6 @@
 }
 
 
-unsigned int StringTable::new_hash(oop string) {
-  ResourceMark rm;
-  int length;
-  jchar* chars = java_lang_String::as_unicode_string(string, length);
-  // Use alternate hashing algorithm on the string
-  return AltHashing::murmur3_32(seed(), chars, length);
-}
-
 // Create a new table and using alternate hash code, populate the new table
 // with the existing strings.   Set flag to use the alternate hash code afterwards.
 void StringTable::rehash_table() {
@@ -853,10 +833,6 @@
   if (DumpSharedSpaces) return;
   StringTable* new_table = new StringTable();
 
-  // Initialize new global seed for hashing.
-  _seed = AltHashing::compute_seed();
-  assert(seed() != 0, "shouldn't be zero");
-
   // Rehash the table
   the_table()->move_to(new_table);
 
--- a/src/share/vm/classfile/symbolTable.hpp	Tue Jul 03 17:35:00 2012 -0700
+++ b/src/share/vm/classfile/symbolTable.hpp	Wed Jul 04 15:55:45 2012 -0400
@@ -81,7 +81,6 @@
 
   // Set if one bucket is out of balance due to hash algorithm deficiency
   static bool _needs_rehashing;
-  static jint _seed;
 
   // For statistics
   static int symbols_removed;
@@ -124,11 +123,6 @@
   static Arena* arena() { return _arena; }  // called for statistics
 
   static void initialize_symbols(int arena_alloc_size = 0);
-
-  static bool use_alternate_hashcode()  { return _seed != 0; }
-  static jint seed()                    { return _seed; }
-
-  unsigned int new_hash(Symbol* sym);
 public:
   enum {
     symbol_alloc_batch_size = 8,
@@ -247,7 +241,6 @@
 
   // Set if one bucket is out of balance due to hash algorithm deficiency
   static bool _needs_rehashing;
-  static jint _seed;
 
   static oop intern(Handle string_or_null, jchar* chars, int length, TRAPS);
   oop basic_add(int index, Handle string_or_null, jchar* name, int len,
@@ -261,11 +254,6 @@
   StringTable(HashtableBucket<mtSymbol>* t, int number_of_entries)
     : Hashtable<oop, mtSymbol>((int)StringTableSize, sizeof (HashtableEntry<oop, mtSymbol>), t,
                      number_of_entries) {}
-
-  static bool use_alternate_hashcode()  { return _seed != 0; }
-  static jint seed()                    { return _seed; }
-
-  unsigned int new_hash(oop s);
 public:
   // The string table
   static StringTable* the_table() { return _the_table; }
--- a/src/share/vm/utilities/hashtable.cpp	Tue Jul 03 17:35:00 2012 -0700
+++ b/src/share/vm/utilities/hashtable.cpp	Wed Jul 04 15:55:45 2012 -0400
@@ -23,6 +23,8 @@
  */
 
 #include "precompiled.hpp"
+#include "classfile/altHashing.hpp"
+#include "classfile/javaClasses.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/filemap.hpp"
 #include "memory/resourceArea.hpp"
@@ -90,12 +92,33 @@
   return false;
 }
 
+template <class T, MEMFLAGS F> jint Hashtable<T, F>::_seed = 0;
+
+template <class T, MEMFLAGS F> unsigned int Hashtable<T, F>::new_hash(Symbol* sym) {
+  ResourceMark rm;
+  // Use alternate hashing algorithm on this symbol.
+  return AltHashing::murmur3_32(seed(), (const jbyte*)sym->as_C_string(), sym->utf8_length());
+}
+
+template <class T, MEMFLAGS F> unsigned int Hashtable<T, F>::new_hash(oop string) {
+  ResourceMark rm;
+  int length;
+  jchar* chars = java_lang_String::as_unicode_string(string, length);
+  // Use alternate hashing algorithm on the string
+  return AltHashing::murmur3_32(seed(), chars, length);
+}
+
 // Create a new table and using alternate hash code, populate the new table
 // with the existing elements.   This can be used to change the hash code
 // and could in the future change the size of the table.
 
 template <class T, MEMFLAGS F> void Hashtable<T, F>::move_to(Hashtable<T, F>* new_table) {
-  int saved_entry_count = BasicHashtable<F>::number_of_entries();
+
+  // Initialize the global seed for hashing.
+  _seed = AltHashing::compute_seed();
+  assert(seed() != 0, "shouldn't be zero");
+
+  int saved_entry_count = this->number_of_entries();
 
   // Iterate through the table and create a new entry for the new table
   for (int i = 0; i < new_table->table_size(); ++i) {
--- a/src/share/vm/utilities/hashtable.hpp	Tue Jul 03 17:35:00 2012 -0700
+++ b/src/share/vm/utilities/hashtable.hpp	Wed Jul 04 15:55:45 2012 -0400
@@ -278,7 +278,14 @@
 
   // Function to move these elements into the new table.
   void move_to(Hashtable<T, F>* new_table);
-  virtual unsigned int new_hash(T) { ShouldNotReachHere(); return 0; } // should be overridden
+  static bool use_alternate_hashcode()  { return _seed != 0; }
+  static jint seed()                    { return _seed; }
+
+ private:
+  static jint _seed;
+
+  unsigned int new_hash(Symbol* s);
+  unsigned int new_hash(oop string);
 };