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
--- a/hotspot/src/share/vm/classfile/symbolTable.cpp Tue Jul 03 17:35:00 2012 -0700
+++ b/hotspot/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/hotspot/src/share/vm/classfile/symbolTable.hpp Tue Jul 03 17:35:00 2012 -0700
+++ b/hotspot/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/hotspot/src/share/vm/utilities/hashtable.cpp Tue Jul 03 17:35:00 2012 -0700
+++ b/hotspot/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/hotspot/src/share/vm/utilities/hashtable.hpp Tue Jul 03 17:35:00 2012 -0700
+++ b/hotspot/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);
};