# HG changeset patch # User coleenp # Date 1341431745 14400 # Node ID ace99a6ffc834542dc736839ea8f0d67e93fa3ad # Parent 65906dc96aa1d312f307ecd87cea17cb3f2ed1b5 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 diff -r 65906dc96aa1 -r ace99a6ffc83 src/share/vm/classfile/symbolTable.cpp --- 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); diff -r 65906dc96aa1 -r ace99a6ffc83 src/share/vm/classfile/symbolTable.hpp --- 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* t, int number_of_entries) : Hashtable((int)StringTableSize, sizeof (HashtableEntry), 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; } diff -r 65906dc96aa1 -r ace99a6ffc83 src/share/vm/utilities/hashtable.cpp --- 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 jint Hashtable::_seed = 0; + +template unsigned int Hashtable::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 unsigned int Hashtable::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 void Hashtable::move_to(Hashtable* new_table) { - int saved_entry_count = BasicHashtable::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) { diff -r 65906dc96aa1 -r ace99a6ffc83 src/share/vm/utilities/hashtable.hpp --- 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* 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); };