# HG changeset patch # User acorn # Date 1327984050 18000 # Node ID b2cd0ee8f7789a884962a2ed882f8b9829969e04 # Parent d96c130c939924acf813c6254de978543bff8e90 7114376: Make system dictionary hashtable bucket array size configurable Summary: 7u4 new experimental flag -XX:PredictedClassLoadedCount=# Reviewed-by: dholmes, phh, dcubed diff -r d96c130c9399 -r b2cd0ee8f778 agent/src/share/classes/sun/jvm/hotspot/memory/LoaderConstraintTable.java --- a/agent/src/share/classes/sun/jvm/hotspot/memory/LoaderConstraintTable.java Mon Jan 30 05:08:09 2012 -0800 +++ b/agent/src/share/classes/sun/jvm/hotspot/memory/LoaderConstraintTable.java Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2012 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 @@ -42,15 +42,6 @@ private static synchronized void initialize(TypeDataBase db) { Type type = db.lookupType("LoaderConstraintTable"); - nofBuckets = db.lookupIntConstant("LoaderConstraintTable::_nof_buckets").intValue(); - } - - // Fields - private static int nofBuckets; - - // Accessors - public static int getNumOfBuckets() { - return nofBuckets; } public LoaderConstraintTable(Address addr) { diff -r d96c130c9399 -r b2cd0ee8f778 agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java --- a/agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java Mon Jan 30 05:08:09 2012 -0800 +++ b/agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2012, 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 @@ -36,7 +36,6 @@ private static AddressField placeholdersField; private static AddressField loaderConstraintTableField; private static sun.jvm.hotspot.types.OopField javaSystemLoaderField; - private static int nofBuckets; private static sun.jvm.hotspot.types.OopField objectKlassField; private static sun.jvm.hotspot.types.OopField classLoaderKlassField; @@ -62,7 +61,6 @@ placeholdersField = type.getAddressField("_placeholders"); loaderConstraintTableField = type.getAddressField("_loader_constraints"); javaSystemLoaderField = type.getOopField("_java_system_loader"); - nofBuckets = db.lookupIntConstant("SystemDictionary::_nof_buckets").intValue(); objectKlassField = type.getOopField(WK_KLASS("Object_klass")); classLoaderKlassField = type.getOopField(WK_KLASS("ClassLoader_klass")); @@ -142,10 +140,6 @@ return newOop(javaSystemLoaderField.getValue()); } - public static int getNumOfBuckets() { - return nofBuckets; - } - private static Oop newOop(OopHandle handle) { return VM.getVM().getObjectHeap().newOop(handle); } diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/classfile/dictionary.cpp --- a/src/share/vm/classfile/dictionary.cpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/classfile/dictionary.cpp Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2012, 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 @@ -618,7 +618,8 @@ ResourceMark rm; HandleMark hm; - tty->print_cr("Java system dictionary (classes=%d)", number_of_entries()); + tty->print_cr("Java system dictionary (table_size=%d, classes=%d)", + table_size(), number_of_entries()); tty->print_cr("^ indicates that initiating loader is different from " "defining loader"); diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/classfile/systemDictionary.cpp --- a/src/share/vm/classfile/systemDictionary.cpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/classfile/systemDictionary.cpp Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2012, 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 @@ -64,6 +64,9 @@ int SystemDictionary::_number_of_modifications = 0; +int SystemDictionary::_sdgeneration = 0; +const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103, + 20201,40423,99991}; oop SystemDictionary::_system_loader_lock_obj = NULL; @@ -1178,8 +1181,8 @@ klassOop SystemDictionary::find_shared_class(Symbol* class_name) { if (shared_dictionary() != NULL) { - unsigned int d_hash = dictionary()->compute_hash(class_name, Handle()); - int d_index = dictionary()->hash_to_index(d_hash); + unsigned int d_hash = shared_dictionary()->compute_hash(class_name, Handle()); + int d_index = shared_dictionary()->hash_to_index(d_hash); return shared_dictionary()->find_shared_class(d_index, d_hash, class_name); } else { return NULL; @@ -1750,7 +1753,21 @@ placeholders()->oops_do(blk); } - +// Calculate a "good" systemdictionary size based +// on predicted or current loaded classes count +int SystemDictionary::calculate_systemdictionary_size(int classcount) { + int newsize = _old_default_sdsize; + if ((classcount > 0) && !DumpSharedSpaces) { + int desiredsize = classcount/_average_depth_goal; + for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1; + newsize = _primelist[++_sdgeneration]) { + if (desiredsize <= newsize) { + break; + } + } + } + return newsize; +} bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) { bool result = dictionary()->do_unloading(is_alive); constraints()->purge_loader_constraints(is_alive); @@ -1873,7 +1890,8 @@ // Allocate arrays assert(dictionary() == NULL, "SystemDictionary should only be initialized once"); - _dictionary = new Dictionary(_nof_buckets); + _sdgeneration = 0; + _dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount)); _placeholders = new PlaceholderTable(_nof_buckets); _number_of_modifications = 0; _loader_constraints = new LoaderConstraintTable(_loader_constraint_size); diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/classfile/systemDictionary.hpp --- a/src/share/vm/classfile/systemDictionary.hpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/classfile/systemDictionary.hpp Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2012, 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 @@ -346,6 +346,8 @@ // loaders. Returns "true" iff something was unloaded. static bool do_unloading(BoolObjectClosure* is_alive); + static int calculate_systemdictionary_size(int loadedclasses); + // Applies "f->do_oop" to all root oops in the system dictionary. static void oops_do(OopClosure* f); @@ -538,12 +540,20 @@ _loader_constraint_size = 107, // number of entries in constraint table _resolution_error_size = 107, // number of entries in resolution error table _invoke_method_size = 139, // number of entries in invoke method table - _nof_buckets = 1009 // number of buckets in hash table + _nof_buckets = 1009, // number of buckets in hash table for placeholders + _old_default_sdsize = 1009, // backward compat for system dictionary size + _prime_array_size = 8, // array of primes for system dictionary size + _average_depth_goal = 3 // goal for lookup length }; // Static variables + // hashtable sizes for system dictionary to allow growth + // prime numbers for system dictionary size + static int _sdgeneration; + static const int _primelist[_prime_array_size]; + // Hashtable holding loaded classes. static Dictionary* _dictionary; diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/runtime/globals.hpp --- a/src/share/vm/runtime/globals.hpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/runtime/globals.hpp Mon Jan 30 23:27:30 2012 -0500 @@ -1042,6 +1042,9 @@ notproduct(bool, PrintSystemDictionaryAtExit, false, \ "Prints the system dictionary at exit") \ \ + experimental(intx, PredictedLoadedClassCount, 0, \ + "Experimental: Tune loaded class cache starting size.") \ + \ diagnostic(bool, UnsyncloadClass, false, \ "Unstable: VM calls loadClass unsynchronized. Custom " \ "class loader must call VM synchronized for findClass " \ diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/runtime/vmStructs.cpp --- a/src/share/vm/runtime/vmStructs.cpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/runtime/vmStructs.cpp Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2000, 2012, 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 @@ -2261,13 +2261,6 @@ \ declare_constant(SymbolTable::symbol_table_size) \ \ - /********************/ \ - /* SystemDictionary */ \ - /********************/ \ - \ - declare_constant(SystemDictionary::_loader_constraint_size) \ - declare_constant(SystemDictionary::_nof_buckets) \ - \ /***********************************/ \ /* LoaderConstraintTable constants */ \ /***********************************/ \ diff -r d96c130c9399 -r b2cd0ee8f778 src/share/vm/utilities/hashtable.hpp --- a/src/share/vm/utilities/hashtable.hpp Mon Jan 30 05:08:09 2012 -0800 +++ b/src/share/vm/utilities/hashtable.hpp Mon Jan 30 23:27:30 2012 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2012, 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 @@ -183,7 +183,6 @@ // Accessor int entry_size() const { return _entry_size; } - int table_size() { return _table_size; } // The following method is MT-safe and may be used with caution. BasicHashtableEntry* bucket(int i); @@ -195,6 +194,7 @@ BasicHashtableEntry* new_entry(unsigned int hashValue); public: + int table_size() { return _table_size; } void set_entry(int index, BasicHashtableEntry* entry); void add_entry(int index, BasicHashtableEntry* entry);