Mercurial > hg > truffle
view src/share/vm/runtime/fieldType.hpp @ 2368:dde920245681
6896099: Integrate CMS heap ergo with default heap sizing ergo
6627787: CMS: JVM refuses to start up with -Xms16m -Xmx16m
7000125: CMS: Anti-monotone young gen sizing with respect to maximum whole heap size specification
7027529: CMS: retire CMSUseOldDefaults flag
Summary: Simplify CMS heap sizing code, relying on ergonomic initial sizing consistent with other collectors for the most part, controlling only young gen sizing to rein in pause times. Make CMS young gen sizing default statically cpu-dependant. Remove inconsistencies wrt generation sizing and policy code, allowing for the fixing for 6627787 and 7000125. For 7027529, retire the flag CMSUseOldDefaults which had been introduced as a bridge from JDK 5 to JDK 6 a number of years ago.
Reviewed-by: brutisso, poonam
author | ysr |
---|---|
date | Wed, 16 Mar 2011 10:37:08 -0700 |
parents | 3582bf76420e |
children | 1d1603768966 |
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/* * Copyright (c) 1997, 2010, 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 * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_RUNTIME_FIELDTYPE_HPP #define SHARE_VM_RUNTIME_FIELDTYPE_HPP #include "memory/allocation.hpp" #include "oops/symbol.hpp" // Note: FieldType should be based on the SignatureIterator (or vice versa). // In any case, this structure should be re-thought at some point. // A FieldType is used to determine the type of a field from a signature string. // Information returned by get_array_info, which is scoped to decrement // reference count if a Symbol is created in the case of T_OBJECT class FieldArrayInfo : public StackObj { friend class FieldType; // field type can set these fields. int _dimension; Symbol* _object_key; public: int dimension() { return _dimension; } Symbol* object_key() { return _object_key; } // basic constructor FieldArrayInfo() : _dimension(0), _object_key(NULL) {} // destructor decrements object key's refcount if created ~FieldArrayInfo() { if (_object_key != NULL) _object_key->decrement_refcount(); } }; class FieldType: public AllStatic { private: static void skip_optional_size(Symbol* signature, int* index); static bool is_valid_array_signature(Symbol* signature); public: // Return basic type static BasicType basic_type(Symbol* signature); // Testing static bool is_array(Symbol* signature) { return signature->utf8_length() > 1 && signature->byte_at(0) == '[' && is_valid_array_signature(signature); } static bool is_obj(Symbol* signature) { int sig_length = signature->utf8_length(); // Must start with 'L' and end with ';' return (sig_length >= 2 && (signature->byte_at(0) == 'L') && (signature->byte_at(sig_length - 1) == ';')); } // Parse field and extract array information. Works for T_ARRAY only. static BasicType get_array_info(Symbol* signature, FieldArrayInfo& ai, TRAPS); }; #endif // SHARE_VM_RUNTIME_FIELDTYPE_HPP