view src/share/vm/ci/ciSymbol.hpp @ 2149:7e37af9d69ef

7011379: G1: overly long concurrent marking cycles Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads. Reviewed-by: johnc, ysr
author tonyp
date Wed, 19 Jan 2011 09:35:17 -0500
parents f95d63e2154a
children 06f017f7daa7 3582bf76420e
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/*
 * Copyright (c) 1999, 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.
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 */

#ifndef SHARE_VM_CI_CISYMBOL_HPP
#define SHARE_VM_CI_CISYMBOL_HPP

#include "ci/ciObject.hpp"
#include "ci/ciObjectFactory.hpp"
#include "classfile/vmSymbols.hpp"
#include "oops/symbolOop.hpp"

// ciSymbol
//
// This class represents a symbolOop in the HotSpot virtual
// machine.
class ciSymbol : public ciObject {
  CI_PACKAGE_ACCESS
  // These friends all make direct use of get_symbolOop:
  friend class ciEnv;
  friend class ciInstanceKlass;
  friend class ciSignature;
  friend class ciMethod;
  friend class ciObjArrayKlass;

private:
  const vmSymbols::SID _sid;
  DEBUG_ONLY( bool sid_ok() { return vmSymbols::find_sid(get_symbolOop()) == _sid; } )

  ciSymbol(symbolOop s);  // normal case, for symbols not mentioned in vmSymbols
  ciSymbol(symbolHandle s, vmSymbols::SID sid);   // for use with vmSymbolHandles

  symbolOop get_symbolOop() const { return (symbolOop)get_oop(); }

  const char* type_string() { return "ciSymbol"; }

  void print_impl(outputStream* st);

  // This is public in symbolOop but private here, because the base can move:
  jbyte*      base();

  // Make a ciSymbol from a C string (implementation).
  static ciSymbol* make_impl(const char* s);

public:
  // The enumeration ID from vmSymbols, or vmSymbols::NO_SID if none.
  vmSymbols::SID sid() const { return _sid; }

  // The text of the symbol as a null-terminated utf8 string.
  const char* as_utf8();
  int         utf8_length();

  // Return the i-th utf8 byte, where i < utf8_length
  int         byte_at(int i);

  // Tests if the symbol starts with the given prefix.
  bool starts_with(const char* prefix, int len) const;

  // Determines where the symbol contains the given substring.
  int index_of_at(int i, const char* str, int len) const;

  // What kind of ciObject is this?
  bool is_symbol() { return true; }

  void print_symbol_on(outputStream* st);
  void print_symbol() {
    print_symbol_on(tty);
  }

  // Make a ciSymbol from a C string.
  // Consider adding to vmSymbols.hpp instead of using this constructor.
  // (Your code will be less subject to typographical bugs.)
  static ciSymbol* make(const char* s);

#define CI_SYMBOL_DECLARE(name, ignore_def) \
  static ciSymbol* name() { return ciObjectFactory::vm_symbol_at(vmSymbols::VM_SYMBOL_ENUM_NAME(name)); }
  VM_SYMBOLS_DO(CI_SYMBOL_DECLARE, CI_SYMBOL_DECLARE)
#undef CI_SYMBOL_DECLARE
};

#endif // SHARE_VM_CI_CISYMBOL_HPP