view src/share/vm/utilities/constantTag.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents a45484ea312d
children ad8c8ca4ab0f
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/*
 * Copyright 1997-2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

// constant tags in Java .class files


enum {
  // See jvm.h for shared JVM_CONSTANT_XXX tags
  // NOTE: replicated in SA in vm/agent/sun/jvm/hotspot/utilities/ConstantTag.java
  // Hotspot specific tags
  JVM_CONSTANT_Invalid                  = 0,    // For bad value initialization
  JVM_CONSTANT_InternalMin              = 100,  // First implementation tag (aside from bad value of course)
  JVM_CONSTANT_UnresolvedClass          = 100,  // Temporary tag until actual use
  JVM_CONSTANT_ClassIndex               = 101,  // Temporary tag while constructing constant pool
  JVM_CONSTANT_UnresolvedString         = 102,  // Temporary tag until actual use
  JVM_CONSTANT_StringIndex              = 103,  // Temporary tag while constructing constant pool
  JVM_CONSTANT_UnresolvedClassInError   = 104,  // Error tag due to resolution error
  JVM_CONSTANT_InternalMax              = 104   // Last implementation tag
};


class constantTag VALUE_OBJ_CLASS_SPEC {
 private:
  jbyte _tag;
 public:
  bool is_klass() const             { return _tag == JVM_CONSTANT_Class; }
  bool is_field () const            { return _tag == JVM_CONSTANT_Fieldref; }
  bool is_method() const            { return _tag == JVM_CONSTANT_Methodref; }
  bool is_interface_method() const  { return _tag == JVM_CONSTANT_InterfaceMethodref; }
  bool is_string() const            { return _tag == JVM_CONSTANT_String; }
  bool is_int() const               { return _tag == JVM_CONSTANT_Integer; }
  bool is_float() const             { return _tag == JVM_CONSTANT_Float; }
  bool is_long() const              { return _tag == JVM_CONSTANT_Long; }
  bool is_double() const            { return _tag == JVM_CONSTANT_Double; }
  bool is_name_and_type() const     { return _tag == JVM_CONSTANT_NameAndType; }
  bool is_utf8() const              { return _tag == JVM_CONSTANT_Utf8; }

  bool is_invalid() const           { return _tag == JVM_CONSTANT_Invalid; }

  bool is_unresolved_klass() const {
    return _tag == JVM_CONSTANT_UnresolvedClass || _tag == JVM_CONSTANT_UnresolvedClassInError;
  }

  bool is_unresolved_klass_in_error() const {
    return _tag == JVM_CONSTANT_UnresolvedClassInError;
  }

  bool is_klass_index() const       { return _tag == JVM_CONSTANT_ClassIndex; }
  bool is_unresolved_string() const { return _tag == JVM_CONSTANT_UnresolvedString; }
  bool is_string_index() const      { return _tag == JVM_CONSTANT_StringIndex; }

  bool is_klass_reference() const   { return is_klass_index() || is_unresolved_klass(); }
  bool is_klass_or_reference() const{ return is_klass() || is_klass_reference(); }
  bool is_field_or_method() const   { return is_field() || is_method() || is_interface_method(); }
  bool is_symbol() const            { return is_utf8(); }

  constantTag(jbyte tag) {
    assert((tag >= 0 && tag <= JVM_CONSTANT_NameAndType) ||
           (tag >= JVM_CONSTANT_InternalMin && tag <= JVM_CONSTANT_InternalMax), "Invalid constant tag");
    _tag = tag;
  }

  jbyte value()                      { return _tag; }

  void print_on(outputStream* st) const PRODUCT_RETURN;
};