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1 /*
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2 * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 // A Klass is the part of the klassOop that provides:
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26 // 1: language level class object (method dictionary etc.)
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27 // 2: provide vm dispatch behavior for the object
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28 // Both functions are combined into one C++ class. The toplevel class "Klass"
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29 // implements purpose 1 whereas all subclasses provide extra virtual functions
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30 // for purpose 2.
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31
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32 // One reason for the oop/klass dichotomy in the implementation is
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33 // that we don't want a C++ vtbl pointer in every object. Thus,
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34 // normal oops don't have any virtual functions. Instead, they
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35 // forward all "virtual" functions to their klass, which does have
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36 // a vtbl and does the C++ dispatch depending on the object's
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37 // actual type. (See oop.inline.hpp for some of the forwarding code.)
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38 // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"!
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39
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40 // Klass layout:
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41 // [header ] klassOop
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42 // [klass pointer ] klassOop
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43 // [C++ vtbl ptr ] (contained in Klass_vtbl)
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44 // [layout_helper ]
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45 // [super_check_offset ] for fast subtype checks
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46 // [secondary_super_cache] for fast subtype checks
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47 // [secondary_supers ] array of 2ndary supertypes
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48 // [primary_supers 0]
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49 // [primary_supers 1]
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50 // [primary_supers 2]
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51 // ...
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52 // [primary_supers 7]
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53 // [java_mirror ]
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54 // [super ]
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55 // [name ]
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56 // [first subklass]
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57 // [next_sibling ] link to chain additional subklasses
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58 // [modifier_flags]
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59 // [access_flags ]
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60 // [verify_count ] - not in product
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61 // [alloc_count ]
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62 // [last_biased_lock_bulk_revocation_time] (64 bits)
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63 // [prototype_header]
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64 // [biased_lock_revocation_count]
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65
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66
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67 // Forward declarations.
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68 class klassVtable;
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69 class KlassHandle;
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70 class OrderAccess;
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71
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72 // Holder (or cage) for the C++ vtable of each kind of Klass.
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73 // We want to tightly constrain the location of the C++ vtable in the overall layout.
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74 class Klass_vtbl {
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75 protected:
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76 // The following virtual exists only to force creation of a C++ vtable,
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77 // so that this class truly is the location of the vtable of all Klasses.
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78 virtual void unused_initial_virtual() { }
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79
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80 public:
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81 // The following virtual makes Klass_vtbl play a second role as a
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82 // factory protocol for subclasses of Klass ("sub-Klasses").
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83 // Here's how it works....
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84 //
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85 // This VM uses metaobjects as factories for their instances.
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86 //
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87 // In order to initialize the C++ vtable of a new instance, its
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88 // metaobject is forced to use the C++ placed new operator to
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89 // allocate the instance. In a typical C++-based system, each
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90 // sub-class would have its own factory routine which
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91 // directly uses the placed new operator on the desired class,
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92 // and then calls the appropriate chain of C++ constructors.
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93 //
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94 // However, this system uses shared code to performs the first
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95 // allocation and initialization steps for all sub-Klasses.
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96 // (See base_create_klass() and base_create_array_klass().)
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97 // This does not factor neatly into a hierarchy of C++ constructors.
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98 // Each caller of these shared "base_create" routines knows
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99 // exactly which sub-Klass it is creating, but the shared routine
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100 // does not, even though it must perform the actual allocation.
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101 //
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102 // Therefore, the caller of the shared "base_create" must wrap
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103 // the specific placed new call in a virtual function which
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104 // performs the actual allocation and vtable set-up. That
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105 // virtual function is here, Klass_vtbl::allocate_permanent.
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106 //
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107 // The arguments to Universe::allocate_permanent() are passed
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108 // straight through the placed new operator, which in turn
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109 // obtains them directly from this virtual call.
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110 //
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111 // This virtual is called on a temporary "example instance" of the
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112 // sub-Klass being instantiated, a C++ auto variable. The "real"
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113 // instance created by this virtual is on the VM heap, where it is
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114 // equipped with a klassOopDesc header.
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115 //
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116 // It is merely an accident of implementation that we use "example
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117 // instances", but that is why the virtual function which implements
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118 // each sub-Klass factory happens to be defined by the same sub-Klass
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119 // for which it creates instances.
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120 //
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121 // The vtbl_value() call (see below) is used to strip away the
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122 // accidental Klass-ness from an "example instance" and present it as
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123 // a factory. Think of each factory object as a mere container of the
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124 // C++ vtable for the desired sub-Klass. Since C++ does not allow
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125 // direct references to vtables, the factory must also be delegated
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126 // the task of allocating the instance, but the essential point is
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127 // that the factory knows how to initialize the C++ vtable with the
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128 // right pointer value. All other common initializations are handled
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129 // by the shared "base_create" subroutines.
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130 //
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131 virtual void* allocate_permanent(KlassHandle& klass, int size, TRAPS) const = 0;
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132 void post_new_init_klass(KlassHandle& klass, klassOop obj, int size) const;
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133
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134 // Every subclass on which vtbl_value is called must include this macro.
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135 // Delay the installation of the klassKlass pointer until after the
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136 // the vtable for a new klass has been installed (after the call to new()).
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137 #define DEFINE_ALLOCATE_PERMANENT(thisKlass) \
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138 void* allocate_permanent(KlassHandle& klass_klass, int size, TRAPS) const { \
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139 void* result = new(klass_klass, size, THREAD) thisKlass(); \
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140 if (HAS_PENDING_EXCEPTION) return NULL; \
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141 klassOop new_klass = ((Klass*) result)->as_klassOop(); \
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142 OrderAccess::storestore(); \
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143 post_new_init_klass(klass_klass, new_klass, size); \
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144 return result; \
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145 }
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146
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147 bool null_vtbl() { return *(intptr_t*)this == 0; }
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148
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149 protected:
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150 void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS);
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151 };
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152
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153
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154 class Klass : public Klass_vtbl {
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155 friend class VMStructs;
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156 protected:
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157 // note: put frequently-used fields together at start of klass structure
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158 // for better cache behavior (may not make much of a difference but sure won't hurt)
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159 enum { _primary_super_limit = 8 };
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160
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161 // The "layout helper" is a combined descriptor of object layout.
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162 // For klasses which are neither instance nor array, the value is zero.
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163 //
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164 // For instances, layout helper is a positive number, the instance size.
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165 // This size is already passed through align_object_size and scaled to bytes.
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166 // The low order bit is set if instances of this class cannot be
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167 // allocated using the fastpath.
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168 //
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169 // For arrays, layout helper is a negative number, containing four
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170 // distinct bytes, as follows:
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171 // MSB:[tag, hsz, ebt, log2(esz)]:LSB
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172 // where:
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173 // tag is 0x80 if the elements are oops, 0xC0 if non-oops
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174 // hsz is array header size in bytes (i.e., offset of first element)
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175 // ebt is the BasicType of the elements
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176 // esz is the element size in bytes
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177 // This packed word is arranged so as to be quickly unpacked by the
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178 // various fast paths that use the various subfields.
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179 //
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180 // The esz bits can be used directly by a SLL instruction, without masking.
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181 //
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182 // Note that the array-kind tag looks like 0x00 for instance klasses,
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183 // since their length in bytes is always less than 24Mb.
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184 //
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185 // Final note: This comes first, immediately after Klass_vtbl,
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186 // because it is frequently queried.
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187 jint _layout_helper;
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188
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189 // The fields _super_check_offset, _secondary_super_cache, _secondary_supers
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190 // and _primary_supers all help make fast subtype checks. See big discussion
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191 // in doc/server_compiler/checktype.txt
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192 //
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193 // Where to look to observe a supertype (it is &_secondary_super_cache for
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194 // secondary supers, else is &_primary_supers[depth()].
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195 juint _super_check_offset;
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196
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197 public:
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198 oop* oop_block_beg() const { return adr_secondary_super_cache(); }
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199 oop* oop_block_end() const { return adr_next_sibling() + 1; }
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200
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201 protected:
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202 //
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203 // The oop block. All oop fields must be declared here and only oop fields
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204 // may be declared here. In addition, the first and last fields in this block
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205 // must remain first and last, unless oop_block_beg() and/or oop_block_end()
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206 // are updated. Grouping the oop fields in a single block simplifies oop
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207 // iteration.
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208 //
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209
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210 // Cache of last observed secondary supertype
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211 klassOop _secondary_super_cache;
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212 // Array of all secondary supertypes
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213 objArrayOop _secondary_supers;
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214 // Ordered list of all primary supertypes
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215 klassOop _primary_supers[_primary_super_limit];
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216 // java/lang/Class instance mirroring this class
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217 oop _java_mirror;
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218 // Superclass
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219 klassOop _super;
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220 // Class name. Instance classes: java/lang/String, etc. Array classes: [I,
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221 // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes.
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222 symbolOop _name;
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223 // First subclass (NULL if none); _subklass->next_sibling() is next one
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224 klassOop _subklass;
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225 // Sibling link (or NULL); links all subklasses of a klass
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226 klassOop _next_sibling;
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227
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228 //
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229 // End of the oop block.
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230 //
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231
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232 jint _modifier_flags; // Processed access flags, for use by Class.getModifiers.
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233 AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here.
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234
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235 #ifndef PRODUCT
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236 int _verify_count; // to avoid redundant verifies
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237 #endif
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238
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239 juint _alloc_count; // allocation profiling support - update klass_size_in_bytes() if moved/deleted
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240
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241 // Biased locking implementation and statistics
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242 // (the 64-bit chunk goes first, to avoid some fragmentation)
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243 jlong _last_biased_lock_bulk_revocation_time;
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244 markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type
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245 jint _biased_lock_revocation_count;
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246
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247 public:
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248
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249 // returns the enclosing klassOop
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250 klassOop as_klassOop() const {
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251 // see klassOop.hpp for layout.
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252 return (klassOop) (((char*) this) - sizeof(klassOopDesc));
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253 }
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254
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255 public:
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256 // Allocation
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257 const Klass_vtbl& vtbl_value() const { return *this; } // used only on "example instances"
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258 static KlassHandle base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
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259 static klassOop base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS);
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260
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261 // super
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262 klassOop super() const { return _super; }
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263 void set_super(klassOop k) { oop_store_without_check((oop*) &_super, (oop) k); }
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264
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265 // initializes _super link, _primary_supers & _secondary_supers arrays
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266 void initialize_supers(klassOop k, TRAPS);
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267 void initialize_supers_impl1(klassOop k);
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268 void initialize_supers_impl2(klassOop k);
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269
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270 // klass-specific helper for initializing _secondary_supers
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271 virtual objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS);
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272
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273 // java_super is the Java-level super type as specified by Class.getSuperClass.
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274 virtual klassOop java_super() const { return NULL; }
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275
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276 juint super_check_offset() const { return _super_check_offset; }
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277 void set_super_check_offset(juint o) { _super_check_offset = o; }
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278
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279 klassOop secondary_super_cache() const { return _secondary_super_cache; }
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280 void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); }
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281
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282 objArrayOop secondary_supers() const { return _secondary_supers; }
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283 void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); }
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284
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285 // Return the element of the _super chain of the given depth.
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286 // If there is no such element, return either NULL or this.
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287 klassOop primary_super_of_depth(juint i) const {
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288 assert(i < primary_super_limit(), "oob");
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289 klassOop super = _primary_supers[i];
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290 assert(super == NULL || super->klass_part()->super_depth() == i, "correct display");
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291 return super;
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292 }
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293
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294 // Can this klass be a primary super? False for interfaces and arrays of
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295 // interfaces. False also for arrays or classes with long super chains.
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296 bool can_be_primary_super() const {
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297 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc);
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298 return super_check_offset() != secondary_offset;
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299 }
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300 virtual bool can_be_primary_super_slow() const;
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301
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302 // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit].
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303 juint super_depth() const {
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304 if (!can_be_primary_super()) {
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305 return primary_super_limit();
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306 } else {
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307 juint d = (super_check_offset() - (primary_supers_offset_in_bytes() + sizeof(oopDesc))) / sizeof(klassOop);
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308 assert(d < primary_super_limit(), "oob");
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309 assert(_primary_supers[d] == as_klassOop(), "proper init");
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310 return d;
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311 }
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312 }
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313
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314 // java mirror
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315 oop java_mirror() const { return _java_mirror; }
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316 void set_java_mirror(oop m) { oop_store((oop*) &_java_mirror, m); }
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317
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318 // modifier flags
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319 jint modifier_flags() const { return _modifier_flags; }
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320 void set_modifier_flags(jint flags) { _modifier_flags = flags; }
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321
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322 // size helper
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323 int layout_helper() const { return _layout_helper; }
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324 void set_layout_helper(int lh) { _layout_helper = lh; }
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325
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326 // Note: for instances layout_helper() may include padding.
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327 // Use instanceKlass::contains_field_offset to classify field offsets.
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328
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329 // sub/superklass links
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330 instanceKlass* superklass() const;
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331 Klass* subklass() const;
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332 Klass* next_sibling() const;
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333 void append_to_sibling_list(); // add newly created receiver to superklass' subklass list
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334 void remove_from_sibling_list(); // remove receiver from sibling list
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335 protected: // internal accessors
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336 klassOop subklass_oop() const { return _subklass; }
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337 klassOop next_sibling_oop() const { return _next_sibling; }
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338 void set_subklass(klassOop s);
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339 void set_next_sibling(klassOop s);
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340
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341 oop* adr_super() const { return (oop*)&_super; }
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342 oop* adr_primary_supers() const { return (oop*)&_primary_supers[0]; }
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343 oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; }
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344 oop* adr_secondary_supers()const { return (oop*)&_secondary_supers; }
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345 oop* adr_java_mirror() const { return (oop*)&_java_mirror; }
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346 oop* adr_name() const { return (oop*)&_name; }
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347 oop* adr_subklass() const { return (oop*)&_subklass; }
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348 oop* adr_next_sibling() const { return (oop*)&_next_sibling; }
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349
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350 public:
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351 // Allocation profiling support
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352 juint alloc_count() const { return _alloc_count; }
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353 void set_alloc_count(juint n) { _alloc_count = n; }
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354 virtual juint alloc_size() const = 0;
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355 virtual void set_alloc_size(juint n) = 0;
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356
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357 // Compiler support
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358 static int super_offset_in_bytes() { return offset_of(Klass, _super); }
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359 static int super_check_offset_offset_in_bytes() { return offset_of(Klass, _super_check_offset); }
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360 static int primary_supers_offset_in_bytes(){ return offset_of(Klass, _primary_supers); }
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361 static int secondary_super_cache_offset_in_bytes() { return offset_of(Klass, _secondary_super_cache); }
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362 static int secondary_supers_offset_in_bytes() { return offset_of(Klass, _secondary_supers); }
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363 static int java_mirror_offset_in_bytes() { return offset_of(Klass, _java_mirror); }
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364 static int modifier_flags_offset_in_bytes(){ return offset_of(Klass, _modifier_flags); }
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365 static int layout_helper_offset_in_bytes() { return offset_of(Klass, _layout_helper); }
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366 static int access_flags_offset_in_bytes() { return offset_of(Klass, _access_flags); }
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367
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368 // Unpacking layout_helper:
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369 enum {
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370 _lh_neutral_value = 0, // neutral non-array non-instance value
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371 _lh_instance_slow_path_bit = 0x01,
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372 _lh_log2_element_size_shift = BitsPerByte*0,
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373 _lh_log2_element_size_mask = BitsPerLong-1,
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374 _lh_element_type_shift = BitsPerByte*1,
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375 _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask
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376 _lh_header_size_shift = BitsPerByte*2,
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377 _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask
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378 _lh_array_tag_bits = 2,
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379 _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits,
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380 _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30
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381 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30
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382 };
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383
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384 static int layout_helper_size_in_bytes(jint lh) {
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385 assert(lh > (jint)_lh_neutral_value, "must be instance");
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386 return (int) lh & ~_lh_instance_slow_path_bit;
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387 }
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388 static bool layout_helper_needs_slow_path(jint lh) {
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389 assert(lh > (jint)_lh_neutral_value, "must be instance");
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390 return (lh & _lh_instance_slow_path_bit) != 0;
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391 }
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392 static bool layout_helper_is_instance(jint lh) {
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393 return (jint)lh > (jint)_lh_neutral_value;
|
|
394 }
|
|
395 static bool layout_helper_is_javaArray(jint lh) {
|
|
396 return (jint)lh < (jint)_lh_neutral_value;
|
|
397 }
|
|
398 static bool layout_helper_is_typeArray(jint lh) {
|
|
399 // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift);
|
|
400 return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift);
|
|
401 }
|
|
402 static bool layout_helper_is_objArray(jint lh) {
|
|
403 // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift);
|
|
404 return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift);
|
|
405 }
|
|
406 static int layout_helper_header_size(jint lh) {
|
|
407 assert(lh < (jint)_lh_neutral_value, "must be array");
|
|
408 int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask;
|
|
409 assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity");
|
|
410 return hsize;
|
|
411 }
|
|
412 static BasicType layout_helper_element_type(jint lh) {
|
|
413 assert(lh < (jint)_lh_neutral_value, "must be array");
|
|
414 int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask;
|
|
415 assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity");
|
|
416 return (BasicType) btvalue;
|
|
417 }
|
|
418 static int layout_helper_log2_element_size(jint lh) {
|
|
419 assert(lh < (jint)_lh_neutral_value, "must be array");
|
|
420 int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask;
|
|
421 assert(l2esz <= LogBitsPerLong, "sanity");
|
|
422 return l2esz;
|
|
423 }
|
|
424 static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) {
|
|
425 return (tag << _lh_array_tag_shift)
|
|
426 | (hsize << _lh_header_size_shift)
|
|
427 | ((int)etype << _lh_element_type_shift)
|
|
428 | (log2_esize << _lh_log2_element_size_shift);
|
|
429 }
|
|
430 static jint instance_layout_helper(jint size, bool slow_path_flag) {
|
|
431 return (size << LogHeapWordSize)
|
|
432 | (slow_path_flag ? _lh_instance_slow_path_bit : 0);
|
|
433 }
|
|
434 static int layout_helper_to_size_helper(jint lh) {
|
|
435 assert(lh > (jint)_lh_neutral_value, "must be instance");
|
|
436 // Note that the following expression discards _lh_instance_slow_path_bit.
|
|
437 return lh >> LogHeapWordSize;
|
|
438 }
|
|
439 // Out-of-line version computes everything based on the etype:
|
|
440 static jint array_layout_helper(BasicType etype);
|
|
441
|
|
442 // What is the maximum number of primary superclasses any klass can have?
|
|
443 #ifdef PRODUCT
|
|
444 static juint primary_super_limit() { return _primary_super_limit; }
|
|
445 #else
|
|
446 static juint primary_super_limit() {
|
|
447 assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob");
|
|
448 return FastSuperclassLimit;
|
|
449 }
|
|
450 #endif
|
|
451
|
|
452 // vtables
|
|
453 virtual klassVtable* vtable() const { return NULL; }
|
|
454
|
|
455 static int klass_size_in_bytes() { return offset_of(Klass, _alloc_count) + sizeof(juint); } // all "visible" fields
|
|
456
|
|
457 // subclass check
|
|
458 bool is_subclass_of(klassOop k) const;
|
|
459 // subtype check: true if is_subclass_of, or if k is interface and receiver implements it
|
|
460 bool is_subtype_of(klassOop k) const {
|
|
461 juint off = k->klass_part()->super_check_offset();
|
|
462 klassOop sup = *(klassOop*)( (address)as_klassOop() + off );
|
|
463 const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc);
|
|
464 if (sup == k) {
|
|
465 return true;
|
|
466 } else if (off != secondary_offset) {
|
|
467 return false;
|
|
468 } else {
|
|
469 return search_secondary_supers(k);
|
|
470 }
|
|
471 }
|
|
472 bool search_secondary_supers(klassOop k) const;
|
|
473
|
|
474 // Find LCA in class heirarchy
|
|
475 Klass *LCA( Klass *k );
|
|
476
|
|
477 // Check whether reflection/jni/jvm code is allowed to instantiate this class;
|
|
478 // if not, throw either an Error or an Exception.
|
|
479 virtual void check_valid_for_instantiation(bool throwError, TRAPS);
|
|
480
|
|
481 // Casting
|
|
482 static Klass* cast(klassOop k) {
|
|
483 assert(k->is_klass(), "cast to Klass");
|
|
484 return k->klass_part();
|
|
485 }
|
|
486
|
|
487 // array copying
|
|
488 virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS);
|
|
489
|
|
490 // tells if the class should be initialized
|
|
491 virtual bool should_be_initialized() const { return false; }
|
|
492 // initializes the klass
|
|
493 virtual void initialize(TRAPS);
|
|
494 // lookup operation for MethodLookupCache
|
|
495 friend class MethodLookupCache;
|
|
496 virtual methodOop uncached_lookup_method(symbolOop name, symbolOop signature) const;
|
|
497 public:
|
|
498 methodOop lookup_method(symbolOop name, symbolOop signature) const {
|
|
499 return uncached_lookup_method(name, signature);
|
|
500 }
|
|
501
|
|
502 // array class with specific rank
|
|
503 klassOop array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); }
|
|
504
|
|
505 // array class with this klass as element type
|
|
506 klassOop array_klass(TRAPS) { return array_klass_impl(false, THREAD); }
|
|
507
|
|
508 // These will return NULL instead of allocating on the heap:
|
|
509 // NB: these can block for a mutex, like other functions with TRAPS arg.
|
|
510 klassOop array_klass_or_null(int rank);
|
|
511 klassOop array_klass_or_null();
|
|
512
|
|
513 virtual oop protection_domain() { return NULL; }
|
|
514 virtual oop class_loader() const { return NULL; }
|
|
515
|
|
516 protected:
|
|
517 virtual klassOop array_klass_impl(bool or_null, int rank, TRAPS);
|
|
518 virtual klassOop array_klass_impl(bool or_null, TRAPS);
|
|
519
|
|
520 public:
|
|
521 virtual void remove_unshareable_info();
|
|
522
|
|
523 protected:
|
|
524 // computes the subtype relationship
|
|
525 virtual bool compute_is_subtype_of(klassOop k);
|
|
526 public:
|
|
527 // subclass accessor (here for convenience; undefined for non-klass objects)
|
|
528 virtual bool is_leaf_class() const { fatal("not a class"); return false; }
|
|
529 public:
|
|
530 // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
|
|
531 // These functions describe behavior for the oop not the KLASS.
|
|
532
|
|
533 // actual oop size of obj in memory
|
|
534 virtual int oop_size(oop obj) const = 0;
|
|
535
|
|
536 // actual oop size of this klass in memory
|
|
537 virtual int klass_oop_size() const = 0;
|
|
538
|
|
539 // Returns the Java name for a class (Resource allocated)
|
|
540 // For arrays, this returns the name of the element with a leading '['.
|
|
541 // For classes, this returns the name with the package separators
|
|
542 // turned into '.'s.
|
|
543 const char* external_name() const;
|
|
544 // Returns the name for a class (Resource allocated) as the class
|
|
545 // would appear in a signature.
|
|
546 // For arrays, this returns the name of the element with a leading '['.
|
|
547 // For classes, this returns the name with a leading 'L' and a trailing ';'
|
|
548 // and the package separators as '/'.
|
|
549 virtual char* signature_name() const;
|
|
550
|
|
551 // garbage collection support
|
|
552 virtual void oop_follow_contents(oop obj) = 0;
|
|
553 virtual int oop_adjust_pointers(oop obj) = 0;
|
|
554
|
|
555 // Parallel Scavenge and Parallel Old
|
|
556 PARALLEL_GC_DECLS_PV
|
|
557
|
|
558 public:
|
|
559 // type testing operations
|
|
560 virtual bool oop_is_instance_slow() const { return false; }
|
|
561 virtual bool oop_is_instanceRef() const { return false; }
|
|
562 virtual bool oop_is_array() const { return false; }
|
|
563 virtual bool oop_is_objArray_slow() const { return false; }
|
|
564 virtual bool oop_is_symbol() const { return false; }
|
|
565 virtual bool oop_is_klass() const { return false; }
|
|
566 virtual bool oop_is_thread() const { return false; }
|
|
567 virtual bool oop_is_method() const { return false; }
|
|
568 virtual bool oop_is_constMethod() const { return false; }
|
|
569 virtual bool oop_is_methodData() const { return false; }
|
|
570 virtual bool oop_is_constantPool() const { return false; }
|
|
571 virtual bool oop_is_constantPoolCache() const { return false; }
|
|
572 virtual bool oop_is_typeArray_slow() const { return false; }
|
|
573 virtual bool oop_is_arrayKlass() const { return false; }
|
|
574 virtual bool oop_is_objArrayKlass() const { return false; }
|
|
575 virtual bool oop_is_typeArrayKlass() const { return false; }
|
|
576 virtual bool oop_is_compiledICHolder() const { return false; }
|
|
577 virtual bool oop_is_instanceKlass() const { return false; }
|
|
578
|
|
579 bool oop_is_javaArray_slow() const {
|
|
580 return oop_is_objArray_slow() || oop_is_typeArray_slow();
|
|
581 }
|
|
582
|
|
583 // Fast non-virtual versions, used by oop.inline.hpp and elsewhere:
|
|
584 #ifndef ASSERT
|
|
585 #define assert_same_query(xval, xcheck) xval
|
|
586 #else
|
|
587 private:
|
|
588 static bool assert_same_query(bool xval, bool xslow) {
|
|
589 assert(xval == xslow, "slow and fast queries agree");
|
|
590 return xval;
|
|
591 }
|
|
592 public:
|
|
593 #endif
|
|
594 inline bool oop_is_instance() const { return assert_same_query(
|
|
595 layout_helper_is_instance(layout_helper()),
|
|
596 oop_is_instance_slow()); }
|
|
597 inline bool oop_is_javaArray() const { return assert_same_query(
|
|
598 layout_helper_is_javaArray(layout_helper()),
|
|
599 oop_is_javaArray_slow()); }
|
|
600 inline bool oop_is_objArray() const { return assert_same_query(
|
|
601 layout_helper_is_objArray(layout_helper()),
|
|
602 oop_is_objArray_slow()); }
|
|
603 inline bool oop_is_typeArray() const { return assert_same_query(
|
|
604 layout_helper_is_typeArray(layout_helper()),
|
|
605 oop_is_typeArray_slow()); }
|
|
606 #undef assert_same_query
|
|
607
|
|
608 // Unless overridden, oop is parsable if it has a klass pointer.
|
|
609 virtual bool oop_is_parsable(oop obj) const { return true; }
|
|
610
|
|
611 // Access flags
|
|
612 AccessFlags access_flags() const { return _access_flags; }
|
|
613 void set_access_flags(AccessFlags flags) { _access_flags = flags; }
|
|
614
|
|
615 bool is_public() const { return _access_flags.is_public(); }
|
|
616 bool is_final() const { return _access_flags.is_final(); }
|
|
617 bool is_interface() const { return _access_flags.is_interface(); }
|
|
618 bool is_abstract() const { return _access_flags.is_abstract(); }
|
|
619 bool is_super() const { return _access_flags.is_super(); }
|
|
620 bool is_synthetic() const { return _access_flags.is_synthetic(); }
|
|
621 void set_is_synthetic() { _access_flags.set_is_synthetic(); }
|
|
622 bool has_finalizer() const { return _access_flags.has_finalizer(); }
|
|
623 bool has_final_method() const { return _access_flags.has_final_method(); }
|
|
624 void set_has_finalizer() { _access_flags.set_has_finalizer(); }
|
|
625 void set_has_final_method() { _access_flags.set_has_final_method(); }
|
|
626 bool is_cloneable() const { return _access_flags.is_cloneable(); }
|
|
627 void set_is_cloneable() { _access_flags.set_is_cloneable(); }
|
|
628 bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); }
|
|
629 void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); }
|
|
630 bool has_miranda_methods () const { return access_flags().has_miranda_methods(); }
|
|
631 void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); }
|
|
632
|
|
633 // Biased locking support
|
|
634 // Note: the prototype header is always set up to be at least the
|
|
635 // prototype markOop. If biased locking is enabled it may further be
|
|
636 // biasable and have an epoch.
|
|
637 markOop prototype_header() const { return _prototype_header; }
|
|
638 // NOTE: once instances of this klass are floating around in the
|
|
639 // system, this header must only be updated at a safepoint.
|
|
640 // NOTE 2: currently we only ever set the prototype header to the
|
|
641 // biasable prototype for instanceKlasses. There is no technical
|
|
642 // reason why it could not be done for arrayKlasses aside from
|
|
643 // wanting to reduce the initial scope of this optimization. There
|
|
644 // are potential problems in setting the bias pattern for
|
|
645 // JVM-internal oops.
|
|
646 inline void set_prototype_header(markOop header);
|
|
647 static int prototype_header_offset_in_bytes() { return offset_of(Klass, _prototype_header); }
|
|
648
|
|
649 int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }
|
|
650 // Atomically increments biased_lock_revocation_count and returns updated value
|
|
651 int atomic_incr_biased_lock_revocation_count();
|
|
652 void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; }
|
|
653 jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; }
|
|
654 void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; }
|
|
655
|
|
656
|
|
657 // garbage collection support
|
|
658 virtual void follow_weak_klass_links(
|
|
659 BoolObjectClosure* is_alive, OopClosure* keep_alive);
|
|
660
|
|
661 // Prefetch within oop iterators. This is a macro because we
|
|
662 // can't guarantee that the compiler will inline it. In 64-bit
|
|
663 // it generally doesn't. Signature is
|
|
664 //
|
|
665 // static void prefetch_beyond(oop* const start,
|
|
666 // oop* const end,
|
|
667 // const intx foffset,
|
|
668 // const Prefetch::style pstyle);
|
|
669 #define prefetch_beyond(start, end, foffset, pstyle) { \
|
|
670 const intx foffset_ = (foffset); \
|
|
671 const Prefetch::style pstyle_ = (pstyle); \
|
|
672 assert(foffset_ > 0, "prefetch beyond, not behind"); \
|
|
673 if (pstyle_ != Prefetch::do_none) { \
|
|
674 oop* ref = (start); \
|
|
675 if (ref < (end)) { \
|
|
676 switch (pstyle_) { \
|
|
677 case Prefetch::do_read: \
|
|
678 Prefetch::read(*ref, foffset_); \
|
|
679 break; \
|
|
680 case Prefetch::do_write: \
|
|
681 Prefetch::write(*ref, foffset_); \
|
|
682 break; \
|
|
683 default: \
|
|
684 ShouldNotReachHere(); \
|
|
685 break; \
|
|
686 } \
|
|
687 } \
|
|
688 } \
|
|
689 }
|
|
690
|
|
691 // iterators
|
|
692 virtual int oop_oop_iterate(oop obj, OopClosure* blk) = 0;
|
|
693 virtual int oop_oop_iterate_v(oop obj, OopClosure* blk) {
|
|
694 return oop_oop_iterate(obj, blk);
|
|
695 }
|
|
696
|
|
697 // Iterates "blk" over all the oops in "obj" (of type "this") within "mr".
|
|
698 // (I don't see why the _m should be required, but without it the Solaris
|
|
699 // C++ gives warning messages about overridings of the "oop_oop_iterate"
|
|
700 // defined above "hiding" this virtual function. (DLD, 6/20/00)) */
|
|
701 virtual int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) = 0;
|
|
702 virtual int oop_oop_iterate_v_m(oop obj, OopClosure* blk, MemRegion mr) {
|
|
703 return oop_oop_iterate_m(obj, blk, mr);
|
|
704 }
|
|
705
|
|
706 // Versions of the above iterators specialized to particular subtypes
|
|
707 // of OopClosure, to avoid closure virtual calls.
|
|
708 #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
|
|
709 virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \
|
|
710 /* Default implementation reverts to general version. */ \
|
|
711 return oop_oop_iterate(obj, blk); \
|
|
712 } \
|
|
713 \
|
|
714 /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \
|
|
715 (I don't see why the _m should be required, but without it the Solaris \
|
|
716 C++ gives warning messages about overridings of the "oop_oop_iterate" \
|
|
717 defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \
|
|
718 virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \
|
|
719 OopClosureType* blk, \
|
|
720 MemRegion mr) { \
|
|
721 return oop_oop_iterate_m(obj, blk, mr); \
|
|
722 }
|
|
723
|
|
724 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL)
|
|
725 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_3(Klass_OOP_OOP_ITERATE_DECL)
|
|
726
|
|
727 virtual void array_klasses_do(void f(klassOop k)) {}
|
|
728 virtual void with_array_klasses_do(void f(klassOop k));
|
|
729
|
|
730 // Return self, except for abstract classes with exactly 1
|
|
731 // implementor. Then return the 1 concrete implementation.
|
|
732 Klass *up_cast_abstract();
|
|
733
|
|
734 // klass name
|
|
735 symbolOop name() const { return _name; }
|
|
736 void set_name(symbolOop n) { oop_store_without_check((oop*) &_name, (oop) n); }
|
|
737
|
|
738 friend class klassKlass;
|
|
739
|
|
740 public:
|
|
741 // jvm support
|
|
742 virtual jint compute_modifier_flags(TRAPS) const;
|
|
743
|
|
744 public:
|
|
745 // JVMTI support
|
|
746 virtual jint jvmti_class_status() const;
|
|
747
|
|
748 #ifndef PRODUCT
|
|
749 public:
|
|
750 // Printing
|
|
751 virtual void oop_print_on (oop obj, outputStream* st);
|
|
752 virtual void oop_print_value_on(oop obj, outputStream* st);
|
|
753 #endif
|
|
754
|
|
755 public:
|
|
756 // Verification
|
|
757 virtual const char* internal_name() const = 0;
|
|
758 virtual void oop_verify_on(oop obj, outputStream* st);
|
|
759 virtual void oop_verify_old_oop(oop obj, oop* p, bool allow_dirty);
|
|
760 // tells whether obj is partially constructed (gc during class loading)
|
|
761 virtual bool oop_partially_loaded(oop obj) const { return false; }
|
|
762 virtual void oop_set_partially_loaded(oop obj) {};
|
|
763
|
|
764 #ifndef PRODUCT
|
|
765 void verify_vtable_index(int index);
|
|
766 #endif
|
|
767 };
|