src/share/vm/oops/oop.inline.hpp

Fri, 16 Nov 2012 09:19:12 -0500

author
coleenp
date
Fri, 16 Nov 2012 09:19:12 -0500
changeset 4280
80e866b1d053
parent 4159
8e47bac5643a
child 4523
10d5f25a7c67
child 4542
db9981fd3124
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #ifndef SHARE_VM_OOPS_OOP_INLINE_HPP
    26 #define SHARE_VM_OOPS_OOP_INLINE_HPP
    28 #include "gc_implementation/shared/ageTable.hpp"
    29 #include "gc_implementation/shared/markSweep.inline.hpp"
    30 #include "gc_interface/collectedHeap.inline.hpp"
    31 #include "memory/barrierSet.inline.hpp"
    32 #include "memory/cardTableModRefBS.hpp"
    33 #include "memory/genCollectedHeap.hpp"
    34 #include "memory/generation.hpp"
    35 #include "memory/specialized_oop_closures.hpp"
    36 #include "oops/arrayKlass.hpp"
    37 #include "oops/arrayOop.hpp"
    38 #include "oops/klass.hpp"
    39 #include "oops/markOop.inline.hpp"
    40 #include "oops/oop.hpp"
    41 #include "runtime/atomic.hpp"
    42 #include "runtime/os.hpp"
    43 #ifdef TARGET_ARCH_x86
    44 # include "bytes_x86.hpp"
    45 #endif
    46 #ifdef TARGET_ARCH_sparc
    47 # include "bytes_sparc.hpp"
    48 #endif
    49 #ifdef TARGET_ARCH_zero
    50 # include "bytes_zero.hpp"
    51 #endif
    52 #ifdef TARGET_ARCH_arm
    53 # include "bytes_arm.hpp"
    54 #endif
    55 #ifdef TARGET_ARCH_ppc
    56 # include "bytes_ppc.hpp"
    57 #endif
    59 // Implementation of all inlined member functions defined in oop.hpp
    60 // We need a separate file to avoid circular references
    62 inline void oopDesc::release_set_mark(markOop m) {
    63   OrderAccess::release_store_ptr(&_mark, m);
    64 }
    66 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
    67   return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
    68 }
    70 inline Klass* oopDesc::klass() const {
    71   if (UseCompressedKlassPointers) {
    72     return decode_klass_not_null(_metadata._compressed_klass);
    73   } else {
    74     return _metadata._klass;
    75   }
    76 }
    78 inline Klass* oopDesc::klass_or_null() const volatile {
    79   // can be NULL in CMS
    80   if (UseCompressedKlassPointers) {
    81     return decode_klass(_metadata._compressed_klass);
    82   } else {
    83     return _metadata._klass;
    84   }
    85 }
    87 inline int oopDesc::klass_gap_offset_in_bytes() {
    88   assert(UseCompressedKlassPointers, "only applicable to compressed klass pointers");
    89   return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);
    90 }
    92 inline Klass** oopDesc::klass_addr() {
    93   // Only used internally and with CMS and will not work with
    94   // UseCompressedOops
    95   assert(!UseCompressedKlassPointers, "only supported with uncompressed klass pointers");
    96   return (Klass**) &_metadata._klass;
    97 }
    99 inline narrowOop* oopDesc::compressed_klass_addr() {
   100   assert(UseCompressedKlassPointers, "only called by compressed klass pointers");
   101   return (narrowOop*) &_metadata._compressed_klass;
   102 }
   104 inline void oopDesc::set_klass(Klass* k) {
   105   // since klasses are promoted no store check is needed
   106   assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
   107   assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
   108   if (UseCompressedKlassPointers) {
   109     *compressed_klass_addr() = encode_klass_not_null(k);
   110   } else {
   111     *klass_addr() = k;
   112   }
   113 }
   115 inline int oopDesc::klass_gap() const {
   116   return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
   117 }
   119 inline void oopDesc::set_klass_gap(int v) {
   120   if (UseCompressedKlassPointers) {
   121     *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
   122   }
   123 }
   125 inline void oopDesc::set_klass_to_list_ptr(oop k) {
   126   // This is only to be used during GC, for from-space objects, so no
   127   // barrier is needed.
   128   if (UseCompressedKlassPointers) {
   129     _metadata._compressed_klass = encode_heap_oop(k);  // may be null (parnew overflow handling)
   130   } else {
   131     _metadata._klass = (Klass*)(address)k;
   132   }
   133 }
   135 inline oop oopDesc::list_ptr_from_klass() {
   136   // This is only to be used during GC, for from-space objects.
   137   if (UseCompressedKlassPointers) {
   138     return decode_heap_oop(_metadata._compressed_klass);
   139   } else {
   140     // Special case for GC
   141     return (oop)(address)_metadata._klass;
   142   }
   143 }
   145 inline void   oopDesc::init_mark()                 { set_mark(markOopDesc::prototype_for_object(this)); }
   147 inline bool oopDesc::is_a(Klass* k)        const { return klass()->is_subtype_of(k); }
   149 inline bool oopDesc::is_instance()           const { return klass()->oop_is_instance(); }
   150 inline bool oopDesc::is_instanceMirror()     const { return klass()->oop_is_instanceMirror(); }
   151 inline bool oopDesc::is_instanceRef()        const { return klass()->oop_is_instanceRef(); }
   152 inline bool oopDesc::is_array()              const { return klass()->oop_is_array(); }
   153 inline bool oopDesc::is_objArray()           const { return klass()->oop_is_objArray(); }
   154 inline bool oopDesc::is_typeArray()          const { return klass()->oop_is_typeArray(); }
   156 inline void*     oopDesc::field_base(int offset)        const { return (void*)&((char*)this)[offset]; }
   158 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
   159 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
   160 inline jbyte*    oopDesc::byte_field_addr(int offset)   const { return (jbyte*)   field_base(offset); }
   161 inline jchar*    oopDesc::char_field_addr(int offset)   const { return (jchar*)   field_base(offset); }
   162 inline jboolean* oopDesc::bool_field_addr(int offset)   const { return (jboolean*)field_base(offset); }
   163 inline jint*     oopDesc::int_field_addr(int offset)    const { return (jint*)    field_base(offset); }
   164 inline jshort*   oopDesc::short_field_addr(int offset)  const { return (jshort*)  field_base(offset); }
   165 inline jlong*    oopDesc::long_field_addr(int offset)   const { return (jlong*)   field_base(offset); }
   166 inline jfloat*   oopDesc::float_field_addr(int offset)  const { return (jfloat*)  field_base(offset); }
   167 inline jdouble*  oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
   168 inline address*  oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
   171 // Functions for getting and setting oops within instance objects.
   172 // If the oops are compressed, the type passed to these overloaded functions
   173 // is narrowOop.  All functions are overloaded so they can be called by
   174 // template functions without conditionals (the compiler instantiates via
   175 // the right type and inlines the appopriate code).
   177 inline bool oopDesc::is_null(oop obj)       { return obj == NULL; }
   178 inline bool oopDesc::is_null(Klass* obj)  { return obj == NULL; }
   179 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }
   181 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
   182 // offset from the heap base.  Saving the check for null can save instructions
   183 // in inner GC loops so these are separated.
   185 inline bool check_obj_alignment(oop obj) {
   186   return (intptr_t)obj % MinObjAlignmentInBytes == 0;
   187 }
   188 inline bool check_klass_alignment(Klass* obj) {
   189   return (intptr_t)obj % KlassAlignmentInBytes == 0;
   190 }
   192 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
   193   assert(!is_null(v), "oop value can never be zero");
   194   assert(check_obj_alignment(v), "Address not aligned");
   195   assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
   196   address base = Universe::narrow_oop_base();
   197   int    shift = Universe::narrow_oop_shift();
   198   uint64_t  pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
   199   assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
   200   uint64_t result = pd >> shift;
   201   assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
   202   assert(decode_heap_oop(result) == v, "reversibility");
   203   return (narrowOop)result;
   204 }
   206 inline narrowOop oopDesc::encode_heap_oop(oop v) {
   207   return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
   208 }
   210 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
   211   assert(!is_null(v), "narrow oop value can never be zero");
   212   address base = Universe::narrow_oop_base();
   213   int    shift = Universe::narrow_oop_shift();
   214   oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
   215   assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
   216   return result;
   217 }
   219 inline oop oopDesc::decode_heap_oop(narrowOop v) {
   220   return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
   221 }
   223 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
   224 inline oop oopDesc::decode_heap_oop(oop v)  { return v; }
   226 // Encoding and decoding for klass field.  It is copied code, but someday
   227 // might not be the same as oop.
   229 inline narrowOop oopDesc::encode_klass_not_null(Klass* v) {
   230   assert(!is_null(v), "oop value can never be zero");
   231   assert(check_klass_alignment(v), "Address not aligned");
   232   address base = Universe::narrow_klass_base();
   233   int    shift = Universe::narrow_klass_shift();
   234   uint64_t  pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
   235   assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
   236   uint64_t result = pd >> shift;
   237   assert((result & CONST64(0xffffffff00000000)) == 0, "narrow klass pointer overflow");
   238   assert(decode_klass(result) == v, "reversibility");
   239   return (narrowOop)result;
   240 }
   242 inline narrowOop oopDesc::encode_klass(Klass* v) {
   243   return (is_null(v)) ? (narrowOop)0 : encode_klass_not_null(v);
   244 }
   246 inline Klass* oopDesc::decode_klass_not_null(narrowOop v) {
   247   assert(!is_null(v), "narrow oop value can never be zero");
   248   address base = Universe::narrow_klass_base();
   249   int    shift = Universe::narrow_klass_shift();
   250   Klass* result = (Klass*)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
   251   assert(check_klass_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
   252   return result;
   253 }
   255 inline Klass* oopDesc::decode_klass(narrowOop v) {
   256   return is_null(v) ? (Klass*)NULL : decode_klass_not_null(v);
   257 }
   259 // Load an oop out of the Java heap as is without decoding.
   260 // Called by GC to check for null before decoding.
   261 inline oop       oopDesc::load_heap_oop(oop* p)          { return *p; }
   262 inline narrowOop oopDesc::load_heap_oop(narrowOop* p)    { return *p; }
   264 // Load and decode an oop out of the Java heap into a wide oop.
   265 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p)       { return *p; }
   266 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
   267   return decode_heap_oop_not_null(*p);
   268 }
   270 // Load and decode an oop out of the heap accepting null
   271 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
   272 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
   273   return decode_heap_oop(*p);
   274 }
   276 // Store already encoded heap oop into the heap.
   277 inline void oopDesc::store_heap_oop(oop* p, oop v)                 { *p = v; }
   278 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v)     { *p = v; }
   280 // Encode and store a heap oop.
   281 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
   282   *p = encode_heap_oop_not_null(v);
   283 }
   284 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
   286 // Encode and store a heap oop allowing for null.
   287 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
   288   *p = encode_heap_oop(v);
   289 }
   290 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
   292 // Store heap oop as is for volatile fields.
   293 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
   294   OrderAccess::release_store_ptr(p, v);
   295 }
   296 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
   297                                             narrowOop v) {
   298   OrderAccess::release_store(p, v);
   299 }
   301 inline void oopDesc::release_encode_store_heap_oop_not_null(
   302                                                 volatile narrowOop* p, oop v) {
   303   // heap oop is not pointer sized.
   304   OrderAccess::release_store(p, encode_heap_oop_not_null(v));
   305 }
   307 inline void oopDesc::release_encode_store_heap_oop_not_null(
   308                                                       volatile oop* p, oop v) {
   309   OrderAccess::release_store_ptr(p, v);
   310 }
   312 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
   313                                                            oop v) {
   314   OrderAccess::release_store_ptr(p, v);
   315 }
   316 inline void oopDesc::release_encode_store_heap_oop(
   317                                                 volatile narrowOop* p, oop v) {
   318   OrderAccess::release_store(p, encode_heap_oop(v));
   319 }
   322 // These functions are only used to exchange oop fields in instances,
   323 // not headers.
   324 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
   325   if (UseCompressedOops) {
   326     // encode exchange value from oop to T
   327     narrowOop val = encode_heap_oop(exchange_value);
   328     narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
   329     // decode old from T to oop
   330     return decode_heap_oop(old);
   331   } else {
   332     return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
   333   }
   334 }
   336 // In order to put or get a field out of an instance, must first check
   337 // if the field has been compressed and uncompress it.
   338 inline oop oopDesc::obj_field(int offset) const {
   339   return UseCompressedOops ?
   340     load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
   341     load_decode_heap_oop(obj_field_addr<oop>(offset));
   342 }
   343 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
   344   volatile oop value = obj_field(offset);
   345   OrderAccess::acquire();
   346   return value;
   347 }
   348 inline void oopDesc::obj_field_put(int offset, oop value) {
   349   UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
   350                       oop_store(obj_field_addr<oop>(offset),       value);
   351 }
   353 inline Metadata* oopDesc::metadata_field(int offset) const {
   354   return *metadata_field_addr(offset);
   355 }
   357 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
   358   *metadata_field_addr(offset) = value;
   359 }
   361 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
   362   UseCompressedOops ?
   363     encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
   364     encode_store_heap_oop(obj_field_addr<oop>(offset),       value);
   365 }
   366 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
   367   OrderAccess::release();
   368   obj_field_put(offset, value);
   369   OrderAccess::fence();
   370 }
   372 inline jbyte oopDesc::byte_field(int offset) const                  { return (jbyte) *byte_field_addr(offset);    }
   373 inline void oopDesc::byte_field_put(int offset, jbyte contents)     { *byte_field_addr(offset) = (jint) contents; }
   375 inline jboolean oopDesc::bool_field(int offset) const               { return (jboolean) *bool_field_addr(offset); }
   376 inline void oopDesc::bool_field_put(int offset, jboolean contents)  { *bool_field_addr(offset) = (jint) contents; }
   378 inline jchar oopDesc::char_field(int offset) const                  { return (jchar) *char_field_addr(offset);    }
   379 inline void oopDesc::char_field_put(int offset, jchar contents)     { *char_field_addr(offset) = (jint) contents; }
   381 inline jint oopDesc::int_field(int offset) const                    { return *int_field_addr(offset);        }
   382 inline void oopDesc::int_field_put(int offset, jint contents)       { *int_field_addr(offset) = contents;    }
   384 inline jshort oopDesc::short_field(int offset) const                { return (jshort) *short_field_addr(offset);  }
   385 inline void oopDesc::short_field_put(int offset, jshort contents)   { *short_field_addr(offset) = (jint) contents;}
   387 inline jlong oopDesc::long_field(int offset) const                  { return *long_field_addr(offset);       }
   388 inline void oopDesc::long_field_put(int offset, jlong contents)     { *long_field_addr(offset) = contents;   }
   390 inline jfloat oopDesc::float_field(int offset) const                { return *float_field_addr(offset);      }
   391 inline void oopDesc::float_field_put(int offset, jfloat contents)   { *float_field_addr(offset) = contents;  }
   393 inline jdouble oopDesc::double_field(int offset) const              { return *double_field_addr(offset);     }
   394 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
   396 inline address oopDesc::address_field(int offset) const              { return *address_field_addr(offset);     }
   397 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
   399 inline oop oopDesc::obj_field_acquire(int offset) const {
   400   return UseCompressedOops ?
   401              decode_heap_oop((narrowOop)
   402                OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
   403            : decode_heap_oop((oop)
   404                OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
   405 }
   406 inline void oopDesc::release_obj_field_put(int offset, oop value) {
   407   UseCompressedOops ?
   408     oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
   409     oop_store((volatile oop*)      obj_field_addr<oop>(offset),       value);
   410 }
   412 inline jbyte oopDesc::byte_field_acquire(int offset) const                  { return OrderAccess::load_acquire(byte_field_addr(offset));     }
   413 inline void oopDesc::release_byte_field_put(int offset, jbyte contents)     { OrderAccess::release_store(byte_field_addr(offset), contents); }
   415 inline jboolean oopDesc::bool_field_acquire(int offset) const               { return OrderAccess::load_acquire(bool_field_addr(offset));     }
   416 inline void oopDesc::release_bool_field_put(int offset, jboolean contents)  { OrderAccess::release_store(bool_field_addr(offset), contents); }
   418 inline jchar oopDesc::char_field_acquire(int offset) const                  { return OrderAccess::load_acquire(char_field_addr(offset));     }
   419 inline void oopDesc::release_char_field_put(int offset, jchar contents)     { OrderAccess::release_store(char_field_addr(offset), contents); }
   421 inline jint oopDesc::int_field_acquire(int offset) const                    { return OrderAccess::load_acquire(int_field_addr(offset));      }
   422 inline void oopDesc::release_int_field_put(int offset, jint contents)       { OrderAccess::release_store(int_field_addr(offset), contents);  }
   424 inline jshort oopDesc::short_field_acquire(int offset) const                { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
   425 inline void oopDesc::release_short_field_put(int offset, jshort contents)   { OrderAccess::release_store(short_field_addr(offset), contents);     }
   427 inline jlong oopDesc::long_field_acquire(int offset) const                  { return OrderAccess::load_acquire(long_field_addr(offset));       }
   428 inline void oopDesc::release_long_field_put(int offset, jlong contents)     { OrderAccess::release_store(long_field_addr(offset), contents);   }
   430 inline jfloat oopDesc::float_field_acquire(int offset) const                { return OrderAccess::load_acquire(float_field_addr(offset));      }
   431 inline void oopDesc::release_float_field_put(int offset, jfloat contents)   { OrderAccess::release_store(float_field_addr(offset), contents);  }
   433 inline jdouble oopDesc::double_field_acquire(int offset) const              { return OrderAccess::load_acquire(double_field_addr(offset));     }
   434 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
   436 inline address oopDesc::address_field_acquire(int offset) const             { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
   437 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
   439 inline int oopDesc::size_given_klass(Klass* klass)  {
   440   int lh = klass->layout_helper();
   441   int s;
   443   // lh is now a value computed at class initialization that may hint
   444   // at the size.  For instances, this is positive and equal to the
   445   // size.  For arrays, this is negative and provides log2 of the
   446   // array element size.  For other oops, it is zero and thus requires
   447   // a virtual call.
   448   //
   449   // We go to all this trouble because the size computation is at the
   450   // heart of phase 2 of mark-compaction, and called for every object,
   451   // alive or dead.  So the speed here is equal in importance to the
   452   // speed of allocation.
   454   if (lh > Klass::_lh_neutral_value) {
   455     if (!Klass::layout_helper_needs_slow_path(lh)) {
   456       s = lh >> LogHeapWordSize;  // deliver size scaled by wordSize
   457     } else {
   458       s = klass->oop_size(this);
   459     }
   460   } else if (lh <= Klass::_lh_neutral_value) {
   461     // The most common case is instances; fall through if so.
   462     if (lh < Klass::_lh_neutral_value) {
   463       // Second most common case is arrays.  We have to fetch the
   464       // length of the array, shift (multiply) it appropriately,
   465       // up to wordSize, add the header, and align to object size.
   466       size_t size_in_bytes;
   467 #ifdef _M_IA64
   468       // The Windows Itanium Aug 2002 SDK hoists this load above
   469       // the check for s < 0.  An oop at the end of the heap will
   470       // cause an access violation if this load is performed on a non
   471       // array oop.  Making the reference volatile prohibits this.
   472       // (%%% please explain by what magic the length is actually fetched!)
   473       volatile int *array_length;
   474       array_length = (volatile int *)( (intptr_t)this +
   475                           arrayOopDesc::length_offset_in_bytes() );
   476       assert(array_length > 0, "Integer arithmetic problem somewhere");
   477       // Put into size_t to avoid overflow.
   478       size_in_bytes = (size_t) array_length;
   479       size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
   480 #else
   481       size_t array_length = (size_t) ((arrayOop)this)->length();
   482       size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
   483 #endif
   484       size_in_bytes += Klass::layout_helper_header_size(lh);
   486       // This code could be simplified, but by keeping array_header_in_bytes
   487       // in units of bytes and doing it this way we can round up just once,
   488       // skipping the intermediate round to HeapWordSize.  Cast the result
   489       // of round_to to size_t to guarantee unsigned division == right shift.
   490       s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
   491         HeapWordSize);
   493       // UseParNewGC, UseParallelGC and UseG1GC can change the length field
   494       // of an "old copy" of an object array in the young gen so it indicates
   495       // the grey portion of an already copied array. This will cause the first
   496       // disjunct below to fail if the two comparands are computed across such
   497       // a concurrent change.
   498       // UseParNewGC also runs with promotion labs (which look like int
   499       // filler arrays) which are subject to changing their declared size
   500       // when finally retiring a PLAB; this also can cause the first disjunct
   501       // to fail for another worker thread that is concurrently walking the block
   502       // offset table. Both these invariant failures are benign for their
   503       // current uses; we relax the assertion checking to cover these two cases below:
   504       //     is_objArray() && is_forwarded()   // covers first scenario above
   505       //  || is_typeArray()                    // covers second scenario above
   506       // If and when UseParallelGC uses the same obj array oop stealing/chunking
   507       // technique, we will need to suitably modify the assertion.
   508       assert((s == klass->oop_size(this)) ||
   509              (Universe::heap()->is_gc_active() &&
   510               ((is_typeArray() && UseParNewGC) ||
   511                (is_objArray()  && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
   512              "wrong array object size");
   513     } else {
   514       // Must be zero, so bite the bullet and take the virtual call.
   515       s = klass->oop_size(this);
   516     }
   517   }
   519   assert(s % MinObjAlignment == 0, "alignment check");
   520   assert(s > 0, "Bad size calculated");
   521   return s;
   522 }
   525 inline int oopDesc::size()  {
   526   return size_given_klass(klass());
   527 }
   529 inline void update_barrier_set(void* p, oop v) {
   530   assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
   531   oopDesc::bs()->write_ref_field(p, v);
   532 }
   534 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
   535   oopDesc::bs()->write_ref_field_pre(p, v);
   536 }
   538 template <class T> inline void oop_store(T* p, oop v) {
   539   if (always_do_update_barrier) {
   540     oop_store((volatile T*)p, v);
   541   } else {
   542     update_barrier_set_pre(p, v);
   543     oopDesc::encode_store_heap_oop(p, v);
   544     update_barrier_set((void*)p, v);  // cast away type
   545   }
   546 }
   548 template <class T> inline void oop_store(volatile T* p, oop v) {
   549   update_barrier_set_pre((T*)p, v);   // cast away volatile
   550   // Used by release_obj_field_put, so use release_store_ptr.
   551   oopDesc::release_encode_store_heap_oop(p, v);
   552   update_barrier_set((void*)p, v);    // cast away type
   553 }
   555 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
   556 // (without having to remember the function name this calls).
   557 inline void oop_store_raw(HeapWord* addr, oop value) {
   558   if (UseCompressedOops) {
   559     oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
   560   } else {
   561     oopDesc::encode_store_heap_oop((oop*)addr, value);
   562   }
   563 }
   565 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
   566                                                 volatile HeapWord *dest,
   567                                                 oop compare_value,
   568                                                 bool prebarrier) {
   569   if (UseCompressedOops) {
   570     if (prebarrier) {
   571       update_barrier_set_pre((narrowOop*)dest, exchange_value);
   572     }
   573     // encode exchange and compare value from oop to T
   574     narrowOop val = encode_heap_oop(exchange_value);
   575     narrowOop cmp = encode_heap_oop(compare_value);
   577     narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
   578     // decode old from T to oop
   579     return decode_heap_oop(old);
   580   } else {
   581     if (prebarrier) {
   582       update_barrier_set_pre((oop*)dest, exchange_value);
   583     }
   584     return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
   585   }
   586 }
   588 // Used only for markSweep, scavenging
   589 inline bool oopDesc::is_gc_marked() const {
   590   return mark()->is_marked();
   591 }
   593 inline bool oopDesc::is_locked() const {
   594   return mark()->is_locked();
   595 }
   597 inline bool oopDesc::is_unlocked() const {
   598   return mark()->is_unlocked();
   599 }
   601 inline bool oopDesc::has_bias_pattern() const {
   602   return mark()->has_bias_pattern();
   603 }
   606 // used only for asserts
   607 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
   608   oop obj = (oop) this;
   609   if (!check_obj_alignment(obj)) return false;
   610   if (!Universe::heap()->is_in_reserved(obj)) return false;
   611   // obj is aligned and accessible in heap
   612   if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
   614   // Header verification: the mark is typically non-NULL. If we're
   615   // at a safepoint, it must not be null.
   616   // Outside of a safepoint, the header could be changing (for example,
   617   // another thread could be inflating a lock on this object).
   618   if (ignore_mark_word) {
   619     return true;
   620   }
   621   if (mark() != NULL) {
   622     return true;
   623   }
   624   return !SafepointSynchronize::is_at_safepoint();
   625 }
   628 // used only for asserts
   629 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
   630   return this == NULL ? true : is_oop(ignore_mark_word);
   631 }
   633 #ifndef PRODUCT
   634 // used only for asserts
   635 inline bool oopDesc::is_unlocked_oop() const {
   636   if (!Universe::heap()->is_in_reserved(this)) return false;
   637   return mark()->is_unlocked();
   638 }
   639 #endif // PRODUCT
   641 inline void oopDesc::follow_contents(void) {
   642   assert (is_gc_marked(), "should be marked");
   643   klass()->oop_follow_contents(this);
   644 }
   646 // Used by scavengers
   648 inline bool oopDesc::is_forwarded() const {
   649   // The extra heap check is needed since the obj might be locked, in which case the
   650   // mark would point to a stack location and have the sentinel bit cleared
   651   return mark()->is_marked();
   652 }
   654 // Used by scavengers
   655 inline void oopDesc::forward_to(oop p) {
   656   assert(check_obj_alignment(p),
   657          "forwarding to something not aligned");
   658   assert(Universe::heap()->is_in_reserved(p),
   659          "forwarding to something not in heap");
   660   markOop m = markOopDesc::encode_pointer_as_mark(p);
   661   assert(m->decode_pointer() == p, "encoding must be reversable");
   662   set_mark(m);
   663 }
   665 // Used by parallel scavengers
   666 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
   667   assert(check_obj_alignment(p),
   668          "forwarding to something not aligned");
   669   assert(Universe::heap()->is_in_reserved(p),
   670          "forwarding to something not in heap");
   671   markOop m = markOopDesc::encode_pointer_as_mark(p);
   672   assert(m->decode_pointer() == p, "encoding must be reversable");
   673   return cas_set_mark(m, compare) == compare;
   674 }
   676 // Note that the forwardee is not the same thing as the displaced_mark.
   677 // The forwardee is used when copying during scavenge and mark-sweep.
   678 // It does need to clear the low two locking- and GC-related bits.
   679 inline oop oopDesc::forwardee() const {
   680   return (oop) mark()->decode_pointer();
   681 }
   683 inline bool oopDesc::has_displaced_mark() const {
   684   return mark()->has_displaced_mark_helper();
   685 }
   687 inline markOop oopDesc::displaced_mark() const {
   688   return mark()->displaced_mark_helper();
   689 }
   691 inline void oopDesc::set_displaced_mark(markOop m) {
   692   mark()->set_displaced_mark_helper(m);
   693 }
   695 // The following method needs to be MT safe.
   696 inline uint oopDesc::age() const {
   697   assert(!is_forwarded(), "Attempt to read age from forwarded mark");
   698   if (has_displaced_mark()) {
   699     return displaced_mark()->age();
   700   } else {
   701     return mark()->age();
   702   }
   703 }
   705 inline void oopDesc::incr_age() {
   706   assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
   707   if (has_displaced_mark()) {
   708     set_displaced_mark(displaced_mark()->incr_age());
   709   } else {
   710     set_mark(mark()->incr_age());
   711   }
   712 }
   715 inline intptr_t oopDesc::identity_hash() {
   716   // Fast case; if the object is unlocked and the hash value is set, no locking is needed
   717   // Note: The mark must be read into local variable to avoid concurrent updates.
   718   markOop mrk = mark();
   719   if (mrk->is_unlocked() && !mrk->has_no_hash()) {
   720     return mrk->hash();
   721   } else if (mrk->is_marked()) {
   722     return mrk->hash();
   723   } else {
   724     return slow_identity_hash();
   725   }
   726 }
   728 inline int oopDesc::adjust_pointers() {
   729   debug_only(int check_size = size());
   730   int s = klass()->oop_adjust_pointers(this);
   731   assert(s == check_size, "should be the same");
   732   return s;
   733 }
   735 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix)                        \
   736                                                                            \
   737 inline int oopDesc::oop_iterate(OopClosureType* blk) {                     \
   738   SpecializationStats::record_call();                                      \
   739   return klass()->oop_oop_iterate##nv_suffix(this, blk);               \
   740 }                                                                          \
   741                                                                            \
   742 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) {       \
   743   SpecializationStats::record_call();                                      \
   744   return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr);       \
   745 }
   748 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
   749   // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
   750   // the do_oop calls, but turns off all other features in ExtendedOopClosure.
   751   NoHeaderExtendedOopClosure cl(blk);
   752   return oop_iterate(&cl);
   753 }
   755 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
   756   NoHeaderExtendedOopClosure cl(blk);
   757   return oop_iterate(&cl, mr);
   758 }
   760 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
   761 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
   763 #ifndef SERIALGC
   764 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)              \
   765                                                                            \
   766 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) {           \
   767   SpecializationStats::record_call();                                      \
   768   return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk);     \
   769 }
   771 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
   772 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
   773 #endif // !SERIALGC
   775 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP

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