Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 // Implementation of all inlined member functions defined in oop.hpp

 // We need a separate file to avoid circular references

 inline void oopDesc::release_set_mark(markOop m) {

   OrderAccess::release_store_ptr(&_mark, m);

 }

 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {

   return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);

 }

 inline klassOop oopDesc::klass() const {

   if (UseCompressedOops) {

     return (klassOop)decode_heap_oop_not_null(_metadata._compressed_klass);

   } else {

     return _metadata._klass;

   }

 }

 inline klassOop oopDesc::klass_or_null() const volatile {

   // can be NULL in CMS

   if (UseCompressedOops) {

     return (klassOop)decode_heap_oop(_metadata._compressed_klass);

   } else {

     return _metadata._klass;

   }

 }

 inline int oopDesc::klass_gap_offset_in_bytes() {

   assert(UseCompressedOops, "only applicable to compressed headers");

   return oopDesc::klass_offset_in_bytes() + sizeof(narrowOop);

 }

 inline oop* oopDesc::klass_addr() {

   // Only used internally and with CMS and will not work with

   // UseCompressedOops

   assert(!UseCompressedOops, "only supported with uncompressed oops");

   return (oop*) &_metadata._klass;

 }

 inline narrowOop* oopDesc::compressed_klass_addr() {

   assert(UseCompressedOops, "only called by compressed oops");

   return (narrowOop*) &_metadata._compressed_klass;

 }

 inline void oopDesc::set_klass(klassOop k) {

   // since klasses are promoted no store check is needed

   assert(Universe::is_bootstrapping() || k != NULL, "must be a real klassOop");

   assert(Universe::is_bootstrapping() || k->is_klass(), "not a klassOop");

   if (UseCompressedOops) {

     oop_store_without_check(compressed_klass_addr(), (oop)k);

   } else {

     oop_store_without_check(klass_addr(), (oop) k);

   }

 }

 inline int oopDesc::klass_gap() const {

   return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());

 }

 inline void oopDesc::set_klass_gap(int v) {

   if (UseCompressedOops) {

     *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;

   }

 }

 inline void oopDesc::set_klass_to_list_ptr(oop k) {

   // This is only to be used during GC, for from-space objects, so no

   // barrier is needed.

   if (UseCompressedOops) {

     _metadata._compressed_klass = encode_heap_oop(k);  // may be null (parnew overflow handling)

   } else {

     _metadata._klass = (klassOop)k;

   }

 }

 inline void   oopDesc::init_mark()                 { set_mark(markOopDesc::prototype_for_object(this)); }

 inline Klass* oopDesc::blueprint()           const { return klass()->klass_part(); }

 inline bool oopDesc::is_a(klassOop k)        const { return blueprint()->is_subtype_of(k); }

 inline bool oopDesc::is_instance()           const { return blueprint()->oop_is_instance(); }

 inline bool oopDesc::is_instanceRef()        const { return blueprint()->oop_is_instanceRef(); }

 inline bool oopDesc::is_array()              const { return blueprint()->oop_is_array(); }

 inline bool oopDesc::is_objArray()           const { return blueprint()->oop_is_objArray(); }

 inline bool oopDesc::is_typeArray()          const { return blueprint()->oop_is_typeArray(); }

 inline bool oopDesc::is_javaArray()          const { return blueprint()->oop_is_javaArray(); }

 inline bool oopDesc::is_symbol()             const { return blueprint()->oop_is_symbol(); }

 inline bool oopDesc::is_klass()              const { return blueprint()->oop_is_klass(); }

 inline bool oopDesc::is_thread()             const { return blueprint()->oop_is_thread(); }

 inline bool oopDesc::is_method()             const { return blueprint()->oop_is_method(); }

 inline bool oopDesc::is_constMethod()        const { return blueprint()->oop_is_constMethod(); }

 inline bool oopDesc::is_methodData()         const { return blueprint()->oop_is_methodData(); }

 inline bool oopDesc::is_constantPool()       const { return blueprint()->oop_is_constantPool(); }

 inline bool oopDesc::is_constantPoolCache()  const { return blueprint()->oop_is_constantPoolCache(); }

 inline bool oopDesc::is_compiledICHolder()   const { return blueprint()->oop_is_compiledICHolder(); }

 inline void*     oopDesc::field_base(int offset)        const { return (void*)&((char*)this)[offset]; }

 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }

 inline jbyte*    oopDesc::byte_field_addr(int offset)   const { return (jbyte*)   field_base(offset); }

 inline jchar*    oopDesc::char_field_addr(int offset)   const { return (jchar*)   field_base(offset); }

 inline jboolean* oopDesc::bool_field_addr(int offset)   const { return (jboolean*)field_base(offset); }

 inline jint*     oopDesc::int_field_addr(int offset)    const { return (jint*)    field_base(offset); }

 inline jshort*   oopDesc::short_field_addr(int offset)  const { return (jshort*)  field_base(offset); }

 inline jlong*    oopDesc::long_field_addr(int offset)   const { return (jlong*)   field_base(offset); }

 inline jfloat*   oopDesc::float_field_addr(int offset)  const { return (jfloat*)  field_base(offset); }

 inline jdouble*  oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }

 inline address*  oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }

 // Functions for getting and setting oops within instance objects.

 // If the oops are compressed, the type passed to these overloaded functions

 // is narrowOop.  All functions are overloaded so they can be called by

 // template functions without conditionals (the compiler instantiates via

 // the right type and inlines the appopriate code).

 inline bool oopDesc::is_null(oop obj)       { return obj == NULL; }

 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; }

 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit

 // offset from the heap base.  Saving the check for null can save instructions

 // in inner GC loops so these are separated.

 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {

   assert(!is_null(v), "oop value can never be zero");

   address base = Universe::narrow_oop_base();

   int    shift = Universe::narrow_oop_shift();

   uint64_t  pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));

   assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");

   uint64_t result = pd >> shift;

   assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");

   return (narrowOop)result;

 }

 inline narrowOop oopDesc::encode_heap_oop(oop v) {

   return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);

 }

 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {

   assert(!is_null(v), "narrow oop value can never be zero");

   address base = Universe::narrow_oop_base();

   int    shift = Universe::narrow_oop_shift();

   return (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));

 }

 inline oop oopDesc::decode_heap_oop(narrowOop v) {

   return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);

 }

 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }

 inline oop oopDesc::decode_heap_oop(oop v)  { return v; }

 // Load an oop out of the Java heap as is without decoding.

 // Called by GC to check for null before decoding.

 inline oop       oopDesc::load_heap_oop(oop* p)          { return *p; }

 inline narrowOop oopDesc::load_heap_oop(narrowOop* p)    { return *p; }

 // Load and decode an oop out of the Java heap into a wide oop.

 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p)       { return *p; }

 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {

   return decode_heap_oop_not_null(*p);

 }

 // Load and decode an oop out of the heap accepting null

 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }

 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {

   return decode_heap_oop(*p);

 }

 // Store already encoded heap oop into the heap.

 inline void oopDesc::store_heap_oop(oop* p, oop v)                 { *p = v; }

 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v)     { *p = v; }

 // Encode and store a heap oop.

 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {

   *p = encode_heap_oop_not_null(v);

 }

 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }

 // Encode and store a heap oop allowing for null.

 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {

   *p = encode_heap_oop(v);

 }

 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }

 // Store heap oop as is for volatile fields.

 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {

   OrderAccess::release_store_ptr(p, v);

 }

 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,

                                             narrowOop v) {

   OrderAccess::release_store(p, v);

 }

 inline void oopDesc::release_encode_store_heap_oop_not_null(

                                                 volatile narrowOop* p, oop v) {

   // heap oop is not pointer sized.

   OrderAccess::release_store(p, encode_heap_oop_not_null(v));

 }

 inline void oopDesc::release_encode_store_heap_oop_not_null(

                                                       volatile oop* p, oop v) {

   OrderAccess::release_store_ptr(p, v);

 }

 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,

                                                            oop v) {

   OrderAccess::release_store_ptr(p, v);

 }

 inline void oopDesc::release_encode_store_heap_oop(

                                                 volatile narrowOop* p, oop v) {

   OrderAccess::release_store(p, encode_heap_oop(v));

 }

 // These functions are only used to exchange oop fields in instances,

 // not headers.

 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {

   if (UseCompressedOops) {

     // encode exchange value from oop to T

     narrowOop val = encode_heap_oop(exchange_value);

     narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);

     // decode old from T to oop

     return decode_heap_oop(old);

   } else {

     return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);

   }

 }

 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,

                                                 volatile HeapWord *dest,

                                                 oop compare_value) {

   if (UseCompressedOops) {

     // encode exchange and compare value from oop to T

     narrowOop val = encode_heap_oop(exchange_value);

     narrowOop cmp = encode_heap_oop(compare_value);

     narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);

     // decode old from T to oop

     return decode_heap_oop(old);

   } else {

     return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);

   }

 }

 // In order to put or get a field out of an instance, must first check

 // if the field has been compressed and uncompress it.

 inline oop oopDesc::obj_field(int offset) const {

   return UseCompressedOops ?

     load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :

     load_decode_heap_oop(obj_field_addr<oop>(offset));

 }

 inline void oopDesc::obj_field_put(int offset, oop value) {

   UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :

                       oop_store(obj_field_addr<oop>(offset),       value);

 }

 inline void oopDesc::obj_field_raw_put(int offset, oop value) {

   UseCompressedOops ?

     encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :

     encode_store_heap_oop(obj_field_addr<oop>(offset),       value);

 }

 inline jbyte oopDesc::byte_field(int offset) const                  { return (jbyte) *byte_field_addr(offset);    }

 inline void oopDesc::byte_field_put(int offset, jbyte contents)     { *byte_field_addr(offset) = (jint) contents; }

 inline jboolean oopDesc::bool_field(int offset) const               { return (jboolean) *bool_field_addr(offset); }

 inline void oopDesc::bool_field_put(int offset, jboolean contents)  { *bool_field_addr(offset) = (jint) contents; }

 inline jchar oopDesc::char_field(int offset) const                  { return (jchar) *char_field_addr(offset);    }

 inline void oopDesc::char_field_put(int offset, jchar contents)     { *char_field_addr(offset) = (jint) contents; }

 inline jint oopDesc::int_field(int offset) const                    { return *int_field_addr(offset);        }

 inline void oopDesc::int_field_put(int offset, jint contents)       { *int_field_addr(offset) = contents;    }

 inline jshort oopDesc::short_field(int offset) const                { return (jshort) *short_field_addr(offset);  }

 inline void oopDesc::short_field_put(int offset, jshort contents)   { *short_field_addr(offset) = (jint) contents;}

 inline jlong oopDesc::long_field(int offset) const                  { return *long_field_addr(offset);       }

 inline void oopDesc::long_field_put(int offset, jlong contents)     { *long_field_addr(offset) = contents;   }

 inline jfloat oopDesc::float_field(int offset) const                { return *float_field_addr(offset);      }

 inline void oopDesc::float_field_put(int offset, jfloat contents)   { *float_field_addr(offset) = contents;  }

 inline jdouble oopDesc::double_field(int offset) const              { return *double_field_addr(offset);     }

 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }

 inline address oopDesc::address_field(int offset) const              { return *address_field_addr(offset);     }

 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }

 inline oop oopDesc::obj_field_acquire(int offset) const {

   return UseCompressedOops ?

              decode_heap_oop((narrowOop)

                OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))

            : decode_heap_oop((oop)

                OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));

 }

 inline void oopDesc::release_obj_field_put(int offset, oop value) {

   UseCompressedOops ?

     oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :

     oop_store((volatile oop*)      obj_field_addr<oop>(offset),       value);

 }

 inline jbyte oopDesc::byte_field_acquire(int offset) const                  { return OrderAccess::load_acquire(byte_field_addr(offset));     }

 inline void oopDesc::release_byte_field_put(int offset, jbyte contents)     { OrderAccess::release_store(byte_field_addr(offset), contents); }

 inline jboolean oopDesc::bool_field_acquire(int offset) const               { return OrderAccess::load_acquire(bool_field_addr(offset));     }

 inline void oopDesc::release_bool_field_put(int offset, jboolean contents)  { OrderAccess::release_store(bool_field_addr(offset), contents); }

 inline jchar oopDesc::char_field_acquire(int offset) const                  { return OrderAccess::load_acquire(char_field_addr(offset));     }

 inline void oopDesc::release_char_field_put(int offset, jchar contents)     { OrderAccess::release_store(char_field_addr(offset), contents); }

 inline jint oopDesc::int_field_acquire(int offset) const                    { return OrderAccess::load_acquire(int_field_addr(offset));      }

 inline void oopDesc::release_int_field_put(int offset, jint contents)       { OrderAccess::release_store(int_field_addr(offset), contents);  }

 inline jshort oopDesc::short_field_acquire(int offset) const                { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }

 inline void oopDesc::release_short_field_put(int offset, jshort contents)   { OrderAccess::release_store(short_field_addr(offset), contents);     }

 inline jlong oopDesc::long_field_acquire(int offset) const                  { return OrderAccess::load_acquire(long_field_addr(offset));       }

 inline void oopDesc::release_long_field_put(int offset, jlong contents)     { OrderAccess::release_store(long_field_addr(offset), contents);   }

 inline jfloat oopDesc::float_field_acquire(int offset) const                { return OrderAccess::load_acquire(float_field_addr(offset));      }

 inline void oopDesc::release_float_field_put(int offset, jfloat contents)   { OrderAccess::release_store(float_field_addr(offset), contents);  }

 inline jdouble oopDesc::double_field_acquire(int offset) const              { return OrderAccess::load_acquire(double_field_addr(offset));     }

 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }

 inline int oopDesc::size_given_klass(Klass* klass)  {

   int lh = klass->layout_helper();

   int s  = lh >> LogHeapWordSize;  // deliver size scaled by wordSize

   // lh is now a value computed at class initialization that may hint

   // at the size.  For instances, this is positive and equal to the

   // size.  For arrays, this is negative and provides log2 of the

   // array element size.  For other oops, it is zero and thus requires

   // a virtual call.

   //

   // We go to all this trouble because the size computation is at the

   // heart of phase 2 of mark-compaction, and called for every object,

   // alive or dead.  So the speed here is equal in importance to the

   // speed of allocation.

   if (lh <= Klass::_lh_neutral_value) {

     // The most common case is instances; fall through if so.

     if (lh < Klass::_lh_neutral_value) {

       // Second most common case is arrays.  We have to fetch the

       // length of the array, shift (multiply) it appropriately,

       // up to wordSize, add the header, and align to object size.

       size_t size_in_bytes;

 #ifdef _M_IA64

       // The Windows Itanium Aug 2002 SDK hoists this load above

       // the check for s < 0.  An oop at the end of the heap will

       // cause an access violation if this load is performed on a non

       // array oop.  Making the reference volatile prohibits this.

       // (%%% please explain by what magic the length is actually fetched!)

       volatile int *array_length;

       array_length = (volatile int *)( (intptr_t)this +

                           arrayOopDesc::length_offset_in_bytes() );

       assert(array_length > 0, "Integer arithmetic problem somewhere");

       // Put into size_t to avoid overflow.

       size_in_bytes = (size_t) array_length;

       size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);

 #else

       size_t array_length = (size_t) ((arrayOop)this)->length();

       size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);

 #endif

       size_in_bytes += Klass::layout_helper_header_size(lh);

       // This code could be simplified, but by keeping array_header_in_bytes

       // in units of bytes and doing it this way we can round up just once,

       // skipping the intermediate round to HeapWordSize.  Cast the result

       // of round_to to size_t to guarantee unsigned division == right shift.

       s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /

         HeapWordSize);

       // UseParNewGC, UseParallelGC and UseG1GC can change the length field

       // of an "old copy" of an object array in the young gen so it indicates

       // the grey portion of an already copied array. This will cause the first

       // disjunct below to fail if the two comparands are computed across such

       // a concurrent change.

       // UseParNewGC also runs with promotion labs (which look like int

       // filler arrays) which are subject to changing their declared size

       // when finally retiring a PLAB; this also can cause the first disjunct

       // to fail for another worker thread that is concurrently walking the block

       // offset table. Both these invariant failures are benign for their

       // current uses; we relax the assertion checking to cover these two cases below:

       //     is_objArray() && is_forwarded()   // covers first scenario above

       //  || is_typeArray()                    // covers second scenario above

       // If and when UseParallelGC uses the same obj array oop stealing/chunking

       // technique, we will need to suitably modify the assertion.

       assert((s == klass->oop_size(this)) ||

              (Universe::heap()->is_gc_active() &&

               ((is_typeArray() && UseParNewGC) ||

                (is_objArray()  && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),

              "wrong array object size");

     } else {

       // Must be zero, so bite the bullet and take the virtual call.

       s = klass->oop_size(this);

     }

   }

   assert(s % MinObjAlignment == 0, "alignment check");

   assert(s > 0, "Bad size calculated");

   return s;

 }

 inline int oopDesc::size()  {

   return size_given_klass(blueprint());

 }

 inline bool oopDesc::is_parsable() {

   return blueprint()->oop_is_parsable(this);

 }

 inline bool oopDesc::is_conc_safe() {

   return blueprint()->oop_is_conc_safe(this);

 }

 inline void update_barrier_set(void* p, oop v) {

   assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");

   oopDesc::bs()->write_ref_field(p, v);

 }

 inline void update_barrier_set_pre(void* p, oop v) {

   oopDesc::bs()->write_ref_field_pre(p, v);

 }

 template <class T> inline void oop_store(T* p, oop v) {

   if (always_do_update_barrier) {

     oop_store((volatile T*)p, v);

   } else {

     update_barrier_set_pre(p, v);

     oopDesc::encode_store_heap_oop(p, v);

     update_barrier_set(p, v);

   }

 }

 template <class T> inline void oop_store(volatile T* p, oop v) {

   update_barrier_set_pre((void*)p, v);

   // Used by release_obj_field_put, so use release_store_ptr.

   oopDesc::release_encode_store_heap_oop(p, v);

   update_barrier_set((void*)p, v);

 }

 template <class T> inline void oop_store_without_check(T* p, oop v) {

   // XXX YSR FIX ME!!!

   if (always_do_update_barrier) {

     oop_store(p, v);

   } else {

     assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier(p, v),

            "oop store without store check failed");

     oopDesc::encode_store_heap_oop(p, v);

   }

 }

 // When it absolutely has to get there.

 template <class T> inline void oop_store_without_check(volatile T* p, oop v) {

   // XXX YSR FIX ME!!!

   if (always_do_update_barrier) {

     oop_store(p, v);

   } else {

     assert(!Universe::heap()->barrier_set()->write_ref_needs_barrier((T*)p, v),

            "oop store without store check failed");

     oopDesc::release_encode_store_heap_oop(p, v);

   }

 }

 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops

 // (without having to remember the function name this calls).

 inline void oop_store_raw(HeapWord* addr, oop value) {

   if (UseCompressedOops) {

     oopDesc::encode_store_heap_oop((narrowOop*)addr, value);

   } else {

     oopDesc::encode_store_heap_oop((oop*)addr, value);

   }

 }

 // Used only for markSweep, scavenging

 inline bool oopDesc::is_gc_marked() const {

   return mark()->is_marked();

 }

 inline bool oopDesc::is_locked() const {

   return mark()->is_locked();

 }

 inline bool oopDesc::is_unlocked() const {

   return mark()->is_unlocked();

 }

 inline bool oopDesc::has_bias_pattern() const {

   return mark()->has_bias_pattern();

 }

 inline bool check_obj_alignment(oop obj) {

   return (intptr_t)obj % MinObjAlignmentInBytes == 0;

 }

 // used only for asserts

 inline bool oopDesc::is_oop(bool ignore_mark_word) const {

   oop obj = (oop) this;

   if (!check_obj_alignment(obj)) return false;

   if (!Universe::heap()->is_in_reserved(obj)) return false;

   // obj is aligned and accessible in heap

   // try to find metaclass cycle safely without seg faulting on bad input

   // we should reach klassKlassObj by following klass link at most 3 times

   for (int i = 0; i < 3; i++) {

     obj = obj->klass_or_null();

     // klass should be aligned and in permspace

     if (!check_obj_alignment(obj)) return false;

     if (!Universe::heap()->is_in_permanent(obj)) return false;

   }

   if (obj != Universe::klassKlassObj()) {

     // During a dump, the _klassKlassObj moved to a shared space.

     if (DumpSharedSpaces && Universe::klassKlassObj()->is_shared()) {

       return true;

     }

     return false;

   }

   // Header verification: the mark is typically non-NULL. If we're

   // at a safepoint, it must not be null.

   // Outside of a safepoint, the header could be changing (for example,

   // another thread could be inflating a lock on this object).

   if (ignore_mark_word) {

     return true;

   }

   if (mark() != NULL) {

     return true;

   }

   return !SafepointSynchronize::is_at_safepoint();

 }

 // used only for asserts

 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {

   return this == NULL ? true : is_oop(ignore_mark_word);

 }

 #ifndef PRODUCT

 // used only for asserts

 inline bool oopDesc::is_unlocked_oop() const {

   if (!Universe::heap()->is_in_reserved(this)) return false;

   return mark()->is_unlocked();

 }

 #endif // PRODUCT

 inline void oopDesc::follow_header() {

   if (UseCompressedOops) {

     MarkSweep::mark_and_push(compressed_klass_addr());

   } else {

     MarkSweep::mark_and_push(klass_addr());

   }

 }

 inline void oopDesc::follow_contents(void) {

   assert (is_gc_marked(), "should be marked");

   blueprint()->oop_follow_contents(this);

 }

 // Used by scavengers

 inline bool oopDesc::is_forwarded() const {

   // The extra heap check is needed since the obj might be locked, in which case the

   // mark would point to a stack location and have the sentinel bit cleared

   return mark()->is_marked();

 }

 // Used by scavengers

 inline void oopDesc::forward_to(oop p) {

   assert(Universe::heap()->is_in_reserved(p),

          "forwarding to something not in heap");

   markOop m = markOopDesc::encode_pointer_as_mark(p);

   assert(m->decode_pointer() == p, "encoding must be reversable");

   set_mark(m);

 }

 // Used by parallel scavengers

 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {

   assert(Universe::heap()->is_in_reserved(p),

          "forwarding to something not in heap");

   markOop m = markOopDesc::encode_pointer_as_mark(p);

   assert(m->decode_pointer() == p, "encoding must be reversable");

   return cas_set_mark(m, compare) == compare;

 }

 // Note that the forwardee is not the same thing as the displaced_mark.

 // The forwardee is used when copying during scavenge and mark-sweep.

 // It does need to clear the low two locking- and GC-related bits.

 inline oop oopDesc::forwardee() const {

   return (oop) mark()->decode_pointer();

 }

 inline bool oopDesc::has_displaced_mark() const {

   return mark()->has_displaced_mark_helper();

 }

 inline markOop oopDesc::displaced_mark() const {

   return mark()->displaced_mark_helper();

 }

 inline void oopDesc::set_displaced_mark(markOop m) {

   mark()->set_displaced_mark_helper(m);

 }

 // The following method needs to be MT safe.

 inline int oopDesc::age() const {

   assert(!is_forwarded(), "Attempt to read age from forwarded mark");

   if (has_displaced_mark()) {

     return displaced_mark()->age();

   } else {

     return mark()->age();

   }

 }

 inline void oopDesc::incr_age() {

   assert(!is_forwarded(), "Attempt to increment age of forwarded mark");

   if (has_displaced_mark()) {

     set_displaced_mark(displaced_mark()->incr_age());

   } else {

     set_mark(mark()->incr_age());

   }

 }

 inline intptr_t oopDesc::identity_hash() {

   // Fast case; if the object is unlocked and the hash value is set, no locking is needed

   // Note: The mark must be read into local variable to avoid concurrent updates.

   markOop mrk = mark();

   if (mrk->is_unlocked() && !mrk->has_no_hash()) {

     return mrk->hash();

   } else if (mrk->is_marked()) {

     return mrk->hash();

   } else {

     return slow_identity_hash();

   }

 }

 inline void oopDesc::oop_iterate_header(OopClosure* blk) {

   if (UseCompressedOops) {

     blk->do_oop(compressed_klass_addr());

   } else {

     blk->do_oop(klass_addr());

   }

 }

 inline void oopDesc::oop_iterate_header(OopClosure* blk, MemRegion mr) {

   if (UseCompressedOops) {

     if (mr.contains(compressed_klass_addr())) {

       blk->do_oop(compressed_klass_addr());

     }

   } else {

     if (mr.contains(klass_addr())) blk->do_oop(klass_addr());

   }

 }

 inline int oopDesc::adjust_pointers() {

   debug_only(int check_size = size());

   int s = blueprint()->oop_adjust_pointers(this);

   assert(s == check_size, "should be the same");

   return s;

 }

 inline void oopDesc::adjust_header() {

   if (UseCompressedOops) {

     MarkSweep::adjust_pointer(compressed_klass_addr());

   } else {

     MarkSweep::adjust_pointer(klass_addr());

   }

 }

 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix)                        \

                                                                            \

 inline int oopDesc::oop_iterate(OopClosureType* blk) {                     \

   SpecializationStats::record_call();                                      \

   return blueprint()->oop_oop_iterate##nv_suffix(this, blk);               \

 }                                                                          \

                                                                            \

 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) {       \

   SpecializationStats::record_call();                                      \

   return blueprint()->oop_oop_iterate##nv_suffix##_m(this, blk, mr);       \

 }

 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)

 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)

 #ifndef SERIALGC

 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)              \

                                                                            \

 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) {           \

   SpecializationStats::record_call();                                      \

   return blueprint()->oop_oop_iterate_backwards##nv_suffix(this, blk);     \

 }

 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)

 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)

 #endif // !SERIALGC

 inline bool oopDesc::is_shared() const {

   return CompactingPermGenGen::is_shared(this);

 }

 inline bool oopDesc::is_shared_readonly() const {

   return CompactingPermGenGen::is_shared_readonly(this);

 }

 inline bool oopDesc::is_shared_readwrite() const {

   return CompactingPermGenGen::is_shared_readwrite(this);

 }