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

Mon, 02 Dec 2013 10:26:14 +0100

author
goetz
date
Mon, 02 Dec 2013 10:26:14 +0100
changeset 6493
3205e78d8193
parent 5784
190899198332
child 6680
78bbf4d43a14
permissions
-rw-r--r--

8029396: PPC64 (part 212): Several memory ordering fixes in C-code.
Summary: memory ordering fixes in GC and other runtime code showing on PPC64.
Reviewed-by: kvn, coleenp

     1 /*
     2  * Copyright (c) 1997, 2013, 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.inline.hpp"
    39 #include "oops/markOop.inline.hpp"
    40 #include "oops/oop.hpp"
    41 #include "runtime/atomic.hpp"
    42 #include "runtime/os.hpp"
    43 #include "utilities/macros.hpp"
    44 #ifdef TARGET_ARCH_x86
    45 # include "bytes_x86.hpp"
    46 #endif
    47 #ifdef TARGET_ARCH_sparc
    48 # include "bytes_sparc.hpp"
    49 #endif
    50 #ifdef TARGET_ARCH_zero
    51 # include "bytes_zero.hpp"
    52 #endif
    53 #ifdef TARGET_ARCH_arm
    54 # include "bytes_arm.hpp"
    55 #endif
    56 #ifdef TARGET_ARCH_ppc
    57 # include "bytes_ppc.hpp"
    58 #endif
    60 // Implementation of all inlined member functions defined in oop.hpp
    61 // We need a separate file to avoid circular references
    63 inline void oopDesc::release_set_mark(markOop m) {
    64   OrderAccess::release_store_ptr(&_mark, m);
    65 }
    67 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
    68   return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark);
    69 }
    71 inline Klass* oopDesc::klass() const {
    72   if (UseCompressedClassPointers) {
    73     return Klass::decode_klass_not_null(_metadata._compressed_klass);
    74   } else {
    75     return _metadata._klass;
    76   }
    77 }
    79 inline Klass* oopDesc::klass_or_null() const volatile {
    80   // can be NULL in CMS
    81   if (UseCompressedClassPointers) {
    82     return Klass::decode_klass(_metadata._compressed_klass);
    83   } else {
    84     return _metadata._klass;
    85   }
    86 }
    88 inline int oopDesc::klass_gap_offset_in_bytes() {
    89   assert(UseCompressedClassPointers, "only applicable to compressed klass pointers");
    90   return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass);
    91 }
    93 inline Klass** oopDesc::klass_addr() {
    94   // Only used internally and with CMS and will not work with
    95   // UseCompressedOops
    96   assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
    97   return (Klass**) &_metadata._klass;
    98 }
   100 inline narrowKlass* oopDesc::compressed_klass_addr() {
   101   assert(UseCompressedClassPointers, "only called by compressed klass pointers");
   102   return &_metadata._compressed_klass;
   103 }
   105 inline void oopDesc::set_klass(Klass* k) {
   106   // since klasses are promoted no store check is needed
   107   assert(Universe::is_bootstrapping() || k != NULL, "must be a real Klass*");
   108   assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass*");
   109   if (UseCompressedClassPointers) {
   110     *compressed_klass_addr() = Klass::encode_klass_not_null(k);
   111   } else {
   112     *klass_addr() = k;
   113   }
   114 }
   116 inline int oopDesc::klass_gap() const {
   117   return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
   118 }
   120 inline void oopDesc::set_klass_gap(int v) {
   121   if (UseCompressedClassPointers) {
   122     *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
   123   }
   124 }
   126 inline void oopDesc::set_klass_to_list_ptr(oop k) {
   127   // This is only to be used during GC, for from-space objects, so no
   128   // barrier is needed.
   129   if (UseCompressedClassPointers) {
   130     _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k);  // may be null (parnew overflow handling)
   131   } else {
   132     _metadata._klass = (Klass*)(address)k;
   133   }
   134 }
   136 inline oop oopDesc::list_ptr_from_klass() {
   137   // This is only to be used during GC, for from-space objects.
   138   if (UseCompressedClassPointers) {
   139     return decode_heap_oop((narrowOop)_metadata._compressed_klass);
   140   } else {
   141     // Special case for GC
   142     return (oop)(address)_metadata._klass;
   143   }
   144 }
   146 inline void   oopDesc::init_mark()                 { set_mark(markOopDesc::prototype_for_object(this)); }
   148 inline bool oopDesc::is_a(Klass* k)        const { return klass()->is_subtype_of(k); }
   150 inline bool oopDesc::is_instance()           const { return klass()->oop_is_instance(); }
   151 inline bool oopDesc::is_instanceMirror()     const { return klass()->oop_is_instanceMirror(); }
   152 inline bool oopDesc::is_instanceRef()        const { return klass()->oop_is_instanceRef(); }
   153 inline bool oopDesc::is_array()              const { return klass()->oop_is_array(); }
   154 inline bool oopDesc::is_objArray()           const { return klass()->oop_is_objArray(); }
   155 inline bool oopDesc::is_typeArray()          const { return klass()->oop_is_typeArray(); }
   157 inline void*     oopDesc::field_base(int offset)        const { return (void*)&((char*)this)[offset]; }
   159 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); }
   160 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
   161 inline jbyte*    oopDesc::byte_field_addr(int offset)   const { return (jbyte*)   field_base(offset); }
   162 inline jchar*    oopDesc::char_field_addr(int offset)   const { return (jchar*)   field_base(offset); }
   163 inline jboolean* oopDesc::bool_field_addr(int offset)   const { return (jboolean*)field_base(offset); }
   164 inline jint*     oopDesc::int_field_addr(int offset)    const { return (jint*)    field_base(offset); }
   165 inline jshort*   oopDesc::short_field_addr(int offset)  const { return (jshort*)  field_base(offset); }
   166 inline jlong*    oopDesc::long_field_addr(int offset)   const { return (jlong*)   field_base(offset); }
   167 inline jfloat*   oopDesc::float_field_addr(int offset)  const { return (jfloat*)  field_base(offset); }
   168 inline jdouble*  oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); }
   169 inline address*  oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); }
   172 // Functions for getting and setting oops within instance objects.
   173 // If the oops are compressed, the type passed to these overloaded functions
   174 // is narrowOop.  All functions are overloaded so they can be called by
   175 // template functions without conditionals (the compiler instantiates via
   176 // the right type and inlines the appopriate code).
   178 inline bool oopDesc::is_null(oop 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 cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0;
   187 }
   189 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
   190   assert(!is_null(v), "oop value can never be zero");
   191   assert(check_obj_alignment(v), "Address not aligned");
   192   assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
   193   address base = Universe::narrow_oop_base();
   194   int    shift = Universe::narrow_oop_shift();
   195   uint64_t  pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
   196   assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
   197   uint64_t result = pd >> shift;
   198   assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
   199   assert(decode_heap_oop(result) == v, "reversibility");
   200   return (narrowOop)result;
   201 }
   203 inline narrowOop oopDesc::encode_heap_oop(oop v) {
   204   return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
   205 }
   207 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
   208   assert(!is_null(v), "narrow oop value can never be zero");
   209   address base = Universe::narrow_oop_base();
   210   int    shift = Universe::narrow_oop_shift();
   211   oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
   212   assert(check_obj_alignment(result), err_msg("address not aligned: " PTR_FORMAT, (void*) result));
   213   return result;
   214 }
   216 inline oop oopDesc::decode_heap_oop(narrowOop v) {
   217   return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
   218 }
   220 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; }
   221 inline oop oopDesc::decode_heap_oop(oop v)  { return v; }
   223 // Load an oop out of the Java heap as is without decoding.
   224 // Called by GC to check for null before decoding.
   225 inline oop       oopDesc::load_heap_oop(oop* p)          { return *p; }
   226 inline narrowOop oopDesc::load_heap_oop(narrowOop* p)    { return *p; }
   228 // Load and decode an oop out of the Java heap into a wide oop.
   229 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p)       { return *p; }
   230 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
   231   return decode_heap_oop_not_null(*p);
   232 }
   234 // Load and decode an oop out of the heap accepting null
   235 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; }
   236 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) {
   237   return decode_heap_oop(*p);
   238 }
   240 // Store already encoded heap oop into the heap.
   241 inline void oopDesc::store_heap_oop(oop* p, oop v)                 { *p = v; }
   242 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v)     { *p = v; }
   244 // Encode and store a heap oop.
   245 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
   246   *p = encode_heap_oop_not_null(v);
   247 }
   248 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
   250 // Encode and store a heap oop allowing for null.
   251 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
   252   *p = encode_heap_oop(v);
   253 }
   254 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; }
   256 // Store heap oop as is for volatile fields.
   257 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) {
   258   OrderAccess::release_store_ptr(p, v);
   259 }
   260 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p,
   261                                             narrowOop v) {
   262   OrderAccess::release_store(p, v);
   263 }
   265 inline void oopDesc::release_encode_store_heap_oop_not_null(
   266                                                 volatile narrowOop* p, oop v) {
   267   // heap oop is not pointer sized.
   268   OrderAccess::release_store(p, encode_heap_oop_not_null(v));
   269 }
   271 inline void oopDesc::release_encode_store_heap_oop_not_null(
   272                                                       volatile oop* p, oop v) {
   273   OrderAccess::release_store_ptr(p, v);
   274 }
   276 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p,
   277                                                            oop v) {
   278   OrderAccess::release_store_ptr(p, v);
   279 }
   280 inline void oopDesc::release_encode_store_heap_oop(
   281                                                 volatile narrowOop* p, oop v) {
   282   OrderAccess::release_store(p, encode_heap_oop(v));
   283 }
   286 // These functions are only used to exchange oop fields in instances,
   287 // not headers.
   288 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) {
   289   if (UseCompressedOops) {
   290     // encode exchange value from oop to T
   291     narrowOop val = encode_heap_oop(exchange_value);
   292     narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest);
   293     // decode old from T to oop
   294     return decode_heap_oop(old);
   295   } else {
   296     return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest);
   297   }
   298 }
   300 // In order to put or get a field out of an instance, must first check
   301 // if the field has been compressed and uncompress it.
   302 inline oop oopDesc::obj_field(int offset) const {
   303   return UseCompressedOops ?
   304     load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) :
   305     load_decode_heap_oop(obj_field_addr<oop>(offset));
   306 }
   307 inline volatile oop oopDesc::obj_field_volatile(int offset) const {
   308   volatile oop value = obj_field(offset);
   309   OrderAccess::acquire();
   310   return value;
   311 }
   312 inline void oopDesc::obj_field_put(int offset, oop value) {
   313   UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) :
   314                       oop_store(obj_field_addr<oop>(offset),       value);
   315 }
   317 inline Metadata* oopDesc::metadata_field(int offset) const {
   318   return *metadata_field_addr(offset);
   319 }
   321 inline void oopDesc::metadata_field_put(int offset, Metadata* value) {
   322   *metadata_field_addr(offset) = value;
   323 }
   325 inline void oopDesc::obj_field_put_raw(int offset, oop value) {
   326   UseCompressedOops ?
   327     encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) :
   328     encode_store_heap_oop(obj_field_addr<oop>(offset),       value);
   329 }
   330 inline void oopDesc::obj_field_put_volatile(int offset, oop value) {
   331   OrderAccess::release();
   332   obj_field_put(offset, value);
   333   OrderAccess::fence();
   334 }
   336 inline jbyte oopDesc::byte_field(int offset) const                  { return (jbyte) *byte_field_addr(offset);    }
   337 inline void oopDesc::byte_field_put(int offset, jbyte contents)     { *byte_field_addr(offset) = (jint) contents; }
   339 inline jboolean oopDesc::bool_field(int offset) const               { return (jboolean) *bool_field_addr(offset); }
   340 inline void oopDesc::bool_field_put(int offset, jboolean contents)  { *bool_field_addr(offset) = (jint) contents; }
   342 inline jchar oopDesc::char_field(int offset) const                  { return (jchar) *char_field_addr(offset);    }
   343 inline void oopDesc::char_field_put(int offset, jchar contents)     { *char_field_addr(offset) = (jint) contents; }
   345 inline jint oopDesc::int_field(int offset) const                    { return *int_field_addr(offset);        }
   346 inline void oopDesc::int_field_put(int offset, jint contents)       { *int_field_addr(offset) = contents;    }
   348 inline jshort oopDesc::short_field(int offset) const                { return (jshort) *short_field_addr(offset);  }
   349 inline void oopDesc::short_field_put(int offset, jshort contents)   { *short_field_addr(offset) = (jint) contents;}
   351 inline jlong oopDesc::long_field(int offset) const                  { return *long_field_addr(offset);       }
   352 inline void oopDesc::long_field_put(int offset, jlong contents)     { *long_field_addr(offset) = contents;   }
   354 inline jfloat oopDesc::float_field(int offset) const                { return *float_field_addr(offset);      }
   355 inline void oopDesc::float_field_put(int offset, jfloat contents)   { *float_field_addr(offset) = contents;  }
   357 inline jdouble oopDesc::double_field(int offset) const              { return *double_field_addr(offset);     }
   358 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; }
   360 inline address oopDesc::address_field(int offset) const              { return *address_field_addr(offset);     }
   361 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; }
   363 inline oop oopDesc::obj_field_acquire(int offset) const {
   364   return UseCompressedOops ?
   365              decode_heap_oop((narrowOop)
   366                OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset)))
   367            : decode_heap_oop((oop)
   368                OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset)));
   369 }
   370 inline void oopDesc::release_obj_field_put(int offset, oop value) {
   371   UseCompressedOops ?
   372     oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) :
   373     oop_store((volatile oop*)      obj_field_addr<oop>(offset),       value);
   374 }
   376 inline jbyte oopDesc::byte_field_acquire(int offset) const                  { return OrderAccess::load_acquire(byte_field_addr(offset));     }
   377 inline void oopDesc::release_byte_field_put(int offset, jbyte contents)     { OrderAccess::release_store(byte_field_addr(offset), contents); }
   379 inline jboolean oopDesc::bool_field_acquire(int offset) const               { return OrderAccess::load_acquire(bool_field_addr(offset));     }
   380 inline void oopDesc::release_bool_field_put(int offset, jboolean contents)  { OrderAccess::release_store(bool_field_addr(offset), contents); }
   382 inline jchar oopDesc::char_field_acquire(int offset) const                  { return OrderAccess::load_acquire(char_field_addr(offset));     }
   383 inline void oopDesc::release_char_field_put(int offset, jchar contents)     { OrderAccess::release_store(char_field_addr(offset), contents); }
   385 inline jint oopDesc::int_field_acquire(int offset) const                    { return OrderAccess::load_acquire(int_field_addr(offset));      }
   386 inline void oopDesc::release_int_field_put(int offset, jint contents)       { OrderAccess::release_store(int_field_addr(offset), contents);  }
   388 inline jshort oopDesc::short_field_acquire(int offset) const                { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); }
   389 inline void oopDesc::release_short_field_put(int offset, jshort contents)   { OrderAccess::release_store(short_field_addr(offset), contents);     }
   391 inline jlong oopDesc::long_field_acquire(int offset) const                  { return OrderAccess::load_acquire(long_field_addr(offset));       }
   392 inline void oopDesc::release_long_field_put(int offset, jlong contents)     { OrderAccess::release_store(long_field_addr(offset), contents);   }
   394 inline jfloat oopDesc::float_field_acquire(int offset) const                { return OrderAccess::load_acquire(float_field_addr(offset));      }
   395 inline void oopDesc::release_float_field_put(int offset, jfloat contents)   { OrderAccess::release_store(float_field_addr(offset), contents);  }
   397 inline jdouble oopDesc::double_field_acquire(int offset) const              { return OrderAccess::load_acquire(double_field_addr(offset));     }
   398 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); }
   400 inline address oopDesc::address_field_acquire(int offset) const             { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); }
   401 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); }
   403 inline int oopDesc::size_given_klass(Klass* klass)  {
   404   int lh = klass->layout_helper();
   405   int s;
   407   // lh is now a value computed at class initialization that may hint
   408   // at the size.  For instances, this is positive and equal to the
   409   // size.  For arrays, this is negative and provides log2 of the
   410   // array element size.  For other oops, it is zero and thus requires
   411   // a virtual call.
   412   //
   413   // We go to all this trouble because the size computation is at the
   414   // heart of phase 2 of mark-compaction, and called for every object,
   415   // alive or dead.  So the speed here is equal in importance to the
   416   // speed of allocation.
   418   if (lh > Klass::_lh_neutral_value) {
   419     if (!Klass::layout_helper_needs_slow_path(lh)) {
   420       s = lh >> LogHeapWordSize;  // deliver size scaled by wordSize
   421     } else {
   422       s = klass->oop_size(this);
   423     }
   424   } else if (lh <= Klass::_lh_neutral_value) {
   425     // The most common case is instances; fall through if so.
   426     if (lh < Klass::_lh_neutral_value) {
   427       // Second most common case is arrays.  We have to fetch the
   428       // length of the array, shift (multiply) it appropriately,
   429       // up to wordSize, add the header, and align to object size.
   430       size_t size_in_bytes;
   431 #ifdef _M_IA64
   432       // The Windows Itanium Aug 2002 SDK hoists this load above
   433       // the check for s < 0.  An oop at the end of the heap will
   434       // cause an access violation if this load is performed on a non
   435       // array oop.  Making the reference volatile prohibits this.
   436       // (%%% please explain by what magic the length is actually fetched!)
   437       volatile int *array_length;
   438       array_length = (volatile int *)( (intptr_t)this +
   439                           arrayOopDesc::length_offset_in_bytes() );
   440       assert(array_length > 0, "Integer arithmetic problem somewhere");
   441       // Put into size_t to avoid overflow.
   442       size_in_bytes = (size_t) array_length;
   443       size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh);
   444 #else
   445       size_t array_length = (size_t) ((arrayOop)this)->length();
   446       size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
   447 #endif
   448       size_in_bytes += Klass::layout_helper_header_size(lh);
   450       // This code could be simplified, but by keeping array_header_in_bytes
   451       // in units of bytes and doing it this way we can round up just once,
   452       // skipping the intermediate round to HeapWordSize.  Cast the result
   453       // of round_to to size_t to guarantee unsigned division == right shift.
   454       s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) /
   455         HeapWordSize);
   457       // UseParNewGC, UseParallelGC and UseG1GC can change the length field
   458       // of an "old copy" of an object array in the young gen so it indicates
   459       // the grey portion of an already copied array. This will cause the first
   460       // disjunct below to fail if the two comparands are computed across such
   461       // a concurrent change.
   462       // UseParNewGC also runs with promotion labs (which look like int
   463       // filler arrays) which are subject to changing their declared size
   464       // when finally retiring a PLAB; this also can cause the first disjunct
   465       // to fail for another worker thread that is concurrently walking the block
   466       // offset table. Both these invariant failures are benign for their
   467       // current uses; we relax the assertion checking to cover these two cases below:
   468       //     is_objArray() && is_forwarded()   // covers first scenario above
   469       //  || is_typeArray()                    // covers second scenario above
   470       // If and when UseParallelGC uses the same obj array oop stealing/chunking
   471       // technique, we will need to suitably modify the assertion.
   472       assert((s == klass->oop_size(this)) ||
   473              (Universe::heap()->is_gc_active() &&
   474               ((is_typeArray() && UseParNewGC) ||
   475                (is_objArray()  && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))),
   476              "wrong array object size");
   477     } else {
   478       // Must be zero, so bite the bullet and take the virtual call.
   479       s = klass->oop_size(this);
   480     }
   481   }
   483   assert(s % MinObjAlignment == 0, "alignment check");
   484   assert(s > 0, "Bad size calculated");
   485   return s;
   486 }
   489 inline int oopDesc::size()  {
   490   return size_given_klass(klass());
   491 }
   493 inline void update_barrier_set(void* p, oop v, bool release = false) {
   494   assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!");
   495   oopDesc::bs()->write_ref_field(p, v, release);
   496 }
   498 template <class T> inline void update_barrier_set_pre(T* p, oop v) {
   499   oopDesc::bs()->write_ref_field_pre(p, v);
   500 }
   502 template <class T> inline void oop_store(T* p, oop v) {
   503   if (always_do_update_barrier) {
   504     oop_store((volatile T*)p, v);
   505   } else {
   506     update_barrier_set_pre(p, v);
   507     oopDesc::encode_store_heap_oop(p, v);
   508     // always_do_update_barrier == false =>
   509     // Either we are at a safepoint (in GC) or CMS is not used. In both
   510     // cases it's unnecessary to mark the card as dirty with release sematics.
   511     update_barrier_set((void*)p, v, false /* release */);  // cast away type
   512   }
   513 }
   515 template <class T> inline void oop_store(volatile T* p, oop v) {
   516   update_barrier_set_pre((T*)p, v);   // cast away volatile
   517   // Used by release_obj_field_put, so use release_store_ptr.
   518   oopDesc::release_encode_store_heap_oop(p, v);
   519   // When using CMS we must mark the card corresponding to p as dirty
   520   // with release sematics to prevent that CMS sees the dirty card but
   521   // not the new value v at p due to reordering of the two
   522   // stores. Note that CMS has a concurrent precleaning phase, where
   523   // it reads the card table while the Java threads are running.
   524   update_barrier_set((void*)p, v, true /* release */);    // cast away type
   525 }
   527 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops
   528 // (without having to remember the function name this calls).
   529 inline void oop_store_raw(HeapWord* addr, oop value) {
   530   if (UseCompressedOops) {
   531     oopDesc::encode_store_heap_oop((narrowOop*)addr, value);
   532   } else {
   533     oopDesc::encode_store_heap_oop((oop*)addr, value);
   534   }
   535 }
   537 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value,
   538                                                 volatile HeapWord *dest,
   539                                                 oop compare_value,
   540                                                 bool prebarrier) {
   541   if (UseCompressedOops) {
   542     if (prebarrier) {
   543       update_barrier_set_pre((narrowOop*)dest, exchange_value);
   544     }
   545     // encode exchange and compare value from oop to T
   546     narrowOop val = encode_heap_oop(exchange_value);
   547     narrowOop cmp = encode_heap_oop(compare_value);
   549     narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp);
   550     // decode old from T to oop
   551     return decode_heap_oop(old);
   552   } else {
   553     if (prebarrier) {
   554       update_barrier_set_pre((oop*)dest, exchange_value);
   555     }
   556     return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value);
   557   }
   558 }
   560 // Used only for markSweep, scavenging
   561 inline bool oopDesc::is_gc_marked() const {
   562   return mark()->is_marked();
   563 }
   565 inline bool oopDesc::is_locked() const {
   566   return mark()->is_locked();
   567 }
   569 inline bool oopDesc::is_unlocked() const {
   570   return mark()->is_unlocked();
   571 }
   573 inline bool oopDesc::has_bias_pattern() const {
   574   return mark()->has_bias_pattern();
   575 }
   578 // used only for asserts
   579 inline bool oopDesc::is_oop(bool ignore_mark_word) const {
   580   oop obj = (oop) this;
   581   if (!check_obj_alignment(obj)) return false;
   582   if (!Universe::heap()->is_in_reserved(obj)) return false;
   583   // obj is aligned and accessible in heap
   584   if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false;
   586   // Header verification: the mark is typically non-NULL. If we're
   587   // at a safepoint, it must not be null.
   588   // Outside of a safepoint, the header could be changing (for example,
   589   // another thread could be inflating a lock on this object).
   590   if (ignore_mark_word) {
   591     return true;
   592   }
   593   if (mark() != NULL) {
   594     return true;
   595   }
   596   return !SafepointSynchronize::is_at_safepoint();
   597 }
   600 // used only for asserts
   601 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const {
   602   return this == NULL ? true : is_oop(ignore_mark_word);
   603 }
   605 #ifndef PRODUCT
   606 // used only for asserts
   607 inline bool oopDesc::is_unlocked_oop() const {
   608   if (!Universe::heap()->is_in_reserved(this)) return false;
   609   return mark()->is_unlocked();
   610 }
   611 #endif // PRODUCT
   613 inline void oopDesc::follow_contents(void) {
   614   assert (is_gc_marked(), "should be marked");
   615   klass()->oop_follow_contents(this);
   616 }
   618 // Used by scavengers
   620 inline bool oopDesc::is_forwarded() const {
   621   // The extra heap check is needed since the obj might be locked, in which case the
   622   // mark would point to a stack location and have the sentinel bit cleared
   623   return mark()->is_marked();
   624 }
   626 // Used by scavengers
   627 inline void oopDesc::forward_to(oop p) {
   628   assert(check_obj_alignment(p),
   629          "forwarding to something not aligned");
   630   assert(Universe::heap()->is_in_reserved(p),
   631          "forwarding to something not in heap");
   632   markOop m = markOopDesc::encode_pointer_as_mark(p);
   633   assert(m->decode_pointer() == p, "encoding must be reversable");
   634   set_mark(m);
   635 }
   637 // Used by parallel scavengers
   638 inline bool oopDesc::cas_forward_to(oop p, markOop compare) {
   639   assert(check_obj_alignment(p),
   640          "forwarding to something not aligned");
   641   assert(Universe::heap()->is_in_reserved(p),
   642          "forwarding to something not in heap");
   643   markOop m = markOopDesc::encode_pointer_as_mark(p);
   644   assert(m->decode_pointer() == p, "encoding must be reversable");
   645   return cas_set_mark(m, compare) == compare;
   646 }
   648 // Note that the forwardee is not the same thing as the displaced_mark.
   649 // The forwardee is used when copying during scavenge and mark-sweep.
   650 // It does need to clear the low two locking- and GC-related bits.
   651 inline oop oopDesc::forwardee() const {
   652   return (oop) mark()->decode_pointer();
   653 }
   655 inline bool oopDesc::has_displaced_mark() const {
   656   return mark()->has_displaced_mark_helper();
   657 }
   659 inline markOop oopDesc::displaced_mark() const {
   660   return mark()->displaced_mark_helper();
   661 }
   663 inline void oopDesc::set_displaced_mark(markOop m) {
   664   mark()->set_displaced_mark_helper(m);
   665 }
   667 // The following method needs to be MT safe.
   668 inline uint oopDesc::age() const {
   669   assert(!is_forwarded(), "Attempt to read age from forwarded mark");
   670   if (has_displaced_mark()) {
   671     return displaced_mark()->age();
   672   } else {
   673     return mark()->age();
   674   }
   675 }
   677 inline void oopDesc::incr_age() {
   678   assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
   679   if (has_displaced_mark()) {
   680     set_displaced_mark(displaced_mark()->incr_age());
   681   } else {
   682     set_mark(mark()->incr_age());
   683   }
   684 }
   687 inline intptr_t oopDesc::identity_hash() {
   688   // Fast case; if the object is unlocked and the hash value is set, no locking is needed
   689   // Note: The mark must be read into local variable to avoid concurrent updates.
   690   markOop mrk = mark();
   691   if (mrk->is_unlocked() && !mrk->has_no_hash()) {
   692     return mrk->hash();
   693   } else if (mrk->is_marked()) {
   694     return mrk->hash();
   695   } else {
   696     return slow_identity_hash();
   697   }
   698 }
   700 inline int oopDesc::adjust_pointers() {
   701   debug_only(int check_size = size());
   702   int s = klass()->oop_adjust_pointers(this);
   703   assert(s == check_size, "should be the same");
   704   return s;
   705 }
   707 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix)                        \
   708                                                                            \
   709 inline int oopDesc::oop_iterate(OopClosureType* blk) {                     \
   710   SpecializationStats::record_call();                                      \
   711   return klass()->oop_oop_iterate##nv_suffix(this, blk);               \
   712 }                                                                          \
   713                                                                            \
   714 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) {       \
   715   SpecializationStats::record_call();                                      \
   716   return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr);       \
   717 }
   720 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) {
   721   // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
   722   // the do_oop calls, but turns off all other features in ExtendedOopClosure.
   723   NoHeaderExtendedOopClosure cl(blk);
   724   return oop_iterate(&cl);
   725 }
   727 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
   728   NoHeaderExtendedOopClosure cl(blk);
   729   return oop_iterate(&cl, mr);
   730 }
   732 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN)
   733 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN)
   735 #if INCLUDE_ALL_GCS
   736 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)              \
   737                                                                            \
   738 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) {           \
   739   SpecializationStats::record_call();                                      \
   740   return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk);     \
   741 }
   743 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN)
   744 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN)
   745 #endif // INCLUDE_ALL_GCS
   747 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP

mercurial