jdk8-mips64-public/hotspot: src/share/vm/oops/oop.hpp@e1162778c1c8 (annotated)

src/share/vm/oops/oop.hpp@e1162778c1c8 (annotated)

src/share/vm/oops/oop.hpp

Thu, 07 Apr 2011 09:53:20 -0700

author: johnc
date: Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781: e1162778c1c8
parent 2658: c7f3d0b4570f
child 3131: b0efc7ee3b31
permissions: -rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

 /*
  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_OOPS_OOP_HPP
 #define SHARE_VM_OOPS_OOP_HPP
 #include "memory/iterator.hpp"
 #include "memory/memRegion.hpp"
 #include "memory/specialized_oop_closures.hpp"
 #include "utilities/top.hpp"
 // oopDesc is the top baseclass for objects classes.  The {name}Desc classes describe
 // the format of Java objects so the fields can be accessed from C++.
 // oopDesc is abstract.
 // (see oopHierarchy for complete oop class hierarchy)
 //
 // no virtual functions allowed
 // store into oop with store check
 template <class T> void oop_store(T* p, oop v);
 template <class T> void oop_store(volatile T* p, oop v);
 // store into oop without store check
 template <class T> void oop_store_without_check(T* p, oop v);
 template <class T> void oop_store_without_check(volatile T* p, oop v);
 extern bool always_do_update_barrier;
 // Forward declarations.
 class OopClosure;
 class ScanClosure;
 class FastScanClosure;
 class FilteringClosure;
 class BarrierSet;
 class CMSIsAliveClosure;
 class PSPromotionManager;
 class ParCompactionManager;
 class oopDesc {
   friend class VMStructs;
  private:
   volatile markOop  _mark;
   union _metadata {
     wideKlassOop    _klass;
     narrowOop       _compressed_klass;
   } _metadata;
   // Fast access to barrier set.  Must be initialized.
   static BarrierSet* _bs;
  public:
   enum ConcSafeType {
     IsUnsafeConc = false,
     IsSafeConc   = true
   };
   markOop  mark() const         { return _mark; }
   markOop* mark_addr() const    { return (markOop*) &_mark; }
   void set_mark(volatile markOop m)      { _mark = m;   }
   void    release_set_mark(markOop m);
   markOop cas_set_mark(markOop new_mark, markOop old_mark);
   // Used only to re-initialize the mark word (e.g., of promoted
   // objects during a GC) -- requires a valid klass pointer
   void init_mark();
   klassOop klass() const;
   klassOop klass_or_null() const volatile;
   oop* klass_addr();
   narrowOop* compressed_klass_addr();
   void set_klass(klassOop k);
   // For klass field compression
   int klass_gap() const;
   void set_klass_gap(int z);
   // For when the klass pointer is being used as a linked list "next" field.
   void set_klass_to_list_ptr(oop k);
   // size of object header, aligned to platform wordSize
   static int header_size()          { return sizeof(oopDesc)/HeapWordSize; }
   Klass* blueprint() const;
   // Returns whether this is an instance of k or an instance of a subclass of k
   bool is_a(klassOop k)  const;
   // Returns the actual oop size of the object
   int size();
   // Sometimes (for complicated concurrency-related reasons), it is useful
   // to be able to figure out the size of an object knowing its klass.
   int size_given_klass(Klass* klass);
   // Some perm gen objects are not parseble immediately after
   // installation of their klass pointer.
   bool is_parsable();
   // Some perm gen objects that have been allocated and initialized
   // can be changed by the VM when not at a safe point (class rededfinition
   // is an example).  Such objects should not be examined by the
   // concurrent processing of a garbage collector if is_conc_safe()
   // returns false.
   bool is_conc_safe();
   // type test operations (inlined in oop.inline.h)
   bool is_instance()           const;
   bool is_instanceMirror()     const;
   bool is_instanceRef()        const;
   bool is_array()              const;
   bool is_objArray()           const;
   bool is_klass()              const;
   bool is_thread()             const;
   bool is_method()             const;
   bool is_constMethod()        const;
   bool is_methodData()         const;
   bool is_constantPool()       const;
   bool is_constantPoolCache()  const;
   bool is_typeArray()          const;
   bool is_javaArray()          const;
   bool is_compiledICHolder()   const;
  private:
   // field addresses in oop
   void*     field_base(int offset)        const;
   jbyte*    byte_field_addr(int offset)   const;
   jchar*    char_field_addr(int offset)   const;
   jboolean* bool_field_addr(int offset)   const;
   jint*     int_field_addr(int offset)    const;
   jshort*   short_field_addr(int offset)  const;
   jlong*    long_field_addr(int offset)   const;
   jfloat*   float_field_addr(int offset)  const;
   jdouble*  double_field_addr(int offset) const;
   address*  address_field_addr(int offset) const;
  public:
   // Need this as public for garbage collection.
   template <class T> T* obj_field_addr(int offset) const;
   static bool is_null(oop obj);
   static bool is_null(narrowOop obj);
   // Decode an oop pointer from a narrowOop if compressed.
   // These are overloaded for oop and narrowOop as are the other functions
   // below so that they can be called in template functions.
   static oop decode_heap_oop_not_null(oop v);
   static oop decode_heap_oop_not_null(narrowOop v);
   static oop decode_heap_oop(oop v);
   static oop decode_heap_oop(narrowOop v);
   // Encode an oop pointer to a narrow oop.  The or_null versions accept
   // null oop pointer, others do not in order to eliminate the
   // null checking branches.
   static narrowOop encode_heap_oop_not_null(oop v);
   static narrowOop encode_heap_oop(oop v);
   // Load an oop out of the Java heap
   static narrowOop load_heap_oop(narrowOop* p);
   static oop       load_heap_oop(oop* p);
   // Load an oop out of Java heap and decode it to an uncompressed oop.
   static oop load_decode_heap_oop_not_null(narrowOop* p);
   static oop load_decode_heap_oop_not_null(oop* p);
   static oop load_decode_heap_oop(narrowOop* p);
   static oop load_decode_heap_oop(oop* p);
   // Store an oop into the heap.
   static void store_heap_oop(narrowOop* p, narrowOop v);
   static void store_heap_oop(oop* p, oop v);
   // Encode oop if UseCompressedOops and store into the heap.
   static void encode_store_heap_oop_not_null(narrowOop* p, oop v);
   static void encode_store_heap_oop_not_null(oop* p, oop v);
   static void encode_store_heap_oop(narrowOop* p, oop v);
   static void encode_store_heap_oop(oop* p, oop v);
   static void release_store_heap_oop(volatile narrowOop* p, narrowOop v);
   static void release_store_heap_oop(volatile oop* p, oop v);
   static void release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v);
   static void release_encode_store_heap_oop_not_null(volatile oop* p, oop v);
   static void release_encode_store_heap_oop(volatile narrowOop* p, oop v);
   static void release_encode_store_heap_oop(volatile oop* p, oop v);
   static oop atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest);
   static oop atomic_compare_exchange_oop(oop exchange_value,
                                          volatile HeapWord *dest,
                                          oop compare_value);
   // Access to fields in a instanceOop through these methods.
   oop obj_field(int offset) const;
   void obj_field_put(int offset, oop value);
   void obj_field_raw_put(int offset, oop value);
   jbyte byte_field(int offset) const;
   void byte_field_put(int offset, jbyte contents);
   jchar char_field(int offset) const;
   void char_field_put(int offset, jchar contents);
   jboolean bool_field(int offset) const;
   void bool_field_put(int offset, jboolean contents);
   jint int_field(int offset) const;
   void int_field_put(int offset, jint contents);
   jshort short_field(int offset) const;
   void short_field_put(int offset, jshort contents);
   jlong long_field(int offset) const;
   void long_field_put(int offset, jlong contents);
   jfloat float_field(int offset) const;
   void float_field_put(int offset, jfloat contents);
   jdouble double_field(int offset) const;
   void double_field_put(int offset, jdouble contents);
   address address_field(int offset) const;
   void address_field_put(int offset, address contents);
   oop obj_field_acquire(int offset) const;
   void release_obj_field_put(int offset, oop value);
   jbyte byte_field_acquire(int offset) const;
   void release_byte_field_put(int offset, jbyte contents);
   jchar char_field_acquire(int offset) const;
   void release_char_field_put(int offset, jchar contents);
   jboolean bool_field_acquire(int offset) const;
   void release_bool_field_put(int offset, jboolean contents);
   jint int_field_acquire(int offset) const;
   void release_int_field_put(int offset, jint contents);
   jshort short_field_acquire(int offset) const;
   void release_short_field_put(int offset, jshort contents);
   jlong long_field_acquire(int offset) const;
   void release_long_field_put(int offset, jlong contents);
   jfloat float_field_acquire(int offset) const;
   void release_float_field_put(int offset, jfloat contents);
   jdouble double_field_acquire(int offset) const;
   void release_double_field_put(int offset, jdouble contents);
   address address_field_acquire(int offset) const;
   void release_address_field_put(int offset, address contents);
   // printing functions for VM debugging
   void print_on(outputStream* st) const;         // First level print
   void print_value_on(outputStream* st) const;   // Second level print.
   void print_address_on(outputStream* st) const; // Address printing
   // printing on default output stream
   void print();
   void print_value();
   void print_address();
   // return the print strings
   char* print_string();
   char* print_value_string();
   // verification operations
   void verify_on(outputStream* st);
   void verify();
   void verify_old_oop(oop* p, bool allow_dirty);
   void verify_old_oop(narrowOop* p, bool allow_dirty);
   // tells whether this oop is partially constructed (gc during class loading)
   bool partially_loaded();
   void set_partially_loaded();
   // locking operations
   bool is_locked()   const;
   bool is_unlocked() const;
   bool has_bias_pattern() const;
   // asserts
   bool is_oop(bool ignore_mark_word = false) const;
   bool is_oop_or_null(bool ignore_mark_word = false) const;
 #ifndef PRODUCT
   bool is_unlocked_oop() const;
 #endif
   // garbage collection
   bool is_gc_marked() const;
   // Apply "MarkSweep::mark_and_push" to (the address of) every non-NULL
   // reference field in "this".
   void follow_contents(void);
   void follow_header(void);
 #ifndef SERIALGC
   // Parallel Scavenge
   void push_contents(PSPromotionManager* pm);
   // Parallel Old
   void update_contents(ParCompactionManager* cm);
   void follow_contents(ParCompactionManager* cm);
   void follow_header(ParCompactionManager* cm);
 #endif // SERIALGC
   bool is_perm() const;
   bool is_perm_or_null() const;
   bool is_scavengable() const;
   bool is_shared() const;
   bool is_shared_readonly() const;
   bool is_shared_readwrite() const;
   // Forward pointer operations for scavenge
   bool is_forwarded() const;
   void forward_to(oop p);
   bool cas_forward_to(oop p, markOop compare);
 #ifndef SERIALGC
   // Like "forward_to", but inserts the forwarding pointer atomically.
   // Exactly one thread succeeds in inserting the forwarding pointer, and
   // this call returns "NULL" for that thread; any other thread has the
   // value of the forwarding pointer returned and does not modify "this".
   oop forward_to_atomic(oop p);
 #endif // SERIALGC
   oop forwardee() const;
   // Age of object during scavenge
   int age() const;
   void incr_age();
   // Adjust all pointers in this object to point at it's forwarded location and
   // return the size of this oop.  This is used by the MarkSweep collector.
   int adjust_pointers();
   void adjust_header();
 #ifndef SERIALGC
   // Parallel old
   void update_header();
 #endif // SERIALGC
   // mark-sweep support
   void follow_body(int begin, int end);
   // Fast access to barrier set
   static BarrierSet* bs()            { return _bs; }
   static void set_bs(BarrierSet* bs) { _bs = bs; }
   // iterators, returns size of object
 #define OOP_ITERATE_DECL(OopClosureType, nv_suffix)                      \
   int oop_iterate(OopClosureType* blk);                                  \
   int oop_iterate(OopClosureType* blk, MemRegion mr);  // Only in mr.
   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DECL)
   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DECL)
 #ifndef SERIALGC
 #define OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)            \
   int oop_iterate_backwards(OopClosureType* blk);
   ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DECL)
   ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DECL)
 #endif
   void oop_iterate_header(OopClosure* blk);
   void oop_iterate_header(OopClosure* blk, MemRegion mr);
   // identity hash; returns the identity hash key (computes it if necessary)
   // NOTE with the introduction of UseBiasedLocking that identity_hash() might reach a
   // safepoint if called on a biased object. Calling code must be aware of that.
   intptr_t identity_hash();
   intptr_t slow_identity_hash();
   // marks are forwarded to stack when object is locked
   bool     has_displaced_mark() const;
   markOop  displaced_mark() const;
   void     set_displaced_mark(markOop m);
   // for code generation
   static int mark_offset_in_bytes()    { return offset_of(oopDesc, _mark); }
   static int klass_offset_in_bytes()   { return offset_of(oopDesc, _metadata._klass); }
   static int klass_gap_offset_in_bytes();
 };
 #endif // SHARE_VM_OOPS_OOP_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/oop.hpp@e1162778c1c8 (annotated)

src/share/vm/oops/oop.hpp