view src/share/vm/opto/locknode.hpp @ 3249:e1162778c1c8

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
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents b92c45f2bc75
children 1d1603768966
line wrap: on
line source

/*
 * Copyright (c) 1999, 2010, 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_OPTO_LOCKNODE_HPP
#define SHARE_VM_OPTO_LOCKNODE_HPP

#include "opto/node.hpp"
#include "opto/opcodes.hpp"
#include "opto/subnode.hpp"
#ifdef TARGET_ARCH_MODEL_x86_32
# include "adfiles/ad_x86_32.hpp"
#endif
#ifdef TARGET_ARCH_MODEL_x86_64
# include "adfiles/ad_x86_64.hpp"
#endif
#ifdef TARGET_ARCH_MODEL_sparc
# include "adfiles/ad_sparc.hpp"
#endif
#ifdef TARGET_ARCH_MODEL_zero
# include "adfiles/ad_zero.hpp"
#endif
#ifdef TARGET_ARCH_MODEL_arm
# include "adfiles/ad_arm.hpp"
#endif
#ifdef TARGET_ARCH_MODEL_ppc
# include "adfiles/ad_ppc.hpp"
#endif

//------------------------------BoxLockNode------------------------------------
class BoxLockNode : public Node {
public:
  const int _slot;
  RegMask   _inmask;
  bool _is_eliminated;    // indicates this lock was safely eliminated

  BoxLockNode( int lock );
  virtual int Opcode() const;
  virtual void emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const;
  virtual uint size(PhaseRegAlloc *ra_) const;
  virtual const RegMask &in_RegMask(uint) const;
  virtual const RegMask &out_RegMask() const;
  virtual uint size_of() const;
  virtual uint hash() const;
  virtual uint cmp( const Node &n ) const;
  virtual const class Type *bottom_type() const { return TypeRawPtr::BOTTOM; }
  virtual uint ideal_reg() const { return Op_RegP; }

  static OptoReg::Name stack_slot(Node* box_node);

  bool is_eliminated()  { return _is_eliminated; }
  // mark lock as eliminated.
  void set_eliminated() { _is_eliminated = true; }

#ifndef PRODUCT
  virtual void format( PhaseRegAlloc *, outputStream *st ) const;
  virtual void dump_spec(outputStream *st) const { st->print("  Lock %d",_slot); }
#endif
};

//------------------------------FastLockNode-----------------------------------
class FastLockNode: public CmpNode {
private:
  BiasedLockingCounters* _counters;

public:
  FastLockNode(Node *ctrl, Node *oop, Node *box) : CmpNode(oop,box) {
    init_req(0,ctrl);
    init_class_id(Class_FastLock);
    _counters = NULL;
  }
  Node* obj_node() const { return in(1); }
  Node* box_node() const { return in(2); }

  // FastLock and FastUnlockNode do not hash, we need one for each correspoding
  // LockNode/UnLockNode to avoid creating Phi's.
  virtual uint hash() const ;                  // { return NO_HASH; }
  virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const { return TypeInt::CC; }
  const Type *sub(const Type *t1, const Type *t2) const { return TypeInt::CC;}

  void create_lock_counter(JVMState* s);
  BiasedLockingCounters* counters() const { return _counters; }
};


//------------------------------FastUnlockNode---------------------------------
class FastUnlockNode: public CmpNode {
public:
  FastUnlockNode(Node *ctrl, Node *oop, Node *box) : CmpNode(oop,box) {
    init_req(0,ctrl);
    init_class_id(Class_FastUnlock);
  }
  Node* obj_node() const { return in(1); }
  Node* box_node() const { return in(2); }


  // FastLock and FastUnlockNode do not hash, we need one for each correspoding
  // LockNode/UnLockNode to avoid creating Phi's.
  virtual uint hash() const ;                  // { return NO_HASH; }
  virtual uint cmp( const Node &n ) const ;    // Always fail, except on self
  virtual int Opcode() const;
  virtual const Type *Value( PhaseTransform *phase ) const { return TypeInt::CC; }
  const Type *sub(const Type *t1, const Type *t2) const { return TypeInt::CC;}

};

#endif // SHARE_VM_OPTO_LOCKNODE_HPP