src/share/vm/oops/compiledICHolderOop.hpp

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

author
johnc
date
Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781
e1162778c1c8
parent 2314
f95d63e2154a
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

duke@435 1 /*
stefank@2314 2 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #ifndef SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP
stefank@2314 26 #define SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP
stefank@2314 27
stefank@2314 28 #include "oops/oop.hpp"
stefank@2314 29
duke@435 30 // A compiledICHolderOop is a helper object for the inline cache implementation.
duke@435 31 // It holds an intermediate value (method+klass pair) used when converting from
duke@435 32 // compiled to an interpreted call.
duke@435 33 //
duke@435 34 // compiledICHolderOops are always allocated permanent (to avoid traversing the
duke@435 35 // codeCache during scavenge).
duke@435 36
duke@435 37
duke@435 38 class compiledICHolderOopDesc : public oopDesc {
duke@435 39 friend class VMStructs;
duke@435 40 private:
duke@435 41 methodOop _holder_method;
duke@435 42 klassOop _holder_klass; // to avoid name conflict with oopDesc::_klass
duke@435 43 public:
duke@435 44 // accessors
duke@435 45 methodOop holder_method() const { return _holder_method; }
duke@435 46 klassOop holder_klass() const { return _holder_klass; }
duke@435 47
duke@435 48 void set_holder_method(methodOop m) { oop_store_without_check((oop*)&_holder_method, (oop)m); }
duke@435 49 void set_holder_klass(klassOop k) { oop_store_without_check((oop*)&_holder_klass, (oop)k); }
duke@435 50
duke@435 51 static int header_size() { return sizeof(compiledICHolderOopDesc)/HeapWordSize; }
duke@435 52 static int object_size() { return align_object_size(header_size()); }
duke@435 53
duke@435 54 // interpreter support (offsets in bytes)
duke@435 55 static int holder_method_offset() { return offset_of(compiledICHolderOopDesc, _holder_method); }
duke@435 56 static int holder_klass_offset() { return offset_of(compiledICHolderOopDesc, _holder_klass); }
duke@435 57
duke@435 58 // GC support
duke@435 59 oop* adr_holder_method() const { return (oop*)&_holder_method; }
duke@435 60 oop* adr_holder_klass() const { return (oop*)&_holder_klass; }
duke@435 61 };
stefank@2314 62
stefank@2314 63 #endif // SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP

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