Thu, 07 Apr 2011 09:53:20 -0700
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_CPCACHEKLASS_HPP |
stefank@2314 | 26 | #define SHARE_VM_OOPS_CPCACHEKLASS_HPP |
stefank@2314 | 27 | |
stefank@2314 | 28 | #include "oops/arrayKlass.hpp" |
stefank@2314 | 29 | #include "oops/cpCacheOop.hpp" |
stefank@2314 | 30 | #include "oops/instanceKlass.hpp" |
stefank@2314 | 31 | |
coleenp@548 | 32 | class constantPoolCacheKlass: public Klass { |
coleenp@548 | 33 | juint _alloc_size; // allocation profiling support |
duke@435 | 34 | public: |
duke@435 | 35 | // Dispatched klass operations |
duke@435 | 36 | bool oop_is_constantPoolCache() const { return true; } |
duke@435 | 37 | int oop_size(oop obj) const; |
duke@435 | 38 | int klass_oop_size() const { return object_size(); } |
duke@435 | 39 | |
duke@435 | 40 | // Allocation |
duke@435 | 41 | DEFINE_ALLOCATE_PERMANENT(constantPoolCacheKlass); |
ysr@2533 | 42 | constantPoolCacheOop allocate(int length, TRAPS); |
duke@435 | 43 | static klassOop create_klass(TRAPS); |
duke@435 | 44 | |
duke@435 | 45 | // Casting from klassOop |
duke@435 | 46 | static constantPoolCacheKlass* cast(klassOop k) { |
duke@435 | 47 | assert(k->klass_part()->oop_is_constantPoolCache(), "cast to constantPoolCacheKlass"); |
duke@435 | 48 | return (constantPoolCacheKlass*)k->klass_part(); |
duke@435 | 49 | } |
duke@435 | 50 | |
duke@435 | 51 | // Sizing |
coleenp@548 | 52 | static int header_size() { return oopDesc::header_size() + sizeof(constantPoolCacheKlass)/HeapWordSize; } |
coleenp@548 | 53 | int object_size() const { return align_object_size(header_size()); } |
duke@435 | 54 | |
duke@435 | 55 | // Garbage collection |
duke@435 | 56 | void oop_follow_contents(oop obj); |
duke@435 | 57 | int oop_adjust_pointers(oop obj); |
duke@435 | 58 | |
duke@435 | 59 | // Parallel Scavenge and Parallel Old |
duke@435 | 60 | PARALLEL_GC_DECLS |
duke@435 | 61 | |
duke@435 | 62 | // Iterators |
duke@435 | 63 | int oop_oop_iterate(oop obj, OopClosure* blk); |
duke@435 | 64 | int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr); |
duke@435 | 65 | |
coleenp@548 | 66 | // Allocation profiling support |
coleenp@548 | 67 | juint alloc_size() const { return _alloc_size; } |
coleenp@548 | 68 | void set_alloc_size(juint n) { _alloc_size = n; } |
coleenp@548 | 69 | |
duke@435 | 70 | // Printing |
jrose@1590 | 71 | void oop_print_value_on(oop obj, outputStream* st); |
duke@435 | 72 | void oop_print_on(oop obj, outputStream* st); |
duke@435 | 73 | |
duke@435 | 74 | // Verification |
duke@435 | 75 | const char* internal_name() const; |
duke@435 | 76 | void oop_verify_on(oop obj, outputStream* st); |
duke@435 | 77 | }; |
stefank@2314 | 78 | |
stefank@2314 | 79 | #endif // SHARE_VM_OOPS_CPCACHEKLASS_HPP |