Mercurial > jdk8-mips64-public > hotspot / annotate
src/share/vm/oops/instanceRefKlass.hpp@e1162778c1c8 (annotated)
src/share/vm/oops/instanceRefKlass.hpp
Thu, 07 Apr 2011 09:53:20 -0700
- author
- johnc
- date
- Thu, 07 Apr 2011 09:53:20 -0700
- changeset 2781
- e1162778c1c8
- parent 2363
- 7cf1a74771e8
- child 4037
- da91efe96a93
- 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) 1997, 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_INSTANCEREFKLASS_HPP |
| stefank@2314 | 26 | #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP |
| stefank@2314 | 27 | |
| stefank@2314 | 28 | #include "oops/instanceKlass.hpp" |
| stefank@2314 | 29 | |
| duke@435 | 30 | // An instanceRefKlass is a specialized instanceKlass for Java |
| duke@435 | 31 | // classes that are subclasses of java/lang/ref/Reference. |
| duke@435 | 32 | // |
| duke@435 | 33 | // These classes are used to implement soft/weak/final/phantom |
| duke@435 | 34 | // references and finalization, and need special treatment by the |
| duke@435 | 35 | // garbage collector. |
| duke@435 | 36 | // |
| duke@435 | 37 | // During GC discovered reference objects are added (chained) to one |
| duke@435 | 38 | // of the four lists below, depending on the type of reference. |
| duke@435 | 39 | // The linked occurs through the next field in class java/lang/ref/Reference. |
| duke@435 | 40 | // |
| duke@435 | 41 | // Afterwards, the discovered references are processed in decreasing |
| duke@435 | 42 | // order of reachability. Reference objects eligible for notification |
| duke@435 | 43 | // are linked to the static pending_list in class java/lang/ref/Reference, |
| duke@435 | 44 | // and the pending list lock object in the same class is notified. |
| duke@435 | 45 | |
| duke@435 | 46 | |
| duke@435 | 47 | class instanceRefKlass: public instanceKlass { |
| duke@435 | 48 | public: |
| duke@435 | 49 | // Type testing |
| duke@435 | 50 | bool oop_is_instanceRef() const { return true; } |
| duke@435 | 51 | |
| duke@435 | 52 | // Casting from klassOop |
| duke@435 | 53 | static instanceRefKlass* cast(klassOop k) { |
| duke@435 | 54 | assert(k->klass_part()->oop_is_instanceRef(), "cast to instanceRefKlass"); |
| duke@435 | 55 | return (instanceRefKlass*) k->klass_part(); |
| duke@435 | 56 | } |
| duke@435 | 57 | |
| duke@435 | 58 | // allocation |
| duke@435 | 59 | DEFINE_ALLOCATE_PERMANENT(instanceRefKlass); |
| duke@435 | 60 | |
| duke@435 | 61 | // Garbage collection |
| duke@435 | 62 | int oop_adjust_pointers(oop obj); |
| duke@435 | 63 | void oop_follow_contents(oop obj); |
| duke@435 | 64 | |
| duke@435 | 65 | // Parallel Scavenge and Parallel Old |
| duke@435 | 66 | PARALLEL_GC_DECLS |
| duke@435 | 67 | |
| duke@435 | 68 | int oop_oop_iterate(oop obj, OopClosure* blk) { |
| duke@435 | 69 | return oop_oop_iterate_v(obj, blk); |
| duke@435 | 70 | } |
| duke@435 | 71 | int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) { |
| duke@435 | 72 | return oop_oop_iterate_v_m(obj, blk, mr); |
| duke@435 | 73 | } |
| duke@435 | 74 | |
| duke@435 | 75 | #define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ |
| duke@435 | 76 | int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \ |
| duke@435 | 77 | int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr); |
| duke@435 | 78 | |
| duke@435 | 79 | ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL) |
| ysr@777 | 80 | ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL) |
| ysr@777 | 81 | |
| ysr@777 | 82 | #ifndef SERIALGC |
| ysr@777 | 83 | #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ |
| ysr@777 | 84 | int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk); |
| ysr@777 | 85 | |
| ysr@777 | 86 | ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) |
| ysr@777 | 87 | ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL) |
| ysr@777 | 88 | #endif // !SERIALGC |
| duke@435 | 89 | |
| duke@435 | 90 | static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock); |
| duke@435 | 91 | static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock); |
| coleenp@2363 | 92 | static bool owns_pending_list_lock(JavaThread* thread); |
| duke@435 | 93 | |
| duke@435 | 94 | // Update non-static oop maps so 'referent', 'nextPending' and |
| duke@435 | 95 | // 'discovered' will look like non-oops |
| duke@435 | 96 | static void update_nonstatic_oop_maps(klassOop k); |
| duke@435 | 97 | |
| duke@435 | 98 | public: |
| duke@435 | 99 | // Verification |
| duke@435 | 100 | void oop_verify_on(oop obj, outputStream* st); |
| duke@435 | 101 | }; |
| stefank@2314 | 102 | |
| stefank@2314 | 103 | #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP |
