1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "classfile/stringTable.hpp"
28 #include "gc/shared/oopStorage.hpp"
29 #include "oops/access.inline.hpp"
30 #include "oops/oop.hpp"
31 #include "oops/weakHandle.inline.hpp"
32 #include "utilities/debug.hpp"
33 #include "utilities/ostream.hpp"
34
get_storage()35 template <> OopStorage* WeakHandle<vm_class_loader_data>::get_storage() {
36 return SystemDictionary::vm_weak_oop_storage();
37 }
38
get_storage()39 template <> OopStorage* WeakHandle<vm_string_table_data>::get_storage() {
40 return StringTable::weak_storage();
41 }
42
43 template <WeakHandleType T>
create(Handle obj)44 WeakHandle<T> WeakHandle<T>::create(Handle obj) {
45 assert(obj() != NULL, "no need to create weak null oop");
46 oop* oop_addr = get_storage()->allocate();
47 if (oop_addr == NULL) {
48 vm_exit_out_of_memory(sizeof(oop*), OOM_MALLOC_ERROR, "Unable to create new weak oop handle in OopStorage");
49 }
50 // Create WeakHandle with address returned and store oop into it.
51 NativeAccess<ON_PHANTOM_OOP_REF>::oop_store(oop_addr, obj());
52 return WeakHandle(oop_addr);
53 }
54
55 template <WeakHandleType T>
release() const56 void WeakHandle<T>::release() const {
57 // Only release if the pointer to the object has been created.
58 if (_obj != NULL) {
59 // Clear the WeakHandle. For race in creating ClassLoaderData, we can release this
60 // WeakHandle before it is cleared by GC.
61 NativeAccess<ON_PHANTOM_OOP_REF>::oop_store(_obj, (oop)NULL);
62 get_storage()->release(_obj);
63 }
64 }
65
66 template <WeakHandleType T>
print() const67 void WeakHandle<T>::print() const { print_on(tty); }
68
69 template <WeakHandleType T>
print_on(outputStream * st) const70 void WeakHandle<T>::print_on(outputStream* st) const {
71 st->print("WeakHandle: " PTR_FORMAT, p2i(peek()));
72 }
73
74 // Provide instantiation.
75 template class WeakHandle<vm_class_loader_data>;
76 template class WeakHandle<vm_string_table_data>;
77
78