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 35 template <> OopStorage* WeakHandle<vm_class_loader_data>::get_storage() { 36 return SystemDictionary::vm_weak_oop_storage(); 37 } 38 39 template <> OopStorage* WeakHandle<vm_string_table_data>::get_storage() { 40 return StringTable::weak_storage(); 41 } 42 43 template <WeakHandleType T> 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> 56 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> 67 void WeakHandle<T>::print() const { print_on(tty); } 68 69 template <WeakHandleType T> 70 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