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 "gc/shared/oopStorage.hpp" 28 #include "oops/access.inline.hpp" 29 #include "oops/oop.hpp" 30 #include "oops/weakHandle.inline.hpp" 31 #include "utilities/debug.hpp" 32 #include "utilities/ostream.hpp" 33 34 template <> OopStorage* WeakHandle<vm_class_loader_data>::get_storage() { 35 return SystemDictionary::vm_weak_oop_storage(); 36 } 37 38 template <WeakHandleType T> 39 WeakHandle<T> WeakHandle<T>::create(Handle obj) { 40 assert(obj() != NULL, "no need to create weak null oop"); 41 oop* oop_addr = get_storage()->allocate(); 42 if (oop_addr == NULL) { 43 vm_exit_out_of_memory(sizeof(oop*), OOM_MALLOC_ERROR, "Unable to create new weak oop handle in OopStorage"); 44 } 45 // Create WeakHandle with address returned and store oop into it. 46 RootAccess<ON_PHANTOM_OOP_REF>::oop_store(oop_addr, obj()); 47 return WeakHandle(oop_addr); 48 } 49 50 template <WeakHandleType T> 51 void WeakHandle<T>::release() const { 52 // Only release if the pointer to the object has been created. 53 if (_obj != NULL) { 54 // Clear the WeakHandle. For race in creating ClassLoaderData, we can release this 55 // WeakHandle before it is cleared by GC. 56 RootAccess<ON_PHANTOM_OOP_REF>::oop_store(_obj, (oop)NULL); 57 get_storage()->release(_obj); 58 } 59 } 60 61 template <WeakHandleType T> 62 void WeakHandle<T>::print() const { print_on(tty); } 63 64 template <WeakHandleType T> 65 void WeakHandle<T>::print_on(outputStream* st) const { 66 st->print("WeakHandle: " PTR_FORMAT, p2i(peek())); 67 } 68 69 // Provide instantiation. 70 template class WeakHandle<vm_class_loader_data>; 71