| /* |
| * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP |
| #define SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP |
| |
| #ifdef CHECK_UNHANDLED_OOPS |
| |
| // Detect unhanded oops in VM code |
| |
| // The design is that when an oop is declared on the stack as a local |
| // variable, the oop is actually a C++ struct with constructor and |
| // destructor. The constructor adds the oop address on a list |
| // off each thread and the destructor removes the oop. At a potential |
| // safepoint, the stack addresses of the local variable oops are trashed |
| // with a recognizeable value. If the local variable is used again, it |
| // will segfault, indicating an unsafe use of that oop. |
| // eg: |
| // oop o; //register &o on list |
| // funct(); // if potential safepoint - causes clear_naked_oops() |
| // // which trashes o above. |
| // o->do_something(); // Crashes because o is unsafe. |
| // |
| // This code implements the details of the unhandled oop list on the thread. |
| // |
| |
| class oop; |
| class Thread; |
| |
| class UnhandledOopEntry : public CHeapObj<mtThread> { |
| friend class UnhandledOops; |
| private: |
| oop* _oop_ptr; |
| bool _ok_for_gc; |
| address _pc; |
| public: |
| oop* oop_ptr() { return _oop_ptr; } |
| UnhandledOopEntry() : _oop_ptr(NULL), _ok_for_gc(false), _pc(NULL) {} |
| UnhandledOopEntry(oop* op, address pc) : |
| _oop_ptr(op), _ok_for_gc(false), _pc(pc) {} |
| }; |
| |
| |
| class UnhandledOops : public CHeapObj<mtThread> { |
| friend class Thread; |
| private: |
| Thread* _thread; |
| int _level; |
| GrowableArray<UnhandledOopEntry> *_oop_list; |
| void allow_unhandled_oop(oop* op); |
| void clear_unhandled_oops(); |
| UnhandledOops(Thread* thread); |
| ~UnhandledOops(); |
| |
| public: |
| static void dump_oops(UnhandledOops* list); |
| void register_unhandled_oop(oop* op, address pc); |
| void unregister_unhandled_oop(oop* op); |
| }; |
| |
| #ifdef _LP64 |
| const intptr_t BAD_OOP_ADDR = 0xfffffffffffffff1; |
| #else |
| const intptr_t BAD_OOP_ADDR = 0xfffffff1; |
| #endif // _LP64 |
| #endif // CHECK_UNHANDLED_OOPS |
| |
| #endif // SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP |