0N/A/*
2362N/A * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
2362N/A * published by the Free Software Foundation.
0N/A *
2362N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
0N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
0N/A * or visit www.oracle.com if you need additional information or have any
2362N/A * questions.
2362N/A *
2362N/A */
0N/A
0N/A#ifndef SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
0N/A#define SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
0N/A
0N/A#ifdef CHECK_UNHANDLED_OOPS
0N/A
0N/A// Detect unhanded oops in VM code
0N/A
0N/A// The design is that when an oop is declared on the stack as a local
0N/A// variable, the oop is actually a C++ struct with constructor and
0N/A// destructor. The constructor adds the oop address on a list
0N/A// off each thread and the destructor removes the oop. At a potential
0N/A// safepoint, the stack addresses of the local variable oops are trashed
0N/A// with a recognizeable value. If the local variable is used again, it
0N/A// will segfault, indicating an unsafe use of that oop.
0N/A// eg:
0N/A// oop o; //register &o on list
0N/A// funct(); // if potential safepoint - causes clear_naked_oops()
0N/A// // which trashes o above.
0N/A// o->do_something(); // Crashes because o is unsafe.
0N/A//
0N/A// This code implements the details of the unhandled oop list on the thread.
0N/A//
0N/A
0N/Aclass oop;
0N/Aclass Thread;
0N/A
0N/Aclass UnhandledOopEntry {
0N/A friend class UnhandledOops;
0N/A private:
0N/A oop* _oop_ptr;
0N/A bool _ok_for_gc;
0N/A address _pc;
0N/A public:
0N/A oop* oop_ptr() { return _oop_ptr; }
0N/A UnhandledOopEntry() : _oop_ptr(NULL), _ok_for_gc(false), _pc(NULL) {}
0N/A UnhandledOopEntry(oop* op, address pc) :
0N/A _oop_ptr(op), _ok_for_gc(false), _pc(pc) {}
0N/A};
0N/A
0N/A
0N/Aclass UnhandledOops {
0N/A friend class Thread;
0N/A private:
0N/A Thread* _thread;
0N/A int _level;
0N/A GrowableArray<UnhandledOopEntry> *_oop_list;
0N/A void allow_unhandled_oop(oop* op);
0N/A void clear_unhandled_oops();
0N/A UnhandledOops(Thread* thread);
0N/A ~UnhandledOops();
0N/A
0N/A public:
0N/A static void dump_oops(UnhandledOops* list);
0N/A void register_unhandled_oop(oop* op, address pc);
0N/A void unregister_unhandled_oop(oop* op);
0N/A};
0N/A
0N/A#ifdef _LP64
0N/Aconst intptr_t BAD_OOP_ADDR = 0xfffffffffffffff1;
0N/A#else
0N/Aconst intptr_t BAD_OOP_ADDR = 0xfffffff1;
0N/A#endif // _LP64
0N/A#endif // CHECK_UNHANDLED_OOPS
0N/A
0N/A#endif // SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
0N/A