1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/unhandledOops.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,89 @@
1.4 +/*
1.5 + * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
1.29 +#define SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
1.30 +
1.31 +#ifdef CHECK_UNHANDLED_OOPS
1.32 +
1.33 +// Detect unhanded oops in VM code
1.34 +
1.35 +// The design is that when an oop is declared on the stack as a local
1.36 +// variable, the oop is actually a C++ struct with constructor and
1.37 +// destructor. The constructor adds the oop address on a list
1.38 +// off each thread and the destructor removes the oop. At a potential
1.39 +// safepoint, the stack addresses of the local variable oops are trashed
1.40 +// with a recognizeable value. If the local variable is used again, it
1.41 +// will segfault, indicating an unsafe use of that oop.
1.42 +// eg:
1.43 +// oop o; //register &o on list
1.44 +// funct(); // if potential safepoint - causes clear_naked_oops()
1.45 +// // which trashes o above.
1.46 +// o->do_something(); // Crashes because o is unsafe.
1.47 +//
1.48 +// This code implements the details of the unhandled oop list on the thread.
1.49 +//
1.50 +
1.51 +class oop;
1.52 +class Thread;
1.53 +
1.54 +class UnhandledOopEntry : public CHeapObj<mtThread> {
1.55 + friend class UnhandledOops;
1.56 + private:
1.57 + oop* _oop_ptr;
1.58 + bool _ok_for_gc;
1.59 + address _pc;
1.60 + public:
1.61 + oop* oop_ptr() { return _oop_ptr; }
1.62 + UnhandledOopEntry() : _oop_ptr(NULL), _ok_for_gc(false), _pc(NULL) {}
1.63 + UnhandledOopEntry(oop* op, address pc) :
1.64 + _oop_ptr(op), _ok_for_gc(false), _pc(pc) {}
1.65 +};
1.66 +
1.67 +
1.68 +class UnhandledOops : public CHeapObj<mtThread> {
1.69 + friend class Thread;
1.70 + private:
1.71 + Thread* _thread;
1.72 + int _level;
1.73 + GrowableArray<UnhandledOopEntry> *_oop_list;
1.74 + void allow_unhandled_oop(oop* op);
1.75 + void clear_unhandled_oops();
1.76 + UnhandledOops(Thread* thread);
1.77 + ~UnhandledOops();
1.78 +
1.79 + public:
1.80 + static void dump_oops(UnhandledOops* list);
1.81 + void register_unhandled_oop(oop* op, address pc);
1.82 + void unregister_unhandled_oop(oop* op);
1.83 +};
1.84 +
1.85 +#ifdef _LP64
1.86 +const intptr_t BAD_OOP_ADDR = 0xfffffffffffffff1;
1.87 +#else
1.88 +const intptr_t BAD_OOP_ADDR = 0xfffffff1;
1.89 +#endif // _LP64
1.90 +#endif // CHECK_UNHANDLED_OOPS
1.91 +
1.92 +#endif // SHARE_VM_RUNTIME_UNHANDLEDOOPS_HPP
