1 /*
2 * Copyright (c) 2005, 2010, 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 "gc_interface/collectedHeap.hpp"
27 #include "memory/gcLocker.inline.hpp"
28 #include "memory/universe.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/thread.hpp"
31 #include "runtime/unhandledOops.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 #ifdef CHECK_UNHANDLED_OOPS
35 const int free_list_size = 256;
36
37
38 UnhandledOops::UnhandledOops(Thread* thread) {
39 _thread = thread;
40 _oop_list = new (ResourceObj::C_HEAP)
41 GrowableArray<UnhandledOopEntry>(free_list_size, true);
42 _level = 0;
43 }
44
45 UnhandledOops::~UnhandledOops() {
46 delete _oop_list;
47 }
48
49
50 void UnhandledOops::dump_oops(UnhandledOops *list) {
51 for (int k = 0; k < list->_oop_list->length(); k++) {
52 UnhandledOopEntry entry = list->_oop_list->at(k);
53 tty->print(" " INTPTR_FORMAT, entry._oop_ptr);
54 }
55 tty->cr();
56 }
57
58 // For debugging unhandled oop detector _in the debugger_
59 // You don't want to turn it on in compiled code here.
60 static bool unhandled_oop_print=0;
61
62 void UnhandledOops::register_unhandled_oop(oop* op, address pc) {
63 if (!_thread->is_in_stack((address)op))
64 return;
65
66 _level ++;
67 if (unhandled_oop_print) {
68 for (int i=0; i<_level; i++) tty->print(" ");
69 tty->print_cr("r " INTPTR_FORMAT, op);
70 }
71 UnhandledOopEntry entry(op, pc);
72 _oop_list->push(entry);
73 }
74
75
76 bool match_oop_entry(void *op, UnhandledOopEntry e) {
77 return (e.oop_ptr() == op);
78 }
79
80 // Mark unhandled oop as okay for GC - the containing struct has an oops_do and
81 // for some reason the oop has to be on the stack.
82 // May not be called for the current thread, as in the case of
83 // VM_GetOrSetLocal in jvmti.
84 void UnhandledOops::allow_unhandled_oop(oop* op) {
85 assert (CheckUnhandledOops, "should only be called with checking option");
86
87 int i = _oop_list->find_at_end(op, match_oop_entry);
88 assert(i!=-1, "safe for gc oop not in unhandled_oop_list");
89
90 UnhandledOopEntry entry = _oop_list->at(i);
91 assert(!entry._ok_for_gc, "duplicate entry");
92 entry._ok_for_gc = true;
93 _oop_list->at_put(i, entry);
94 }
95
96
97 // Called by the oop destructor to remove unhandled oop from the thread's
98 // oop list. All oops given are assumed to be on the list. If not,
99 // there's a bug in the unhandled oop detector.
100 void UnhandledOops::unregister_unhandled_oop(oop* op) {
101 if (!_thread->is_in_stack((address)op)) return;
102
103 _level --;
104 if (unhandled_oop_print) {
105 for (int i=0; i<_level; i++) tty->print(" ");
106 tty->print_cr("u "INTPTR_FORMAT, op);
107 }
108
109 int i = _oop_list->find_at_end(op, match_oop_entry);
110 assert(i!=-1, "oop not in unhandled_oop_list");
111 _oop_list->remove_at(i);
112 }
113
114 void UnhandledOops::clear_unhandled_oops() {
115 assert (CheckUnhandledOops, "should only be called with checking option");
116 if (_thread->is_gc_locked_out()) {
117 return;
118 }
119 for (int k = 0; k < _oop_list->length(); k++) {
120 UnhandledOopEntry entry = _oop_list->at(k);
121 // If an entry is on the unhandled oop list but isn't on the stack
122 // anymore, it must not have gotten unregistered properly and it's a bug
123 // in the unhandled oop generator.
124 if(!_thread->is_in_stack((address)entry._oop_ptr)) {
125 tty->print_cr("oop_ptr is " INTPTR_FORMAT, (address)entry._oop_ptr);
126 tty->print_cr("thread is " INTPTR_FORMAT " from pc " INTPTR_FORMAT,
127 (address)_thread, (address)entry._pc);
128 assert(false, "heap is corrupted by the unhandled oop detector");
129 }
130 // Set unhandled oops to a pattern that will crash distinctively
131 if (!entry._ok_for_gc) *(intptr_t*)(entry._oop_ptr) = BAD_OOP_ADDR;
132 }
133 }
134 #endif // CHECK_UNHANDLED_OOPS