1 /*
2 * Copyright (c) 2005, 2014, 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 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
35
36 #ifdef CHECK_UNHANDLED_OOPS
37 const int free_list_size = 256;
38
39
40 UnhandledOops::UnhandledOops(Thread* thread) {
41 _thread = thread;
42 _oop_list = new (ResourceObj::C_HEAP, mtInternal)
43 GrowableArray<UnhandledOopEntry>(free_list_size, true);
44 _level = 0;
45 }
46
47 UnhandledOops::~UnhandledOops() {
48 delete _oop_list;
49 }
50
51
52 void UnhandledOops::dump_oops(UnhandledOops *list) {
53 for (int k = 0; k < list->_oop_list->length(); k++) {
54 UnhandledOopEntry entry = list->_oop_list->at(k);
55 tty->print(" " INTPTR_FORMAT, entry._oop_ptr);
56 }
57 tty->cr();
58 }
59
60 // For debugging unhandled oop detector _in the debugger_
61 // You don't want to turn it on in compiled code here.
62 static bool unhandled_oop_print=0;
63
64 void UnhandledOops::register_unhandled_oop(oop* op, address pc) {
65 if (!_thread->is_in_stack((address)op))
66 return;
67
68 _level ++;
69 if (unhandled_oop_print) {
70 for (int i=0; i<_level; i++) tty->print(" ");
71 tty->print_cr("r " INTPTR_FORMAT, op);
72 }
73 UnhandledOopEntry entry(op, pc);
74 _oop_list->push(entry);
75 }
76
77
78 bool match_oop_entry(void *op, UnhandledOopEntry e) {
79 return (e.oop_ptr() == op);
80 }
81
82 // Mark unhandled oop as okay for GC - the containing struct has an oops_do and
83 // for some reason the oop has to be on the stack.
84 // May not be called for the current thread, as in the case of
85 // VM_GetOrSetLocal in jvmti.
86 void UnhandledOops::allow_unhandled_oop(oop* op) {
87 assert (CheckUnhandledOops, "should only be called with checking option");
88
89 int i = _oop_list->find_from_end(op, match_oop_entry);
90 assert(i!=-1, "safe for gc oop not in unhandled_oop_list");
91
92 UnhandledOopEntry entry = _oop_list->at(i);
93 assert(!entry._ok_for_gc, "duplicate entry");
94 entry._ok_for_gc = true;
95 _oop_list->at_put(i, entry);
96 }
97
98
99 // Called by the oop destructor to remove unhandled oop from the thread's
100 // oop list. All oops given are assumed to be on the list. If not,
101 // there's a bug in the unhandled oop detector.
102 void UnhandledOops::unregister_unhandled_oop(oop* op) {
103 if (!_thread->is_in_stack((address)op)) return;
104
105 _level --;
106 if (unhandled_oop_print) {
107 for (int i=0; i<_level; i++) tty->print(" ");
108 tty->print_cr("u "INTPTR_FORMAT, op);
109 }
110
111 int i = _oop_list->find_from_end(op, match_oop_entry);
112 assert(i!=-1, "oop not in unhandled_oop_list");
113 _oop_list->remove_at(i);
114 }
115
116 void UnhandledOops::clear_unhandled_oops() {
117 assert (CheckUnhandledOops, "should only be called with checking option");
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