1 /*
2 * Copyright (c) 2005, 2015, 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/shared/collectedHeap.hpp"
27 #include "oops/oop.inline.hpp"
28 #include "runtime/thread.hpp"
29 #include "runtime/unhandledOops.hpp"
30 #include "utilities/globalDefinitions.hpp"
31
32 #ifdef CHECK_UNHANDLED_OOPS
33 const int free_list_size = 256;
34
35
36 UnhandledOops::UnhandledOops(Thread* thread) {
37 _thread = thread;
38 _oop_list = new (ResourceObj::C_HEAP, mtInternal)
39 GrowableArray<UnhandledOopEntry>(free_list_size, true);
40 _level = 0;
41 }
42
43 UnhandledOops::~UnhandledOops() {
44 delete _oop_list;
45 }
46
47
48 void UnhandledOops::dump_oops(UnhandledOops *list) {
49 for (int k = 0; k < list->_oop_list->length(); k++) {
50 UnhandledOopEntry entry = list->_oop_list->at(k);
51 tty->print(" " INTPTR_FORMAT, p2i(entry._oop_ptr));
52 }
53 tty->cr();
54 }
55
56 // For debugging unhandled oop detector _in the debugger_
57 // You don't want to turn it on in compiled code here.
58 static bool unhandled_oop_print=0;
59
60 void UnhandledOops::register_unhandled_oop(oop* op, address pc) {
61 if (!_thread->is_in_stack((address)op))
62 return;
63
64 _level ++;
65 if (unhandled_oop_print) {
66 for (int i=0; i<_level; i++) tty->print(" ");
67 tty->print_cr("r " INTPTR_FORMAT, p2i(op));
68 }
69 UnhandledOopEntry entry(op, pc);
70 _oop_list->push(entry);
71 }
72
73
74 bool match_oop_entry(void *op, UnhandledOopEntry e) {
75 return (e.oop_ptr() == op);
76 }
77
78 // Mark unhandled oop as okay for GC - the containing struct has an oops_do and
79 // for some reason the oop has to be on the stack.
80 // May not be called for the current thread, as in the case of
81 // VM_GetOrSetLocal in jvmti.
82 void UnhandledOops::allow_unhandled_oop(oop* op) {
83 assert (CheckUnhandledOops, "should only be called with checking option");
84
85 int i = _oop_list->find_from_end(op, match_oop_entry);
86 assert(i!=-1, "safe for gc oop not in unhandled_oop_list");
87
88 UnhandledOopEntry entry = _oop_list->at(i);
89 assert(!entry._ok_for_gc, "duplicate entry");
90 entry._ok_for_gc = true;
91 _oop_list->at_put(i, entry);
92 }
93
94
95 // Called by the oop destructor to remove unhandled oop from the thread's
96 // oop list. All oops given are assumed to be on the list. If not,
97 // there's a bug in the unhandled oop detector.
98 void UnhandledOops::unregister_unhandled_oop(oop* op) {
99 if (!_thread->is_in_stack((address)op)) return;
100
101 _level --;
102 if (unhandled_oop_print) {
103 for (int i=0; i<_level; i++) tty->print(" ");
104 tty->print_cr("u " INTPTR_FORMAT, p2i(op));
105 }
106
107 int i = _oop_list->find_from_end(op, match_oop_entry);
108 assert(i!=-1, "oop not in unhandled_oop_list");
109 _oop_list->remove_at(i);
110 }
111
112 void UnhandledOops::clear_unhandled_oops() {
113 assert (CheckUnhandledOops, "should only be called with checking option");
114
115 for (int k = 0; k < _oop_list->length(); k++) {
116 UnhandledOopEntry entry = _oop_list->at(k);
117 // If an entry is on the unhandled oop list but isn't on the stack
118 // anymore, it must not have gotten unregistered properly and it's a bug
119 // in the unhandled oop generator.
120 if(!_thread->is_in_stack((address)entry._oop_ptr)) {
121 tty->print_cr("oop_ptr is " INTPTR_FORMAT, p2i(entry._oop_ptr));
122 tty->print_cr("thread is " INTPTR_FORMAT " from pc " INTPTR_FORMAT,
123 p2i(_thread), p2i(entry._pc));
124 assert(false, "heap is corrupted by the unhandled oop detector");
125 }
126 // Set unhandled oops to a pattern that will crash distinctively
127 if (!entry._ok_for_gc) *(intptr_t*)(entry._oop_ptr) = BAD_OOP_ADDR;
128 }
129 }
130 #endif // CHECK_UNHANDLED_OOPS