1 /*
2 * Copyright (c) 1997, 2003, 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 "incls/_precompiled.incl"
26 # include "incls/_handles.cpp.incl"
27
28 #ifdef ASSERT
29 oop* HandleArea::allocate_handle(oop obj) {
30 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
31 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
32 assert(SharedSkipVerify || obj->is_oop(), "sanity check");
33 return real_allocate_handle(obj);
34 }
35
36 Handle::Handle(Thread* thread, oop obj) {
37 assert(thread == Thread::current(), "sanity check");
38 if (obj == NULL) {
39 _handle = NULL;
40 } else {
41 _handle = thread->handle_area()->allocate_handle(obj);
42 }
43 }
44
45 #endif
46
47 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
48 oop* bottom = (oop*) chunk->bottom();
49 oop* top = (oop*) chunk_top;
50 uintx handles_visited = top - bottom;
51 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
52 // during GC phase 3, a handle may be a forward pointer that
53 // is not yet valid, so loosen the assertion
54 while (bottom < top) {
55 // assert((*bottom)->is_oop(), "handle should point to oop");
56 assert(Universe::heap()->is_in(*bottom), "handle should be valid heap address");
57 f->do_oop(bottom++);
58 }
59 return handles_visited;
60 }
61
62 // Used for debugging handle allocation.
63 NOT_PRODUCT(jint _nof_handlemarks = 0;)
64
65 void HandleArea::oops_do(OopClosure* f) {
66 uintx handles_visited = 0;
67 // First handle the current chunk. It is filled to the high water mark.
68 handles_visited += chunk_oops_do(f, _chunk, _hwm);
69 // Then handle all previous chunks. They are completely filled.
70 Chunk* k = _first;
71 while(k != _chunk) {
72 handles_visited += chunk_oops_do(f, k, k->top());
73 k = k->next();
74 }
75
76 // The thread local handle areas should not get very large
77 if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {
78 #ifdef ASSERT
79 warning("%d: Visited in HandleMark : %d",
80 _nof_handlemarks, handles_visited);
81 #else
82 warning("Visited in HandleMark : %d", handles_visited);
83 #endif
84 }
85 if (_prev != NULL) _prev->oops_do(f);
86 }
87
88 void HandleMark::initialize(Thread* thread) {
89 _thread = thread;
90 // Save area
91 _area = thread->handle_area();
92 // Save current top
93 _chunk = _area->_chunk;
94 _hwm = _area->_hwm;
95 _max = _area->_max;
96 NOT_PRODUCT(_size_in_bytes = _area->_size_in_bytes;)
97 debug_only(_area->_handle_mark_nesting++);
98 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
99 debug_only(Atomic::inc(&_nof_handlemarks);)
100
101 // Link this in the thread
102 set_previous_handle_mark(thread->last_handle_mark());
103 thread->set_last_handle_mark(this);
104 }
105
106
107 HandleMark::~HandleMark() {
108 HandleArea* area = _area; // help compilers with poor alias analysis
109 assert(area == _thread->handle_area(), "sanity check");
110 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
111 debug_only(area->_handle_mark_nesting--);
112
113 // Debug code to trace the number of handles allocated per mark/
114 #ifdef ASSERT
115 if (TraceHandleAllocation) {
116 size_t handles = 0;
117 Chunk *c = _chunk->next();
118 if (c == NULL) {
119 handles = area->_hwm - _hwm; // no new chunk allocated
120 } else {
121 handles = _max - _hwm; // add rest in first chunk
122 while(c != NULL) {
123 handles += c->length();
124 c = c->next();
125 }
126 handles -= area->_max - area->_hwm; // adjust for last trunk not full
127 }
128 handles /= sizeof(void *); // Adjust for size of a handle
129 if (handles > HandleAllocationLimit) {
130 // Note: _nof_handlemarks is only set in debug mode
131 warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
132 }
133 }
134 #endif
135
136 // Delete later chunks
137 if( _chunk->next() ) {
138 _chunk->next_chop();
139 }
140 // Roll back arena to saved top markers
141 area->_chunk = _chunk;
142 area->_hwm = _hwm;
143 area->_max = _max;
144 NOT_PRODUCT(area->set_size_in_bytes(_size_in_bytes);)
145 #ifdef ASSERT
146 // clear out first chunk (to detect allocation bugs)
147 if (ZapVMHandleArea) {
148 memset(_hwm, badHandleValue, _max - _hwm);
149 }
150 Atomic::dec(&_nof_handlemarks);
151 #endif
152
153 // Unlink this from the thread
154 _thread->set_last_handle_mark(previous_handle_mark());
155 }
156
157 #ifdef ASSERT
158
159 NoHandleMark::NoHandleMark() {
160 HandleArea* area = Thread::current()->handle_area();
161 area->_no_handle_mark_nesting++;
162 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
163 }
164
165
166 NoHandleMark::~NoHandleMark() {
167 HandleArea* area = Thread::current()->handle_area();
168 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
169 area->_no_handle_mark_nesting--;
170 }
171
172
173 ResetNoHandleMark::ResetNoHandleMark() {
174 HandleArea* area = Thread::current()->handle_area();
175 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
176 area->_no_handle_mark_nesting = 0;
177 }
178
179
180 ResetNoHandleMark::~ResetNoHandleMark() {
181 HandleArea* area = Thread::current()->handle_area();
182 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
183 }
184
185 #endif