1 /*
2 * Copyright (c) 1997, 2012, 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 "memory/allocation.inline.hpp"
27 #include "oops/constantPool.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "runtime/handles.inline.hpp"
30 #ifdef TARGET_OS_FAMILY_linux
31 # include "os_linux.inline.hpp"
32 # include "thread_linux.inline.hpp"
33 #endif
34 #ifdef TARGET_OS_FAMILY_solaris
35 # include "os_solaris.inline.hpp"
36 # include "thread_solaris.inline.hpp"
37 #endif
38 #ifdef TARGET_OS_FAMILY_windows
39 # include "os_windows.inline.hpp"
40 # include "thread_windows.inline.hpp"
41 #endif
42 #ifdef TARGET_OS_FAMILY_bsd
43 # include "os_bsd.inline.hpp"
44 # include "thread_bsd.inline.hpp"
45 #endif
46
47 #ifdef ASSERT
48 oop* HandleArea::allocate_handle(oop obj) {
49 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
50 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
51 assert(obj->is_oop(), "sanity check");
52 return real_allocate_handle(obj);
53 }
54
55 Handle::Handle(Thread* thread, oop obj) {
56 assert(thread == Thread::current(), "sanity check");
57 if (obj == NULL) {
58 _handle = NULL;
59 } else {
60 _handle = thread->handle_area()->allocate_handle(obj);
61 }
62 }
63
64 #endif
65
66 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
67 oop* bottom = (oop*) chunk->bottom();
68 oop* top = (oop*) chunk_top;
69 uintx handles_visited = top - bottom;
70 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
71 // during GC phase 3, a handle may be a forward pointer that
72 // is not yet valid, so loosen the assertion
73 while (bottom < top) {
74 // This test can be moved up but for now check every oop.
75
76 assert((*bottom)->is_oop(), "handle should point to oop");
77
78 f->do_oop(bottom++);
79 }
80 return handles_visited;
81 }
82
83 // Used for debugging handle allocation.
84 NOT_PRODUCT(jint _nof_handlemarks = 0;)
85
86 void HandleArea::oops_do(OopClosure* f) {
87 uintx handles_visited = 0;
88 // First handle the current chunk. It is filled to the high water mark.
89 handles_visited += chunk_oops_do(f, _chunk, _hwm);
90 // Then handle all previous chunks. They are completely filled.
91 Chunk* k = _first;
92 while(k != _chunk) {
93 handles_visited += chunk_oops_do(f, k, k->top());
94 k = k->next();
95 }
96
97 // The thread local handle areas should not get very large
98 if (TraceHandleAllocation && handles_visited > TotalHandleAllocationLimit) {
99 #ifdef ASSERT
100 warning("%d: Visited in HandleMark : %d",
101 _nof_handlemarks, handles_visited);
102 #else
103 warning("Visited in HandleMark : %d", handles_visited);
104 #endif
105 }
106 if (_prev != NULL) _prev->oops_do(f);
107 }
108
109 void HandleMark::initialize(Thread* thread) {
110 _thread = thread;
111 // Save area
112 _area = thread->handle_area();
113 // Save current top
114 _chunk = _area->_chunk;
115 _hwm = _area->_hwm;
116 _max = _area->_max;
117 _size_in_bytes = _area->_size_in_bytes;
118 debug_only(_area->_handle_mark_nesting++);
119 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
120 debug_only(Atomic::inc(&_nof_handlemarks);)
121
122 // Link this in the thread
123 set_previous_handle_mark(thread->last_handle_mark());
124 thread->set_last_handle_mark(this);
125 }
126
127
128 HandleMark::~HandleMark() {
129 HandleArea* area = _area; // help compilers with poor alias analysis
130 assert(area == _thread->handle_area(), "sanity check");
131 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
132 debug_only(area->_handle_mark_nesting--);
133
134 // Debug code to trace the number of handles allocated per mark/
135 #ifdef ASSERT
136 if (TraceHandleAllocation) {
137 size_t handles = 0;
138 Chunk *c = _chunk->next();
139 if (c == NULL) {
140 handles = area->_hwm - _hwm; // no new chunk allocated
141 } else {
142 handles = _max - _hwm; // add rest in first chunk
143 while(c != NULL) {
144 handles += c->length();
145 c = c->next();
146 }
147 handles -= area->_max - area->_hwm; // adjust for last trunk not full
148 }
149 handles /= sizeof(void *); // Adjust for size of a handle
150 if (handles > HandleAllocationLimit) {
151 // Note: _nof_handlemarks is only set in debug mode
152 warning("%d: Allocated in HandleMark : %d", _nof_handlemarks, handles);
153 }
154
155 tty->print_cr("Handles %d", handles);
156 }
157 #endif
158
159 // Delete later chunks
160 if( _chunk->next() ) {
161 // reset arena size before delete chunks. Otherwise, the total
162 // arena size could exceed total chunk size
163 assert(area->size_in_bytes() > size_in_bytes(), "Sanity check");
164 area->set_size_in_bytes(size_in_bytes());
165 _chunk->next_chop();
166 } else {
167 assert(area->size_in_bytes() == size_in_bytes(), "Sanity check");
168 }
169 // Roll back arena to saved top markers
170 area->_chunk = _chunk;
171 area->_hwm = _hwm;
172 area->_max = _max;
173 #ifdef ASSERT
174 // clear out first chunk (to detect allocation bugs)
175 if (ZapVMHandleArea) {
176 memset(_hwm, badHandleValue, _max - _hwm);
177 }
178 Atomic::dec(&_nof_handlemarks);
179 #endif
180
181 // Unlink this from the thread
182 _thread->set_last_handle_mark(previous_handle_mark());
183 }
184
185 #ifdef ASSERT
186
187 NoHandleMark::NoHandleMark() {
188 HandleArea* area = Thread::current()->handle_area();
189 area->_no_handle_mark_nesting++;
190 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
191 }
192
193
194 NoHandleMark::~NoHandleMark() {
195 HandleArea* area = Thread::current()->handle_area();
196 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
197 area->_no_handle_mark_nesting--;
198 }
199
200
201 ResetNoHandleMark::ResetNoHandleMark() {
202 HandleArea* area = Thread::current()->handle_area();
203 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
204 area->_no_handle_mark_nesting = 0;
205 }
206
207
208 ResetNoHandleMark::~ResetNoHandleMark() {
209 HandleArea* area = Thread::current()->handle_area();
210 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
211 }
212
213 #endif