1 /*
2 * Copyright (c) 1997, 2018, 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 "oops/valueKlass.hpp"
30 #include "runtime/atomic.hpp"
31 #include "runtime/handles.inline.hpp"
32 #include "runtime/thread.inline.hpp"
33
34 #ifdef ASSERT
35 oop* HandleArea::allocate_handle(oop obj) {
36 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark");
37 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark");
38 assert(oopDesc::is_oop(obj), "not an oop: " INTPTR_FORMAT, p2i(obj));
39 return real_allocate_handle(obj);
40 }
41 #endif
42
43 // Copy constructors and destructors for metadata handles
44 // These do too much to inline.
45 #define DEF_METADATA_HANDLE_FN_NOINLINE(name, type) \
46 name##Handle::name##Handle(const name##Handle &h) { \
47 _value = h._value; \
48 if (_value != NULL) { \
49 assert(_value->is_valid(), "obj is valid"); \
50 if (h._thread != NULL) { \
51 assert(h._thread == Thread::current(), "thread must be current");\
52 _thread = h._thread; \
53 } else { \
54 _thread = Thread::current(); \
55 } \
56 assert (_thread->is_in_stack((address)this), "not on stack?"); \
57 _thread->metadata_handles()->push((Metadata*)_value); \
58 } else { \
59 _thread = NULL; \
60 } \
61 } \
62 name##Handle& name##Handle::operator=(const name##Handle &s) { \
63 remove(); \
64 _value = s._value; \
65 if (_value != NULL) { \
66 assert(_value->is_valid(), "obj is valid"); \
67 if (s._thread != NULL) { \
68 assert(s._thread == Thread::current(), "thread must be current");\
69 _thread = s._thread; \
70 } else { \
71 _thread = Thread::current(); \
72 } \
73 assert (_thread->is_in_stack((address)this), "not on stack?"); \
74 _thread->metadata_handles()->push((Metadata*)_value); \
75 } else { \
76 _thread = NULL; \
77 } \
78 return *this; \
79 } \
80 inline void name##Handle::remove() { \
81 if (_value != NULL) { \
82 int i = _thread->metadata_handles()->find_from_end((Metadata*)_value); \
83 assert(i!=-1, "not in metadata_handles list"); \
84 _thread->metadata_handles()->remove_at(i); \
85 } \
86 } \
87 name##Handle::~name##Handle () { remove(); } \
88
89 DEF_METADATA_HANDLE_FN_NOINLINE(method, Method)
90 DEF_METADATA_HANDLE_FN_NOINLINE(constantPool, ConstantPool)
91
92
93 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
94 oop* bottom = (oop*) chunk->bottom();
95 oop* top = (oop*) chunk_top;
96 uintx handles_visited = top - bottom;
97 BufferedValuesDealiaser* dealiaser = NULL;
98 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
99 // during GC phase 3, a handle may be a forward pointer that
100 // is not yet valid, so loosen the assertion
101 while (bottom < top) {
102 if (Universe::heap()->is_in_reserved_or_null(*bottom)) {
103 f->do_oop(bottom);
104 } else {
105 if (VTBuffer::is_in_vt_buffer(*bottom)) {
106 if(dealiaser == NULL) {
107 dealiaser = Thread::current()->buffered_values_dealiaser();
108 }
109 dealiaser->oops_do(f, *bottom);
110 }
111 }
112 bottom++;
113 }
114 return handles_visited;
115 }
116
117 // Used for debugging handle allocation.
118 NOT_PRODUCT(jint _nof_handlemarks = 0;)
119
120 void HandleArea::oops_do(OopClosure* f) {
121 uintx handles_visited = 0;
122 // First handle the current chunk. It is filled to the high water mark.
123 handles_visited += chunk_oops_do(f, _chunk, _hwm);
124 // Then handle all previous chunks. They are completely filled.
125 Chunk* k = _first;
126 while(k != _chunk) {
127 handles_visited += chunk_oops_do(f, k, k->top());
128 k = k->next();
129 }
130
131 if (_prev != NULL) _prev->oops_do(f);
132 }
133
134 void HandleMark::initialize(Thread* thread) {
135 _thread = thread;
136 // Save area
137 _area = thread->handle_area();
138 // Save current top
139 _chunk = _area->_chunk;
140 _hwm = _area->_hwm;
141 _max = _area->_max;
142 _size_in_bytes = _area->_size_in_bytes;
143 debug_only(_area->_handle_mark_nesting++);
144 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
145 debug_only(Atomic::inc(&_nof_handlemarks);)
146
147 // Link this in the thread
148 set_previous_handle_mark(thread->last_handle_mark());
149 thread->set_last_handle_mark(this);
150 }
151
152
153 HandleMark::~HandleMark() {
154 HandleArea* area = _area; // help compilers with poor alias analysis
155 assert(area == _thread->handle_area(), "sanity check");
156 assert(area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
157 debug_only(area->_handle_mark_nesting--);
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 void* HandleMark::operator new(size_t size) throw() {
186 return AllocateHeap(size, mtThread);
187 }
188
189 void* HandleMark::operator new [] (size_t size) throw() {
190 return AllocateHeap(size, mtThread);
191 }
192
193 void HandleMark::operator delete(void* p) {
194 FreeHeap(p);
195 }
196
197 void HandleMark::operator delete[](void* p) {
198 FreeHeap(p);
199 }
200
201 #ifdef ASSERT
202
203 NoHandleMark::NoHandleMark() {
204 HandleArea* area = Thread::current()->handle_area();
205 area->_no_handle_mark_nesting++;
206 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
207 }
208
209
210 NoHandleMark::~NoHandleMark() {
211 HandleArea* area = Thread::current()->handle_area();
212 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
213 area->_no_handle_mark_nesting--;
214 }
215
216
217 ResetNoHandleMark::ResetNoHandleMark() {
218 HandleArea* area = Thread::current()->handle_area();
219 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
220 area->_no_handle_mark_nesting = 0;
221 }
222
223
224 ResetNoHandleMark::~ResetNoHandleMark() {
225 HandleArea* area = Thread::current()->handle_area();
226 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
227 }
228
229 #endif // ASSERT