1 /*
2 * Copyright (c) 1997, 2023, 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/method.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/handles.inline.hpp"
31 #include "runtime/javaThread.hpp"
32
33 #ifdef ASSERT
34 #define assert_handle_mark_nesting() \
35 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); \
36 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); \
37
38
39 oop* HandleArea::allocate_handle(oop obj) {
40 assert_handle_mark_nesting();
41 assert(oopDesc::is_oop(obj), "not an oop: " INTPTR_FORMAT, p2i(obj));
42 return real_allocate_handle(obj);
43 }
44
45 oop* HandleArea::allocate_null_handle() {
46 assert_handle_mark_nesting();
47 return real_allocate_handle(nullptr);
48 }
49 #endif
50
51 // Copy constructors and destructors for metadata handles
52 // These do too much to inline.
53 #define DEF_METADATA_HANDLE_FN_NOINLINE(name, type) \
54 name##Handle::name##Handle(const name##Handle &h) { \
55 _value = h._value; \
56 if (_value != nullptr) { \
57 assert(_value->is_valid(), "obj is valid"); \
58 if (h._thread != nullptr) { \
59 assert(h._thread == Thread::current(), "thread must be current");\
60 _thread = h._thread; \
61 } else { \
62 _thread = Thread::current(); \
63 } \
64 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
65 _thread->metadata_handles()->push((Metadata*)_value); \
66 } else { \
67 _thread = nullptr; \
68 } \
69 } \
70 name##Handle& name##Handle::operator=(const name##Handle &s) { \
71 remove(); \
72 _value = s._value; \
73 if (_value != nullptr) { \
74 assert(_value->is_valid(), "obj is valid"); \
75 if (s._thread != nullptr) { \
76 assert(s._thread == Thread::current(), "thread must be current");\
77 _thread = s._thread; \
78 } else { \
79 _thread = Thread::current(); \
80 } \
81 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
82 _thread->metadata_handles()->push((Metadata*)_value); \
83 } else { \
84 _thread = nullptr; \
85 } \
86 return *this; \
87 } \
88 inline void name##Handle::remove() { \
89 if (_value != nullptr) { \
90 int i = _thread->metadata_handles()->find_from_end((Metadata*)_value); \
91 assert(i!=-1, "not in metadata_handles list"); \
92 _thread->metadata_handles()->remove_at(i); \
93 } \
94 } \
95 name##Handle::~name##Handle () { remove(); } \
96
97 DEF_METADATA_HANDLE_FN_NOINLINE(method, Method)
98 DEF_METADATA_HANDLE_FN_NOINLINE(constantPool, ConstantPool)
99
100
101 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
102 oop* bottom = (oop*) chunk->bottom();
103 oop* top = (oop*) chunk_top;
104 uintx handles_visited = top - bottom;
105 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
106 // during GC phase 3, a handle may be a forward pointer that
107 // is not yet valid, so loosen the assertion
108 while (bottom < top) {
109 f->do_oop(bottom++);
110 }
111 return handles_visited;
112 }
113
114 void HandleArea::oops_do(OopClosure* f) {
115 uintx handles_visited = 0;
116 // First handle the current chunk. It is filled to the high water mark.
117 handles_visited += chunk_oops_do(f, _chunk, _hwm);
118 // Then handle all previous chunks. They are completely filled.
119 Chunk* k = _first;
120 while(k != _chunk) {
121 handles_visited += chunk_oops_do(f, k, k->top());
122 k = k->next();
123 }
124
125 if (_prev != nullptr) _prev->oops_do(f);
126 }
127
128 void HandleMark::initialize(Thread* thread) {
129 _thread = thread; // Not the current thread during thread creation.
130 // Save area
131 _area = thread->handle_area();
132 // Save current top
133 _chunk = _area->_chunk;
134 _hwm = _area->_hwm;
135 _max = _area->_max;
136 _size_in_bytes = _area->_size_in_bytes;
137 debug_only(_area->_handle_mark_nesting++);
138 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
139
140 // Link this in the thread
141 set_previous_handle_mark(thread->last_handle_mark());
142 thread->set_last_handle_mark(this);
143 }
144
145 HandleMark::~HandleMark() {
146 assert(_area == _thread->handle_area(), "sanity check");
147 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
148
149 pop_and_restore();
150 #ifdef ASSERT
151 // clear out first chunk (to detect allocation bugs)
152 if (ZapVMHandleArea) {
153 memset(_hwm, badHandleValue, _max - _hwm);
154 }
155 #endif
156
157 // Unlink this from the thread
158 _thread->set_last_handle_mark(previous_handle_mark());
159 }
160
161 void HandleMark::chop_later_chunks() {
162 // reset arena size before delete chunks. Otherwise, the total
163 // arena size could exceed total chunk size
164 _area->set_size_in_bytes(size_in_bytes());
165 Chunk::next_chop(_chunk);
166 }
167
168 void* HandleMark::operator new(size_t size) throw() {
169 return AllocateHeap(size, mtThread);
170 }
171
172 void* HandleMark::operator new [] (size_t size) throw() {
173 return AllocateHeap(size, mtThread);
174 }
175
176 void HandleMark::operator delete(void* p) {
177 FreeHeap(p);
178 }
179
180 void HandleMark::operator delete[](void* p) {
181 FreeHeap(p);
182 }
183
184 #ifdef ASSERT
185
186 NoHandleMark::NoHandleMark() {
187 HandleArea* area = Thread::current()->handle_area();
188 area->_no_handle_mark_nesting++;
189 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
190 }
191
192
193 NoHandleMark::~NoHandleMark() {
194 HandleArea* area = Thread::current()->handle_area();
195 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
196 area->_no_handle_mark_nesting--;
197 }
198
199
200 ResetNoHandleMark::ResetNoHandleMark() {
201 HandleArea* area = Thread::current()->handle_area();
202 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
203 area->_no_handle_mark_nesting = 0;
204 }
205
206
207 ResetNoHandleMark::~ResetNoHandleMark() {
208 HandleArea* area = Thread::current()->handle_area();
209 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
210 }
211
212 #endif // ASSERT