1 /*
2 * Copyright (c) 1997, 2025, 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 "memory/allocation.inline.hpp"
26 #include "oops/constantPool.hpp"
27 #include "oops/method.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "runtime/handles.inline.hpp"
30 #include "runtime/javaThread.hpp"
31
32 #ifdef ASSERT
33 #define assert_handle_mark_nesting() \
34 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); \
35 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); \
36
37
38 oop* HandleArea::allocate_handle(oop obj) {
39 assert_handle_mark_nesting();
40 assert(oopDesc::is_oop(obj), "not an oop: " INTPTR_FORMAT, p2i(obj));
41 return real_allocate_handle(obj);
42 }
43
44 oop* HandleArea::allocate_null_handle() {
45 assert_handle_mark_nesting();
46 return real_allocate_handle(nullptr);
47 }
48 #endif
49
50 // Copy constructors and destructors for metadata handles
51 // These do too much to inline.
52 #define DEF_METADATA_HANDLE_FN_NOINLINE(name, type) \
53 name##Handle::name##Handle(const name##Handle &h) { \
54 _value = h._value; \
55 if (_value != nullptr) { \
56 assert(_value->is_valid(), "obj is valid"); \
57 if (h._thread != nullptr) { \
58 assert(h._thread == Thread::current(), "thread must be current");\
59 _thread = h._thread; \
60 } else { \
61 _thread = Thread::current(); \
62 } \
63 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
64 _thread->metadata_handles()->push((Metadata*)_value); \
65 } else { \
66 _thread = nullptr; \
67 } \
68 } \
69 name##Handle& name##Handle::operator=(const name##Handle &s) { \
70 remove(); \
71 _value = s._value; \
72 if (_value != nullptr) { \
73 assert(_value->is_valid(), "obj is valid"); \
74 if (s._thread != nullptr) { \
75 assert(s._thread == Thread::current(), "thread must be current");\
76 _thread = s._thread; \
77 } else { \
78 _thread = Thread::current(); \
79 } \
80 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
81 _thread->metadata_handles()->push((Metadata*)_value); \
82 } else { \
83 _thread = nullptr; \
84 } \
85 return *this; \
86 } \
87 inline void name##Handle::remove() { \
88 if (_value != nullptr) { \
89 int i = _thread->metadata_handles()->find_from_end((Metadata*)_value); \
90 assert(i!=-1, "not in metadata_handles list"); \
91 _thread->metadata_handles()->remove_at(i); \
92 } \
93 } \
94 name##Handle::~name##Handle () { remove(); } \
95
96 DEF_METADATA_HANDLE_FN_NOINLINE(method, Method)
97 DEF_METADATA_HANDLE_FN_NOINLINE(constantPool, ConstantPool)
98
99
100 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
101 oop* bottom = (oop*) chunk->bottom();
102 oop* top = (oop*) chunk_top;
103 uintx handles_visited = top - bottom;
104 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
105 // during GC phase 3, a handle may be a forward pointer that
106 // is not yet valid, so loosen the assertion
107 while (bottom < top) {
108 f->do_oop(bottom++);
109 }
110 return handles_visited;
111 }
112
113 void HandleArea::oops_do(OopClosure* f) {
114 uintx handles_visited = 0;
115 // First handle the current chunk. It is filled to the high water mark.
116 handles_visited += chunk_oops_do(f, _chunk, _hwm);
117 // Then handle all previous chunks. They are completely filled.
118 Chunk* k = _first;
119 while(k != _chunk) {
120 handles_visited += chunk_oops_do(f, k, k->top());
121 k = k->next();
122 }
123
124 if (_prev != nullptr) _prev->oops_do(f);
125 }
126
127 void HandleMark::initialize(Thread* thread) {
128 _thread = thread; // Not the current thread during thread creation.
129 // Save area
130 _area = thread->handle_area();
131 // Save current top
132 _chunk = _area->_chunk;
133 _hwm = _area->_hwm;
134 _max = _area->_max;
135 _size_in_bytes = _area->_size_in_bytes;
136 debug_only(_area->_handle_mark_nesting++);
137 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
138
139 // Link this in the thread
140 set_previous_handle_mark(thread->last_handle_mark());
141 thread->set_last_handle_mark(this);
142 }
143
144 HandleMark::~HandleMark() {
145 assert(_area == _thread->handle_area(), "sanity check");
146 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
147
148 pop_and_restore();
149 #ifdef ASSERT
150 // clear out first chunk (to detect allocation bugs)
151 if (ZapVMHandleArea) {
152 memset(_hwm, badHandleValue, _max - _hwm);
153 }
154 #endif
155
156 // Unlink this from the thread
157 _thread->set_last_handle_mark(previous_handle_mark());
158 }
159
160 void HandleMark::chop_later_chunks() {
161 // reset arena size before delete chunks. Otherwise, the total
162 // arena size could exceed total chunk size
163 _area->set_size_in_bytes(size_in_bytes());
164 Chunk::next_chop(_chunk);
165 }
166
167 void* HandleMark::operator new(size_t size) throw() {
168 return AllocateHeap(size, mtThread);
169 }
170
171 void* HandleMark::operator new [] (size_t size) throw() {
172 return AllocateHeap(size, mtThread);
173 }
174
175 void HandleMark::operator delete(void* p) {
176 FreeHeap(p);
177 }
178
179 void HandleMark::operator delete[](void* p) {
180 FreeHeap(p);
181 }
182
183 #ifdef ASSERT
184
185 NoHandleMark::NoHandleMark() {
186 HandleArea* area = Thread::current()->handle_area();
187 area->_no_handle_mark_nesting++;
188 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
189 }
190
191
192 NoHandleMark::~NoHandleMark() {
193 HandleArea* area = Thread::current()->handle_area();
194 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
195 area->_no_handle_mark_nesting--;
196 }
197
198
199 ResetNoHandleMark::ResetNoHandleMark() {
200 HandleArea* area = Thread::current()->handle_area();
201 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
202 area->_no_handle_mark_nesting = 0;
203 }
204
205
206 ResetNoHandleMark::~ResetNoHandleMark() {
207 HandleArea* area = Thread::current()->handle_area();
208 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
209 }
210
211 #endif // ASSERT