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