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 "oops/inlineKlass.hpp"
31 #include "runtime/atomic.hpp"
32 #include "runtime/handles.inline.hpp"
33 #include "runtime/javaThread.hpp"
34
35 #ifdef ASSERT
36 #define assert_handle_mark_nesting() \
37 assert(_handle_mark_nesting > 1, "memory leak: allocating handle outside HandleMark"); \
38 assert(_no_handle_mark_nesting == 0, "allocating handle inside NoHandleMark"); \
39
40
41 oop* HandleArea::allocate_handle(oop obj) {
42 assert_handle_mark_nesting();
43 assert(oopDesc::is_oop(obj), "not an oop: " INTPTR_FORMAT, p2i(obj));
44 return real_allocate_handle(obj);
45 }
46
47 oop* HandleArea::allocate_null_handle() {
48 assert_handle_mark_nesting();
49 return real_allocate_handle(nullptr);
50 }
51 #endif
52
53 // Copy constructors and destructors for metadata handles
54 // These do too much to inline.
55 #define DEF_METADATA_HANDLE_FN_NOINLINE(name, type) \
56 name##Handle::name##Handle(const name##Handle &h) { \
57 _value = h._value; \
58 if (_value != nullptr) { \
59 assert(_value->is_valid(), "obj is valid"); \
60 if (h._thread != nullptr) { \
61 assert(h._thread == Thread::current(), "thread must be current");\
62 _thread = h._thread; \
63 } else { \
64 _thread = Thread::current(); \
65 } \
66 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
67 _thread->metadata_handles()->push((Metadata*)_value); \
68 } else { \
69 _thread = nullptr; \
70 } \
71 } \
72 name##Handle& name##Handle::operator=(const name##Handle &s) { \
73 remove(); \
74 _value = s._value; \
75 if (_value != nullptr) { \
76 assert(_value->is_valid(), "obj is valid"); \
77 if (s._thread != nullptr) { \
78 assert(s._thread == Thread::current(), "thread must be current");\
79 _thread = s._thread; \
80 } else { \
81 _thread = Thread::current(); \
82 } \
83 assert(_thread->is_in_live_stack((address)this), "not on stack?"); \
84 _thread->metadata_handles()->push((Metadata*)_value); \
85 } else { \
86 _thread = nullptr; \
87 } \
88 return *this; \
89 } \
90 inline void name##Handle::remove() { \
91 if (_value != nullptr) { \
92 int i = _thread->metadata_handles()->find_from_end((Metadata*)_value); \
93 assert(i!=-1, "not in metadata_handles list"); \
94 _thread->metadata_handles()->remove_at(i); \
95 } \
96 } \
97 name##Handle::~name##Handle () { remove(); } \
98
99 DEF_METADATA_HANDLE_FN_NOINLINE(method, Method)
100 DEF_METADATA_HANDLE_FN_NOINLINE(constantPool, ConstantPool)
101
102
103 static uintx chunk_oops_do(OopClosure* f, Chunk* chunk, char* chunk_top) {
104 oop* bottom = (oop*) chunk->bottom();
105 oop* top = (oop*) chunk_top;
106 uintx handles_visited = top - bottom;
107 assert(top >= bottom && top <= (oop*) chunk->top(), "just checking");
108 // during GC phase 3, a handle may be a forward pointer that
109 // is not yet valid, so loosen the assertion
110 while (bottom < top) {
111 f->do_oop(bottom++);
112 }
113 return handles_visited;
114 }
115
116 void HandleArea::oops_do(OopClosure* f) {
117 uintx handles_visited = 0;
118 // First handle the current chunk. It is filled to the high water mark.
119 handles_visited += chunk_oops_do(f, _chunk, _hwm);
120 // Then handle all previous chunks. They are completely filled.
121 Chunk* k = _first;
122 while(k != _chunk) {
123 handles_visited += chunk_oops_do(f, k, k->top());
124 k = k->next();
125 }
126
127 if (_prev != nullptr) _prev->oops_do(f);
128 }
129
130 void HandleMark::initialize(Thread* thread) {
131 _thread = thread; // Not the current thread during thread creation.
132 // Save area
133 _area = thread->handle_area();
134 // Save current top
135 _chunk = _area->_chunk;
136 _hwm = _area->_hwm;
137 _max = _area->_max;
138 _size_in_bytes = _area->_size_in_bytes;
139 debug_only(_area->_handle_mark_nesting++);
140 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks");
141
142 // Link this in the thread
143 set_previous_handle_mark(thread->last_handle_mark());
144 thread->set_last_handle_mark(this);
145 }
146
147 HandleMark::~HandleMark() {
148 assert(_area == _thread->handle_area(), "sanity check");
149 assert(_area->_handle_mark_nesting > 0, "must stack allocate HandleMarks" );
150
151 pop_and_restore();
152 #ifdef ASSERT
153 // clear out first chunk (to detect allocation bugs)
154 if (ZapVMHandleArea) {
155 memset(_hwm, badHandleValue, _max - _hwm);
156 }
157 #endif
158
159 // Unlink this from the thread
160 _thread->set_last_handle_mark(previous_handle_mark());
161 }
162
163 void HandleMark::chop_later_chunks() {
164 // reset arena size before delete chunks. Otherwise, the total
165 // arena size could exceed total chunk size
166 _area->set_size_in_bytes(size_in_bytes());
167 Chunk::next_chop(_chunk);
168 }
169
170 void* HandleMark::operator new(size_t size) throw() {
171 return AllocateHeap(size, mtThread);
172 }
173
174 void* HandleMark::operator new [] (size_t size) throw() {
175 return AllocateHeap(size, mtThread);
176 }
177
178 void HandleMark::operator delete(void* p) {
179 FreeHeap(p);
180 }
181
182 void HandleMark::operator delete[](void* p) {
183 FreeHeap(p);
184 }
185
186 #ifdef ASSERT
187
188 NoHandleMark::NoHandleMark() {
189 HandleArea* area = Thread::current()->handle_area();
190 area->_no_handle_mark_nesting++;
191 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
192 }
193
194
195 NoHandleMark::~NoHandleMark() {
196 HandleArea* area = Thread::current()->handle_area();
197 assert(area->_no_handle_mark_nesting > 0, "must stack allocate NoHandleMark" );
198 area->_no_handle_mark_nesting--;
199 }
200
201
202 ResetNoHandleMark::ResetNoHandleMark() {
203 HandleArea* area = Thread::current()->handle_area();
204 _no_handle_mark_nesting = area->_no_handle_mark_nesting;
205 area->_no_handle_mark_nesting = 0;
206 }
207
208
209 ResetNoHandleMark::~ResetNoHandleMark() {
210 HandleArea* area = Thread::current()->handle_area();
211 area->_no_handle_mark_nesting = _no_handle_mark_nesting;
212 }
213
214 #endif // ASSERT