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.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "memory/arena.hpp"
28 #include "memory/metaspace.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "nmt/memTracker.hpp"
31 #include "runtime/os.hpp"
32 #include "runtime/task.hpp"
33 #include "runtime/threadCritical.hpp"
34 #include "utilities/ostream.hpp"
35
36 // allocate using malloc; will fail if no memory available
37 char* AllocateHeap(size_t size,
38 MemTag mem_tag,
39 const NativeCallStack& stack,
40 AllocFailType alloc_failmode /* = AllocFailStrategy::EXIT_OOM*/) {
41 char* p = (char*) os::malloc(size, mem_tag, stack);
42 if (p == nullptr && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
43 vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "AllocateHeap");
44 }
45 return p;
46 }
47
48 char* AllocateHeap(size_t size,
49 MemTag mem_tag,
50 AllocFailType alloc_failmode /* = AllocFailStrategy::EXIT_OOM*/) {
51 return AllocateHeap(size, mem_tag, CALLER_PC, alloc_failmode);
52 }
53
54 char* ReallocateHeap(char *old,
55 size_t size,
56 MemTag mem_tag,
57 AllocFailType alloc_failmode) {
58 char* p = (char*) os::realloc(old, size, mem_tag, CALLER_PC);
59 if (p == nullptr && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
60 vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "ReallocateHeap");
61 }
62 return p;
63 }
64
65 // handles null pointers
66 void FreeHeap(void* p) {
67 os::free(p);
68 }
69
70 void* MetaspaceObj::_shared_metaspace_base = nullptr;
71 void* MetaspaceObj::_shared_metaspace_top = nullptr;
72
73 void* MetaspaceObj::operator new(size_t size, ClassLoaderData* loader_data,
74 size_t word_size,
75 MetaspaceObj::Type type, TRAPS) throw() {
76 // Klass has its own operator new
77 assert(type != ClassType, "class has its own operator new");
78 return Metaspace::allocate(loader_data, word_size, type, /*use_class_space*/ false, THREAD);
79 }
80
81 void* MetaspaceObj::operator new(size_t size, ClassLoaderData* loader_data,
82 size_t word_size,
83 MetaspaceObj::Type type) throw() {
84 assert(!Thread::current()->is_Java_thread(), "only allowed by non-Java thread");
85 assert(type != ClassType, "class has its own operator new");
86 return Metaspace::allocate(loader_data, word_size, type, /*use_class_space*/ false);
87 }
88
89
90 // Work-around -- see JDK-8331086
91 void* MetaspaceObj::operator new(size_t size, MemTag flags) throw() {
92 void* p = AllocateHeap(size, flags, CALLER_PC);
93 memset(p, 0, size);
94 return p;
95 }
96
97 bool MetaspaceObj::is_valid(const MetaspaceObj* p) {
98 // Weed out obvious bogus values first without traversing metaspace
99 if ((size_t)p < os::min_page_size()) {
100 return false;
101 } else if (!is_aligned((address)p, sizeof(MetaWord))) {
102 return false;
103 }
104 return Metaspace::contains((void*)p);
105 }
106
107 void MetaspaceObj::print_address_on(outputStream* st) const {
108 st->print(" {" PTR_FORMAT "}", p2i(this));
109 }
110
111 //
112 // ArenaObj
113 //
114
115 void* ArenaObj::operator new(size_t size, Arena *arena) throw() {
116 return arena->Amalloc(size);
117 }
118
119 //
120 // AnyObj
121 //
122
123 void* AnyObj::operator new(size_t size, Arena *arena) {
124 address res = (address)arena->Amalloc(size);
125 DEBUG_ONLY(set_allocation_type(res, ARENA);)
126 return res;
127 }
128
129 void* AnyObj::operator new(size_t size, MemTag mem_tag) throw() {
130 address res = (address)AllocateHeap(size, mem_tag, CALLER_PC);
131 DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
132 return res;
133 }
134
135 void* AnyObj::operator new(size_t size, const std::nothrow_t& nothrow_constant,
136 MemTag mem_tag) throw() {
137 // should only call this with std::nothrow, use other operator new() otherwise
138 address res = (address)AllocateHeap(size, mem_tag, CALLER_PC, AllocFailStrategy::RETURN_NULL);
139 DEBUG_ONLY(if (res!= nullptr) set_allocation_type(res, C_HEAP);)
140 return res;
141 }
142
143 void AnyObj::operator delete(void* p) {
144 if (p == nullptr) {
145 return;
146 }
147 assert(((AnyObj *)p)->allocated_on_C_heap(),
148 "delete only allowed for C_HEAP objects");
149 DEBUG_ONLY(((AnyObj *)p)->_allocation_t[0] = (uintptr_t)badHeapOopVal;)
150 FreeHeap(p);
151 }
152
153 #ifdef ASSERT
154 void AnyObj::set_allocation_type(address res, allocation_type type) {
155 // Set allocation type in the resource object
156 uintptr_t allocation = (uintptr_t)res;
157 assert((allocation & allocation_mask) == 0, "address should be aligned to 4 bytes at least: " PTR_FORMAT, p2i(res));
158 assert(type <= allocation_mask, "incorrect allocation type");
159 AnyObj* resobj = (AnyObj *)res;
160 resobj->_allocation_t[0] = ~(allocation + type);
161 if (type != STACK_OR_EMBEDDED) {
162 // Called from operator new(), set verification value.
163 resobj->_allocation_t[1] = (uintptr_t)&(resobj->_allocation_t[1]) + type;
164 }
165 }
166
167 AnyObj::allocation_type AnyObj::get_allocation_type() const {
168 assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this, "lost resource object");
169 return (allocation_type)((~_allocation_t[0]) & allocation_mask);
170 }
171
172 bool AnyObj::is_type_set() const {
173 allocation_type type = (allocation_type)(_allocation_t[1] & allocation_mask);
174 return get_allocation_type() == type &&
175 (_allocation_t[1] - type) == (uintptr_t)(&_allocation_t[1]);
176 }
177
178 // This whole business of passing information from AnyObj::operator new
179 // to the AnyObj constructor via fields in the "object" is technically UB.
180 // But it seems to work within the limitations of HotSpot usage (such as no
181 // multiple inheritance) with the compilers and compiler options we're using.
182 // And it gives some possibly useful checking for misuse of AnyObj.
183 void AnyObj::initialize_allocation_info() {
184 if (~(_allocation_t[0] | allocation_mask) != (uintptr_t)this) {
185 // Operator new() is not called for allocations
186 // on stack and for embedded objects.
187 set_allocation_type((address)this, STACK_OR_EMBEDDED);
188 } else if (allocated_on_stack_or_embedded()) { // STACK_OR_EMBEDDED
189 // For some reason we got a value which resembles
190 // an embedded or stack object (operator new() does not
191 // set such type). Keep it since it is valid value
192 // (even if it was garbage).
193 // Ignore garbage in other fields.
194 } else if (is_type_set()) {
195 // Operator new() was called and type was set.
196 assert(!allocated_on_stack_or_embedded(),
197 "not embedded or stack, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
198 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
199 } else {
200 // Operator new() was not called.
201 // Assume that it is embedded or stack object.
202 set_allocation_type((address)this, STACK_OR_EMBEDDED);
203 }
204 _allocation_t[1] = 0; // Zap verification value
205 }
206
207 AnyObj::AnyObj() {
208 initialize_allocation_info();
209 }
210
211 AnyObj::AnyObj(const AnyObj&) {
212 // Initialize _allocation_t as a new object, ignoring object being copied.
213 initialize_allocation_info();
214 }
215
216 AnyObj& AnyObj::operator=(const AnyObj& r) {
217 assert(allocated_on_stack_or_embedded(),
218 "copy only into local, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
219 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
220 // Keep current _allocation_t value;
221 return *this;
222 }
223
224 AnyObj::~AnyObj() {
225 // allocated_on_C_heap() also checks that encoded (in _allocation) address == this.
226 if (!allocated_on_C_heap()) { // AnyObj::delete() will zap _allocation for C_heap.
227 _allocation_t[0] = (uintptr_t)badHeapOopVal; // zap type
228 }
229 }
230 #endif // ASSERT
231
232 //--------------------------------------------------------------------------------------
233 // Non-product code
234
235 #ifndef PRODUCT
236 void AnyObj::print() const { print_on(tty); }
237
238 void AnyObj::print_on(outputStream* st) const {
239 st->print_cr("AnyObj(" PTR_FORMAT ")", p2i(this));
240 }
241
242 ReallocMark::ReallocMark() {
243 #ifdef ASSERT
244 Thread *thread = Thread::current();
245 _nesting = thread->resource_area()->nesting();
246 #endif
247 }
248
249 void ReallocMark::check(Arena* arena) {
250 #ifdef ASSERT
251 if ((arena == nullptr || arena == Thread::current()->resource_area()) &&
252 _nesting != Thread::current()->resource_area()->nesting()) {
253 fatal("allocation bug: array could grow within nested ResourceMark");
254 }
255 #endif
256 }
257
258 #endif // Non-product