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