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 bool MetaspaceObj::is_valid(const MetaspaceObj* p) {
90 // Weed out obvious bogus values first without traversing metaspace
91 if ((size_t)p < os::min_page_size()) {
92 return false;
93 } else if (!is_aligned((address)p, sizeof(MetaWord))) {
94 return false;
95 }
96 return Metaspace::contains((void*)p);
97 }
98
99 void MetaspaceObj::print_address_on(outputStream* st) const {
100 st->print(" {" PTR_FORMAT "}", p2i(this));
101 }
102
103 //
104 // ArenaObj
105 //
106
107 void* ArenaObj::operator new(size_t size, Arena *arena) throw() {
108 return arena->Amalloc(size);
109 }
110
111 //
112 // AnyObj
113 //
114
115 void* AnyObj::operator new(size_t size, Arena *arena) {
116 address res = (address)arena->Amalloc(size);
117 DEBUG_ONLY(set_allocation_type(res, ARENA);)
118 return res;
119 }
120
121 void* AnyObj::operator new(size_t size, MemTag mem_tag) throw() {
122 address res = (address)AllocateHeap(size, mem_tag, CALLER_PC);
123 DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
124 return res;
125 }
126
127 void* AnyObj::operator new(size_t size, const std::nothrow_t& nothrow_constant,
128 MemTag mem_tag) throw() {
129 // should only call this with std::nothrow, use other operator new() otherwise
130 address res = (address)AllocateHeap(size, mem_tag, CALLER_PC, AllocFailStrategy::RETURN_NULL);
131 DEBUG_ONLY(if (res!= nullptr) set_allocation_type(res, C_HEAP);)
132 return res;
133 }
134
135 void AnyObj::operator delete(void* p) {
136 if (p == nullptr) {
137 return;
138 }
139 assert(((AnyObj *)p)->allocated_on_C_heap(),
140 "delete only allowed for C_HEAP objects");
141 DEBUG_ONLY(((AnyObj *)p)->_allocation_t[0] = (uintptr_t)badHeapOopVal;)
142 FreeHeap(p);
143 }
144
145 #ifdef ASSERT
146 void AnyObj::set_allocation_type(address res, allocation_type type) {
147 // Set allocation type in the resource object
148 uintptr_t allocation = (uintptr_t)res;
149 assert((allocation & allocation_mask) == 0, "address should be aligned to 4 bytes at least: " PTR_FORMAT, p2i(res));
150 assert(type <= allocation_mask, "incorrect allocation type");
151 AnyObj* resobj = (AnyObj *)res;
152 resobj->_allocation_t[0] = ~(allocation + type);
153 if (type != STACK_OR_EMBEDDED) {
154 // Called from operator new(), set verification value.
155 resobj->_allocation_t[1] = (uintptr_t)&(resobj->_allocation_t[1]) + type;
156 }
157 }
158
159 AnyObj::allocation_type AnyObj::get_allocation_type() const {
160 assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this, "lost resource object");
161 return (allocation_type)((~_allocation_t[0]) & allocation_mask);
162 }
163
164 bool AnyObj::is_type_set() const {
165 allocation_type type = (allocation_type)(_allocation_t[1] & allocation_mask);
166 return get_allocation_type() == type &&
167 (_allocation_t[1] - type) == (uintptr_t)(&_allocation_t[1]);
168 }
169
170 // This whole business of passing information from AnyObj::operator new
171 // to the AnyObj constructor via fields in the "object" is technically UB.
172 // But it seems to work within the limitations of HotSpot usage (such as no
173 // multiple inheritance) with the compilers and compiler options we're using.
174 // And it gives some possibly useful checking for misuse of AnyObj.
175 void AnyObj::initialize_allocation_info() {
176 if (~(_allocation_t[0] | allocation_mask) != (uintptr_t)this) {
177 // Operator new() is not called for allocations
178 // on stack and for embedded objects.
179 set_allocation_type((address)this, STACK_OR_EMBEDDED);
180 } else if (allocated_on_stack_or_embedded()) { // STACK_OR_EMBEDDED
181 // For some reason we got a value which resembles
182 // an embedded or stack object (operator new() does not
183 // set such type). Keep it since it is valid value
184 // (even if it was garbage).
185 // Ignore garbage in other fields.
186 } else if (is_type_set()) {
187 // Operator new() was called and type was set.
188 assert(!allocated_on_stack_or_embedded(),
189 "not embedded or stack, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
190 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
191 } else {
192 // Operator new() was not called.
193 // Assume that it is embedded or stack object.
194 set_allocation_type((address)this, STACK_OR_EMBEDDED);
195 }
196 _allocation_t[1] = 0; // Zap verification value
197 }
198
199 AnyObj::AnyObj() {
200 initialize_allocation_info();
201 }
202
203 AnyObj::AnyObj(const AnyObj&) {
204 // Initialize _allocation_t as a new object, ignoring object being copied.
205 initialize_allocation_info();
206 }
207
208 AnyObj& AnyObj::operator=(const AnyObj& r) {
209 assert(allocated_on_stack_or_embedded(),
210 "copy only into local, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
211 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
212 // Keep current _allocation_t value;
213 return *this;
214 }
215
216 AnyObj::~AnyObj() {
217 // allocated_on_C_heap() also checks that encoded (in _allocation) address == this.
218 if (!allocated_on_C_heap()) { // AnyObj::delete() will zap _allocation for C_heap.
219 _allocation_t[0] = (uintptr_t)badHeapOopVal; // zap type
220 }
221 }
222 #endif // ASSERT
223
224 //--------------------------------------------------------------------------------------
225 // Non-product code
226
227 #ifndef PRODUCT
228 void AnyObj::print() const { print_on(tty); }
229
230 void AnyObj::print_on(outputStream* st) const {
231 st->print_cr("AnyObj(" PTR_FORMAT ")", p2i(this));
232 }
233
234 ReallocMark::ReallocMark() {
235 #ifdef ASSERT
236 Thread *thread = Thread::current();
237 _nesting = thread->resource_area()->nesting();
238 #endif
239 }
240
241 void ReallocMark::check(Arena* arena) {
242 #ifdef ASSERT
243 if ((arena == nullptr || arena == Thread::current()->resource_area()) &&
244 _nesting != Thread::current()->resource_area()->nesting()) {
245 fatal("allocation bug: array could grow within nested ResourceMark");
246 }
247 #endif
248 }
249
250 #endif // Non-product