1 /*
2 * Copyright (c) 1997, 2024, 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.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/arena.hpp"
29 #include "memory/metaspace.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "nmt/memTracker.hpp"
32 #include "runtime/os.hpp"
33 #include "runtime/task.hpp"
34 #include "runtime/threadCritical.hpp"
35 #include "utilities/ostream.hpp"
36
37 // allocate using malloc; will fail if no memory available
38 char* AllocateHeap(size_t size,
39 MEMFLAGS flags,
40 const NativeCallStack& stack,
41 AllocFailType alloc_failmode /* = AllocFailStrategy::EXIT_OOM*/) {
42 char* p = (char*) os::malloc(size, flags, stack);
43 if (p == nullptr && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
44 vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "AllocateHeap");
45 }
46 return p;
47 }
48
49 char* AllocateHeap(size_t size,
50 MEMFLAGS flags,
51 AllocFailType alloc_failmode /* = AllocFailStrategy::EXIT_OOM*/) {
52 return AllocateHeap(size, flags, CALLER_PC, alloc_failmode);
53 }
54
55 char* ReallocateHeap(char *old,
56 size_t size,
57 MEMFLAGS flag,
58 AllocFailType alloc_failmode) {
59 char* p = (char*) os::realloc(old, size, flag, CALLER_PC);
60 if (p == nullptr && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
61 vm_exit_out_of_memory(size, OOM_MALLOC_ERROR, "ReallocateHeap");
62 }
63 return p;
64 }
65
66 // handles null pointers
67 void FreeHeap(void* p) {
68 os::free(p);
69 }
70
71 void* MetaspaceObj::_shared_metaspace_base = nullptr;
72 void* MetaspaceObj::_shared_metaspace_top = nullptr;
73
74 void* MetaspaceObj::operator new(size_t size, ClassLoaderData* loader_data,
75 size_t word_size,
76 MetaspaceObj::Type type, TRAPS) throw() {
77 // Klass has its own operator new
78 return Metaspace::allocate(loader_data, word_size, type, 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 return Metaspace::allocate(loader_data, word_size, type);
86 }
87
88
89 // Work-around -- see JDK-8331086
90 void* MetaspaceObj::operator new(size_t size, MEMFLAGS flags) throw() {
91 void* p = AllocateHeap(size, flags, CALLER_PC);
92 memset(p, 0, size);
93 return p;
94 }
95
96 bool MetaspaceObj::is_valid(const MetaspaceObj* p) {
97 // Weed out obvious bogus values first without traversing metaspace
98 if ((size_t)p < os::min_page_size()) {
99 return false;
100 } else if (!is_aligned((address)p, sizeof(MetaWord))) {
101 return false;
102 }
103 return Metaspace::contains((void*)p);
104 }
105
106 void MetaspaceObj::print_address_on(outputStream* st) const {
107 st->print(" {" PTR_FORMAT "}", p2i(this));
108 }
109
110 //
111 // ArenaObj
112 //
113
114 void* ArenaObj::operator new(size_t size, Arena *arena) throw() {
115 return arena->Amalloc(size);
116 }
117
118 //
119 // AnyObj
120 //
121
122 void* AnyObj::operator new(size_t size, Arena *arena) {
123 address res = (address)arena->Amalloc(size);
124 DEBUG_ONLY(set_allocation_type(res, ARENA);)
125 return res;
126 }
127
128 void* AnyObj::operator new(size_t size, MEMFLAGS flags) throw() {
129 address res = (address)AllocateHeap(size, flags, CALLER_PC);
130 DEBUG_ONLY(set_allocation_type(res, C_HEAP);)
131 return res;
132 }
133
134 void* AnyObj::operator new(size_t size, const std::nothrow_t& nothrow_constant,
135 MEMFLAGS flags) throw() {
136 // should only call this with std::nothrow, use other operator new() otherwise
137 address res = (address)AllocateHeap(size, flags, CALLER_PC, AllocFailStrategy::RETURN_NULL);
138 DEBUG_ONLY(if (res!= nullptr) set_allocation_type(res, C_HEAP);)
139 return res;
140 }
141
142 void AnyObj::operator delete(void* p) {
143 if (p == nullptr) {
144 return;
145 }
146 assert(((AnyObj *)p)->allocated_on_C_heap(),
147 "delete only allowed for C_HEAP objects");
148 DEBUG_ONLY(((AnyObj *)p)->_allocation_t[0] = (uintptr_t)badHeapOopVal;)
149 FreeHeap(p);
150 }
151
152 #ifdef ASSERT
153 void AnyObj::set_allocation_type(address res, allocation_type type) {
154 // Set allocation type in the resource object
155 uintptr_t allocation = (uintptr_t)res;
156 assert((allocation & allocation_mask) == 0, "address should be aligned to 4 bytes at least: " PTR_FORMAT, p2i(res));
157 assert(type <= allocation_mask, "incorrect allocation type");
158 AnyObj* resobj = (AnyObj *)res;
159 resobj->_allocation_t[0] = ~(allocation + type);
160 if (type != STACK_OR_EMBEDDED) {
161 // Called from operator new(), set verification value.
162 resobj->_allocation_t[1] = (uintptr_t)&(resobj->_allocation_t[1]) + type;
163 }
164 }
165
166 AnyObj::allocation_type AnyObj::get_allocation_type() const {
167 assert(~(_allocation_t[0] | allocation_mask) == (uintptr_t)this, "lost resource object");
168 return (allocation_type)((~_allocation_t[0]) & allocation_mask);
169 }
170
171 bool AnyObj::is_type_set() const {
172 allocation_type type = (allocation_type)(_allocation_t[1] & allocation_mask);
173 return get_allocation_type() == type &&
174 (_allocation_t[1] - type) == (uintptr_t)(&_allocation_t[1]);
175 }
176
177 // This whole business of passing information from AnyObj::operator new
178 // to the AnyObj constructor via fields in the "object" is technically UB.
179 // But it seems to work within the limitations of HotSpot usage (such as no
180 // multiple inheritance) with the compilers and compiler options we're using.
181 // And it gives some possibly useful checking for misuse of AnyObj.
182 void AnyObj::initialize_allocation_info() {
183 if (~(_allocation_t[0] | allocation_mask) != (uintptr_t)this) {
184 // Operator new() is not called for allocations
185 // on stack and for embedded objects.
186 set_allocation_type((address)this, STACK_OR_EMBEDDED);
187 } else if (allocated_on_stack_or_embedded()) { // STACK_OR_EMBEDDED
188 // For some reason we got a value which resembles
189 // an embedded or stack object (operator new() does not
190 // set such type). Keep it since it is valid value
191 // (even if it was garbage).
192 // Ignore garbage in other fields.
193 } else if (is_type_set()) {
194 // Operator new() was called and type was set.
195 assert(!allocated_on_stack_or_embedded(),
196 "not embedded or stack, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
197 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
198 } else {
199 // Operator new() was not called.
200 // Assume that it is embedded or stack object.
201 set_allocation_type((address)this, STACK_OR_EMBEDDED);
202 }
203 _allocation_t[1] = 0; // Zap verification value
204 }
205
206 AnyObj::AnyObj() {
207 initialize_allocation_info();
208 }
209
210 AnyObj::AnyObj(const AnyObj&) {
211 // Initialize _allocation_t as a new object, ignoring object being copied.
212 initialize_allocation_info();
213 }
214
215 AnyObj& AnyObj::operator=(const AnyObj& r) {
216 assert(allocated_on_stack_or_embedded(),
217 "copy only into local, this(" PTR_FORMAT ") type %d a[0]=(" PTR_FORMAT ") a[1]=(" PTR_FORMAT ")",
218 p2i(this), get_allocation_type(), _allocation_t[0], _allocation_t[1]);
219 // Keep current _allocation_t value;
220 return *this;
221 }
222
223 AnyObj::~AnyObj() {
224 // allocated_on_C_heap() also checks that encoded (in _allocation) address == this.
225 if (!allocated_on_C_heap()) { // AnyObj::delete() will zap _allocation for C_heap.
226 _allocation_t[0] = (uintptr_t)badHeapOopVal; // zap type
227 }
228 }
229 #endif // ASSERT
230
231 //--------------------------------------------------------------------------------------
232 // Non-product code
233
234 #ifndef PRODUCT
235 void AnyObj::print() const { print_on(tty); }
236
237 void AnyObj::print_on(outputStream* st) const {
238 st->print_cr("AnyObj(" PTR_FORMAT ")", p2i(this));
239 }
240
241 ReallocMark::ReallocMark() {
242 #ifdef ASSERT
243 Thread *thread = Thread::current();
244 _nesting = thread->resource_area()->nesting();
245 #endif
246 }
247
248 void ReallocMark::check() {
249 #ifdef ASSERT
250 if (_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