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