1 /*
2 * Copyright (c) 1997, 2022, 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 #ifndef SHARE_MEMORY_ALLOCATION_HPP
26 #define SHARE_MEMORY_ALLOCATION_HPP
27
28 #include "memory/allStatic.hpp"
29 #include "utilities/globalDefinitions.hpp"
30 #include "utilities/macros.hpp"
31
32 #include <new>
33
34 class outputStream;
35 class Thread;
36 class JavaThread;
37
38 class AllocFailStrategy {
39 public:
40 enum AllocFailEnum { EXIT_OOM, RETURN_NULL };
41 };
42 typedef AllocFailStrategy::AllocFailEnum AllocFailType;
43
44 // The virtual machine must never call one of the implicitly declared
45 // global allocation or deletion functions. (Such calls may result in
46 // link-time or run-time errors.) For convenience and documentation of
47 // intended use, classes in the virtual machine may be derived from one
48 // of the following allocation classes, some of which define allocation
49 // and deletion functions.
50 // Note: std::malloc and std::free should never called directly.
51
52 //
53 // For objects allocated in the resource area (see resourceArea.hpp).
54 // - ResourceObj
55 //
56 // For objects allocated in the C-heap (managed by: free & malloc and tracked with NMT)
57 // - CHeapObj
58 //
59 // For objects allocated on the stack.
60 // - StackObj
61 //
62 // For classes used as name spaces.
63 // - AllStatic
64 //
65 // For classes in Metaspace (class data)
66 // - MetaspaceObj
67 //
68 // The printable subclasses are used for debugging and define virtual
69 // member functions for printing. Classes that avoid allocating the
70 // vtbl entries in the objects should therefore not be the printable
71 // subclasses.
72 //
73 // The following macros and function should be used to allocate memory
74 // directly in the resource area or in the C-heap, The _OBJ variants
75 // of the NEW/FREE_C_HEAP macros are used for alloc/dealloc simple
76 // objects which are not inherited from CHeapObj, note constructor and
77 // destructor are not called. The preferable way to allocate objects
78 // is using the new operator.
79 //
80 // WARNING: The array variant must only be used for a homogenous array
81 // where all objects are of the exact type specified. If subtypes are
82 // stored in the array then must pay attention to calling destructors
83 // at needed.
84 //
85 // NEW_RESOURCE_ARRAY*
86 // REALLOC_RESOURCE_ARRAY*
87 // FREE_RESOURCE_ARRAY*
88 // NEW_RESOURCE_OBJ*
89 // NEW_C_HEAP_ARRAY*
90 // REALLOC_C_HEAP_ARRAY*
91 // FREE_C_HEAP_ARRAY*
92 // NEW_C_HEAP_OBJ*
93 // FREE_C_HEAP_OBJ
94 //
95 // char* AllocateHeap(size_t size, MEMFLAGS flags, const NativeCallStack& stack, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
96 // char* AllocateHeap(size_t size, MEMFLAGS flags, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
97 // char* ReallocateHeap(char *old, size_t size, MEMFLAGS flag, AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
98 // void FreeHeap(void* p);
99 //
100 // In non product mode we introduce a super class for all allocation classes
101 // that supports printing.
102 // We avoid the superclass in product mode to save space.
103
104 #ifdef PRODUCT
105 #define ALLOCATION_SUPER_CLASS_SPEC
106 #else
107 #define ALLOCATION_SUPER_CLASS_SPEC : public AllocatedObj
108 class AllocatedObj {
109 public:
110 // Printing support
111 void print() const;
112 void print_value() const;
113
114 virtual void print_on(outputStream* st) const;
115 virtual void print_value_on(outputStream* st) const;
116 };
117 #endif
118
119 #define MEMORY_TYPES_DO(f) \
120 /* Memory type by sub systems. It occupies lower byte. */ \
121 f(mtJavaHeap, "Java Heap") /* Java heap */ \
122 f(mtClass, "Class") /* Java classes */ \
123 f(mtThread, "Thread") /* thread objects */ \
124 f(mtThreadStack, "Thread Stack") \
125 f(mtCode, "Code") /* generated code */ \
126 f(mtGC, "GC") \
127 f(mtGCCardSet, "GCCardSet") /* G1 card set remembered set */ \
128 f(mtCompiler, "Compiler") \
129 f(mtJVMCI, "JVMCI") \
130 f(mtInternal, "Internal") /* memory used by VM, but does not belong to */ \
131 /* any of above categories, and not used by */ \
132 /* NMT */ \
133 f(mtOther, "Other") /* memory not used by VM */ \
134 f(mtSymbol, "Symbol") \
135 f(mtNMT, "Native Memory Tracking") /* memory used by NMT */ \
136 f(mtClassShared, "Shared class space") /* class data sharing */ \
137 f(mtChunk, "Arena Chunk") /* chunk that holds content of arenas */ \
138 f(mtTest, "Test") /* Test type for verifying NMT */ \
139 f(mtTracing, "Tracing") \
140 f(mtLogging, "Logging") \
141 f(mtStatistics, "Statistics") \
142 f(mtArguments, "Arguments") \
143 f(mtModule, "Module") \
144 f(mtSafepoint, "Safepoint") \
145 f(mtSynchronizer, "Synchronization") \
146 f(mtServiceability, "Serviceability") \
147 f(mtMetaspace, "Metaspace") \
148 f(mtStringDedup, "String Deduplication") \
149 f(mtObjectMonitor, "Object Monitors") \
150 f(mtNone, "Unknown") \
151 //end
152
153 #define MEMORY_TYPE_DECLARE_ENUM(type, human_readable) \
154 type,
155
156 /*
157 * Memory types
158 */
159 enum class MEMFLAGS {
160 MEMORY_TYPES_DO(MEMORY_TYPE_DECLARE_ENUM)
161 mtValueTypes, // memory for buffered value types
162 mt_number_of_types // number of memory types (mtDontTrack
163 // is not included as validate type)
164 };
165
166 #define MEMORY_TYPE_SHORTNAME(type, human_readable) \
167 constexpr MEMFLAGS type = MEMFLAGS::type;
168
169 // Generate short aliases for the enum values. E.g. mtGC instead of MEMFLAGS::mtGC.
170 MEMORY_TYPES_DO(MEMORY_TYPE_SHORTNAME)
171
172 // Make an int version of the sentinel end value.
173 constexpr int mt_number_of_types = static_cast<int>(MEMFLAGS::mt_number_of_types);
174
175 extern bool NMT_track_callsite;
176
177 class NativeCallStack;
178
179
180 char* AllocateHeap(size_t size,
181 MEMFLAGS flags,
182 const NativeCallStack& stack,
183 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
184 char* AllocateHeap(size_t size,
185 MEMFLAGS flags,
186 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
187
188 char* ReallocateHeap(char *old,
189 size_t size,
190 MEMFLAGS flag,
191 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
192
193 // handles NULL pointers
194 void FreeHeap(void* p);
195
196 template <MEMFLAGS F> class CHeapObj ALLOCATION_SUPER_CLASS_SPEC {
197 public:
198 ALWAYSINLINE void* operator new(size_t size) throw() {
199 return (void*)AllocateHeap(size, F);
200 }
201
202 ALWAYSINLINE void* operator new(size_t size,
203 const NativeCallStack& stack) throw() {
204 return (void*)AllocateHeap(size, F, stack);
205 }
206
207 ALWAYSINLINE void* operator new(size_t size, const std::nothrow_t&,
208 const NativeCallStack& stack) throw() {
209 return (void*)AllocateHeap(size, F, stack, AllocFailStrategy::RETURN_NULL);
210 }
211
212 ALWAYSINLINE void* operator new(size_t size, const std::nothrow_t&) throw() {
213 return (void*)AllocateHeap(size, F, AllocFailStrategy::RETURN_NULL);
214 }
215
216 ALWAYSINLINE void* operator new[](size_t size) throw() {
217 return (void*)AllocateHeap(size, F);
218 }
219
220 ALWAYSINLINE void* operator new[](size_t size,
221 const NativeCallStack& stack) throw() {
222 return (void*)AllocateHeap(size, F, stack);
223 }
224
225 ALWAYSINLINE void* operator new[](size_t size, const std::nothrow_t&,
226 const NativeCallStack& stack) throw() {
227 return (void*)AllocateHeap(size, F, stack, AllocFailStrategy::RETURN_NULL);
228 }
229
230 ALWAYSINLINE void* operator new[](size_t size, const std::nothrow_t&) throw() {
231 return (void*)AllocateHeap(size, F, AllocFailStrategy::RETURN_NULL);
232 }
233
234 void operator delete(void* p) { FreeHeap(p); }
235 void operator delete [] (void* p) { FreeHeap(p); }
236 };
237
238 // Base class for objects allocated on the stack only.
239 // Calling new or delete will result in fatal error.
240
241 class StackObj ALLOCATION_SUPER_CLASS_SPEC {
242 private:
243 void* operator new(size_t size) throw();
244 void* operator new [](size_t size) throw();
245 void operator delete(void* p);
246 void operator delete [](void* p);
247 };
248
249 // Base class for objects stored in Metaspace.
250 // Calling delete will result in fatal error.
251 //
252 // Do not inherit from something with a vptr because this class does
253 // not introduce one. This class is used to allocate both shared read-only
254 // and shared read-write classes.
255 //
256
257 class ClassLoaderData;
258 class MetaspaceClosure;
259
260 class MetaspaceObj {
261 // There are functions that all subtypes of MetaspaceObj are expected
262 // to implement, so that templates which are defined for this class hierarchy
263 // can work uniformly. Within the sub-hierarchy of Metadata, these are virtuals.
264 // Elsewhere in the hierarchy of MetaspaceObj, type(), size(), and/or on_stack()
265 // can be static if constant.
266 //
267 // The following functions are required by MetaspaceClosure:
268 // void metaspace_pointers_do(MetaspaceClosure* it) { <walk my refs> }
269 // int size() const { return align_up(sizeof(<This>), wordSize) / wordSize; }
270 // MetaspaceObj::Type type() const { return <This>Type; }
271 //
272 // The following functions are required by MetadataFactory::free_metadata():
273 // bool on_stack() { return false; }
274 // void deallocate_contents(ClassLoaderData* loader_data);
275
276 friend class VMStructs;
277 // When CDS is enabled, all shared metaspace objects are mapped
278 // into a single contiguous memory block, so we can use these
279 // two pointers to quickly determine if something is in the
280 // shared metaspace.
281 // When CDS is not enabled, both pointers are set to NULL.
282 static void* _shared_metaspace_base; // (inclusive) low address
283 static void* _shared_metaspace_top; // (exclusive) high address
284
285 public:
286
287 // Returns true if the pointer points to a valid MetaspaceObj. A valid
288 // MetaspaceObj is MetaWord-aligned and contained within either
289 // non-shared or shared metaspace.
290 static bool is_valid(const MetaspaceObj* p);
291
292 static bool is_shared(const MetaspaceObj* p) {
293 // If no shared metaspace regions are mapped, _shared_metaspace_{base,top} will
294 // both be NULL and all values of p will be rejected quickly.
295 return (((void*)p) < _shared_metaspace_top &&
296 ((void*)p) >= _shared_metaspace_base);
297 }
298 bool is_shared() const { return MetaspaceObj::is_shared(this); }
299
300 void print_address_on(outputStream* st) const; // nonvirtual address printing
301
302 static void set_shared_metaspace_range(void* base, void* top) {
303 _shared_metaspace_base = base;
304 _shared_metaspace_top = top;
305 }
306
307 static void* shared_metaspace_base() { return _shared_metaspace_base; }
308 static void* shared_metaspace_top() { return _shared_metaspace_top; }
309
310 #define METASPACE_OBJ_TYPES_DO(f) \
311 f(Class) \
312 f(Symbol) \
313 f(TypeArrayU1) \
314 f(TypeArrayU2) \
315 f(TypeArrayU4) \
316 f(TypeArrayU8) \
317 f(TypeArrayOther) \
318 f(Method) \
319 f(ConstMethod) \
320 f(MethodData) \
321 f(ConstantPool) \
322 f(ConstantPoolCache) \
323 f(Annotations) \
324 f(MethodCounters) \
325 f(RecordComponent)
326
327 #define METASPACE_OBJ_TYPE_DECLARE(name) name ## Type,
328 #define METASPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
329
330 enum Type {
331 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
332 METASPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
333 _number_of_types
334 };
335
336 static const char * type_name(Type type) {
337 switch(type) {
338 METASPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
339 default:
340 ShouldNotReachHere();
341 return NULL;
342 }
343 }
344
345 static MetaspaceObj::Type array_type(size_t elem_size) {
346 switch (elem_size) {
347 case 1: return TypeArrayU1Type;
348 case 2: return TypeArrayU2Type;
349 case 4: return TypeArrayU4Type;
350 case 8: return TypeArrayU8Type;
351 default:
352 return TypeArrayOtherType;
353 }
354 }
355
356 void* operator new(size_t size, ClassLoaderData* loader_data,
357 size_t word_size,
358 Type type, JavaThread* thread) throw();
359 // can't use TRAPS from this header file.
360 void* operator new(size_t size, ClassLoaderData* loader_data,
361 size_t word_size,
362 Type type) throw();
363 void operator delete(void* p) { ShouldNotCallThis(); }
364
365 // Declare a *static* method with the same signature in any subclass of MetaspaceObj
366 // that should be read-only by default. See symbol.hpp for an example. This function
367 // is used by the templates in metaspaceClosure.hpp
368 static bool is_read_only_by_default() { return false; }
369 };
370
371 // Base class for classes that constitute name spaces.
372
373 class Arena;
374
375 extern char* resource_allocate_bytes(size_t size,
376 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
377 extern char* resource_allocate_bytes(Thread* thread, size_t size,
378 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
379 extern char* resource_reallocate_bytes( char *old, size_t old_size, size_t new_size,
380 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
381 extern void resource_free_bytes( char *old, size_t size );
382
383 //----------------------------------------------------------------------
384 // Base class for objects allocated in the resource area per default.
385 // Optionally, objects may be allocated on the C heap with
386 // new(ResourceObj::C_HEAP) Foo(...) or in an Arena with new (&arena)
387 // ResourceObj's can be allocated within other objects, but don't use
388 // new or delete (allocation_type is unknown). If new is used to allocate,
389 // use delete to deallocate.
390 class ResourceObj ALLOCATION_SUPER_CLASS_SPEC {
391 public:
392 enum allocation_type { STACK_OR_EMBEDDED = 0, RESOURCE_AREA, C_HEAP, ARENA, allocation_mask = 0x3 };
393 static void set_allocation_type(address res, allocation_type type) NOT_DEBUG_RETURN;
394 #ifdef ASSERT
395 private:
396 // When this object is allocated on stack the new() operator is not
397 // called but garbage on stack may look like a valid allocation_type.
398 // Store negated 'this' pointer when new() is called to distinguish cases.
399 // Use second array's element for verification value to distinguish garbage.
400 uintptr_t _allocation_t[2];
401 bool is_type_set() const;
402 void initialize_allocation_info();
403 public:
404 allocation_type get_allocation_type() const;
405 bool allocated_on_stack_or_embedded() const { return get_allocation_type() == STACK_OR_EMBEDDED; }
406 bool allocated_on_res_area() const { return get_allocation_type() == RESOURCE_AREA; }
407 bool allocated_on_C_heap() const { return get_allocation_type() == C_HEAP; }
408 bool allocated_on_arena() const { return get_allocation_type() == ARENA; }
409 protected:
410 ResourceObj(); // default constructor
411 ResourceObj(const ResourceObj& r); // default copy constructor
412 ResourceObj& operator=(const ResourceObj& r); // default copy assignment
413 ~ResourceObj();
414 #endif // ASSERT
415
416 public:
417 void* operator new(size_t size, allocation_type type, MEMFLAGS flags) throw();
418 void* operator new [](size_t size, allocation_type type, MEMFLAGS flags) throw() = delete;
419 void* operator new(size_t size, const std::nothrow_t& nothrow_constant,
420 allocation_type type, MEMFLAGS flags) throw();
421 void* operator new [](size_t size, const std::nothrow_t& nothrow_constant,
422 allocation_type type, MEMFLAGS flags) throw() = delete;
423 void* operator new(size_t size, Arena *arena) throw();
424 void* operator new [](size_t size, Arena *arena) throw() = delete;
425
426 void* operator new(size_t size) throw() {
427 address res = (address)resource_allocate_bytes(size);
428 DEBUG_ONLY(set_allocation_type(res, RESOURCE_AREA);)
429 return res;
430 }
431
432 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
433 address res = (address)resource_allocate_bytes(size, AllocFailStrategy::RETURN_NULL);
434 DEBUG_ONLY(if (res != NULL) set_allocation_type(res, RESOURCE_AREA);)
435 return res;
436 }
437
438 void* operator new [](size_t size) throw() = delete;
439 void* operator new [](size_t size, const std::nothrow_t& nothrow_constant) throw() = delete;
440 void operator delete(void* p);
441 void operator delete [](void* p) = delete;
442 };
443
444 // One of the following macros must be used when allocating an array
445 // or object to determine whether it should reside in the C heap on in
446 // the resource area.
447
448 #define NEW_RESOURCE_ARRAY(type, size)\
449 (type*) resource_allocate_bytes((size) * sizeof(type))
450
451 #define NEW_RESOURCE_ARRAY_RETURN_NULL(type, size)\
452 (type*) resource_allocate_bytes((size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
453
454 #define NEW_RESOURCE_ARRAY_IN_THREAD(thread, type, size)\
455 (type*) resource_allocate_bytes(thread, (size) * sizeof(type))
456
457 #define NEW_RESOURCE_ARRAY_IN_THREAD_RETURN_NULL(thread, type, size)\
458 (type*) resource_allocate_bytes(thread, (size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
459
460 #define REALLOC_RESOURCE_ARRAY(type, old, old_size, new_size)\
461 (type*) resource_reallocate_bytes((char*)(old), (old_size) * sizeof(type), (new_size) * sizeof(type))
462
463 #define REALLOC_RESOURCE_ARRAY_RETURN_NULL(type, old, old_size, new_size)\
464 (type*) resource_reallocate_bytes((char*)(old), (old_size) * sizeof(type),\
465 (new_size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
466
467 #define FREE_RESOURCE_ARRAY(type, old, size)\
468 resource_free_bytes((char*)(old), (size) * sizeof(type))
469
470 #define FREE_FAST(old)\
471 /* nop */
472
473 #define NEW_RESOURCE_OBJ(type)\
474 NEW_RESOURCE_ARRAY(type, 1)
475
476 #define NEW_RESOURCE_OBJ_RETURN_NULL(type)\
477 NEW_RESOURCE_ARRAY_RETURN_NULL(type, 1)
478
479 #define NEW_C_HEAP_ARRAY3(type, size, memflags, pc, allocfail)\
480 (type*) AllocateHeap((size) * sizeof(type), memflags, pc, allocfail)
481
482 #define NEW_C_HEAP_ARRAY2(type, size, memflags, pc)\
483 (type*) (AllocateHeap((size) * sizeof(type), memflags, pc))
484
485 #define NEW_C_HEAP_ARRAY(type, size, memflags)\
486 (type*) (AllocateHeap((size) * sizeof(type), memflags))
487
488 #define NEW_C_HEAP_ARRAY2_RETURN_NULL(type, size, memflags, pc)\
489 NEW_C_HEAP_ARRAY3(type, (size), memflags, pc, AllocFailStrategy::RETURN_NULL)
490
491 #define NEW_C_HEAP_ARRAY_RETURN_NULL(type, size, memflags)\
492 NEW_C_HEAP_ARRAY2(type, (size), memflags, AllocFailStrategy::RETURN_NULL)
493
494 #define REALLOC_C_HEAP_ARRAY(type, old, size, memflags)\
495 (type*) (ReallocateHeap((char*)(old), (size) * sizeof(type), memflags))
496
497 #define REALLOC_C_HEAP_ARRAY_RETURN_NULL(type, old, size, memflags)\
498 (type*) (ReallocateHeap((char*)(old), (size) * sizeof(type), memflags, AllocFailStrategy::RETURN_NULL))
499
500 #define FREE_C_HEAP_ARRAY(type, old) \
501 FreeHeap((char*)(old))
502
503 // allocate type in heap without calling ctor
504 #define NEW_C_HEAP_OBJ(type, memflags)\
505 NEW_C_HEAP_ARRAY(type, 1, memflags)
506
507 #define NEW_C_HEAP_OBJ_RETURN_NULL(type, memflags)\
508 NEW_C_HEAP_ARRAY_RETURN_NULL(type, 1, memflags)
509
510 // deallocate obj of type in heap without calling dtor
511 #define FREE_C_HEAP_OBJ(objname)\
512 FreeHeap((char*)objname);
513
514
515 //------------------------------ReallocMark---------------------------------
516 // Code which uses REALLOC_RESOURCE_ARRAY should check an associated
517 // ReallocMark, which is declared in the same scope as the reallocated
518 // pointer. Any operation that could __potentially__ cause a reallocation
519 // should check the ReallocMark.
520 class ReallocMark: public StackObj {
521 protected:
522 NOT_PRODUCT(int _nesting;)
523
524 public:
525 ReallocMark() PRODUCT_RETURN;
526 void check() PRODUCT_RETURN;
527 };
528
529 // Helper class to allocate arrays that may become large.
530 // Uses the OS malloc for allocations smaller than ArrayAllocatorMallocLimit
531 // and uses mapped memory for larger allocations.
532 // Most OS mallocs do something similar but Solaris malloc does not revert
533 // to mapped memory for large allocations. By default ArrayAllocatorMallocLimit
534 // is set so that we always use malloc except for Solaris where we set the
535 // limit to get mapped memory.
536 template <class E>
537 class ArrayAllocator : public AllStatic {
538 private:
539 static bool should_use_malloc(size_t length);
540
541 static E* allocate_malloc(size_t length, MEMFLAGS flags);
542 static E* allocate_mmap(size_t length, MEMFLAGS flags);
543
544 static void free_malloc(E* addr, size_t length);
545 static void free_mmap(E* addr, size_t length);
546
547 public:
548 static E* allocate(size_t length, MEMFLAGS flags);
549 static E* reallocate(E* old_addr, size_t old_length, size_t new_length, MEMFLAGS flags);
550 static void free(E* addr, size_t length);
551 };
552
553 // Uses mmaped memory for all allocations. All allocations are initially
554 // zero-filled. No pre-touching.
555 template <class E>
556 class MmapArrayAllocator : public AllStatic {
557 private:
558 static size_t size_for(size_t length);
559
560 public:
561 static E* allocate_or_null(size_t length, MEMFLAGS flags);
562 static E* allocate(size_t length, MEMFLAGS flags);
563 static void free(E* addr, size_t length);
564 };
565
566 // Uses malloc:ed memory for all allocations.
567 template <class E>
568 class MallocArrayAllocator : public AllStatic {
569 public:
570 static size_t size_for(size_t length);
571
572 static E* allocate(size_t length, MEMFLAGS flags);
573 static void free(E* addr);
574 };
575
576 #endif // SHARE_MEMORY_ALLOCATION_HPP