1 /*
2 * Copyright (c) 1997, 2021, 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(mtNone, "Unknown") \
150 //end
151
152 #define MEMORY_TYPE_DECLARE_ENUM(type, human_readable) \
153 type,
154
155 /*
156 * Memory types
157 */
158 enum class MEMFLAGS {
159 MEMORY_TYPES_DO(MEMORY_TYPE_DECLARE_ENUM)
160 mtValueTypes, // memory for buffered value types
161 mt_number_of_types // number of memory types (mtDontTrack
162 // is not included as validate type)
163 };
164
165 #define MEMORY_TYPE_SHORTNAME(type, human_readable) \
166 constexpr MEMFLAGS type = MEMFLAGS::type;
167
168 // Generate short aliases for the enum values. E.g. mtGC instead of MEMFLAGS::mtGC.
169 MEMORY_TYPES_DO(MEMORY_TYPE_SHORTNAME)
170
171 // Make an int version of the sentinel end value.
172 constexpr int mt_number_of_types = static_cast<int>(MEMFLAGS::mt_number_of_types);
173
174 #if INCLUDE_NMT
175
176 extern bool NMT_track_callsite;
177
178 #else
179
180 const bool NMT_track_callsite = false;
181
182 #endif // INCLUDE_NMT
183
184 class NativeCallStack;
185
186
187 char* AllocateHeap(size_t size,
188 MEMFLAGS flags,
189 const NativeCallStack& stack,
190 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
191 char* AllocateHeap(size_t size,
192 MEMFLAGS flags,
193 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
194
195 char* ReallocateHeap(char *old,
196 size_t size,
197 MEMFLAGS flag,
198 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
199
200 // handles NULL pointers
201 void FreeHeap(void* p);
202
203 template <MEMFLAGS F> class CHeapObj ALLOCATION_SUPER_CLASS_SPEC {
204 public:
205 ALWAYSINLINE void* operator new(size_t size) throw() {
206 return (void*)AllocateHeap(size, F);
207 }
208
209 ALWAYSINLINE void* operator new(size_t size,
210 const NativeCallStack& stack) throw() {
211 return (void*)AllocateHeap(size, F, stack);
212 }
213
214 ALWAYSINLINE void* operator new(size_t size, const std::nothrow_t&,
215 const NativeCallStack& stack) throw() {
216 return (void*)AllocateHeap(size, F, stack, AllocFailStrategy::RETURN_NULL);
217 }
218
219 ALWAYSINLINE void* operator new(size_t size, const std::nothrow_t&) throw() {
220 return (void*)AllocateHeap(size, F, AllocFailStrategy::RETURN_NULL);
221 }
222
223 ALWAYSINLINE void* operator new[](size_t size) throw() {
224 return (void*)AllocateHeap(size, F);
225 }
226
227 ALWAYSINLINE void* operator new[](size_t size,
228 const NativeCallStack& stack) throw() {
229 return (void*)AllocateHeap(size, F, stack);
230 }
231
232 ALWAYSINLINE void* operator new[](size_t size, const std::nothrow_t&,
233 const NativeCallStack& stack) throw() {
234 return (void*)AllocateHeap(size, F, stack, AllocFailStrategy::RETURN_NULL);
235 }
236
237 ALWAYSINLINE void* operator new[](size_t size, const std::nothrow_t&) throw() {
238 return (void*)AllocateHeap(size, F, AllocFailStrategy::RETURN_NULL);
239 }
240
241 void operator delete(void* p) { FreeHeap(p); }
242 void operator delete [] (void* p) { FreeHeap(p); }
243 };
244
245 // Base class for objects allocated on the stack only.
246 // Calling new or delete will result in fatal error.
247
248 class StackObj ALLOCATION_SUPER_CLASS_SPEC {
249 private:
250 void* operator new(size_t size) throw();
251 void* operator new [](size_t size) throw();
252 void operator delete(void* p);
253 void operator delete [](void* p);
254 };
255
256 // Base class for objects stored in Metaspace.
257 // Calling delete will result in fatal error.
258 //
259 // Do not inherit from something with a vptr because this class does
260 // not introduce one. This class is used to allocate both shared read-only
261 // and shared read-write classes.
262 //
263
264 class ClassLoaderData;
265 class MetaspaceClosure;
266
267 class MetaspaceObj {
268 // There are functions that all subtypes of MetaspaceObj are expected
269 // to implement, so that templates which are defined for this class hierarchy
270 // can work uniformly. Within the sub-hierarchy of Metadata, these are virtuals.
271 // Elsewhere in the hierarchy of MetaspaceObj, type(), size(), and/or on_stack()
272 // can be static if constant.
273 //
274 // The following functions are required by MetaspaceClosure:
275 // void metaspace_pointers_do(MetaspaceClosure* it) { <walk my refs> }
276 // int size() const { return align_up(sizeof(<This>), wordSize) / wordSize; }
277 // MetaspaceObj::Type type() const { return <This>Type; }
278 //
279 // The following functions are required by MetadataFactory::free_metadata():
280 // bool on_stack() { return false; }
281 // void deallocate_contents(ClassLoaderData* loader_data);
282
283 friend class VMStructs;
284 // When CDS is enabled, all shared metaspace objects are mapped
285 // into a single contiguous memory block, so we can use these
286 // two pointers to quickly determine if something is in the
287 // shared metaspace.
288 // When CDS is not enabled, both pointers are set to NULL.
289 static void* _shared_metaspace_base; // (inclusive) low address
290 static void* _shared_metaspace_top; // (exclusive) high address
291
292 public:
293
294 // Returns true if the pointer points to a valid MetaspaceObj. A valid
295 // MetaspaceObj is MetaWord-aligned and contained within either
296 // non-shared or shared metaspace.
297 static bool is_valid(const MetaspaceObj* p);
298
299 static bool is_shared(const MetaspaceObj* p) {
300 // If no shared metaspace regions are mapped, _shared_metaspace_{base,top} will
301 // both be NULL and all values of p will be rejected quickly.
302 return (((void*)p) < _shared_metaspace_top &&
303 ((void*)p) >= _shared_metaspace_base);
304 }
305 bool is_shared() const { return MetaspaceObj::is_shared(this); }
306
307 void print_address_on(outputStream* st) const; // nonvirtual address printing
308
309 static void set_shared_metaspace_range(void* base, void* top) {
310 _shared_metaspace_base = base;
311 _shared_metaspace_top = top;
312 }
313
314 static void* shared_metaspace_base() { return _shared_metaspace_base; }
315 static void* shared_metaspace_top() { return _shared_metaspace_top; }
316
317 #define METASPACE_OBJ_TYPES_DO(f) \
318 f(Class) \
319 f(Symbol) \
320 f(TypeArrayU1) \
321 f(TypeArrayU2) \
322 f(TypeArrayU4) \
323 f(TypeArrayU8) \
324 f(TypeArrayOther) \
325 f(Method) \
326 f(ConstMethod) \
327 f(MethodData) \
328 f(ConstantPool) \
329 f(ConstantPoolCache) \
330 f(Annotations) \
331 f(MethodCounters) \
332 f(RecordComponent)
333
334 #define METASPACE_OBJ_TYPE_DECLARE(name) name ## Type,
335 #define METASPACE_OBJ_TYPE_NAME_CASE(name) case name ## Type: return #name;
336
337 enum Type {
338 // Types are MetaspaceObj::ClassType, MetaspaceObj::SymbolType, etc
339 METASPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_DECLARE)
340 _number_of_types
341 };
342
343 static const char * type_name(Type type) {
344 switch(type) {
345 METASPACE_OBJ_TYPES_DO(METASPACE_OBJ_TYPE_NAME_CASE)
346 default:
347 ShouldNotReachHere();
348 return NULL;
349 }
350 }
351
352 static MetaspaceObj::Type array_type(size_t elem_size) {
353 switch (elem_size) {
354 case 1: return TypeArrayU1Type;
355 case 2: return TypeArrayU2Type;
356 case 4: return TypeArrayU4Type;
357 case 8: return TypeArrayU8Type;
358 default:
359 return TypeArrayOtherType;
360 }
361 }
362
363 void* operator new(size_t size, ClassLoaderData* loader_data,
364 size_t word_size,
365 Type type, JavaThread* thread) throw();
366 // can't use TRAPS from this header file.
367 void* operator new(size_t size, ClassLoaderData* loader_data,
368 size_t word_size,
369 Type type) throw();
370 void operator delete(void* p) { ShouldNotCallThis(); }
371
372 // Declare a *static* method with the same signature in any subclass of MetaspaceObj
373 // that should be read-only by default. See symbol.hpp for an example. This function
374 // is used by the templates in metaspaceClosure.hpp
375 static bool is_read_only_by_default() { return false; }
376 };
377
378 // Base class for classes that constitute name spaces.
379
380 class Arena;
381
382 extern char* resource_allocate_bytes(size_t size,
383 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
384 extern char* resource_allocate_bytes(Thread* thread, size_t size,
385 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
386 extern char* resource_reallocate_bytes( char *old, size_t old_size, size_t new_size,
387 AllocFailType alloc_failmode = AllocFailStrategy::EXIT_OOM);
388 extern void resource_free_bytes( char *old, size_t size );
389
390 //----------------------------------------------------------------------
391 // Base class for objects allocated in the resource area per default.
392 // Optionally, objects may be allocated on the C heap with
393 // new(ResourceObj::C_HEAP) Foo(...) or in an Arena with new (&arena)
394 // ResourceObj's can be allocated within other objects, but don't use
395 // new or delete (allocation_type is unknown). If new is used to allocate,
396 // use delete to deallocate.
397 class ResourceObj ALLOCATION_SUPER_CLASS_SPEC {
398 public:
399 enum allocation_type { STACK_OR_EMBEDDED = 0, RESOURCE_AREA, C_HEAP, ARENA, allocation_mask = 0x3 };
400 static void set_allocation_type(address res, allocation_type type) NOT_DEBUG_RETURN;
401 #ifdef ASSERT
402 private:
403 // When this object is allocated on stack the new() operator is not
404 // called but garbage on stack may look like a valid allocation_type.
405 // Store negated 'this' pointer when new() is called to distinguish cases.
406 // Use second array's element for verification value to distinguish garbage.
407 uintptr_t _allocation_t[2];
408 bool is_type_set() const;
409 void initialize_allocation_info();
410 public:
411 allocation_type get_allocation_type() const;
412 bool allocated_on_stack() const { return get_allocation_type() == STACK_OR_EMBEDDED; }
413 bool allocated_on_res_area() const { return get_allocation_type() == RESOURCE_AREA; }
414 bool allocated_on_C_heap() const { return get_allocation_type() == C_HEAP; }
415 bool allocated_on_arena() const { return get_allocation_type() == ARENA; }
416 protected:
417 ResourceObj(); // default constructor
418 ResourceObj(const ResourceObj& r); // default copy constructor
419 ResourceObj& operator=(const ResourceObj& r); // default copy assignment
420 ~ResourceObj();
421 #endif // ASSERT
422
423 public:
424 void* operator new(size_t size, allocation_type type, MEMFLAGS flags) throw();
425 void* operator new [](size_t size, allocation_type type, MEMFLAGS flags) throw() = delete;
426 void* operator new(size_t size, const std::nothrow_t& nothrow_constant,
427 allocation_type type, MEMFLAGS flags) throw();
428 void* operator new [](size_t size, const std::nothrow_t& nothrow_constant,
429 allocation_type type, MEMFLAGS flags) throw() = delete;
430 void* operator new(size_t size, Arena *arena) throw();
431 void* operator new [](size_t size, Arena *arena) throw() = delete;
432
433 void* operator new(size_t size) throw() {
434 address res = (address)resource_allocate_bytes(size);
435 DEBUG_ONLY(set_allocation_type(res, RESOURCE_AREA);)
436 return res;
437 }
438
439 void* operator new(size_t size, const std::nothrow_t& nothrow_constant) throw() {
440 address res = (address)resource_allocate_bytes(size, AllocFailStrategy::RETURN_NULL);
441 DEBUG_ONLY(if (res != NULL) set_allocation_type(res, RESOURCE_AREA);)
442 return res;
443 }
444
445 void* operator new [](size_t size) throw() = delete;
446 void* operator new [](size_t size, const std::nothrow_t& nothrow_constant) throw() = delete;
447 void operator delete(void* p);
448 void operator delete [](void* p) = delete;
449 };
450
451 // One of the following macros must be used when allocating an array
452 // or object to determine whether it should reside in the C heap on in
453 // the resource area.
454
455 #define NEW_RESOURCE_ARRAY(type, size)\
456 (type*) resource_allocate_bytes((size) * sizeof(type))
457
458 #define NEW_RESOURCE_ARRAY_RETURN_NULL(type, size)\
459 (type*) resource_allocate_bytes((size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
460
461 #define NEW_RESOURCE_ARRAY_IN_THREAD(thread, type, size)\
462 (type*) resource_allocate_bytes(thread, (size) * sizeof(type))
463
464 #define NEW_RESOURCE_ARRAY_IN_THREAD_RETURN_NULL(thread, type, size)\
465 (type*) resource_allocate_bytes(thread, (size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
466
467 #define REALLOC_RESOURCE_ARRAY(type, old, old_size, new_size)\
468 (type*) resource_reallocate_bytes((char*)(old), (old_size) * sizeof(type), (new_size) * sizeof(type))
469
470 #define REALLOC_RESOURCE_ARRAY_RETURN_NULL(type, old, old_size, new_size)\
471 (type*) resource_reallocate_bytes((char*)(old), (old_size) * sizeof(type),\
472 (new_size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
473
474 #define FREE_RESOURCE_ARRAY(type, old, size)\
475 resource_free_bytes((char*)(old), (size) * sizeof(type))
476
477 #define FREE_FAST(old)\
478 /* nop */
479
480 #define NEW_RESOURCE_OBJ(type)\
481 NEW_RESOURCE_ARRAY(type, 1)
482
483 #define NEW_RESOURCE_OBJ_RETURN_NULL(type)\
484 NEW_RESOURCE_ARRAY_RETURN_NULL(type, 1)
485
486 #define NEW_C_HEAP_ARRAY3(type, size, memflags, pc, allocfail)\
487 (type*) AllocateHeap((size) * sizeof(type), memflags, pc, allocfail)
488
489 #define NEW_C_HEAP_ARRAY2(type, size, memflags, pc)\
490 (type*) (AllocateHeap((size) * sizeof(type), memflags, pc))
491
492 #define NEW_C_HEAP_ARRAY(type, size, memflags)\
493 (type*) (AllocateHeap((size) * sizeof(type), memflags))
494
495 #define NEW_C_HEAP_ARRAY2_RETURN_NULL(type, size, memflags, pc)\
496 NEW_C_HEAP_ARRAY3(type, (size), memflags, pc, AllocFailStrategy::RETURN_NULL)
497
498 #define NEW_C_HEAP_ARRAY_RETURN_NULL(type, size, memflags)\
499 NEW_C_HEAP_ARRAY2(type, (size), memflags, AllocFailStrategy::RETURN_NULL)
500
501 #define REALLOC_C_HEAP_ARRAY(type, old, size, memflags)\
502 (type*) (ReallocateHeap((char*)(old), (size) * sizeof(type), memflags))
503
504 #define REALLOC_C_HEAP_ARRAY_RETURN_NULL(type, old, size, memflags)\
505 (type*) (ReallocateHeap((char*)(old), (size) * sizeof(type), memflags, AllocFailStrategy::RETURN_NULL))
506
507 #define FREE_C_HEAP_ARRAY(type, old) \
508 FreeHeap((char*)(old))
509
510 // allocate type in heap without calling ctor
511 #define NEW_C_HEAP_OBJ(type, memflags)\
512 NEW_C_HEAP_ARRAY(type, 1, memflags)
513
514 #define NEW_C_HEAP_OBJ_RETURN_NULL(type, memflags)\
515 NEW_C_HEAP_ARRAY_RETURN_NULL(type, 1, memflags)
516
517 // deallocate obj of type in heap without calling dtor
518 #define FREE_C_HEAP_OBJ(objname)\
519 FreeHeap((char*)objname);
520
521
522 //------------------------------ReallocMark---------------------------------
523 // Code which uses REALLOC_RESOURCE_ARRAY should check an associated
524 // ReallocMark, which is declared in the same scope as the reallocated
525 // pointer. Any operation that could __potentially__ cause a reallocation
526 // should check the ReallocMark.
527 class ReallocMark: public StackObj {
528 protected:
529 NOT_PRODUCT(int _nesting;)
530
531 public:
532 ReallocMark() PRODUCT_RETURN;
533 void check() PRODUCT_RETURN;
534 };
535
536 // Helper class to allocate arrays that may become large.
537 // Uses the OS malloc for allocations smaller than ArrayAllocatorMallocLimit
538 // and uses mapped memory for larger allocations.
539 // Most OS mallocs do something similar but Solaris malloc does not revert
540 // to mapped memory for large allocations. By default ArrayAllocatorMallocLimit
541 // is set so that we always use malloc except for Solaris where we set the
542 // limit to get mapped memory.
543 template <class E>
544 class ArrayAllocator : public AllStatic {
545 private:
546 static bool should_use_malloc(size_t length);
547
548 static E* allocate_malloc(size_t length, MEMFLAGS flags);
549 static E* allocate_mmap(size_t length, MEMFLAGS flags);
550
551 static void free_malloc(E* addr, size_t length);
552 static void free_mmap(E* addr, size_t length);
553
554 public:
555 static E* allocate(size_t length, MEMFLAGS flags);
556 static E* reallocate(E* old_addr, size_t old_length, size_t new_length, MEMFLAGS flags);
557 static void free(E* addr, size_t length);
558 };
559
560 // Uses mmaped memory for all allocations. All allocations are initially
561 // zero-filled. No pre-touching.
562 template <class E>
563 class MmapArrayAllocator : public AllStatic {
564 private:
565 static size_t size_for(size_t length);
566
567 public:
568 static E* allocate_or_null(size_t length, MEMFLAGS flags);
569 static E* allocate(size_t length, MEMFLAGS flags);
570 static void free(E* addr, size_t length);
571 };
572
573 // Uses malloc:ed memory for all allocations.
574 template <class E>
575 class MallocArrayAllocator : public AllStatic {
576 public:
577 static size_t size_for(size_t length);
578
579 static E* allocate(size_t length, MEMFLAGS flags);
580 static void free(E* addr);
581 };
582
583 #endif // SHARE_MEMORY_ALLOCATION_HPP