1 /* 2 * Copyright (c) 2018, 2019, 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_GC_SHARED_MEMALLOCATOR_HPP 26 #define SHARE_GC_SHARED_MEMALLOCATOR_HPP 27 28 #include "gc/shared/collectedHeap.hpp" 29 #include "memory/memRegion.hpp" 30 #include "oops/oopsHierarchy.hpp" 31 #include "utilities/exceptions.hpp" 32 #include "utilities/macros.hpp" 33 34 // These fascilities are used for allocating, and initializing newly allocated objects. 35 36 class MemAllocator: StackObj { 37 protected: 38 class Allocation; 39 40 Thread* const _thread; 41 Klass* const _klass; 42 const size_t _word_size; 43 44 private: 45 // Allocate from the current thread's TLAB, with broken-out slow path. 46 HeapWord* allocate_inside_tlab(Allocation& allocation) const; 47 HeapWord* allocate_inside_tlab_slow(Allocation& allocation) const; 48 HeapWord* allocate_outside_tlab(Allocation& allocation) const; 49 50 protected: 51 MemAllocator(Klass* klass, size_t word_size, Thread* thread) 52 : _thread(thread), 53 _klass(klass), 54 _word_size(word_size) 55 { } 56 57 // This function clears the memory of the object 58 void mem_clear(HeapWord* mem) const; 59 // This finish constructing an oop by installing the mark word and the Klass* pointer 60 // last. At the point when the Klass pointer is initialized, this is a constructed object 61 // that must be parseable as an oop by concurrent collectors. 62 oop finish(HeapWord* mem) const; 63 64 // Raw memory allocation. This may or may not use TLAB allocations to satisfy the 65 // allocation. A GC implementation may override this function to satisfy the allocation 66 // in any way. But the default is to try a TLAB allocation, and otherwise perform 67 // mem_allocate. 68 virtual HeapWord* mem_allocate(Allocation& allocation) const; 69 70 virtual MemRegion obj_memory_range(oop obj) const { 71 return MemRegion((HeapWord*)obj, _word_size); 72 } 73 74 public: 75 oop allocate() const; 76 virtual oop initialize(HeapWord* mem) const = 0; 77 }; 78 79 class ObjAllocator: public MemAllocator { 80 public: 81 ObjAllocator(Klass* klass, size_t word_size, Thread* thread = Thread::current()) 82 : MemAllocator(klass, word_size, thread) {} 83 virtual oop initialize(HeapWord* mem) const; 84 }; 85 86 class ObjArrayAllocator: public MemAllocator { 87 const int _length; 88 const bool _do_zero; 89 protected: 90 virtual MemRegion obj_memory_range(oop obj) const; 91 92 public: 93 ObjArrayAllocator(Klass* klass, size_t word_size, int length, bool do_zero, 94 Thread* thread = Thread::current()) 95 : MemAllocator(klass, word_size, thread), 96 _length(length), 97 _do_zero(do_zero) {} 98 virtual oop initialize(HeapWord* mem) const; 99 }; 100 101 class ClassAllocator: public MemAllocator { 102 public: 103 ClassAllocator(Klass* klass, size_t word_size, Thread* thread = Thread::current()) 104 : MemAllocator(klass, word_size, thread) {} 105 virtual oop initialize(HeapWord* mem) const; 106 }; 107 108 #endif // SHARE_GC_SHARED_MEMALLOCATOR_HPP