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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //==- llvm/Support/Recycler.h - Recycling Allocator --------------*- C++ -*-==// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file defines the Recycler class template. See the doxygen comment for |
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| 10 | // Recycler for more details. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |||
| 14 | #ifndef LLVM_SUPPORT_RECYCLER_H |
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| 15 | #define LLVM_SUPPORT_RECYCLER_H |
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| 16 | |||
| 17 | #include "llvm/ADT/ilist.h" |
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| 18 | #include "llvm/Support/Allocator.h" |
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| 19 | #include "llvm/Support/ErrorHandling.h" |
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| 20 | #include <cassert> |
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| 21 | |||
| 22 | namespace llvm { |
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| 23 | |||
| 24 | /// PrintRecyclingAllocatorStats - Helper for RecyclingAllocator for |
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| 25 | /// printing statistics. |
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| 26 | /// |
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| 27 | void PrintRecyclerStats(size_t Size, size_t Align, size_t FreeListSize); |
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| 28 | |||
| 29 | /// Recycler - This class manages a linked-list of deallocated nodes |
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| 30 | /// and facilitates reusing deallocated memory in place of allocating |
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| 31 | /// new memory. |
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| 32 | /// |
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| 33 | template <class T, size_t Size = sizeof(T), size_t Align = alignof(T)> |
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| 34 | class Recycler { |
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| 35 | struct FreeNode { |
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| 36 | FreeNode *Next; |
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| 37 | }; |
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| 38 | |||
| 39 | /// List of nodes that have deleted contents and are not in active use. |
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| 40 | FreeNode *FreeList = nullptr; |
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| 41 | |||
| 42 | FreeNode *pop_val() { |
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| 43 | auto *Val = FreeList; |
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| 44 | __asan_unpoison_memory_region(Val, Size); |
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| 45 | FreeList = FreeList->Next; |
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| 46 | __msan_allocated_memory(Val, Size); |
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| 47 | return Val; |
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| 48 | } |
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| 49 | |||
| 50 | void push(FreeNode *N) { |
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| 51 | N->Next = FreeList; |
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| 52 | FreeList = N; |
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| 53 | __asan_poison_memory_region(N, Size); |
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| 54 | } |
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| 55 | |||
| 56 | public: |
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| 57 | ~Recycler() { |
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| 58 | // If this fails, either the callee has lost track of some allocation, |
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| 59 | // or the callee isn't tracking allocations and should just call |
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| 60 | // clear() before deleting the Recycler. |
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| 61 | assert(!FreeList && "Non-empty recycler deleted!"); |
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| 62 | } |
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| 63 | |||
| 64 | /// clear - Release all the tracked allocations to the allocator. The |
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| 65 | /// recycler must be free of any tracked allocations before being |
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| 66 | /// deleted; calling clear is one way to ensure this. |
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| 67 | template<class AllocatorType> |
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| 68 | void clear(AllocatorType &Allocator) { |
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| 69 | while (FreeList) { |
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| 70 | T *t = reinterpret_cast<T *>(pop_val()); |
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| 71 | Allocator.Deallocate(t); |
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| 72 | } |
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| 73 | } |
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| 74 | |||
| 75 | /// Special case for BumpPtrAllocator which has an empty Deallocate() |
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| 76 | /// function. |
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| 77 | /// |
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| 78 | /// There is no need to traverse the free list, pulling all the objects into |
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| 79 | /// cache. |
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| 80 | void clear(BumpPtrAllocator &) { FreeList = nullptr; } |
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| 81 | |||
| 82 | template<class SubClass, class AllocatorType> |
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| 83 | SubClass *Allocate(AllocatorType &Allocator) { |
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| 84 | static_assert(alignof(SubClass) <= Align, |
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| 85 | "Recycler allocation alignment is less than object align!"); |
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| 86 | static_assert(sizeof(SubClass) <= Size, |
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| 87 | "Recycler allocation size is less than object size!"); |
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| 88 | return FreeList ? reinterpret_cast<SubClass *>(pop_val()) |
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| 89 | : static_cast<SubClass *>(Allocator.Allocate(Size, Align)); |
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| 90 | } |
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| 91 | |||
| 92 | template<class AllocatorType> |
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| 93 | T *Allocate(AllocatorType &Allocator) { |
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| 94 | return Allocate<T>(Allocator); |
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| 95 | } |
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| 96 | |||
| 97 | template<class SubClass, class AllocatorType> |
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| 98 | void Deallocate(AllocatorType & /*Allocator*/, SubClass* Element) { |
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| 99 | push(reinterpret_cast<FreeNode *>(Element)); |
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| 100 | } |
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| 101 | |||
| 102 | void PrintStats(); |
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| 103 | }; |
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| 104 | |||
| 105 | template <class T, size_t Size, size_t Align> |
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| 106 | void Recycler<T, Size, Align>::PrintStats() { |
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| 107 | size_t S = 0; |
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| 108 | for (auto *I = FreeList; I; I = I->Next) |
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| 109 | ++S; |
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| 110 | PrintRecyclerStats(Size, Align, S); |
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| 111 | } |
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| 112 | |||
| 113 | } |
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| 114 | |||
| 115 | #endif |