template<size_t kMinOuterSize_ = internal::GenericBuddyAllocator::kDefaultMinOuterSize, size_t kNumBuckets = internal::GenericBuddyAllocator::kDefaultNumBuckets>
class pw::allocator::BuddyAllocator< kMinOuterSize_, kNumBuckets >
Allocator that uses the buddy memory allocation algorithm.
This allocator allocates blocks of memory whose sizes are powers of two. This allows the allocator to satisfy requests to acquire and release memory very quickly, at the possible cost of higher internal fragmentation. In particular:
- The maximum alignment for this allocator is
kMinInnerSize.
- The minimum size of an allocation is
kMinInnerSize. Less may be requested, but it will be satisfied by a block of that inner size.
- The maximum size of an allocation is
kMinInnerSize << (kNumBuckets - 1).
Use this allocator if you know the needed sizes are close to but less than the block inner sizes and you need high allocator performance.
- Template Parameters
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| kMinOuterSize | Outer size of the smallest allocatable block. Must be a power of two. All allocations will use at least this much memory. |
| kNumBuckets | Number of buckets. Must be at least 1. Each additional bucket allows combining blocks into larger blocks. |
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constexpr | BuddyAllocator () |
| | Constructs an allocator. Callers must call Init.
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| | BuddyAllocator (ByteSpan region) |
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| void | InitBuckets (span< UnorderedBucket< BuddyBlock > > buckets, size_t min_outer_size) |
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void | Init (ByteSpan region) |
| | Sets the memory used to allocate blocks.
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| void * | Allocate (Layout layout) |
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| template<typename T , int &... kExplicitGuard, typename... Args> |
| std::enable_if_t<!std::is_array_v< T >, T * > | New (Args &&... args) |
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| template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0> |
| ElementType * | New () |
| |
| template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| ElementType * | New (size_t count) |
| |
| template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| ElementType * | New (size_t count, size_t alignment) |
| | Constructs an alignment-byte aligned array of count objects.
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| template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args> |
| UniquePtr< T > | MakeUnique (Args &&... args) |
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| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| UniquePtr< T > | MakeUnique (size_t size) |
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| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| UniquePtr< T > | MakeUnique (size_t size, size_t alignment) |
| |
| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_bounded_array_v< T >, int > = 0> |
| UniquePtr< T > | MakeUnique () |
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| template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args> |
| SharedPtr< T > | MakeShared (Args &&... args) |
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| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| SharedPtr< T > | MakeShared (size_t size) |
| |
| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| SharedPtr< T > | MakeShared (size_t size, size_t alignment) |
| |
| template<typename T , int &... kExplicitGuard, std::enable_if_t< is_bounded_array_v< T >, int > = 0> |
| SharedPtr< T > | MakeShared () |
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| bool | Resize (void *ptr, size_t new_size) |
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| void * | Reallocate (void *ptr, Layout new_layout) |
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| size_t | GetAllocated () const |
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std::optional< allocator::Fragmentation > | MeasureFragmentation () const |
| | Returns fragmentation information for the allocator's memory region.
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constexpr const Capabilities & | capabilities () const |
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constexpr bool | HasCapability (Capability capability) const |
| | Returns whether a given capability is enabled for this object.
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| void | Deallocate (void *ptr) |
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| template<typename ElementType > |
| void | DeleteArray (ElementType *ptr, size_t count) |
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| StatusWithSize | GetCapacity () const |
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| bool | IsEqual (const Deallocator &other) const |
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| template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0> |
| void | Delete (T *ptr) |
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template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0> |
| void | Delete (ElementType *ptr) |
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template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0> |
| void | Delete (ElementType *ptr, size_t count) |
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Public Member Functions inherited from pw::allocator::internal::GenericBuddyAllocator
1.9.6