137 lines
5.5 KiB
C++
137 lines
5.5 KiB
C++
/** @file AAllocator.hpp
|
|
*
|
|
* @author Roland Conybeare, Dec 2025
|
|
**/
|
|
|
|
#pragma once
|
|
|
|
#include "AllocatorError.hpp"
|
|
#include "AllocInfo.hpp"
|
|
#include "xo/facet/facet_implementation.hpp"
|
|
#include "xo/facet/typeseq.hpp"
|
|
#include <string>
|
|
|
|
namespace xo {
|
|
namespace mm {
|
|
using Copaque = const void *;
|
|
using Opaque = void *;
|
|
|
|
/** @class AAllocator
|
|
* @brief Abstract facet for allocation
|
|
*
|
|
**/
|
|
struct AAllocator {
|
|
/** @defgroup mm-allocator-type-traits allocator type traits **/
|
|
///@{
|
|
/** @brief type used for allocation amounts **/
|
|
using size_type = std::size_t;
|
|
/** @brief type used for allocation responses **/
|
|
using value_type = std::byte *;
|
|
/** object header, if configured **/
|
|
using header_type = std::uint64_t;
|
|
///@}
|
|
|
|
/*
|
|
* <----------------------------size-------------------------->
|
|
* <------------committed-----------><-------uncommitted------>
|
|
* <--allocated-->
|
|
*
|
|
* XXXXXXXXXXXXXXX___________________..........................
|
|
*
|
|
* allocated: in use
|
|
* committed: physical memory obtained
|
|
* uncommitted: mapped in virtual memory, not backed by memory
|
|
*/
|
|
|
|
/** @defgroup mm-allocator-methods Allocator methods **/
|
|
///@{
|
|
|
|
/** RTTI: unique id# for actual runtime data representation **/
|
|
virtual int32_t _typeseq() const noexcept = 0;
|
|
/** optional name for allocator @p d
|
|
* Labeling, for diagnostics.
|
|
**/
|
|
virtual std::string_view name(Copaque d) const noexcept = 0;
|
|
/** reserved size in bytes for allocator @p d.
|
|
* Includes committed + uncommitted memory.
|
|
* Cannot be increased.
|
|
**/
|
|
virtual size_type reserved(Copaque d) const noexcept = 0;
|
|
/** Synonym for @ref committed.
|
|
* Can increase on @ref alloc
|
|
**/
|
|
virtual size_type size(Copaque d) const noexcept = 0;
|
|
/** committed size (physical addresses obtained)
|
|
* for allocator @p d.
|
|
* @ref alloc may auto-increase this
|
|
**/
|
|
virtual size_type committed(Copaque d) const noexcept = 0;
|
|
/** unallocated (but committed) size in bytes for allocator @p d **/
|
|
virtual size_type available(Copaque d) const noexcept = 0;
|
|
/** allocated (i.e. in-use) amount in bytes for allocator @p d **/
|
|
virtual size_type allocated(Copaque d) const noexcept = 0;
|
|
/** true iff allocator @p d is responsible for memory at address @p p.
|
|
**/
|
|
virtual bool contains(Copaque d, const void * p) const noexcept = 0;
|
|
/** report last error **/
|
|
virtual AllocatorError last_error(Copaque d) const noexcept = 0;
|
|
/** fetch alloc info: given memory @p mem previously obtained
|
|
* from {@ref alloc, @ref super_alloc}, get {tseq, age, size} details
|
|
* for that allocation.
|
|
*
|
|
* Non-const @p d because may stash error details
|
|
**/
|
|
virtual AllocInfo alloc_info(Opaque d, value_type mem) const noexcept = 0;
|
|
|
|
/** expand committed space in arena @p d
|
|
* to size at least @p z
|
|
* In practice will round up to a multiple of hugepage size (2MB)
|
|
**/
|
|
virtual bool expand(Opaque d, std::size_t z) const noexcept = 0;
|
|
/** allocate @p z bytes of memory from allocator @p d. **/
|
|
virtual value_type alloc(Opaque d, size_type z) const = 0;
|
|
/** like @ref alloc, but follow with one or more consecutive
|
|
* @ref sub_alloc() calls. This sequence of allocs will share
|
|
* the initial allocation header.
|
|
**/
|
|
virtual value_type super_alloc(Opaque d, size_type z) const = 0;
|
|
/** follow a preceding @ref super_alloc call with additional
|
|
* subsidiary allocs that share the same object header.
|
|
* Must finish sequence with exactly one sub_alloc call
|
|
* with @p complete_flag set. This sub_alloc call may have
|
|
* zero @p z
|
|
**/
|
|
virtual value_type sub_alloc(Opaque d, size_type z, bool complete_flag) const = 0;
|
|
/** reset allocator @p d to empty state **/
|
|
virtual void clear(Opaque d) const = 0;
|
|
/** destruct allocator @p d **/
|
|
virtual void destruct_data(Opaque d) const = 0;
|
|
|
|
///@}
|
|
}; /*AAllocator*/
|
|
|
|
// implementation IAllocator_DRepr of AAllocator for state DRepr
|
|
// should provide a specialization:
|
|
//
|
|
// template <>
|
|
// struct xo::facet::FacetImplementation<AAllocator, DRepr> {
|
|
// using ImplType = IAllocator_DRepr;
|
|
// };
|
|
//
|
|
// then IAllocator_ImplType<DRepr> --> IAllocator_DRepr
|
|
//
|
|
template <typename DRepr>
|
|
using IAllocator_ImplType = xo::facet::FacetImplType<AAllocator, DRepr>;
|
|
|
|
// can't we do this with FacetImplementation<AAllocator, DRepr>
|
|
//
|
|
// template <typename DRepr>
|
|
// struct IAllocator_Impl {};
|
|
|
|
// template <typename DRepr>
|
|
// using IAllocator_ImplType = IAllocator_Impl<DRepr>::ImplType;
|
|
|
|
} /*namespace mm*/
|
|
} /*namespace xo*/
|
|
|
|
/* end AAllocator.hpp */
|