cohtml::IAllocator

Allocator interface used by Cohtml for all memory allocations. The user has to provide an object that implements this interface. Memory allocations in Cohtml are tagged, so the user knows the relative distribution of memory among subsystems.

#include <Library.h>

Public Functions #

Public Functions Documentation #

function IAllocator #

IAllocator()

function Allocate #

virtual void * Allocate(
    unsigned size,
    cohtml::MemTags::MemTagsType memtag
) =0

Allocate size bytes.

Parameters:

• size the number of bytes to allocate
• memtag tag of the subsystem from which the request came

Return: the pointer to the beginning of newly allocated memory.

Warning: the memory must be aligned on 8

function Reallocate #

virtual void * Reallocate(
    void * ptr,
    unsigned size,
    cohtml::MemTags::MemTagsType memtag
) =0

Reallocates the given area of memory. It must be previously allocated by Allocate.

Parameters:

• ptr the pointer to the memory area to be reallocated
• size number of bytes to allocate
• memtag tag of the subsystem from which the request came

function Deallocate #

virtual void Deallocate(
    void * ptr,
    cohtml::MemTags::MemTagsType memtag
) =0

Deallocates the memory previously allocated by Allocate.

Parameters:

• ptr the pointer to the memory to deallocate
• memtag tag of the subsystem from which the request came

function AlignedAllocate #

virtual void * AlignedAllocate(
    unsigned size,
    unsigned alignment,
    cohtml::MemTags::MemTagsType memtag
) =0

Allocate size bytes whose alignment is specified by alignment.

Parameters:

• size number of bytes to allocate
• alignment specifies the alignment
• memtag tag of the subsystem from which the request came

Return: the pointer to the beginning of newly allocated memory

Warning: when specified, memory alignment for allocations should be preserved

function AlignedDeallocate #

virtual void AlignedDeallocate(
    void * ptr,
    cohtml::MemTags::MemTagsType memtag
) =0

Deallocates the memory previously allocated by AlignedAllocate.

Parameters:

• ptr the pointer to the memory to deallocate
• memtag tag of the subsystem from which the request came

function VirtualAllocate #

virtual void * VirtualAllocate(
    void * hint,
    unsigned size,
    int protection,
    int flags,
    cohtml::MemTags::MemTagsType memtag
) =0

Reserves, commits, or changes the state of a memory region.

Parameters:

• hint address of the region to allocate. Address is rounded down to the nearest page boundary.
• size the size of the region, in bytes.
• protection specifies a protection type for the memory region
• flags type of the allocation (commit, reserve etc)
• memtag tag of the subsystem from which the request came

Return: address of the allocated memory region.

Note: the return address must be aligned with the system page size

Warning: all newly committed memory by the provided implementation should be zeroed out

function VirtualFree #

virtual bool VirtualFree(
    void * ptr,
    unsigned size,
    int flags,
    cohtml::MemTags::MemTagsType memtag
) =0

Releases and decommits a memory region.

Parameters:

• ptr a pointer to the address of the memory region.
• size the size of the region in bytes.
• flags type of the allocation (decommit, release etc).
• memtag tag of the subsystem from which the request came

Return: true if the function succeeds, otherwise false.`

function ~IAllocator #

virtual ~IAllocator()