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CComHeap Class

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The latest version of this topic can be found at CComHeap Class.

This class implements IAtlMemMgr using the COM memory allocation functions.

Important

This class and its members cannot be used in applications that execute in the Windows Runtime.

Syntax

class CComHeap : public IAtlMemMgr

Members

Public Methods

Name Description
CComHeap::Allocate Call this method to allocate a block of memory.
CComHeap::Free Call this method to free a block of memory allocated by this memory manager.
CComHeap::GetSize Call this method to get the allocated size of a memory block allocated by this memory manager.
CComHeap::Reallocate Call this method to reallocate memory allocated by this memory manager.

Remarks

CComHeap implements memory allocation functions using the COM allocation functions, including CoTaskMemAlloc, CoTaskMemFree, IMalloc::GetSize, and CoTaskMemRealloc. The maximum amount of memory that can be allocated is equal to INT_MAX (2147483647) bytes.

Example

See the example for IAtlMemMgr.

Inheritance Hierarchy

IAtlMemMgr

CComHeap

Requirements

Header: ATLComMem.h

CComHeap::Allocate

Call this method to allocate a block of memory.

virtual __declspec(allocator) void* Allocate(size_t nBytes) throw();

Parameters

nBytes
The requested number of bytes in the new memory block.

Return Value

Returns a pointer to the start of the newly allocated memory block.

Remarks

Call CComHeap::Free or CComHeap::Reallocate to free the memory allocated by this method.

Implemented using CoTaskMemAlloc.

CComHeap::Free

Call this method to free a block of memory allocated by this memory manager.

virtual void Free(void* p) throw();

Parameters

p
Pointer to memory previously allocated by this memory manager. NULL is a valid value and does nothing.

Remarks

Implemented using CoTaskMemFree.

CComHeap::GetSize

Call this method to get the allocated size of a memory block allocated by this memory manager.

virtual size_t GetSize(void* p) throw();

Parameters

p
Pointer to memory previously allocated by this memory manager.

Return Value

Returns the size of the allocated memory block in bytes.

Remarks

Implemented using IMalloc::GetSize.

CComHeap::Reallocate

Call this method to reallocate memory allocated by this memory manager.

virtual __declspec(allocator) void* Reallocate(void* p, size_t nBytes) throw();

Parameters

p
Pointer to memory previously allocated by this memory manager.

nBytes
The requested number of bytes in the new memory block.

Return Value

Returns a pointer to the start of the newly allocated memory block.

Remarks

Call CComHeap::Free to free the memory allocated by this method.

Implemented using CoTaskMemRealloc.

See Also

DynamicConsumer Sample
Class Overview
CWin32Heap Class
CLocalHeap Class
CGlobalHeap Class
CCRTHeap Class
IAtlMemMgr Class