CGlobalHeap Class

This class implements IAtlMemMgr using the Win32 global heap functions.

Important

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

Syntax

class CGlobalHeap : public IAtlMemMgr

Members

Public Methods

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

Remarks

CGlobalHeap implements memory allocation functions using the Win32 global heap functions.

Note

The global heap functions are slower than other memory management functions and do not provide as many features. Therefore, new applications should use the heap functions. These are available in the CWin32Heap class. Global functions are still used by DDE and the clipboard functions.

Example

See the example for IAtlMemMgr.

Inheritance Hierarchy

IAtlMemMgr

CGlobalHeap

Requirements

Header: atlmem.h

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

Implemented using GlobalAlloc with a flag parameter of GMEM_FIXED.

CGlobalHeap::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 GlobalFree.

CGlobalHeap::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 GlobalSize.

CGlobalHeap::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 CGlobalHeap::Free to free the memory allocated by this method.

Implemented using GlobalReAlloc.

See also

Class Overview
CComHeap Class
CWin32Heap Class
CLocalHeap Class
CCRTHeap Class
IAtlMemMgr Class