IMalloc

Allocates, frees, and manages memory.

When to Implement

In general, you should not implement IMalloc, instead using the OLE implementation, which is guaranteed to be thread-safe in managing task memory. You get a pointer to the OLE task allocator object’s IMalloc through a call to the CoGetMalloc function.

When to Use

Call the methods of IMalloc to allocate and manage memory. The OLE libraries and object handlers also call the IMalloc methods to manage memory. Object handlers should call CoGetMalloc to get a pointer to the IMalloc implementation on the task allocator object, and use the implementation of those methods to manage task memory.

The IMalloc methods Alloc, Free, and Realloc are similar to the C library functions malloc, free, and realloc. For debugging, refer to the functions CoRegisterMallocSpy and CoRevokeMallocSpy.

Methods in Vtable Order

IUnknown Methods	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.

IMalloc Methods	Description
Alloc	Allocates a block of memory.
Realloc	Changes the size of a previously allocated block of memory.
Free	Frees a previously allocated block of memory.
GetSize	Returns the size in bytes of a previously allocated block of memory.
DidAlloc	Determines if this instance of IMalloc was used to allocate the specified block of memory.
HeapMinimize	Minimizes the heap by releasing unused memory to the operating system.

See Also

CoGetMalloc, IMallocSpy, CoRegisterMallocSpy, CoRevokeMallocSpy