CoRegisterMallocSpy function (objbase.h)

Registers an implementation of the IMallocSpy interface, thereafter requiring OLE to call its wrapper methods around every call to the corresponding IMalloc method.


HRESULT CoRegisterMallocSpy(
  [in] LPMALLOCSPY pMallocSpy


[in] pMallocSpy

A pointer to an instance of the IMallocSpy implementation.

Return value

This function can return the standard return value E_INVALIDARG, as well as the following values.

Return code Description
The object was successfully registered.
The object is already registered.


The CoRegisterMallocSpy function registers the IMallocSpy object, which is used to debug calls to IMalloc methods. The function calls QueryInterface on the pointer pMallocSpy for the interface IID_IMallocSpy. This is to ensure that pMallocSpy really points to an implementation of IMallocSpy. By the rules of OLE, it is expected that a successful call to QueryInterface has added a reference (through the AddRef method) to the IMallocSpy object. That is, CoRegisterMallocSpy does not directly call AddRef on pMallocSpy, but fully expects that the QueryInterface call will.

When the IMallocSpy object is registered, whenever there is a call to one of the IMalloc methods, OLE first calls the corresponding IMallocSpy pre-method. Then, after executing the IMalloc method, OLE calls the corresponding IMallocSpy post-method. For example, whenever there is a call to IMalloc::Alloc, from whatever source, OLE calls IMallocSpy::PreAlloc, calls Alloc, and after that allocation is completed, calls IMallocSpy::PostAlloc.


Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header objbase.h
Library Ole32.lib
DLL Ole32.dll

See also