Windows Mobile 6.5
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This interface allocates, frees, and manages memory.

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

Call the methods of IMalloc to allocate and manage memory. The COM 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.

The following table shows the methods for this interface in the order that the compiler calls the methods. Like all COM interfaces, this interface inherits the methods for the IUnknown interface.

IUnknown method Description


Returns pointers to supported interfaces.


Increments reference count.


Decrements reference count.

IMalloc method Description


Allocates a block of memory.


Changes the size of a previously allocated block of memory.


Frees a previously allocated block of memory.


Returns the size in bytes of a previously allocated block of memory.


Determines whether this instance of IMalloc was used to allocate the specified block of memory.


Minimizes the heap by releasing unused memory to the operating system.

To determine whether the platform supports this interface, see Determining Supported COM APIs.

Headerobjidl.h, objidl.idl
Windows Embedded CEWindows CE 3.0 and later
Windows MobileWindows Mobile Version 5.0 and later

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