CoTaskMemFree

CoTaskMemFree is a Windows API function used to release memory that was allocated by the COM task memory allocator via CoTaskMemAlloc. It is part of the Component Object Model (COM) memory management model and is designed to support memory handoffs across component and process boundaries.

The function has the prototype void CoTaskMemFree(void* pv); it does not return a value. If the provided pointer pv is NULL, the call has no effect. Memory allocated with CoTaskMemAlloc should be freed with CoTaskMemFree; do not use general purpose allocators such as HeapFree, LocalFree, or GlobalFree to release it. Using the wrong allocator can lead to leaks or heap corruption.

Usage typically arises when a COM API or a system function returns memory allocated with CoTaskMemAlloc. The caller is responsible for freeing that memory when it is no longer needed, after which the memory is reclaimed by the COM task memory allocator. CoTaskMemFree is safe to call across thread and apartment boundaries, but the pointer must have been allocated with CoTaskMemAlloc.

Related functions include CoTaskMemAlloc (to allocate memory), CoTaskMemSize (to query the size of memory allocated with CoTaskMemAlloc), and general COM memory management guidelines. CoTaskMemFree is implemented by the COM runtime (often associated with Ole32/COM support libraries) and is a standard mechanism for managing memory across COM boundaries.