IUnknown_AtomicRelease function

Releases a Component Object Model (COM) pointer and sets it to NULL.

Syntax

void IUnknown_AtomicRelease(
  _Inout_opt_ void **ppunk
);

Parameters

ppunk [in, out, optional]

Type: void**

The address of a pointer to a COM interface.

Return value

This function does not return a value.

Remarks

If ppunk points to a NULL pointer, no operation is performed. Otherwise, ppunk is assumed to be the address of a COM interface pointer, derived from IUnknown. The function calls the interface's IUnknown::Release method then sets the interface pointer to NULL.

Examples

The following example uses IUnknown_AtomicRelease to release the stream, if it exists. If not, it does nothing.

void sample()
{
    IStream *pstm = NULL;
    CreateStreamOnHGlobal(NULL, TRUE, &pstm);
    
    IUnknown_AtomicRelease((void**)&pstm);
    
    // At this point, pstm is NULL
}

Requirements