Presentation drivers should use SSAllocMem to allocate memory for objects, such as bit maps and regions, to ensure that the returned memory object is a global memory object for which the system can set a new owner, or which can be marked as having no owner.

In some presentation devices, the handling routine for FillLogicalDeviceBlock (OS2_PM_DRV_ENABLE, sub-function 2) allocates global heap space for use by the device contexts. The memory for this heap space is obtained by calling the SSAllocMem function.