Segment functions allocate, free, and convert selectors; lock and unlock memory objects referenced by selectors; and retrieve information about segments. Following are the selector functions:
| Function | Description |
| AllocDStoCSAlias | Accepts a data-segment (DS) selector and returns a code-segment (CS) selector that can be used to execute code in a data segment. |
| AllocSelector | Allocates a new selector. |
| FreeSelector | Frees a selector originally allocated by the Alloc-DStoCSAlias or AllocSelector function. |
| GetCodeInfo | Retrieves information about a code segment. |
| GetSelectorBase | Returns the base of a selector. |
| GetSelectorLimit | Returns the limit of a selector. |
| GlobalFix | Prevents a global memory object from moving in linear memory. |
| GlobalPageLock | Page-locks the memory associated with the specified global selector and increments its page-lock count. Memory that is page-locked cannot be moved or paged out to disk. |
| GlobalPageUnlock | Decrements the page-lock count for the memory associated with the specified global selector. If the page-lock count reaches zero, the memory can be moved and paged out to disk. |
| GlobalUnfix | Unlocks a global memory object previously fixed by the GlobalFix function. |
| LockSegment | Locks a segment in memory. |
| PrestoChangoSelector | Generates a temporary code selector that corresponds to a given data selector or a temporary data selector that corresponds to a given code selector. |
| SetSelectorBase | Sets the base of a selector. |
| SetSelectorLimit | Sets the limit of a selector. |
| UnlockSegment | Unlocks a segment previously locked by the LockSegment function. |
Note:
An application should not use these functions unless it is absolutely necessary. Use of these functions violates preferred Windows programming practices.