DosUnlockSeg

This call unlocks a discardable segment.

Syntax
DosUnlockSeg (Selector)

Parameters

 * Selector (SEL) - input : Segment selector to be unlocked.

Return Code

 * rc (USHORT) - return: Return code descriptions are:
 * 0 NO_ERROR
 * 5 ERROR_ACCESS_DENIED
 * 158 ERROR_NOT_LOCKED

Remarks
DosUnlockSeg is called to free memory for possible discard by the system in a low memory situation. The memory being freed is originally allocated by a call to DosAllocSeg or DosAllocHuge with AllocFlags bit 2 set. This memory may have been reallocated by a call to DosReallocSeg or DosReallocHuge after discard by the system.

Allocation and reallocation calls for discardable memory automatically lock the memory for access by the calling process. Thus, to access the segment, the caller does not have to lock the segment with DosLockSeg. Once a discardable segment is unlocked by a DosUnlockSeg request, access to the segment is gained by a successful DosLockSeg request.

DosUnlockSeg may also be used on segments that are non-discardable, in which case it has no effect.

C

 * 1) define INCL_DOSMEMMGR

USHORT rc = DosUnlockSeg(Selector);

SEL    Selector;      /* Selector to unlock */

USHORT rc;            /* return code */ 

MASM
 EXTRN DosUnlockSeg:FAR INCL_DOSMEMMGR     EQU 1

PUSH  WORD Selector         ;Selector to unlock CALL  DosUnlockSeg

Returns WORD 