DosFreeSeg

Bindings:  C, MASM 

This call deallocates a memory segment. 

 DosFreeSeg    (Selector) 
 

 Selector (SEL) - input 
    Selector of the segment to be freed. 

 rc (USHORT) - return 
    Return code descriptions are: 

    0         NO_ERROR 
    5         ERROR_ACCESS_DENIED 
    212       ERROR_LOCKED 
 
 Remarks 

 DosFreeSeg frees selectors to segments returned by allocation calls to 
 DosAllocSeg, DosAllocShrSeg, and DosAllocHuge.  In addition, DosFreeSeg 
 frees a selector returned by a call to DosCreateCSAlias. If a CS alias 
 selector has been created for a data segment by a call to 
 DosCreateCSAlias, the CS alias selector is still valid after the 
 segment's data selector has been freed. 

 When allocated memory is shared, all selectors to the shared memory must 
 be freed before the memory is deallocated. For example, if memory 
 allocated by DosAllocSeg or  DosAllocHuge has been given to another 
 process with DosGiveSeg, the giver usually frees its selector by a call 
 to DosFreeSeg.  The recipient, in turn, frees the selector passed to it, 
 after it has accessed the shared memory with DosGetSeg. 

 DosFreeSeg decrements the reference count for named shared segments 
 allocated by DosAllocShrSeg.  Access to the segment with  DosGetShrSeg 
 increments this count.  When the count is 0, the memory is deallocated. 

 
 Family API Considerations 

 Some options operate differently in the DOS mode than in OS/2 mode. 
  Therefore, the following restriction applies to DosFreeSeg when coding 
 for the DOS mode: 

 If DosFreeSeg is issued on a CSAliased segment it deallocates the 
 associated memory.  This is inconsistent with the OS/2 mode, because 
 DosFreeSeg must be performed on both the original and CSAliased 
 selectors.