Function _momUnlock() | Xbase++

Ends access to a memory object.

XPPAPIRET _momUnlock(MomHandle mhObj);

MomHandle mhObj

Handle of a memory object locked with _momLock().

Always returns NULL.

_momUnlock() is used to end access to a memory object. This function should be called as soon as the pointer to the object's data (returned by _momLock()) is no longer needed.

The unlock should always take place before the end of the function which has locked the object. Locking a memory object over a longer time span is not illegal, but should be avoided. The more objects are locked in memory the less efficient is the packing of memory, which causes fragmentation.

Since Xbase++ applications have several internal threads, the position of the data in memory can be changed at any time after the call to _momUnlock(), either by _momResize() or internal memory packing. That means the pointer returned by _momLock() can not be used after _momUnlock().

/* 
Generate a memory object and initialize with NULLs. 
*/ 
#include "xppcon.h" 

MomHandle  hNew; 
BYTE      *pNew; 
LONG       size = 50; 

hNew = _momAlloc(size); 
if (hNew != MOM_NULLHANDLE) 
{ 
pNew = _momLock(hNew); 

while (size-- > 0) 
       *pNew++ = 0; 

/* Warning: after the following call the value pNew is invalid */ 
_momUnlock(hNew); 
} 
else 
{ 
/* ... error handling */ 
}

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Function _momUnlock() Foundation