LocalLock
The LocalLock
function locks a local memory object and returns a pointer to the first byte of
the object s memory block. The memory block associated with a locked memory
object cannot be moved or discarded. For memory objects allocated with the
LMEM_MOVEABLE flag, the function increments the object s lock count.
LPVOID LocalLock(
|
HLOCAL hMem |
// handle of local
memory object |
|
); |
|
Parameters
hMem
Identifies
the local memory object. This handle is returned by either the LocalAlloc or LocalReAlloc function.
Return Values
If the
function succeeds, the return value is a pointer to the first byte of the
memory block.
If the
function fails, the return value is NULL. To get extended error information,
call GetLastError.
Remarks
The internal
data structures for each memory object include a lock count that is initially
zero. For movable memory objects, LocalLock increments the count by one,
and the LocalUnlock
function decrements the count by one. For each call that a process makes to LocalLock
for an object, it must eventually call LocalUnlock. Locked memory will
not be moved or discarded unless the memory object is reallocated by using the LocalReAlloc
function. The memory block of a locked memory object remains locked in memory
until its lock count is decremented to zero, at which time it can be moved or
discarded.
Memory
objects allocated with the LMEM_FIXED flag always have a lock count of zero.
For these objects, the value of the returned pointer is equal to the value of
the specified handle.
If the
specified memory block has been discarded or if the memory block has a
zero-byte size, this function returns NULL.
Discarded
objects always have a lock count of zero.
See Also