HeapCompact
The HeapCompact
function attempts to compact a specified heap. It compacts the heap by
coalescing adjacent free blocks of memory and decommitting large free blocks of
memory.
UINT HeapCompact(
|
HANDLE hHeap, |
// handle to the
heap to compact |
|
DWORD dwFlags |
// bit-flags that
control heap access during function operation |
|
); |
|
Parameters
hHeap
Handle to the
heap that the function will attempt to compact.
dwFlags
A set of bit
flags that control heap access during function operation. The following bit
flag has meaning:
|
Value |
Meaning |
|
HEAP_NO_SERIALIZE |
If this
flag is set, heap access is not serialized while the HeapCompact function
accesses the heap; heap access is not mutually exclusive. It is safe to set
this flag only in a limited set of specific situations. For a discussion of
those situations and heap serialization in general, see the Remarks section
of HeapCreate.
If this
flag is clear, heap access is serialized while HeapCompact accesses
the heap; heap access is mutually exclusive. This is the safe and simple
default condition. |
Return Values
If the
function succeeds, the return value is the size, in bytes, of the largest
committed free block in the heap. This is an unsigned integer value.
If the
function fails, the return value is zero. To get extended error information, call
GetLastError.
In the
unlikely case that there is absolutely no space available in the heap, the
function return value is zero, and GetLastError returns the value
NO_ERROR.
Remarks
There is no
guarantee that an application can successfully allocate a memory block of the
size returned by HeapCompact. Other threads or the commit threshold
might prevent such an allocation.
See Also