LocalFree function
Applies to: desktop apps only
Frees the specified local memory object and invalidates its handle.
Note The local functions have greater overhead and provide fewer features than other memory management functions. New applications should use the heap functions unless documentation states that a local function should be used. For more information, see Global and Local Functions.
Syntax
HLOCAL WINAPI LocalFree( __in HLOCAL hMem );
Parameters
- hMem [in]
-
A handle to the local memory object. This handle is returned by either the LocalAlloc or LocalReAlloc function. It is not safe to free memory allocated with GlobalAlloc.
Return value
If the function succeeds, the return value is NULL.
If the function fails, the return value is equal to a handle to the local memory object. To get extended error information, call GetLastError.
Remarks
If the process tries to examine or modify the memory after it has been freed, heap corruption may occur or an access violation exception (EXCEPTION_ACCESS_VIOLATION) may be generated.
If the hMem parameter is NULL, LocalFree ignores the parameter and returns NULL.
The LocalFree function will free a locked memory object. A locked memory object has a lock count greater than zero. The LocalLock function locks a local memory object and increments the lock count by one. The LocalUnlock function unlocks it and decrements the lock count by one. To get the lock count of a local memory object, use the LocalFlags function.
If an application is running under a debug version of the system, LocalFree will issue a message that tells you that a locked object is being freed. If you are debugging the application, LocalFree will enter a breakpoint just before freeing a locked object. This allows you to verify the intended behavior, then continue execution.
Examples
For an example, see LocalAlloc.
Requirements
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Minimum supported client | Windows XP |
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Minimum supported server | Windows Server 2003 |
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Header |
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Library |
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DLL |
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See also
- Global and Local Functions
- GlobalFree
- LocalAlloc
- LocalFlags
- LocalLock
- LocalReAlloc
- LocalUnlock
- Memory Management Functions
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Build date: 2/7/2012
Free Pascal, Windows API, LocalFree
Free Pascal 2.4.4
extracted from Windows unit "Windows.ppu"
function LocalFree
(
hMem : LongWord
)
: LongWord;
stdcall;
- 7/26/2011
- Brad Dinte
- 10/28/2011
- Brad Dinte
[DllImport("kernel32.dll", SetLastError=true, ExactSpelling=true)]
internal static extern IntPtr LocalFree(IntPtr hMem);
<DllImport("kernel32.dll", SetLastError:=True, ExactSpelling:=True)> _
Public Shared Function LocalFree(ByVal hMem As IntPtr) As IntPtr
End Function
Freeing a memory object twice may cause subsequent calls to LocalAlloc to allocated memory multiple times:
Private Sub Main()
Dim xLong1 As Long, xLong2 As Long
Do
xLong1 = LocalAlloc(0&, 200&)
xLong2 = LocalAlloc(0&, 200&)
If xLong2 = xLong1 Then
Debug.Print "Received the same memory twice!"
End If
DoEvents
Call LocalFree(xLong1)
Call LocalFree(xLong1) ' Should be xLong2 to fix
Loop
End Sub
- 12/21/2008
- ControllerUK
