LocalFree function (winbase.h)

Article
10/13/2021

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 LocalFree(
  [in] _Frees_ptr_opt_ HLOCAL hMem
);

Parameters

[in] hMem

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

Requirement	Value
Minimum supported client	Windows XP [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	winbase.h (include Windows.h)
Library	Kernel32.lib
DLL	Kernel32.dll