Who is responsible for deleting FILE_NOTIFY_INFORMATION.FileName?

Question

Winapi's ReadDirectoryChanges uses FILE_NOTIFY_INFORMATION to present it's results. The struct looks like this:

typedef struct _FILE_NOTIFY_INFORMATION {
  DWORD NextEntryOffset;
  DWORD Action;
  DWORD FileNameLength;
  WCHAR FileName[1];
} FILE_NOTIFY_INFORMATION, *PFILE_NOTIFY_INFORMATION;

If I get this struct filled by winapi, how do I correctly delete the FileName WCHAR*? Do I have to delete it?

None of the examples (not that there are many examples) of the ReadDirectoryChanges mention deleting anything. Microsoft of course does not provide any examples at all.

Answer 1

If you use malloc you need call free after you finish using the object.

For example:

DWORD FileNameLength = 100;
PFILE_NOTIFY_INFORMATION file_notify_info = (PFILE_NOTIFY_INFORMATION)malloc(FIELD_OFFSET(FILE_NOTIFY_INFORMATION, FileName[FileNameLength]));

free(file_notify_info);

Refer to "Why do some structures end with an array of size 1?".