problems with QSharedMemory and QSystemSemaphore in Windows

Classes QSharedMemory and QSystemSemaphore currently do not create objects in the global namespace in Windows. That is, the names of the objects that these classes create do not start with "Global\".

In later XP versions, in Windows Vista, and in Windows 7, shared memory and system semaphore objects that do not have a name starting with "Global\" cannot be accessed by other processes. As a result, on these platforms, if a Windows service creates a QSharedMemory or a QSystemSemaphore, other processes cannot access it, although this is a common IPC use case.

As far as we can see, fixing this would require minor changes to functions QSharedMemoryPrivate::handle(), QSharedMemoryPrivate::create(int), and QSystemSemaphorePrivate::handle(QSystemSemaphore::AccessMode).

Another limitation is related to security attributes of QSharedMemory and QSystemSemaphore instances:

There should be an easy way to create these instances such that "Everybody" (i.e., well-known sid "S-1-1-0") is granted GENERIC_ALL-right.