DCMTK

See this Forum posting:

OFMutex::lock() and OFMutex::unlock is a hotspot in our application (which uses dcmtk, obviously :-) on Windows, but not on Linux. On Windows it uses a Windows mutex object, which always require a system call to lock and unlock. Have you considered using a critical section on Windows instead? It is much faster: http://preshing.com/20111124/always-use-a-lightweight-mutex