uses SDL;
procedure SDL_UnlockSurface( surface : PSDL_Surface );
Surfaces that were previously locked using SDL_LockSurface must be unlocked with SDL_UnlockSurface. Surfaces should be unlocked as soon as possible.
It should be noted that since 1.1.8, surface locks are recursive. See SDL_LockSurface .
SDL_LockSurface