Surfaces that were previously locked using \fBSDL_LockSurface\fP must be unlocked with \fBSDL_UnlockSurface\fP\&. Surfaces should be unlocked as soon as possible\&.
.PP
It should be noted that since 1\&.1\&.8, surface locks are recursive\&. See \fI\fBSDL_LockSurface\fP\fR\&.