> > On Mon, 11 Mar 2002, Harold Hunt wrote: > > > Alexander, > > > > Because the following article: > > > > > http://msdn.microsoft.com/library/default.asp?url= > /library/en-us/wcegmm/htm/ > > ddover_51.asp > > > > states that: > > > > "BltFast cannot be used on surfaces that have > an attached clipper." > > Ok. > > > We use a clipper to account for any other > Windows window overlaying our > > window, which would cause a portion of our blit > destiation to be > > undrawable... which would mean that we wouldn't > be allowed to use BltFast. > > > > Now... could we use BltFast in DirectDraw > fullscreen modes? > > Not needed. The blitting does not slow down the > server significantly. I > think the cygwin socket layer slow much more.
Do you have seen the lmbench results on the cygwin list http://sources.redhat.com/ml/cygwin/2002-01/msg01719.html This confirm your statement. *Local* Communication bandwidths in MB/s - bigger is better ----------------------------------------------------------- Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem UNIX reread reread (libc) (hand) read write --------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- ----- BRAMSCHE CYGWIN_NT-5.0 93.9 17.6 40.7 335.0 477.7 145.0 134.0 477. 195.9 BRAMSCHE Linux 2.2.18 343. 235. 64.4 177.7 238.5 71.5 61.4 238. 75.3 I have done some analysing work with this and with the cygwin daemon (cygserver transport classes) there may be a way in the future to implement unix domain sockets with named pipes which speed up unix domain sockets up to 250 MB/s, as I have measured with a quick an dirty sample implementation. (Unfortunally currently I have no time to work on) Another way seems to me in using local connection for the xtrans layer, but there are two ioctl functions missing in cygwin I_FDINSERT and I_RECVFD. I_FDINSERT Creates a message from specified buffer(s), adds information about another STREAM, and sends the message downstream. I_RECVFD Retrieves the reference to an open file description from a message written to a STREAMS-based pipe using the I_SENDFD command, and allocates a new file descriptor in the calling process that refers to this open file description. In any case there is some work to do. Regards Ralf
