<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1"> <title></title> </head> <body> The help desk could not find channels. Can you be a bit more specific? Katsmall the Wise By the way, thanks for the fast responses! Robby Findler wrote: <blockquote type="cite" cite="mid20030422203942.9D6B86BD60@laime.cs.uchicago.edu"> <pre wrap=""> For list-related administrative tasks: <a class="moz-txt-link-freetext" href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> You should probably use channels instead. Have the many threads put values into the channel and then have one thread takes values out of the channel and draws them. (Channels are only in the latest CVS version; in 203 use semaphores (and suffer)) Robby At Tue, 22 Apr 2003 22:35:56 +0200, Katsmall the Wise wrote: </pre> <blockquote type="cite"> <pre wrap=""> For list-related administrative tasks: <a class="moz-txt-link-freetext" href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> I would like to make a procedure, that may be called from many threads, but if it is called from two threads at the same time it will block the second one until the first one finishes, and then run it. I want this because I have many drawing procedures that merely add something to a list, and appearantly some things get deleted because the procedures are called at the same time. Is there a simple solution to this? Katsmall the Wise </pre> </blockquote> <pre wrap=""> </pre> </blockquote> </body> </html>