<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=UTF-8" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> Matthew Flatt schreef: <blockquote cite="mid200505231928.j4NJS8OU048745@slow.flux.utah.edu" type="cite"> <pre wrap=""> You're right --- it won't work. MzScheme semaphores work only with the MzScheme thread scheduler. You'll need to use whatever synchronization primitives the C thread system provides, and then connect to the MzScheme scheduler through scheme_block_until() or scheme_add_evt(). Matthew </pre> </blockquote> From the "Inside" manual: on scheme_block_until() "If <code class="scheme">f</code> ever returns a true value, it must continue to return a true value. " Until when? Until scheme_block_until() returns? Hans </body> </html>