<!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="mid200505232015.j4NKFj3n049278@slow.flux.utah.edu" type="cite"> <pre wrap="">At Mon, 23 May 2005 22:02:16 +0200, Hans Oesterholt-Dijkema wrote: </pre> <blockquote type="cite"> <pre wrap=""> From the "Inside" manual: on scheme_block_until() "If |f| ever returns a true value, it must continue to return a true value. " Until when? Until scheme_block_until() returns? </pre> </blockquote> <pre wrap=""> Yes. (I've adjusted the manual.) Matthew </pre> </blockquote> Thank you. I'm going to implement following: 1. I'll create a C shared variable V=0. 2. I'll start another C-thread, calling PQExec. 3. I'll call scheme_block_until(), with f() returning V. 4. When PQExec returns, the C-thread will set V=1 5. I'll join the C thread. This will probably do the job, although some overhead will be involved when running PQExec through a thread. Another solution might be: Given a C-semaphore: S1=0 1. I'll create a C shared variable V, and Q(eury). 2. I'll create a C-thread that waits on semaphore S1. 3. I'll set Q to the query requested and V=0. 4. I'll post S1, which starts the C-thread, which calls PQExec. 5. Ill call scheme_block_until, with f() returning V. 6. When PQExec returns the C-thread will put the result in R, and then set V to 1, next it will wait on S1. 7. R is returned. Which one would you choose? (note: both solutions will instantiate threads per sqli-connect (see google: sqli/sqld). Hans </body> </html>