Path: utzoo!utgpu!watserv1!watmath!att!pacbell.com!ucsd!usc!sdd.hp.com!spool2.mu.edu!uunet!hsi!genly!chris From: chris@genly.UUCP (Chris Hind Genly) Newsgroups: comp.sys.amiga.programmer Subject: Re: What's a Hanging Forbid!? Message-ID: Date: 25 Jan 91 14:50:05 GMT References: Organization: Eggplant Software Tools, CT, USA Lines: 25 >In article yorkw@stable.ecn.purdue.edu (Willis F York) writes: >Well In WSHELL it checks for Hanging Forbids. > . . . >What IS a hanging Forbid? Forbid() is used to switch from preemptive to non-preemptive task scheduling. Permit() switches back to preemptive task scheduling. They should be used in pairs. Whenever you call Forbid(), within a short amount of time you should call Permit(). If you just call Forbid(), and don't call Permit(), then you have a hanging Forbid(). [Very impolite. You've just turned your machine into a Macintosh :-) ]. You would use Forbid()/Permit() when accessing structures shared by several tasks to prevent the structure from being modified while you were working on it. * * * \|/ * _______ --O-- ____/ KC1VP \____ * /|\ * ______/ (203) 389-8680 \______ ______/ Eggplant Software Tools \________ ______/ 95 Fountain Terr., New Haven, CT, USA, 06515 \_______ / Chris Hind Genly chris@genly.uucp uunet!hsi!genly!chris \ ----------------------------------------------------------------