From owner-freebsd-java Sun Feb 1 22:28:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id WAA10956 for java-outgoing; Sun, 1 Feb 1998 22:28:55 -0800 (PST) (envelope-from owner-freebsd-java@FreeBSD.ORG) Received: from cimlogic.com.au (cimlog.lnk.telstra.net [139.130.51.31]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id WAA10950 for ; Sun, 1 Feb 1998 22:28:50 -0800 (PST) (envelope-from jb@cimlogic.com.au) Received: (from jb@localhost) by cimlogic.com.au (8.8.7/8.8.7) id RAA00645; Mon, 2 Feb 1998 17:33:12 +1100 (EST) (envelope-from jb) From: John Birrell Message-Id: <199802020633.RAA00645@cimlogic.com.au> Subject: Re: TimeSlicing in JVM In-Reply-To: <199802020605.XAA26684@mt.sri.com> from Nate Williams at "Feb 1, 98 11:05:41 pm" To: nate@mt.sri.com (Nate Williams) Date: Mon, 2 Feb 1998 17:33:12 +1100 (EST) Cc: SSANKARA.IN.oracle.com.ofcmail@in.oracle.com, freebsd-java@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL32 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-java@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org X-To-Unsubscribe: mail to majordomo@FreeBSD.org "unsubscribe java" Nate Williams wrote: > One of the really nasty things in the current green-thread port which > exists on all *nix platforms which don't use kernel threads is that a > single thread can sit in a tight loop and never let go, which means that > if you have one errant thread your entire VM is hosed. This is a *bad* > thing, but I don't see any way around it w/out kernel support. That's not quite true 8-) in all cases. By leaving a timer running, a thread running in a tight loop can be interrupted by a SIGVTALRM and the user-thread kernel can schedule another thread. libc_r does this. So tight loops or thread-hogs are OK provided that the thread doesn't hand on to locked resources. It's non-blocking syscalls that end in tears. Regards, -- John Birrell - jb@cimlogic.com.au; jb@netbsd.org; jb@freebsd.org CIMlogic Pty Ltd, GPO Box 117A, Melbourne Vic 3001, Australia +61 418 353 137