- From: Henrik Frystyk Nielsen <frystyk@w3.org>
- Date: Fri, 31 May 1996 12:15:48 -0400
- To: www-lib-bugs@w3.org
------- Forwarded Message Return-Path: smaines@best.com Return-Path: <smaines@best.com> Received: from www10.w3.org by www18.w3.org (5.0/NSCS-1.0S) id AA05518; Tue, 23 Apr 1996 07:05:33 +0500 Received: from dns1.noc.best.net by www10.w3.org (5.0/NSCS-1.0S) id AA03378; Tue, 23 Apr 1996 07:05:31 +0500 Received: from [206.86.9.17] (smaines.vip.best.com [206.86.9.17]) by dns1.noc.best.net (8.6.12/8.6.5) with SMTP id EAA08547 for <libwww@w3.org>; Tue, 23 Apr 1996 04:05:24 -0700 Message-Id: <v01540b00ada1e9fba3a8@[206.86.9.17]> Mime-Version: 1.0 Date: Tue, 23 Apr 1996 04:05:49 -0700 To: libwww@w3.org From: smaines@best.com (Scott Maines) Subject: HTRequest_setCallback (wide) Content-Type: text/plain; charset="us-ascii" Content-Length: 2091 > Putting a request into a Context > > When multiple requests can be initiated simultaneously it is in >general not possible > to predict the order that the results return to the application. This >is a function of the > size of the individual data objects, net work speed etc. In order to >keep track of > ordering of the requests, for example in the history list, it is >necessary to put them > into some kind of context. The Library provides the hooks for >maintaining a context > together with the Request object by the following methods: > > > typedef int HTRequestCallback (HTRequest * request, void *param); > > extern void HTRequest_setCallback (HTRequest *request, >HTRequestCallback *cb); > extern HTRequestCallback *HTRequest_callback (HTRequest *request); - -from WWW/Library/User/Using.html#req Does this mechanism work? I have been unable to find where the HTRequestCallback is ever called, and I am begining to suspect that it is vestigal. I want to issue a request asynchronously, and be notified by callback when it is done. How do I do that, and is it possible to do so without idling? I am developing on a Macintosh, using PowerPlant. I can create threads, and control them using callbacks. It is not at all clear where- in doing, say, an HTLoadAbsolute- I would expect to be able to suspend a thread, and upon what callback event I might resume it. I've been through the HTML documentation provided, and have not found how precisely the event module ".. is overridden by the application as described in the 'User's Guide'". I can see that some functionality akin to HTEvent_Loop is necessary, but a simple analysis of the code, compiled on a Macintosh, shows that once HTEvent_stopLoop is called, HTEndLoop can only be set to zero manually. This suggests to me that the functionality is not in fact completely implemented. I have not as of yet studied the Arena version of the code in light of this problem. What is the expectation as to the migration of improvements made there into libwww proper? Scott Maines smaines@best.com ------- End of Forwarded Message -- Henrik Frystyk Nielsen, <frystyk@w3.org> World-Wide Web Consortium, MIT/LCS NE43-356 545 Technology Square, Cambridge MA 02139, USA
Received on Friday, 31 May 1996 12:15:49 UTC