<!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 ><div style='font-size:10pt;font-family:Verdana,Arial,Helvetica,sans-serif;'>Thank you Tim.<br><br>From what I have gathered in this thread, the process is (loosely speaking, I will tighten up my terminology when I see the outline of the parts and delve into the details)...<br><br>0. VM references stack for Oop<br>1. Using the Oop, VM references the header on the object in ObjectMemory (see comment in ObjectMemory)<br>2.....<br><br>Just that fact that it goes out to ObjectMemory, instead of "receiver class methodDict" to me, hints at some interesting stuff and is a<br>very important distinction.<br><br><br>Thank you all again, <br><div id="1"><br><br>tty<br>---- On Sun, 08 Dec 2013 09:57:33 -0800 <b>tim Rowledge<tim@rowledge.org></b> wrote ---- <br></div><br><blockquote style="border-left: 1px solid #0000FF; padding-left: 6px; margin:0 0 0 5px"><br> <br>On 08-12-2013, at 8:19 AM, gettimothy <<a subj="" mailid="gettimothy%40zoho.com" href="mailto:gettimothy@zoho.com" target="_blank">gettimothy@zoho.com</a>> wrote: <br> <br>> No need to go into details as I am just attempting to avoid a misconception. <br>> <br>> On page 5 of 28 on Tim Rowledge's (very useful and enjoyable, btw) A Tour of the Squeak Object Engine <br>> I am unclear as to what object's header' refers to in step I. <br>> <br>> <br>> To send a message to a receiver, the VM has to:- <br>> I. find the class of the receiver by examining the object's header. <br>> II. lookup the message in the list of messages understood by that class <br>> (the class's MethodDictionary) <br>> ........etc… <br> <br>Back on page 2 of my doc, - <br>> 1. Creating Objects <br>> <br>> Unlike structures in C or records in Pascal, Smalltalk objects are not simply chunks of memory to which we have pointers, and so we need something more sophisticated than the C library malloc() function in order to create new ones. <br>> Smalltalk creates objects by allocating a chunk of the object memory and then building a header that provides the VM with important information such as the class of the object, the size and some content format description. <br> <br>I really ought to update the doc and add some more diagrams etc. <br> <br>tim <br>-- <br>tim Rowledge; <a subj="" mailid="tim%40rowledge.org" href="mailto:tim@rowledge.org" target="_blank">tim@rowledge.org</a>; <a href="http://www.rowledge.org/tim" target="_blank">http://www.rowledge.org/tim</a> <br>Useful Latin Phrases:- Recedite, plebes! Gero rem imperialem! = Stand aside plebians! I am on imperial business. <br> <br> <br></blockquote><br></div></body></html>