From: Michael Mueller <muellerix@...>
Date: 2003-03-11T22:10:44+09:00
Subject: Re: WIN32OLE: Passing an Array

Well... at least now I know that it's not my fault ;-)
Thanks for the hint - but I still have no idea how to bypass that prob. Does 
anyone have a suggestion?

Michael

pj wrote:

>> my program crashes with a segmentation fault.
>> I guess the problem lies in the arrays being passed to the method. I
>> searched the web/usenet for any hints on how to pass an array to an ole
>> object but found absolutely nothing.
> 
> I am a clueless newbie in Ruby, knowing nearly less than nothing, but
> arrays in COM (ie, OLE, ie, ActiveX, whichever name of the week you
> like) are often passed as type SAFEARRAY. This is a structure holding
> a dynamically allocated array (a traditional array of consecutive
> bytes), but, and this is important, it is allocated using a task
> allocator. That is, you cannot make one from your heap manager, unless
> your heap manager is cooperating with the task allocator.
> 
> There is a caveat: there are rules about memory ownership across COM
> calls. If you are the caller, and you pass the ARRAY as a top-level IN
> parameter only, then you own the memory, and the callee isn't allowed
> to change it, and in this case, I believe you can get away with it not
> being allocated from the task allocator.