Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!wuarchive!brutus.cs.uiuc.edu!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!sdsu!ucsd!hub!6600pete
From: 6600pete@hub.UUCP
Newsgroups: comp.sys.mac.programmer
Subject: Re: HLock
Message-ID: <3332@hub.UUCP>
Date: 16 Dec 89 09:43:30 GMT
References: <3331@hub.UUCP>
Sender: news@hub.UUCP
Lines: 24

From article <3331@hub.UUCP>, by 6500stom@hub.UUCP ():
> The way to remember if you need to lock your handle is if you pass
> a field in the handle to any procedure that might move memory--even
> if its one of your own routines in a different segment.

Oh, Joshling, I can't bear it. I tell you how to post and immediately you
go spreading misinformation! :-)

DTS' official position now is that there are so many patched traps running
around calling the Memory Manager that you need to lock and unlock handles
around ANY trap call. The list, in other words, is no longer valid. For
the record, the following situations involve locked handles:

   passing elements of records pointed to by dereferenced handles as Pascal
      "var" parameters
   assigning return values from function-style traps to elements of records
      pointed to by dereferenced handles
   inside Pascal "with" statements which include handles in the "with"

Can anyone think of any other situations?
-------------------------------------------------------------------------------
Pete Gontier   | InterNet: 6600pete@ucsbuxa.ucsb.edu, BitNet: 6600pete@ucsbuxa
Editor, Macker | Online Macintosh Programming Journal; mail for subscription
Hire this kid  | Mac, DOS, C, Pascal, asm, excellent communication skills