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NNTP-Posting-Date: Fri, 29 Apr 2005 02:25:48 -0500
From: tmoran@acm.org
Newsgroups: comp.lang.ada
Subject: Re: [newbie question] tasks and protected types
References: <1114747457.868019.93210@f14g2000cwb.googlegroups.com>
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Date: Fri, 29 Apr 2005 02:25:48 -0500
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Date: 2005-04-29T02:25:48-05:00
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1) Msg is a zero length string.  But you try to store Str in it, which
will only work if Str is also a null string.  This is one of those few
places in Ada where you really are forced to use an access type and
a "new" (unless somebody has a better idea).
2) G is a single object accessed simultaneously by two tasks.  Who
knows what unpleasantness may result.
3) Your output file is also a single object accessed simultaneously by
two tasks.  You may be lucky and have that work for a while, or you
may not be lucky.

When compiled and run with Janus Ada I get:

** Unhandled CONSTRAINT_ERROR
   Array length check failed
On Line Number 34 In MANAGE.DOOR.START
Called from line number 29 In MANAGE.DOOR
  ## Reraised On Line Number 51 In MANAGE
**** DEADLOCK DETECTED; program halted ****