From: tmoran@acm.org
Subject: Re: Ada Tasks vs Linux processes
Date: Wed, 04 Apr 2001 16:36:52 GMT
Date: 2001-04-04T16:36:52+00:00 [thread overview]
Message-ID: <E4Iy6.1270$4L4.246512@news1.frmt1.sfba.home.com> (raw)
In-Reply-To: 3AC8FA76.C6AD4B53@boeing.com
> ... by delaying until the next clock tick.
Note this is a change from Ada 83, where the delay had to be "at
least" that specified. Suppose there's a piece of hardware that
needs 500 mics to settle after some operation, before it can next
be accessed. Given a Duration'small of 10*mics, the unsuspecting
programmer might write "delay 500*mics;". With a System.Tick of
1000 mics, that would delay somewhere between 1 and 2 ms, a safe
time for the hardware to settle down, when compiled with Ada 83.
In Ada 95 it need only take a single tick, which might happen
within a few mics of reaching the "delay" statement and thus long
before the hardware is ready. Crash and burn.
next prev parent reply other threads:[~2001-04-04 16:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-04-01 15:27 Ada Tasks vs Linux processes Frank
2001-04-01 22:32 ` David C. Hoos, Sr.
2001-04-02 17:30 ` tmoran
2001-04-02 18:00 ` Robert A Duff
2001-04-02 18:20 ` Ehud Lamm
2001-04-02 22:17 ` Jeffrey Carter
2001-04-04 16:36 ` tmoran [this message]
2001-04-04 17:18 ` Gary Scott
2001-04-04 19:18 ` tmoran
2001-04-02 19:57 ` Frank
2001-04-03 11:28 ` Matthias Kretschmer
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