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Re: 32 bits time_t and Y2038 issue

From pozz <pozzugno@gmail.com>
Newsgroups comp.arch.embedded
Subject Re: 32 bits time_t and Y2038 issue
Date 2025-03-21 22:40 +0100
Organization A noiseless patient Spider
Message-ID <vrkmd9$2dn3k$1@dont-email.me> (permalink)
References (9 earlier) <vre61i$laqo$1@dont-email.me> <vrek8d$8us$1@reader1.panix.com> <vrerlm$18bs6$1@dont-email.me> <vrffbi$1tnem$1@paganini.bofh.team> <vrgjff$2qpu7$1@dont-email.me>

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Il 20/03/2025 09:26, David Brown ha scritto:
> On 19/03/2025 23:09, Waldek Hebisch wrote:
>> David Brown <david.brown@hesbynett.no> wrote:
>>> On 19/03/2025 15:27, Grant Edwards wrote:
>>>> On 2025-03-19, David Brown <david.brown@hesbynett.no> wrote:
>>>>
>>>>> There are certainly a few things that Cygwin can handle that msys2
>>>>> cannot.  For example, cygwin provides the "fork" system call that is
>>>>> very slow and expensive on Windows, but fundamental to old *nix
>>>>> software.
>>>>
>>>> I believe Windows inherited that from VAX/VMS via Dave Cutler.
>>>
>>> I am always a bit wary of people saying features were copied from VMS
>>> into Windows NT, simply because the same person was a major part of the
>>> development.  Windows NT was the descendent of DOS-based Windows, which
>>> in turn was the descendent of DOS.  These previous systems had nothing
>>> remotely like "fork", but Windows already had multi-threading.  When you
>>> have decent thread support, the use of "fork" is much lower - equally,
>>> in the *nix world at the time, the use-case for threading was much lower
>>> because they had good "fork" support.  Thus Windows NT did not get
>>> "fork" because it was not worth the effort - making existing thread
>>> support better was a lot more important.
>>
>> Actually, Microsoft folks say that Windows NT kernel supports fork.
>> It was used to implement Posix subsystem.  IIUC they claim that
>> trouble is in upper layers: much of Windows API is _not_ kernel
>> and implementing well behaving fork means that all layers below
>> user program, starting from kernel would have to implement
>> fork.
>>
>> So this complicated layered structure seem to be main technical
>> reason of not having fork at API level.  And this structure
>> is like VMS and Mica.  Part of this layering could be motivated
>> by early Windows split between DOS and Windows proper, but
>> as Grant explained, VMS influence was stronger.
>>
>> IIUC early NT developement was part of joint IBM-Microsoft
>> effort to create OS/2, so clearly DOS and Windows influence
>> were limited.  Only later Microsoft decided to merge
>> classic Windows and NT and effectively abandon other
>> system iterfaces than Windows API.
>>
> 
> DOS and Windows were a relevant part of OS/2 development too.  Both IBM 
> and MS were fully aware that if OS/2 and/or NT were to succeed, 
> compatibility with existing software was essential.  But more than that, 
> compatibility with existing software /developers/ was essential.
> 
> But you are absolutely right that the NT kernel was originally intended 
> to support different API's or "personalities" (I think that was the term 
> used) - at least WinAPI, OS/2 and POSIX.  It was also the intention that 
> the OS/2 kernel would be similarly flexible, so that users could pick 
> their base system and run all sorts of different software on top.  IBM 
> and MS worked together for interoperability.  Having at least minimal 
> support for "fork" would have been necessary (along with things like 
> case-sensitive filename support).
> 
> However, it did not take long for MS to realise that they could stab IBM 
> in the back and take everything for themselves - through a mixture of 
> technical, economic, legal and illegal shenanigans, they killed off OS/2 
> as an OS and as an API, and dropped everything but the WinAPI interface. 
>   (As you point out, much of that was at a higher level than the kernel 
> itself.)
> 
> 
> There's a lot of interesting detail here from you and Grant, which I 
> appreciate.  However, we've strayed a long way from the OP's original 
> question and topic, and it's not really about embedded systems any more. 
>   I hope Pozz got what he needed before we drifted!

Yes, David, thank you very much all of you for a very interesting 
discussion.

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Thread

32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-11 16:22 +0100
  Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-11 17:32 +0100
    Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-11 23:21 +0100
      Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-12 10:33 +0100
        Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-12 16:48 +0100
          Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-12 17:39 +0100
            Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-12 18:13 +0100
              Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-12 19:18 +0100
                Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-13 09:57 +0100
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-13 16:51 +0100
                Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-14 13:27 +0100
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-14 14:20 +0100
    Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-12 08:44 +0100
      Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-12 11:14 +0100
      Re: 32 bits time_t and Y2038 issue antispam@fricas.org (Waldek Hebisch) - 2025-03-14 01:48 +0000
        Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-14 08:36 +0100
    Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-15 16:30 +0000
      Re: 32 bits time_t and Y2038 issue Grant Edwards <invalid@invalid.invalid> - 2025-03-15 17:02 +0000
        Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-15 23:26 +0000
      Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-18 09:21 +0100
        Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-18 11:34 +0100
          Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-18 17:31 +0100
            Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-18 20:29 +0100
              Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-21 09:20 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-21 13:54 +0100
                Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-21 20:53 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-22 11:19 +0100
                Re: 32 bits time_t and Y2038 issue antispam@fricas.org (Waldek Hebisch) - 2025-03-21 14:35 +0000
          Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-18 18:28 +0000
            Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-18 20:43 +0100
              Re: 32 bits time_t and Y2038 issue Grant Edwards <invalid@invalid.invalid> - 2025-03-18 20:58 +0000
                Re: 32 bits time_t and Y2038 issue Hans-Bernhard Bröker <HBBroeker@gmail.com> - 2025-03-18 23:31 +0100
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-19 11:24 +0100
                Re: 32 bits time_t and Y2038 issue Grant Edwards <invalid@invalid.invalid> - 2025-03-19 14:27 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-19 17:33 +0100
                Re: 32 bits time_t and Y2038 issue Grant Edwards <invalid@invalid.invalid> - 2025-03-19 19:08 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-19 21:14 +0100
                Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-21 09:48 +0000
                Re: 32 bits time_t and Y2038 issue Grant Edwards <invalid@invalid.invalid> - 2025-03-21 13:27 +0000
                Re: 32 bits time_t and Y2038 issue antispam@fricas.org (Waldek Hebisch) - 2025-03-19 22:09 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-20 09:26 +0100
                Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-21 22:40 +0100
                Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-21 09:23 +0000
                Re: 32 bits time_t and Y2038 issue Hans-Bernhard Bröker <HBBroeker@gmail.com> - 2025-03-21 22:38 +0100
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-19 08:24 +0100
              Re: 32 bits time_t and Y2038 issue antispam@fricas.org (Waldek Hebisch) - 2025-03-21 14:04 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-21 16:45 +0100
                Re: 32 bits time_t and Y2038 issue pozz <pozzugno@gmail.com> - 2025-03-21 22:51 +0100
                Re: 32 bits time_t and Y2038 issue Hans-Bernhard Bröker <HBBroeker@gmail.com> - 2025-03-22 00:00 +0100
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-22 14:29 +0100
                Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-22 14:46 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-22 17:57 +0100
                Re: 32 bits time_t and Y2038 issue antispam@fricas.org (Waldek Hebisch) - 2025-03-22 15:57 +0000
                Re: 32 bits time_t and Y2038 issue David Brown <david.brown@hesbynett.no> - 2025-03-22 18:02 +0100
        Re: 32 bits time_t and Y2038 issue Michael Schwingen <news-1513678000@discworld.dascon.de> - 2025-03-18 18:44 +0000

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