[Lazarus] Why development remains constant for msdos?

[Mark Morgan Lloyd]

Michael Schnell wrote:
> On 09/24/2013 10:58 AM, Nikolay Nikolov wrote:
>>
>> When you try to create a thread, your program terminates and writes a 
>> message that threading is not supported.
> 
> While this absolutely does make sense, one could think about alternatives.
> 
> AFAIK, (at least for some archs) there is a variant of the pthread 
> (="POSIX thread") library, that internally does "user-land 
> multithreading". IIRC, the original POSIX definition was done with 
> exactly this in mind and, regarding Linux, the original Linux 
> implementations (aka "Linux Threads")  was not fully compatible with 
> POSIX. Only some years ago, the Linux changed it's way of Kernel-based 
> thread handling to the POSIX compatible "NPTL" implementation.
> 
> Thus it should be possible to link fpc projects to a user-land thread 
> enabled version of pthreadlib and allow for working with TThread in DOS.

The change happened at different times on different architectures. I've 
definitely had to write (Lazarus) code to take this into account, since 
the PID behaviour differed.

But since AIUI LinuxThreads generally attempted to use multiple 
processes, getting that to work on DOS might be a problem. It would 
probably be easier to start off with coroutines, and then to change them 
into real threads by preemption.

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

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