[Info-vax] pthread_kill() replacement for VMS?

[Bill Gunshannon]

On 7/27/2017 9:46 AM, David Froble wrote:
> John Reagan wrote:
>> On Thursday, July 27, 2017 at 8:59:52 AM UTC-4, John E. Malmberg wrote:
>>> Hello all,
>>>
>>> One of the gnulib tests is doing a pthread_kill call which does not 
>>> exist on VMS.
>>>
>>> Is there a quick fix to create such a routine?
>>>
>>> Regards,
>>> -John
>>
>> Ah, pthread_kill.  The "standard" way to write non-portable code.
>>
>> It is mixing both threads and signals together.  Signals are an 
>> emulation of the CRTL, not really part of the OS.  In some cases, you 
>> can turn the pthread_kill into pthread_cancel/pthread_testcancel.
>>
>> Here's the stock answer from the threads notefile when pthread_kill 
>> has been asked for over the years (in particular, from others who 
>> ported the gnulib going as far back as the early 2000s)
>>
>> "The foremost is that UNIX signals are emulated on OpenVMS, and that 
>> emulation
>> is provided by the C RTL, not by the base OS.  Thus, the C RTL would 
>> be the
>> logical host for pthead_kill(), not the threads library.  However, the 
>> C RTL,
>> by design, cannot contain any static references to the threads 
>> library, nor
>> does it have any ability to effect signal delivery in a thread other 
>> than the
>> current one, and so considerable support would have to be provided by the
>> threads library for the C RTL.  (All of this is ignoring the fact that 
>> the
>> signal handler vector and signal delivery masks are currently global 
>> and not
>> per-thread.)"
> 
> Another example of software anarchy in place of well thought out 
> software architecture.
> 
> Just like the attempt to implement byte range locking in the CRTL, 
> instead of the logical place, the DLM that exists to provide locking.
> 
> Yes, in the end, it's all ones and zeros, and just a long string of 
> instructions being executed.  But, when something is fundamentally an OS 
> feature, that's where is should be, not fudged in elsewhere.

Funny you should say this. I used to say it all the time but
the Ada fanatics still insisted that no matter how warped or
incompatible it was between compilers multi-tasking should
remain a part of the language as opposed to a part of the OS. :-)

bill