Re: problems of gnuplot 5.4 with pipes in Windows

[Tait <gnu...@t4...>]

I don't know anything about this code, so feel free to tell me 
I'm misdirected but...

In ConsoleGetch(), _get_osfhandle is used on stdin. MS cautions 
[1] this might not be valid, and ConsoleGetch() does not check 
h!=-2. GetStdHandle or CreateFile [2] might be a better choice?

MsgWaitForMultipleObjects is described as a "very tricky" API 
[3]. Although nothing else seems to fall afoul of [4]'s 
recommendations, I don't know why WaitForSingleObject isn't used 
instead, or just plain ReadFile. MS notes fread locks out other
threads [5]. Is the writer ever another thread?

As an incidental note, pipes created from cmd like in bug 2412 
appear to be anonymous pipes and those do not support 
asynchronous read/write. [6] I don't think this matters here, 
but I mention it in case anybody thought they were going to get 
clever.

[1] https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/get-osfhandle?view=msvc-160
[2] https://docs.microsoft.com/en-us/windows/console/console-handles
[3] https://docs.microsoft.com/en-us/archive/blogs/larryosterman/things-you-shouldnt-do-part-4-msgwaitformultipleobjects-is-a-very-tricky-api
[4] https://devblogs.microsoft.com/oldnewthing/20050217-00/?p=36423
[5] https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/fread?view=msvc-160
[6] https://docs.microsoft.com/en-us/windows/win32/ipc/anonymous-pipe-operations

(Dropped CCs because this isn't about the Python problem anymore.)

Ethan A Merritt <me...@uw...> said (on 2021/06/19):
> ...
> My understanding is that this is a known problem when combining specifically
> gnuplot version 5.4 and Windows version 10.
> 
> Issue tracker here
>    https://sourceforge.net/p/gnuplot/bugs/2412/