[luatex] lualatex / includegraphics / open files

[luigi scarso]

On Fri, Dec 1, 2017 at 1:49 PM, Knut Petersen <Knut_Petersen at t-online.de> wrote:
> Hi everybody!
>
> Assume that the files testa.pdf, testb.pdf and testc.pdf exist.
>
> Further assume there is a file mwe.tex:
>
> \NeedsTeXFormat{LaTeX2e}
> \documentclass[12pt]{letter}
> \usepackage{shellesc,graphicx}
> \begin{document}
> \includegraphics{testa.pdf}\newpage
> \includegraphics{testb.pdf}\newpage
> \includegraphics{testc.pdf}\newpage
> \immediate\write18{ lsof | grep latex | grep test | less -S }
> \end{document}
>
> If (on a linux system) you execute
>
> lualatex --shell-escape mwe
>
>
> and
>
> xelatex --shell-escape mwe
>
> you see a difference: the included pdf files are open if you use
> lualatex, they are _not_open_ when xelatex is used.
>
> That difference is not a problem if you want to include only a few
> files, but it is a problem if you want to include a few thousands
> of pdfs - on most sytems there is a limit of about 1024 open files.
>
> That limit can be raised, but at least in my case that does
> not really help: using write18 to start a program when many file
> descriptors are open might expose a bug in the c++ library if "many"
> is "more than 1023". If that child uses execve() to start another child,
> that execve fails with a "*** buffer overflow detected ***" message.
>
> Is this is a problem of luatex? I don't know, but I think it is.
>
> Keeping all files that are included by \includegraphics open is a
> wasteful use of limited system resources (file descriptors) , and xetex
> demonstrates that it is not necessary.
>
> BTW: In my tests xelatex fails to include more than 5005 pdfs  correctly.
> Pdfs 5005+ are read,  white space is reserved, but the actual content of
> the included pdfs is missing. Nothing unusual is written to the log.
>
> System used:
>
> Linux, 64bit (i4790K, 32GB)
> OpenSuSE Tumbleweed
> LuaTeX, Version 1.0.4 (TeX Live 2017/TeX Live for SUSE Linux)
> XeTeX 3.14159265-2.6-0.99998 (TeX Live 2017/TeX Live for SUSE Linux)
>
>
> Knut
>
Thank you for the report, we are testing.




-- 
luigi