Re: ncurses: tgetent leaks nearly 10 KB of memory every time it is called

[Thomas Dickey]

On Thu, 15 Jun 2006, Matt wrote:

> GNU screen calls tgetent twice every time a user reattaches to a
> screen session. I don't know why it does that, but due to the
> memory leak in ncurses version 5.2-20020615, which is what ships
> with FreeBSD as the standard curses/terminfo library, GNU screen
> leaks 20 KB per session reattachment.

ok.  So it's annoying, but not really hundreds of times (usually)

> Many users on my system start a screen session and run processes
> inside it for months or years, so these leaks add up quick. In the
> past six months, my screen session has grown from 6 MB to 83 MB
> (I tend to detach and reattach several times a day). My system ran
> out of swap space a while back primarily due to this leak.

oh - I would do that on dayjob stuff, but my home machines get rebooted 
according to whatever I'm working on.

> So, since it's such a pain to upgrade ncurses on FreeBSD (they have
> FreeBSD-specific hacks that I don't want to dig into), I'm hacking
> a simple tgetent cache into my copy of GNU screen, since those
> tgetent calls are just getting the same answer every time. I suspect
> it will be at least a year before the FreeBSD folks make a new
> release that incorporates ncurses 5.5; until then this hack will
> get me by.
>
> I tried installing the FreeBSD port of ncurses 5.5 and linking GNU
> screen with that, but it doesn't work right -- it needs the
> FreeBSD-specific hacks that have been made to the ncurses build
> that the base system uses. It sure would be nice if those hacks

I pointed out to someone working on the ncurses port recently that most 
(if not all) of it can be done simply by using ncurses' configure script
options

         --enable-termcap \
         --disable-database \
         --enable-getcap

That was enough for the port, which I see here is the same as the base 
system:

http://www.freebsd.org/cgi/cvsweb.cgi/~checkout~/src/lib/libncurses/termcap.c?rev=1.2.2.2&content-type=text/plain

> weren't necessary, so I could just drop in the new version of ncurses
> and enjoy. Maybe the hacks are for some kind of BSD backward
> compatibility? Backward being the key word there. :)

not really compatibility - it's just politics (let's not go there)

--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net