Re: Libpq memory leak

On Fri, Sep 24, 2010 at 06:11:31PM +0400, Dmitriy Igrishin wrote:
> Hey Vladimir,
>
>
>
> 2010/9/24 Polyakov Vladimir <vvpolyakov@gmail.com>
>
> > Program written in C using Libpq, which receives large files (BYTEA)
> > has a memory leak.
> > I need to free ALL of the used memory after each sql query.
> >
> > after each call PQclear() I drop the buffer:
> >    conn->inBuffer = realloc(conn->inBuffer, 8192);
> >    conn->inBufSize = 8192;


This is a known unsafe use of the realloc() function. If if fails to
allocate memory, you just lost the conn->inBuffer, thus leaking memory
in your own code. Fix this first, and then see if you still have the
issue with memory leaks, because it's possible you're just leaking it
with a bad realloc() idiom.

> >
> > It works, but ..
> > I noticed that in some cases PQclear() does not clear the memory.
> > This happens only when the program receives certain files...
> >
> > Why do you need realloc() after PQclear()?
>
> --
> Regards,
> Dmitriy