[fpc-devel] How to use fpFlock?

ik idokan at gmail.com
Tue May 6 08:08:17 CEST 2008

flock in Linux (at least) is blocking by default unless passed with
specific parameter.

You can try also to create a mutex that only when removed you will
access the procedure/function that try to write to the file, and the
process that created the mutex is the only one that can write to that
You of course remove it when you closed the file.

Just an idea...


On Fri, May 2, 2008 at 5:35 AM, amir <amir at aavani.net> wrote:
> Hi,
>  I have many process wanting to write in a file. Each process is going to
> open the file as a writeonly (using Assignfile and rewrite or fpOpen with
> o_WrOnly). But there is a risk that two processes simultaneously trying to
> write a message in the file. I want to use fpflock to avoid this. Is it
> possible? What I done is something like this:
>  AssignFile (OutputFile, FileName);
>  fpflock (OutputFile, LOCK_EX);
>  Rewrite (OutputFile);
>  ...
>  The description of fpFlock does not  say anything about the default
> behavior of fpFlock (Is it blocking?). What I saw told me that it is not
> blocking.
>  Is it the correct way of using fpFlock?
>  _______________________________________________
>  fpc-devel maillist  -  fpc-devel at lists.freepascal.org
>  http://lists.freepascal.org/mailman/listinfo/fpc-devel


More information about the fpc-devel mailing list