2009/12/3 H.Merijn Brand <[email protected]>:
> Any objections to me committing below change?
While the originator of this request updates his ticket, maybe a smarter
implementation is reasonable:
I could modify S::S opentable() to request opening for reading/writing,
so you could differ between LOCK_SH and LOCK_EX automatically.
Further, it could be suitable to or LOCK_NB, which allows to avoid deadlocks.
Sorry for generating extra wishes ;)
/Jens
> --8<---
> --- DBI-svn/lib/DBD/File.pm 2009-12-03 17:47:15.000000000 +0100
> +++ DBI-svn/lib/DBD/File.pm 2009-12-03 17:49:20.000000000 +0100
> @@ -162,6 +162,7 @@ sub connect ($$;$$$)
> f_ext => 1, # file extension
> f_schema => 1, # schema name
> f_tables => 1, # base directory
> + f_lock => 1, # Table locking mode
> };
> $this->{sql_valid_attrs} = {
> sql_handler => 1, # Nano or S:S
> @@ -725,12 +726,17 @@ sub open_table ($$$$$)
> }
> $fh and binmode $fh;
> if ($locking and $fh) {
> - if ($lockMode) {
> + my $lm = defined $data->{Database}{f_lock}
> + && $data->{Database}{f_lock} =~ m/^[012]$/
> + ? $data->{Database}{f_lock}
> + : $lockMode ? 2 : 1;
> + if ($lm == 2) {
> flock $fh, 2 or croak "Cannot obtain exclusive lock on $file: $!";
> }
> - else {
> + elsif ($lm == 1) {
> flock $fh, 1 or croak "Cannot obtain shared lock on $file: $!";
> }
> + # $lm = 0 is forced no locking at all
> }
> my $columns = {};
> my $array = [];
> @@ -929,6 +935,29 @@ tables into the same (or no) schema:
> Defining f_schema to the empty string is equal to setting it to C<undef>,
> this to enable the DSN to be C<dbi:CSV:f_schema=;f_dir=.>.
>
> +=item f_lock
> +
> +With this attribute, you can force locking mode (if locking is supported
> +at all) for opening tables. By default, tables are opened with a shared
> +lock for reading, and with an exclusive lock for writing. The supported
> +modes are:
> +
> +=over 2
> +
> +=item 0
> +
> +Force no locking at all.
> +
> +=item 1
> +
> +Only shared locks will be used.
> +
> +=item 2
> +
> +Only exclusive locks will be used.
> +
> +=back
> +
> =back
>
> =head2 Driver private methods
> -->8---
>
> --
> H.Merijn Brand http://tux.nl Perl Monger http://amsterdam.pm.org/
> using & porting perl 5.6.2, 5.8.x, 5.10.x, 5.11.x on HP-UX 10.20, 11.00,
> 11.11, 11.23, and 11.31, OpenSuSE 10.3, 11.0, and 11.1, AIX 5.2 and 5.3.
> http://mirrors.develooper.com/hpux/ http://www.test-smoke.org/
> http://qa.perl.org http://www.goldmark.org/jeff/stupid-disclaimers/
>
