alarm (Win32) Emulated using timers that must be explicitly polled whenever Perl wants to dispatch "safe signals" and therefore cannot interrupt blocking system calls.

Hello beckmanel,

From the documentation DBI/Signal Handling and Canceling Operations:

my $failed;
eval {
    local $SIG{ALRM} = sub { die "TIMEOUT\n" }; # N.B. \n required
    eval {
    alarm($seconds);
    ... code to execute with timeout here (which may die) ...
        1;
    } or $failed = 1;
    # outer eval catches alarm that might fire JUST before this alarm(
+0)
    alarm(0);  # cancel alarm (if code ran fast)
    die "$@" if $failed;
    1;
} or $failed = 1;
if ( $failed ) {
    if ( defined $@ and $@ eq "TIMEOUT\n" ) { ... }
    else { ... } # some other error
}
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I am not able to replicate your code so I can identify the problem but the code bellow works for me:

my $failed;
my $seconds = 12;
eval{
    Config::Simple->import_from("".$path."", \%config)
    or die Config::Simple->error();

    my $dbh = DBI->connect("dbi:mysql::".$config{'MySQL.host'}.":".$co
+nfig{'MySQL.port'}."", 
               "".$config{'MySQL.user'}."",
               "".$config{'MySQL.pass'}."",
               { 'PrintError' => 1, 'RaiseError' => 1 , 'AutoInactiveD
+estroy' => 1 } 
    ) or die "Could not connect to ". $config{'MySQL.host'} .": ". $DB
+I::errstr ."\n";

    local $SIG{ALRM} = sub { die "db_timeout" };
    eval {
    alarm($seconds);
    $dbh->do("USE Thanos1983");
        # or die "Error: " .dbh->errstr. "\n";
    1;
    } or $failed = 1;
    # outer eval catches alarm that might fire JUST before this alarm(
+0)
    alarm(0);  # cancel alarm (if code ran fast)
    die "$@" if $failed;
    1;
} or $failed = 1;

if ( $failed ) {
    if ( defined $@ and $@ eq "TIMEOUT\n" ) { ... }
    else { print "Error\n" } # some other error
}

__END__

$ perl test.pl 
DBD::mysql::db do failed: Unknown database 'Thanos1983' at test.pl lin
+e 30.
Error
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Also usually when I use prepare() I use it like this:

my $sth = $dbh->prepare("SELECT `ID`, `Y-Values` FROM `".$config{'MySQ
+L.table'}."` WHERE 1");

if (!$sth->execute()) {
    die "Error: ". $sth->errstr ."\n";
}
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Update: For login purposes I prefer to use Log::Log4perl.

Hope this helps, BR.

Code like below used to help me to cope with timeouts for blocking IO on Windows. Of course introducing threads may be undesirable or totally unusable for your purposes, i.e. not sure if it's worth anything.

use strict;
use warnings;
use threads;
use threads::shared;

my $err :shared = '';
 
sub timed_action (&$;@) {
    my ( $code, $timeout, @args ) = @_;

    local $SIG{ TERM } = sub { threads-> exit };
    lock( $err = '' );
 
    my $t = async {
        { lock $err }
        my $result = eval { $code-> ( @args )};
        lock( $err = $@ );
        cond_signal $err;
        return $result
    };
    if ( !cond_timedwait $err, time + $timeout ) {
        $err = 'Timeout!!!';
        $t-> kill( 'TERM' );
    }
    if ( $err ) {
        print "$err\n";
        $t-> detach;
        return undef
    }
    return $t-> join;
}

# let's test it

use LWP::Simple;
timed_action { get 'http://10.255.255.1' or die } 3;
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Never? Never is a very big word.

If you're in a transaction, it doesn't matter what the timer interrupts and it will all be left in a predictable state. Tools like DBIx::Class with DBIx::Class::Storage::TxnScopeGuard and perhaps Sys::SigAction make things like what the OP requested semitrivial.

Don't give generic, half-right advice; fixing the issue is indeed the best thing to do here. Give 100% on-point advice with working code or don't participate.