You have something there that MySql is immune to SIGALRM.

Here's another test script I wrote to test SIGALRM in a script running MySql: 

#!/usr/bin/perl 

require 'myconfigure.cgi';
$timeout = 5;
use DBI;
$keywords = "Whether rocking natural-curls, a-short";

print "Content-type: text/html\n\n";
sub do_search {

    $time1 = time;

    $dbh=DBI->connect("dbi:mysql:$database:localhost","$username","$pa
+ssword");

    $keywords_quoted = $dbh ->quote ($keywords);
    $query="SELECT count(*) FROM $websites_table WHERE MATCH(title) AG
+AINST ($keywords_quoted)";
    $sth=$dbh->prepare(qq{$query});
    $sth->execute();
    $total_count = $sth->fetchrow_array ();
    $sth->finish;
    $dbh->disconnect ||die("Couldn't disconnect to database!\n");
    $time2 = time;
    $time_ran = $time2 - $time1;

}

eval {        
    local $SIG{ALRM} = sub { die "alarm\n" }; 
    alarm $timeout;        
    &do_search;        
    alarm 0;    
}; 

if($@) {        
    $time2 = time;
    $time_ran = $time2 - $time1;

    print "$@, Time Ran: $time_ran, Total Count: $total_count\n";
    exit;

}

print "Time Ran: $time_ran, Total Count: $total_count\n";
exit;

[download]

Above script basically do a search for the number of matches of $keywords in $websites_table. I've used a timeout of 5 seconds( $timeout = 5;) to limit the time of search, i.e. exit if search takes more than 5 seconds.

When it timeouts by the eval{} block, it will indicate how much time the script has ran as shown by the variable $time_ran in the if($@) loop.

But I'm getting funny results when it timeout. It overshoots the timeout limit of 5 sec condiderably. In one instance, I got a value of $time_ran = 18.

How do I fix this problem?

In reply to Re^4: Perl Alarm Not Working by aceofspace
in thread Perl Alarm Not Working by aceofspace

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