# update shared counters
use threads;
use threads::shared; # needed for shared variables

my $TotalsLock:shared;  # variable to be the lock
my $MsgCnt:shared;
my $TotalBytes:shared;
....
{ 
    lock $TotalsLock;  # I have locked access
    $MsgCnt++;
    $TotalBytes += $bytesThisemail;
} # lock released at end of enclosing scope

##</code><code>##

# update shared counters
use threads;
use threads::shared; # needed for shared variables

my $TotalsLock:shared;  # variable to be the lock
my $MsgCnt:shared;
my $TotalBytes:shared;
....
{ 
    lock $TotalsLock;  # I have locked access
    print "Activity Totals: $MsgCnt $TotalBytes]n";
} # lock released at end of enclosing scope