perl中的lock

 #!/usr/bin/env perl -w
 use strict;
 use threads;
 use threads::shared;

 my $count:shared = ;
 print "count的起始值为:$count\n";
 sub th_lock{
         $count++;
         print "已把变量增加1并锁定10秒\n";
         lock($count);
         sleep();
 }
 sub th_wait{
         print "准备量锁定count\n";
         lock($count);
         print "变量锁定成功\n";
 }
 my $th_lock = threads->new(\&th_lock);
 my $th_wait = threads->new('th_wait');
 $th_lock->join();
 $th_wait->join;
 print "count的最后值为:$count\n";