How can I update a global variable across threads as I am getting garbage value for the variable across threads.
Below is sample code which shows the problem
use strict;
use warnings;
use threads;
my $currentWrite = 10;
my $totalSize = 1000;
sub Progress {
my $size = shift;
$currentWrite += $size;
my $currentProgress = $currentWrite / 100;
print "Done ", $currentProgress, " of ", $totalSize, "\n";
}
sub test {
my $countRef = shift;
my $count = $$countRef;
Progress ( 11);
print "Current count is $count\n";
}
Progress(10);
my $numThreads = 5;
my @arrThreads;
for my $i ( 1 .. $numThreads) {
my $t = threads->create( \&test, \$i);
push( @arrThreads, $t);
}
foreach (@arrThreads) {
my $num = $_->join;
}
Below is the output of above program.
# perl thrprog.pl
Done 0.2 of 1000
Done 0.31 of 1000
Current count is 2
Done 0.31 of 1000
Current count is 1
Done 0.31 of 1000
Current count is 3
Done 0.31 of 1000
Current count is 4
Done 0.31 of 1000
Current count is 5
How to share the data across threads so that the value get updated properly.