Channel Synchronization in Perl

Our example demonstrates how to synchronize execution across different parts of a Perl program. We’ll use a simple threading model to illustrate this concept. In Perl, we can use threads and shared variables to achieve similar functionality to Go’s goroutines and channels.

use strict;
use warnings;
use threads;
use Thread::Queue;
use Time::HiRes qw(sleep);

# This is the function we'll run in a thread. The
# $done queue will be used to notify the main thread
# that this function's work is done.
sub worker {
    my $done = shift;
    
    print "working...";
    sleep(1);  # Sleep for 1 second
    print "done\n";
    
    # Enqueue a value to notify that we're done.
    $done->enqueue(1);
}

sub main {
    # Create a new queue to communicate between threads
    my $done = Thread::Queue->new();
    
    # Start a worker thread, giving it the queue to notify on.
    my $thread = threads->create(\&worker, $done);
    
    # Block until we receive a notification from the
    # worker on the queue.
    $done->dequeue();
    
    # Wait for the thread to finish
    $thread->join();
}

main();

To run the program:

$ perl channel-synchronization.pl
working...done

In this Perl version, we use threads instead of goroutines, and a Thread::Queue instead of a channel. The worker function is run in a separate thread, and it uses the $done queue to signal when it’s finished.

The main function creates a new queue, starts the worker thread, and then waits for a value to be enqueued on the $done queue. This blocks the main thread until the worker thread signals that it’s done.

If you removed the $done->dequeue(); line from this program, the program would exit before the worker thread even started, similar to the Go version.

Note that Perl’s threading model is different from Go’s goroutines. Perl threads are more heavyweight and are not as commonly used for concurrent programming as goroutines are in Go. For more complex concurrent operations in Perl, you might want to consider using event-driven programming or other concurrency models that are more idiomatic to Perl.