How Perl programmers efficiently manage asynchronous program flows
Pyramid of Doom
Asynchronous program flow quickly degenerates into unreadable code if it lacks an overarching concept to provide structure. Fortunately, the JavaScript community has invented some functional tricks that also help tame asynchronous Perl code.
Even experts can unintentionally build race conditions into their code. Even they can easily overlook the side effects when multithreading suddenly interrupts the flow of code. Emergency teams later have to discover the causes, which involves a huge amount of effort. After all, the error the customer reports occurs only sporadically, because it only occurs given the temporal coincidence of certain events that cannot be easily reproduced by the development department.
One Thread Is Enough
If only one thread is running – as in a JavaScript application – then there can be no such race conditions, because the CPU runs the code as written, and nothing unexpected interrupts the flow. In other words, this approach has its benefits.
For a program with only one thread to run as fast as one with multiple threads, however, it must not be allowed to sit and twiddle its thumbs while, for example, a much slower network operation is in progress. To allow this to happen, the programmer relinquishes control over selected parts of the program to an event loop, which executes the events asynchronously. Once a programmer's brain has mastered the jump to asynchronous program flows, even complicated processes are wonderfully easy to write. Before that happens, however, some hurdles must be taken.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.
-
Go-Based Botnet Attacking IoT Devices
Using an SSH credential brute-force attack, the Go-based PumaBot is exploiting IoT devices everywhere.
-
Plasma 6.5 Promises Better Memory Optimization
With the stable Plasma 6.4 on the horizon, KDE has a few new tricks up its sleeve for Plasma 6.5.
-
KaOS 2025.05 Officially Qt5 Free
If you're a fan of independent Linux distributions, the team behind KaOS is proud to announce the latest iteration that includes kernel 6.14 and KDE's Plasma 6.3.5.
-
Linux Kernel 6.15 Now Available
The latest Linux kernel is now available with several new features/improvements and the usual bug fixes.
-
Microsoft Makes Surprising WSL Announcement
In a move that might surprise some users, Microsoft has made Windows Subsystem for Linux open source.
-
Red Hat Releases RHEL 10 Early
Red Hat quietly rolled out the official release of RHEL 10.0 a bit early.
-
openSUSE Joins End of 10
openSUSE has decided to not only join the End of 10 movement but it also will no longer support the Deepin Desktop Environment.
-
New Version of Flatpak Released
Flatpak 1.16.1 is now available as the latest, stable version with various improvements.