Insider Tips: Locks
Competitive Thinking
A genuine multitasking system like Linux runs many processes concurrently. Programs must compete for data access. Assigning locks to files ensures exclusive access and prevents the possibility of data.
Most Linux machines have an MTA, a Mail Transfer Agent. This can be Postfix, Exim or even Sendmail. The MTA either uses a Fetchmail process or TCP to fetch email messages. When the MTA finds a message addressed to the local user, it passes the message on to the Local Delivery Agent (LDA). And the LDA stores the message in a mailbox file, after possibly taking a detour via a filter such as Procmail. If two messages arrive at the same time, the MTA will hand both of them to an LDA process at the same (see Figure 1). Each process will then attempt to write to the same mailbox file, again at the same time. If you are lucky, the messages end up in the right file, but in the wrong order, but you are far more likely to lose a file as the processes overwrite each other’s data.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
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.