Building Better Desktop Applications

Creating robust desktop applications comes with a unique set of challenges. These applications often require careful planning to balance features, performance, and user experience. Here are some key design considerations to help you streamline the development process for your next desktop app.

Speeding up big builds

One of the biggest bottlenecks in desktop app development is managing large codebases heavy with features. Without careful attention, the code/build/test cycle can easily drag down productivity due to long compile times. Add in multi-platform builds, unit tests, and continuous integration (CI) systems compiling multiple variants, and the slowdown gets even worse.

That’s why we like to reduce compilation times wherever possible. Here are a few things we do to make builds faster:

• Use pre-compiled headers: These can save minutes off your builds in big code bases by avoiding redundant compiler work.
• Leverage caching tools like ccache: ccache reuses cached compiler results when files remain unchanged, slashing rebuild times.
• Explore distributed compilers: If your setup supports it, distribute the build process across multiple computers to parallelize the workload and drastically reduce build times.

Every second saved in compilation is a second gained for more meaningful work. Even small improvements in build times add up over the course of a project.

Mastering multithreading

Multithreaded programming is critical for high-performance desktop applications, but it’s also known for introducing tough-to-find bugs. Data corruption and race conditions are common pitfalls. A few techniques can help you avoid these pitfalls and make multithreading less daunting:

• Document your approach: Clearly comment on the multithreading behavior of variables, objects, or classes, specifying which threads use them and how synchronization or mutex protects them. This clarity helps other developers use your code so that future changes don’t introduce subtle bugs.
• Use a thread sanitizer: Thread sanitizers are great for detecting data races during testing. While they introduce runtime and memory overhead, they can save hours of troubleshooting.
• Use safe structures: Whenever possible, use thread-safe abstractions, immutable (const) objects, message passing, and atomic operations rather than creating custom classes with shared data that requires synchronization.

Designing plug-in architectures

Plug-ins are a common requirement for desktop applications to enable third-party or optional features. A well-designed plug-in system can extend your app’s capabilities while keeping the mainline code clean.

But without proper planning, plug-ins can introduce new challenges. They can reduce compiler optimizations across the code base or result in code that’s harder to test. Plug-ins can create issues if they are too tightly coupled to the mainline code, which makes it difficult to change the code base without breaking a host of plug-ins. A plug-in API that’s designed with an excessively generic interface can leave developers struggling to understand it and unable to create needed functionality. And a plug-in API that’s overly specific can limit the type and capability of plug-in features.

You need a plug-in API that’s carefully thought out to avoid these types of problems. The key to an effective plug-in architecture is keeping the scope manageable:

• Limit plug-ins to optional features: Core functionality should be part of the main development branch to avoid plug-ins from overcomplicating your project.
• Iterate on plug-in APIs carefully: A good plug-in system needs a stable, well-defined API, but modifying it or expanding it too often can create unnecessary headaches for developers. Take the time to build and thoroughly test a full-featured API upfront to ensure plug-ins integrate seamlessly without hindering performance.

Simplifying configuration

User configuration is a common requirement for desktop apps but troubleshooting configuration problems can be a major pain point. To make life easier for both users and support teams, use text-based configuration files instead of binary formats, databases, or system registries. There are several reasons why text-based configurations work better:

• Easier troubleshooting: Support staff can walk users through fixes or email a “safe mode” configuration to reset problematic settings.
• Platform consistency: Formats like XML, INI, or plist behave the same across platforms, unlike platform-specific solutions like the Windows Registry.
• Advanced customization: For advanced users, text configurations allow for tweaking esoteric settings without needing to build a GUI with lots of esoteric options.

This small design choice can save both development and support teams countless hours while enhancing the user experience.

Leveraging shared libraries

As you decompose your application into subsystems, consider structuring them as shared libraries, which will make it easier to test, maintain, and distribute your app. Here’s why this approach works well:

• Improved unit testing: By linking your main application and test executables to shared libraries, you can write focused unit tests for individual subsystems.
• Reduced build times: Shared libraries save space and compilation time compared to static libraries, particularly during iterative development.
• Simpler patching: For distributed applications with multiple primary components (as long as the ABI remains the same), shared libraries streamline the patching process for end users.

Decomposing your app with a few strategic shared libraries can improve your development workflow while enhancing modularity and maintainability.

Build smarter, not harder

Developing desktop applications is no small feat, but focusing on a handful of design considerations can make the process smoother and more efficient. Prioritize speeding up big builds to reduce developer downtime, document your multithreading strategies to avoid subtle bugs, and implement a plug-in architecture that balances extensibility with simplicity. And opt for text-based configurations to simplify troubleshooting and leverage shared libraries to improve testing and distribution.

Looking for more tips? My Desktop Development Best Practices whitepaper explores more strategies like these and has other insights to help you build better apps.