How can you improve game networking performance with multithreading?

1 Benefits of multithreading

Multithreading can improve game networking performance in several ways. First, it can reduce the impact of network latency, which is the delay between sending and receiving data. By using a separate thread for network communication, you can avoid blocking the main game loop or other critical tasks that depend on user input or rendering. Second, it can increase the throughput and scalability of your game server, which is the amount of data and players that it can handle. By using multiple threads for processing incoming and outgoing packets, you can distribute the workload and avoid bottlenecks or timeouts. Third, it can enhance the security and reliability of your game network, which is the protection and recovery of your data. By using a separate thread for encryption, compression, or error correction, you can prevent malicious attacks or data corruption.

2 Challenges of multithreading

Multithreading also introduces some challenges and complexities that you need to consider and address. One of the main challenges is synchronization, which is the coordination and consistency of data and actions across different threads. For example, you need to ensure that the network thread and the game thread have access to the same game state and do not overwrite or interfere with each other. Another challenge is concurrency, which is the occurrence and management of multiple events at the same time. For example, you need to handle the situation where the network thread receives a packet that contradicts or conflicts with the game thread's logic or expectations. A third challenge is performance, which is the efficiency and optimization of your multithreaded code. For example, you need to avoid excessive overhead or resource contention that may negate the benefits of multithreading.

3 Solutions for multithreading

To overcome the challenges of multithreading, you need to apply some best practices and techniques that can help you design and implement your multithreaded game networking code. One of the best practices is to use a message queue or a buffer for communication between threads. This way, you can decouple the network thread and the game thread and avoid direct data access or modification. You can also use a lock or a mutex to protect shared data or resources from simultaneous access or modification by different threads. Another best practice is to use a state machine or a protocol for handling concurrency issues. This way, you can define and follow a set of rules or steps for processing network events and resolving conflicts or inconsistencies. You can also use a timeout or a retry mechanism to deal with network failures or errors. A third best practice is to use a profiler or a debugger to measure and improve your multithreaded performance. This way, you can identify and eliminate any sources of overhead or contention that may affect your network speed or quality.

4 Implementation of multithreading

The implementation of multithreading in your game networking code depends on the game engine or framework that you use. Different engines or frameworks may provide different tools or libraries for creating and managing threads, as well as different APIs or interfaces for network communication. For example, Unity offers the System.Threading namespace for multithreading, and the UnityEngine.Networking namespace for network communication. Unreal Engine offers the FRunnable and FRunnableThread classes for multithreading, and the UNetDriver and UNetConnection classes for network communication. You need to familiarize yourself with the documentation and examples of your chosen engine or framework, and follow the guidelines and conventions for multithreading and network programming.

5 Examples of multithreading

To illustrate how multithreading can improve game networking performance, here are some examples of games that use multithreading for network communication. One example is Counter-Strike: Global Offensive, a multiplayer first-person shooter game that uses a separate thread for network communication to reduce latency and improve responsiveness. Another example is World of Warcraft, a massively multiplayer online role-playing game that uses multiple threads for network communication to increase throughput and scalability. A third example is Fortnite, a multiplayer online battle royale game that uses a separate thread for network encryption to enhance security and reliability.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?