How to use mutex in Unreal Engine

Unreal Engine has an alternative implementation of std::mutex called FCriticalSection which makes it possible for your data to be safely accessed from different threads. This takes the same approach, handling it with one thread locking until the other thread completes the necessary operations. There are two ways to handle lock/unlock logic. The first is low-level, which is used to directly lock and unlock threads. Use with caution due to possible deadlocks ....

December 21, 2022 · 2 min · Georgy Treshchev

How to properly work with UObjects in background threads (GC)

This short article addresses the question of how to work with UObjects in a thread-safe way when passing them to some workers, asynchronous tasks, thread pools, or whatever else using a non-game thread. One of the most important issues here is garbage collection. When we pass a UObject* that is not set to root directly to a background thread, it is possible that the passed UObject may be silently deleted by the garbage collector....

November 30, 2022 · 1 min · Georgy Treshchev

How to async task in Unreal Engine

Unreal Engine has a nice feature called AsyncTask, which is used to execute a code asynchronously. It works by running certain code on a specified thread, and this functionality is mostly used when the task is heavy enough to be executed instantly without blocking the game thread. It also provides a solution to all issues arising from multithreading, in particular, accessing parameters from one thread that are supposed to be used and/or edited in another thread....

July 31, 2022 · 2 min · Georgy Treshchev

How to create a multi-threaded for loop in Unreal Engine

Unreal Engine has different approaches to parallelize your code and one of them is ParallelFor. It is used when it is necessary to execute code multiple times with different number-based inputs, basically what a regular for loop does. But unlike a regular for loop that executes sequentially, ParallelFor runs on different threads, with possible different order of execution. Let’s say our task is to simply sum the values from the TArray<int32> array....

July 23, 2022 · 2 min · Georgy Treshchev