Posts Tagged threading

Thread Synchronization Performance

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Multi-threading is essential to performance on all modern processors. Using multiple threads brings along with it the challenge of synchronizing data access across those threads. Unity’s job system can do some of this for us, but it certainly doesn’t handle every case. For times when it doesn’t, C# provides us with a bunch of synchronization options. Which are fastest? Today we’ll find out!

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How Many Temp Allocators Are there?

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Last time we saw that jobs apparently have their own Temp allocator. Still, it was unclear how many of these allocators there are. One per job job? One per thread? Just one? Today we’ll run an experiment to find the answer!

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Temp Memory Reuse

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Temp memory is backed by a fixed size block that’s cleared by Unity every frame. Allocations on subsequent frames return pointers to this same block. The allocated memory therefore isn’t unique. How much of a problem is this? Today we’ll do some experiments to find out!

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Allocating Memory Within a Job: Part 2

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Last week’s article came to the conclusion that allocating Temp memory from within a job was safe. This week we’ll look into that a little deeper to find out that it might not be as safe as it looks!

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Allocating Memory Within a Job

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What do you do when a job you’re writing needs to allocate memory? You could allocate it outside of the job and pass it in, but that presents several problems. You can also allocate memory from within a job. Today we’ll look into how that works and some limitations that come along with it.

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Free Performance with Burst

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Unity 2019.1 was released last week and the Burst compiler is now out of Preview. It promises superior performance by generating more optimal code than with IL2CPP. Let’s try it out and see if the performance lives up to the hype!

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NativeIntPtr and NativeLongPtr: Part 2

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Last week’s article introduced two new native collection types: NativeIntPtr and NativeLongPtr. These were useful for both IJob and IJobParallelFor jobs, but performance was degraded in IJobParallelFor. Today we’ll remedy that, explore some more aspects of Unity’s native collection and job systems, and learn more about CPU caches along the way.

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C# Tasks vs. Unity Jobs

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Two weeks ago we tested the performance of the async and await keywords plus the C# Task system against Unity’s new C# jobs system. This tested the usual combination of async and await with the Task system, but didn’t test the Task system directly against Unity’s C# jobs system. Today we’ll test that and, in so doing, see how to use the Task system without the async and await keywords.

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How Async and Await Work

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Last week’s article tested the performance of the async and await keywords plus the C# Task system against Unity’s new C# jobs system. This week we’ll go in depth with async and await to learn how they work, how they relate to the Task system, and how we can customize them for our own uses.

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How IL2CPP implements lock, volatile, [ThreadStatic], and Interlocked

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Writing multi-threaded code is one of the keys to maximizing performance. Currently, this means creating your own threads and synchronizing them with C# keywords like lock and volatile as well as .NET classes like [ThreadStatic] and Interlocked. Today we’ll take a look at how these are implemented behind the scenes by IL2CPP to get some understanding of what we’re really telling the computer to do when we use them.

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