C#•5mo ago

✅ Faster & thread safe random number generator?

Is there a good library for getting pseudo random numbers, faster than System.Random? I've done some looking but had a hard time coming up with much.

37 Replies

Angius•5mo ago

Do you find the speed of System.Random a bottleneck?

MechWarrior99OP•5mo ago

Yeah, not a massive one, but definitely is one.

Angius•5mo ago

Are you using multiple instances of Random, or Random.Shared? Or some singleton you yourself made

MechWarrior99OP•5mo ago

I have a large process which I create a new instance of Random for each time, since the process runs in a Task in a separate thread.

Angius•5mo ago

Random.Shared is thread-safe, IIRC

ParaLogia•5mo ago

yep https://learn.microsoft.com/en-us/dotnet/api/system.random.shared

Random.Shared Property (System)

Provides a thread-safe Random instance that may be used concurrently from any thread.

MODiX•5mo ago

Angius

REPL Result: Success

using System;
using System.Threading.Tasks;

Parallel.For(0, 10, x =>
{
    var value = Random.Shared.Next(); 
    Console.WriteLine(value);
});

using System;
using System.Threading.Tasks;

Parallel.For(0, 10, x =>
{
    var value = Random.Shared.Next(); 
    Console.WriteLine(value);
});

Console Output

1562793860548352853
252507751
1548914677
1900456204
1478899365
11502557
1227585618
1038092387

1986991436

1562793860548352853
252507751
1548914677
1900456204
1478899365
11502557
1227585618
1038092387

1986991436

Compile: 356.154ms | Execution: 96.933ms | React with ❌ to remove this embed.

Angius•5mo ago

Well this got one empty line lmao Could just be Modix though

MechWarrior99OP•5mo ago

Ah good to know, but I actually reset the seed each time, which is why I create a new instance each time.

Angius•5mo ago

You need deterministic random?

MechWarrior99OP•5mo ago

Yeah

Angius•5mo ago

Then I don't think you'll get much faster than System.Random Though you can always look for some nugers Maybe there's something that provides slightly worse randomness but is more performant I only know a less-performant way, RandomNumberGenerator, but this one's cryptographically secure

MechWarrior99OP•5mo ago

Yeah I don't really mind if it is a bit worse randomness (I think at least haha)

ParaLogia•5mo ago

https://xkcd.com/221/ ?

xkcd: Random Number

RFC 1149.5 specifies 4 as the standard IEEE-vetted random number.

MechWarrior99OP•5mo ago

I remember seeing something about using xor-shift to get random numbers, but couldn't find a lot on it. 🤔

Angius•5mo ago

https://en.wikipedia.org/wiki/Xorshift Seems simple to implement

Unknown User•5mo ago

Message Not Public

Angius•5mo ago

Unknown User•5mo ago

Message Not Public

Angius•5mo ago

Ooooh, I was wondering what's that long number lol

Unknown User•5mo ago

Message Not Public

ParaLogia•5mo ago

lol

MODiX•5mo ago

TeBeCo

REPL Result: Success

using System;
using System.Threading.Tasks;

Parallel.For(0, 50, x =>
{
    Console.WriteLine("aaaaaaaaaaaaaaaaaaaaaaaa");
});

using System;
using System.Threading.Tasks;

Parallel.For(0, 50, x =>
{
    Console.WriteLine("aaaaaaaaaaaaaaaaaaaaaaaa");
});

Console Output

aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaa

aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaa
aaa

More...

View on Hastebin

Compile: 380.625ms | Execution: 95.150ms | React with ❌ to remove this embed.

Unknown User•5mo ago

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MechWarrior99OP•5mo ago

Oh thanks for the link. I didn't realize that is literally what it is called. Or that it seems pretty easy to implement. I might give that a go and see how it performs. Still a bit surprised there isn't more libraries for C# that deal with random numbers and randomness (just in general)

MODiX•5mo ago

Angius

REPL Result: Success

using System;
using System.Threading.Tasks;
using System.Collections.Concurrent;

ConcurrentBag<int> cb = [];
Parallel.For(0, 10, x =>
{
    var val = Random.Shared.Next(); 
    cb.Add(val);
});
Console.WriteLine(string.Join('\n', cb));

using System;
using System.Threading.Tasks;
using System.Collections.Concurrent;

ConcurrentBag<int> cb = [];
Parallel.For(0, 10, x =>
{
    var val = Random.Shared.Next(); 
    cb.Add(val);
});
Console.WriteLine(string.Join('\n', cb));

Console Output

Compile: 469.303ms | Execution: 109.025ms | React with ❌ to remove this embed.

Unknown User•5mo ago

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Angius•5mo ago

This should be thread-safe 99% of the time it's just not needed

Unknown User•5mo ago

Message Not Public

MechWarrior99OP•5mo ago

Yeah, guess that is true. So... not that surprising haha Huh interesting, thanks for the link

Angius•5mo ago

Btw, just so we know what we're working with, what's the .NET version you're using?

MechWarrior99OP•5mo ago

I'm using .NET 8.0

Angius•5mo ago

Good, good

sibber•5mo ago

xorshift is an option if you want to sacrifice even randomness for performance

Unknown User•5mo ago

Message Not Public

MODiX•5mo ago

Stop asking about XorShift, just use System.Random and probably also Random.Shared.Next.... quote from the article bellow:

Despite the similar-sounding name, the “Xoroshiro/Xoshiro” algorithms approaches the problem differently from the preceding “Xorshift” family.

Note: Versions of the Xoshiro number generator are used in the System.Random class in the forthcoming .NET 6.x onwards

https://blogs.siliconorchid.com/post/coding-inspiration/randomness-in-dotnet

Unknown User•5mo ago

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✅ Faster & thread safe random number generator?