exabrial 3 hours ago

> Fray is a concurrency testing tool for Java that can help you find and debug tricky race conditions that manifest as assertion violations, run-time exceptions, or deadlocks. It performs controlled concurrency testing using state-of-the-art techniques such as probabilistic concurrency testing or partial order sampling.

> Fray also provides deterministic replay capabilities for debugging specific thread interleavings. Fray is designed to be easy to use and can be integrated into existing testing frameworks.

I wish I had this 20 years ago.

MaxBarraclough 10 hours ago

Neat to see sleep calls artificially introduced to reliably recreate the deadlock. [0]

Looks like fixing the underlying bug is still in-progress, [1] I wonder how many lines of code it will take.

[0] https://github.com/aoli-al/jdk/commit/625420ba82d2b0ebac24d9...

[1] https://bugs.openjdk.org/browse/JDK-8358601

  • trhway 3 hours ago

    without reworking of the code all these checks of the executor and queue state and queue manipulations have to be under a mutex, and that is just a few lines.

latchkey 11 hours ago

Maybe it is just me, but I can't read the text in the code because the font is nearly white on white.

  • masklinn 11 hours ago

    The light mode is fine, but you're right the dark mode is truly awful, the code blocks are unreadable.

    edit: for some reason the author overrode the background color on code blocks via an inline style of

        background-color:#f0f0f0
    
    from

        var(--code-background-color) = #f2f2f2
    
    to make the background nigh imperceptibly darker, but then while the stylesheet properly switches the to #01242e in dark mode the inline override stays and blows it to bit.

    Not that it's amazing if you remove the inline stle, on account of operators and method names being styled pretty dark (#666 and #4070a0).

    • aoli-al 11 hours ago

      Thanks for pointing it out! Just did a quick fix using Claude :)

      • malcolmgreaves 11 hours ago

        On mobile (Safari), the lines in the code blocks have different font sizes. They also have different fonts. Some are like 3-4x the size of other lines. No idea what could be going wrong, but it does unfortunately make the code blocks difficult to follow along.

        • aoli-al 10 hours ago

          should be fixed as well :)

          • NooneAtAll3 9 hours ago

            any chance you can make light/dark mode switch a UI button?

            • masklinn an hour ago

              On desktop I’d suggest installing an extension that adds a toggle (they exist for Firefox and chrome at least): adding a toggle manually is a bit of a chore, especially if the css system you use does not build that in.

  • 9d 7 hours ago

    [flagged]

TYMorningCoffee 6 hours ago

Impressive! Can't wait to try Fray out at work.