DEV Community

decillion
decillion

Posted on

5 2

Software Transactional Memory in Go

I have recently written decillion/go-stm, which is a software transactional memory (STM) implementation for Go. It provides a new way of synchronization to Go programmers, while it is still experimental one.

The package enables one to atomically execute a sequence of operations on shared variables without explicit locking. I present a simple example below. Please see the repository or a blog post (in Japanese) for further information.


// Initialize two transactional variables.
x := New(0)
y := New(0)

// Define a transaction that transfer 100 from x to y.
transfer := func(rec *TRec) interface{} {
    currX := rec.Load(x).(int) // Read the value of x.
    currY := rec.Load(y).(int) // Read the value of y.
    rec.Store(x, currX-100)    // Write currX-100 to x.
    rec.Store(y, currY+100)    // Write currY-100 to y.
    return nil
}

// Execute the transaction atomically.
Atomically(transfer)
Enter fullscreen mode Exit fullscreen mode

If you want to know more about the STM itself, I recommend you to read the article, Beautiful concurrency, written by Simon Peyton Jones.

There has been another STM package written by lukechampine. It provides a richer STM interface but is less performant than the present package. Here is the result of a very simple benchmark, in which two transactional variables are atomically incremented or read. The benchmark is taken at Ubuntu 17.10 on a DigitalOcean's High CPU Droplet with 32 cores.

Benchmark_Read90Write10_decillion-4         10000000           156 ns/op
Benchmark_Read90Write10_decillion-8         10000000           144 ns/op
Benchmark_Read90Write10_decillion-16        10000000           214 ns/op
Benchmark_Read90Write10_decillion-32         5000000           289 ns/op

Benchmark_Read90Write10_lukechampine-4       2000000           761 ns/op
Benchmark_Read90Write10_lukechampine-8       2000000           822 ns/op
Benchmark_Read90Write10_lukechampine-16      2000000           912 ns/op
Benchmark_Read90Write10_lukechampine-32      2000000           966 ns/op
Enter fullscreen mode Exit fullscreen mode

Sentry image

Hands-on debugging session: instrument, monitor, and fix

Join Lazar for a hands-on session where you’ll build it, break it, debug it, and fix it. You’ll set up Sentry, track errors, use Session Replay and Tracing, and leverage some good ol’ AI to find and fix issues fast.

RSVP here →

Top comments (0)

Image of Docusign

🛠️ Bring your solution into Docusign. Reach over 1.6M customers.

Docusign is now extensible. Overcome challenges with disconnected products and inaccessible data by bringing your solutions into Docusign and publishing to 1.6M customers in the App Center.

Learn more