java virtual threads vs kotlin coroutines

src: Voxxed Days Thessaloniki 2023 - Async Showdown: Java Virtual Threads vs. Kotlin Coroutines - Invidious

Abstract

Virtual thread suspension:

• blocking methods in java.* package
  • e.g. I/O calls, reading/writing streams
• except
  • synchronized blocks
  • native methods / foreign functions

Virtual threads use cases:

• thread-per-request style server applications
• highly concurrent, I/O bound code
  • not CPU-bound

Java virtual threads vs Kotlin coroutines

• virtual threads vs suspending functions
• structured concurrency vs structured concurrency
• scoped values vs coroutine context

The differences lay in the fundamentals: implicit vs explicit

• virtual threads:
  • transparently implemented, minimal code changes needed
  • implicitly suspending methods
• kotlin coroutines:
  • different coding style
  • explicitly suspending functions

Use cases:

• kotlin coroutines
  • async computations
  • async UI
  • futures
  • (sequence) generators
  • channel-based concurrency
  • actor-based concurrency
  • etc
• java virtual threads
  • I/O bound JVM applications