What alternative would they be referring to? Green threads were only (re-)introduced to Java in version 21 in 2023.
I think what they're trying to say is that Java's green thread implementation has special support for async I/O. Threads that block on I/O aren't polled for completion by the runtime, instead they use OS async features under the hood.
This allows Java's green threads to compete performance-wise with async/await solutions, but with cleaner code that doesn't need colored functions.
In older green thread implementations in other languages, I/O can actually cause significant CPU overhead due to polling threads that are blocked by I/O requests.
alt Hacker News
What alternative would they be referring to? Green threads were only (re-)introduced to Java in version 21 in 2023.
I think what they're trying to say is that Java's green thread implementation has special support for async I/O. Threads that block on I/O aren't polled for completion by the runtime, instead they use OS async features under the hood.
This allows Java's green threads to compete performance-wise with async/await solutions, but with cleaner code that doesn't need colored functions.
In older green thread implementations in other languages, I/O can actually cause significant CPU overhead due to polling threads that are blocked by I/O requests.