You can create threads with standard Thread properties, such as the thread name, using Thread.Builder. While Thread.Builder.OfVirtual creates virtual threads, Thread.Builder.OfPlatform creates platform threads. The retrieveURLs method creates a list of tasks (one for each URL) and submits them to the executor, then waits for the results. The executor starts a new virtual thread for each task, which calls getURL. For simplicity, only tasks that complete successfully are returned.

This is useful if your application needs to make many parallel network calls to external services such
as REST APIs, or open many connections to external databases (via JDBC)
or similar. Having to manage virtual threads has its performance penalty. For applications with a smaller load, Threads might outperform virtual ones, simply because the context switching is low when there are few active clients.

Intro to virtual threads: A new approach to Java concurrency

Instead of waiting for a result, the programmer indicates which method should be called when the result has become available, and perhaps another method that is called in case of failure. This gets unpleasant quickly, as the callbacks nest ever more deeply. A server http://fishing-russ.ru/news/rybalka_na_sudaka/2014-12-06-120 application called EchoServer listens on a specific port and launches a fresh virtual thread with each new connection. A client application called EchoClient establishes a connection with the server and transmits commands submitted via the command line.

• Instead of waiting for a result, the programmer indicates which method should be called when the result has become available, and perhaps another method that is called in case of failure.
• The default pool size (parallelism) equals the number of CPU cores, and the maximum pool size is at most 256.
• Routines (aka. Subroutines) are reusable pieces of code that are usually called multiple times during execution.
• It’s not an error but a behavior that limits the application’s scalability.
• We’ve already seen how Kotlin coroutines implement continuations (Kotlin Coroutines – A Comprehensive Introduction – Suspending Functions).
• Many applications make use of data stores, message brokers, and remote services.

You use familiar programming structures—branches, loops, try blocks—instead of a pipeline of callbacks. A function can return a promise, for example, the result of an HTTP request, and then caller functions can chain their logic to it. This is how concurrency is achieved in most popular languages. Java also has promised, but they are called Futures, however, only the CompletableFuture has the complete feature list of a Promise.

Spring blog

Virtual Threads impact not only Spring Framework but all surrounding integrations, such as database drivers, messaging systems, HTTP clients, and many more. Many of these projects are aware of the need to improve their synchronized behavior to unleash the full potential of Project Loom. For this demonstration, I’ve created a simple Java application with the Maven archetype. It is worth noting that Thread.ofVirtual().start(runnable) is equivalent to Thread.startVirtualThread(runnable).

We’ll explain all the information printed by the log in a while. For now, let’s focus solely on thread name and execution interleaving. As we said, both projects are still evolving, so the final version of the features might differ from what we will see here.