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World Congress 2024 • Aug 20, 2024 • Session details

Java's Project Loom & Co - the end for reactive programming?

Jan Weinschenker

Are reactive frameworks becoming obsolete? Discover how Java 21's Project Loom uses virtual threads to deliver massive, non-blocking concurrency without sacrificing simple, sequential code.

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#1 about 2 min

Introduction to Project Loom and reactive programming

This presentation introduces the competing paradigms of Project Loom and reactive programming.

#2 about 3 min

Goals and concepts behind Java Project Loom

Virtual threads aim to drastically reduce the effort of writing and maintaining concurrent applications.

#3 about 3 min

Core principles of reactive programming and responsiveness

Message-driven models help applications remain responsive and resilient during unpredictable load spikes.

#4 about 3 min

Understanding thread states and blocking consequences

Traditional blocked threads waste processing time while waiting for external service responses.

#5 about 4 min

Approaches to non-blocking software before Project Loom

Previous concurrency solutions relied on callbacks, complex reactive frameworks, or Kotlin coroutines.

#6 about 2 min

Failing concurrency with standard Java thread limitations

A standard imperative Java approach fails with out-of-memory errors when processing massive concurrent delays.

#7 about 4 min

Solving thread blocking with reactive frameworks and Kotlin

Refactoring code with Spring WebFlux or Kotlin coroutines successfully resolves massive thread-blocking bottlenecks.

#8 about 3 min

Simplifying concurrent code with Java 21 virtual threads

Java 21 virtual threads efficiently process high-volume concurrency without requiring developers to abandon imperative code.

#9 about 2 min

Mechanics of virtual and carrier threads in Java

The Java Virtual Machine automatically unmounts blocked virtual threads to keep carrier threads freely available.

#10 about 2 min

Evaluating the future of reactive programming in Java

Project Loom provides a simpler concurrency solution that minimizes the need to learn complex reactive frameworks.

Matching moments

1:27 min

Introduction to Loom and its impact on concurrency

Ivan Šarić Ivan Šarić · Europe 2026 Virtual

46 sec

Contrasting Project Loom virtual threads with reactive semantics

Josh Long · World Congress 2022

1:56 min

Overview of Project Loom and virtual threads

Christian Woerz · LIVE

1:11 min

Origins of Project Loom and lightweight threading semantics

Ivan Šarić Ivan Šarić · Europe 2026 Virtual

2:31 min

Contextual history of reactive programming in Java ecosystems

Ivan Šarić Ivan Šarić · Europe 2026 Virtual

9:17 min

Exploring reactive programming implications and virtual thread usage

David Vlijmincx · LIVE

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