#concurrency

7 post(s)

Spring Boot Virtual Threads:Flip One Flag, Then Fix What Breaks

Enable spring.threads.virtual.enabled on Boot 3.2+, understand what Tomcat and the application task executor actually switch, and size Hikari, RestClient, and observability so the flag does not become a thundering herd.

Java

Scoped Values:Share Immutable Context Without ThreadLocal Pain

What Java scoped values are (JEP 506 / Java 25), how they differ from ThreadLocal, why they fit virtual threads, and how to bind request context with where/run and where/call.

Java

Locks After Loom:When `synchronized` Still Wins

After virtual threads, when intrinsic locks still win — pinning vs JEP 491, wait/notify, monitors, and ReentrantLock — so you do not treat synchronized as obsolete.

Java

Virtual Threads:Millions of Tasks Without a Thread Pool Circus

What Java virtual threads are (JEP 444 / Java 21), how they differ from platform threads, when they win for I/O-bound work, and the pinning and ThreadLocal gotchas—plus what Java 25 changed.

Java

BlockingQueue:Hand Off Work Without a Busy Wait

Use BlockingQueue to pass work between threads — put/take that block, offer/poll with timeouts, and when to pick Array, Linked, Delay, Synchronous, or Transfer queues.

Java

ConcurrentHashMap:Shared Maps Without Synchronizing the Whole Table

Use ConcurrentHashMap for a shared map — per-bin concurrency, no nulls, weakly consistent iterators, and atomic compute/merge — not Hashtable and not synchronizedMap.

Java

CompletableFuture:Compose Async Work Without Callback Hell

Compose async Java work with CompletableFuture — supplyAsync, thenApply, thenCompose, allOf — without nested callbacks, and when virtual threads are the simpler path.