asmhatreandClaude Sonnet 5
4a74153d87
Adds JMH put/get throughput benchmarks (synchronizedMap vs ConcurrentHashMap, swept at 1/2/4/8 threads), a computeIfAbsent recursion trap demo (CHM tolerates recursion into a different key but throws IllegalStateException on the same key; plain HashMap throws ConcurrentModificationException even single-threaded), and a null-handling demo (CHM rejects null keys/values on put() and null keys on get() too). 7/7 JUnit tests pass; all output/ transcripts captured from real runs. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01FhzLY5p6okFva3qsnsRyvM
21 lines
1.3 KiB
Markdown
21 lines
1.3 KiB
Markdown
# java-core-examples
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Runnable companion code for ankurm.com's Java-core / concurrency series. One Maven module per
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article; each module's own README has that article's version table, quickstart, and traps.
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| Module | Post |
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| [`jmm`](jmm/) | The Java Memory Model Explained: volatile, happens-before, and Why Your Double-Checked Lock Failed |
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| [`locks`](locks/) | synchronized vs ReentrantLock vs StampedLock: Benchmarks and a Decision Table |
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| [`atomics`](atomics/) | Java Atomics and VarHandle: CAS, LongAdder, and When Atomics Beat Locks |
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| [`vt-pinning`](vt-pinning/) | Diagnosing Virtual Thread Pinning in Production: JFR Events, jcmd, and Real Fixes |
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| [`synchronizers`](synchronizers/) | CountDownLatch vs CyclicBarrier vs Phaser vs Semaphore in Java |
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| [`executors`](executors/) | ExecutorService Done Right: Shutdown, try-with-resources and Virtual Thread Executors |
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| [`concurrency-interview`](concurrency-interview/) | Top 40 Java Concurrency Interview Questions and Answers (2026) |
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| [`arithmetic`](arithmetic/) | Add Two Numbers in Java Without Overflow: addExact, Widening, and BigInteger |
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| [`hashmap-concurrenthashmap`](hashmap-concurrenthashmap/) | Java HashMap vs ConcurrentHashMap: Complete Interview Guide |
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## License
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MIT - see [LICENSE](LICENSE).
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