Add demo for JEP 345 - NUMA-Aware Memory Allocation for G1

src/main/java/org/javademos/init/Java14DemoLoader.java

@@ -6,6 +6,7 @@
 import org.javademos.commons.IDemoLoader;
 import org.javademos.java14.jep305.InstanceofPatternMatchingPreview;
 import org.javademos.java14.jep343.PackagingToolIncubatorDemo;
+import org.javademos.java14.jep345.NumaAwareG1Demo;
 import org.javademos.java14.jep349.JFREventStreamingDemo;
 import org.javademos.java14.jep352.NonVolatileMappedByteBuffersDemo;
 import org.javademos.java14.jep358.NullPointerDemo;
@@ -29,6 +30,7 @@ public class Java14DemoLoader implements IDemoLoader {
     public void loadDemos(Map<Integer, IDemo> demos) {
         demos.put(305, new InstanceofPatternMatchingPreview());
         demos.put(343, new PackagingToolIncubatorDemo());
+        demos.put(345, new NumaAwareG1Demo());
         demos.put(349, new JFREventStreamingDemo());
         demos.put(352, new NonVolatileMappedByteBuffersDemo());
         demos.put(358, new NullPointerDemo());

src/main/java/org/javademos/java14/jep345/NumaAwareG1Demo.java

@@ -0,0 +1,93 @@
+package org.javademos.java14.jep345;
+
+import org.javademos.commons.IDemo;
+
+/// Demo for JDK 14 feature JEP 345 - NUMA-Aware Memory Allocation for G1.
+///
+/// This JEP improves G1 garbage collector performance on large multi-socket machines
+/// by implementing NUMA (Non-Uniform Memory Access) aware memory allocation.
+/// This allows the G1 GC to allocate memory from multiple NUMA nodes, improving
+/// performance and memory locality for applications running on NUMA hardware.
+///
+/// JEP history:
+/// - JDK 14: [JEP 345 - NUMA-Aware Memory Allocation for G1](https://openjdk.org/jeps/345)
+///
+/// Further reading:
+/// - [JEP 345: NUMA-Aware Memory Allocation for G1](https://openjdk.org/jeps/345)
+/// - [G1 Garbage Collector](https://docs.oracle.com/en/java/javase/14/gctuning/garbage-first-garbage-collector.html)
+///
+/// @author Abhineshhh
+public class NumaAwareG1Demo implements IDemo {
+
+    @Override
+    public void demo() {
+        info(345);
+
+        // NUMA (Non-Uniform Memory Access) is a computer memory design used in
+        // multi-processor systems where memory access time depends on the memory
+        // location relative to the processor. In NUMA systems, a processor can
+        // access its own local memory faster than non-local memory (memory local
+        // to another processor or shared between processors).
+        //
+        // Before JEP 345 (Java 14):
+        // - G1 GC allocated memory from a single NUMA node
+        // - On multi-socket machines, this caused poor memory locality
+        // - Remote memory access caused performance degradation
+        // - The heap was not distributed across available NUMA nodes
+        //
+        // After JEP 345 (Java 14):
+        // - G1 GC can allocate memory from multiple NUMA nodes
+        // - Better memory locality for application threads
+        // - Improved performance on NUMA hardware
+        // - Automatic distribution of heap across NUMA nodes
+        //
+        // How to enable NUMA-aware memory allocation for G1:
+        // Use the following JVM options:
+        //
+        //   -XX:+UseG1GC                    (Enable G1 Garbage Collector)
+        //   -XX:+UseNUMA                    (Enable NUMA-aware allocations)
+        //
+        // Example command:
+        //   java -XX:+UseG1GC -XX:+UseNUMA -Xms4g -Xmx4g MyApplication
+        //
+        // Benefits on NUMA systems:
+        // 1. Improved throughput - threads access local memory more frequently
+        // 2. Reduced latency - fewer remote memory accesses
+        // 3. Better scalability - utilizes all NUMA nodes effectively
+        // 4. Automatic optimization - no application code changes needed
+        //
+        // When to use:
+        // - Running on multi-socket servers (2+ CPUs)
+        // - Large heap sizes (several GB or more)
+        // - Memory-intensive applications
+        // - Applications with high allocation rates
+        //
+        // Notes:
+        // - NUMA support requires underlying OS and hardware support
+        // - The JVM must be running on a NUMA-capable system
+        // - Use with Linux numactl or Windows NUMA API for best results
+        // - Monitor with tools like numastat (Linux) to verify NUMA usage
+        //
+        // Example numactl command (Linux):
+        //   numactl --interleave=all java -XX:+UseG1GC -XX:+UseNUMA MyApp
+        //
+        // Performance considerations:
+        // - For small heaps (<4GB), NUMA awareness may not provide significant benefit
+        // - For large heaps (>16GB) on multi-socket systems, can improve performance by 10-30%
+        // - Thread affinity and memory locality are automatically managed by G1
+        //
+        // Compatibility:
+        // - Works with all G1 GC features (concurrent marking, evacuation, etc.)
+        // - Can be combined with other G1 tuning options
+        // - No application code changes required
+        //
+        // To verify NUMA is active, check JVM logs with:
+        //   -Xlog:gc+heap+numa=debug
+        //
+        // This will show NUMA node allocation information during GC cycles.
+
+        System.out.println("\nNUMA-Aware G1 is a JVM-level optimization.");
+        System.out.println("No code changes are required - just use appropriate JVM flags.");
+        System.out.println("Enable with: -XX:+UseG1GC -XX:+UseNUMA");
+    }
+}

src/main/resources/JDK14Info.json

@@ -15,6 +15,14 @@
   "link": true,
   "code": false
   },
+  {
+    "jep": 345,
+    "jdk": 14,
+    "name": "JEP 345 - NUMA-Aware Memory Allocation for G1",
+    "dscr": "Improves G1 GC to allocate memory from multiple NUMA nodes for better performance on multi-socket machines",
+    "link": false,
+    "code": true
+  },
   {
     "jep": 349,
     "jdk": 14,