Implement MMapDirectory with Java 21 Project Panama Preview API

buildSrc/scriptDepVersions.gradle

@@ -22,7 +22,7 @@
 ext {
   scriptDepVersions = [
       "apache-rat": "0.14",
-      "asm": "9.4",
+      "asm": "9.5",
       "commons-codec": "1.13",
       "ecj": "3.30.0",
       "flexmark": "0.61.24",

gradle/generation/extract-jdk-apis.gradle

@@ -27,7 +27,7 @@ configure(rootProject) {
 configure(project(":lucene:core")) {
   ext {
     apijars = file('src/generated/jdk');
-    mrjarJavaVersions = [ 19, 20 ]
+    mrjarJavaVersions = [ 19, 20, 21 ]
   }
 
   configurations {

gradle/generation/extract-jdk-apis/ExtractJdkApis.java

@@ -55,7 +55,8 @@ public final class ExtractJdkApis {
 
   static final Map<Integer,List<String>> CLASSFILE_PATTERNS = Map.of(
       19, List.of(PATTERN_PANAMA_FOREIGN),
-      20, List.of(PATTERN_PANAMA_FOREIGN, PATTERN_VECTOR_VM_INTERNALS, PATTERN_VECTOR_INCUBATOR)      
+      20, List.of(PATTERN_PANAMA_FOREIGN, PATTERN_VECTOR_VM_INTERNALS, PATTERN_VECTOR_INCUBATOR),
+      21, List.of(PATTERN_PANAMA_FOREIGN)
   );
 
   public static void main(String... args) throws IOException {

gradle/template.gradle.properties

@@ -102,5 +102,5 @@ tests.jvms=@TEST_JVMS@
 org.gradle.java.installations.auto-download=true
 
 # Set these to enable automatic JVM location discovery.
-org.gradle.java.installations.fromEnv=JAVA17_HOME,JAVA19_HOME,JAVA20_HOME,JAVA21_HOME,RUNTIME_JAVA_HOME
+org.gradle.java.installations.fromEnv=JAVA17_HOME,JAVA19_HOME,JAVA20_HOME,JAVA21_HOME,JAVA22_HOME,RUNTIME_JAVA_HOME
 #org.gradle.java.installations.paths=(custom paths)

lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java

@@ -76,9 +76,9 @@
  *   <li>{@code permission java.lang.RuntimePermission "accessClassInPackage.sun.misc";}
  * </ul>
  *
- * <p>On exactly <b>Java 19</b> and <b>Java 20</b> this class will use the modern {@code
- * MemorySegment} API which allows to safely unmap (if you discover any problems with this preview
- * API, you can disable it by using system property {@link #ENABLE_MEMORY_SEGMENTS_SYSPROP}).
+ * <p>On exactly <b>Java 19 / 20 / 21</b> this class will use the modern {@code MemorySegment} API
+ * which allows to safely unmap (if you discover any problems with this preview API, you can disable
+ * it by using system property {@link #ENABLE_MEMORY_SEGMENTS_SYSPROP}).
  *
  * <p><b>NOTE:</b> Accessing this class either directly or indirectly from a thread while it's
  * interrupted can close the underlying channel immediately if at the same time the thread is
@@ -123,7 +123,7 @@ public class MMapDirectory extends FSDirectory {
    * Default max chunk size:
    *
    * <ul>
-   *   <li>16 GiBytes for 64 bit <b>Java 19</b> and <b>Java 20</b> JVMs
+   *   <li>16 GiBytes for 64 bit <b>Java 19 / 20 / 21</b> JVMs
    *   <li>1 GiBytes for other 64 bit JVMs
    *   <li>256 MiBytes for 32 bit JVMs
    * </ul>
@@ -346,7 +346,7 @@ private static MMapIndexInputProvider lookupProvider() {
     }
     final var lookup = MethodHandles.lookup();
     final int runtimeVersion = Runtime.version().feature();
-    if (runtimeVersion == 19 || runtimeVersion == 20) {
+    if (runtimeVersion >= 19 && runtimeVersion <= 21) {
       try {
         final var cls = lookup.findClass("org.apache.lucene.store.MemorySegmentIndexInputProvider");
         // we use method handles, so we do not need to deal with setAccessible as we have private
@@ -366,9 +366,9 @@ private static MMapIndexInputProvider lookupProvider() {
         throw new LinkageError(
             "MemorySegmentIndexInputProvider is missing in Lucene JAR file", cnfe);
       }
-    } else if (runtimeVersion >= 21) {
+    } else if (runtimeVersion >= 22) {
       LOG.warning(
-          "You are running with Java 21 or later. To make full use of MMapDirectory, please update Apache Lucene.");
+          "You are running with Java 22 or later. To make full use of MMapDirectory, please update Apache Lucene.");
     }
     return new MappedByteBufferIndexInputProvider();
   }