Gracefully handle absence of Unsafe.defineAnonymousClass (#16)

openjdk · Jun 29, 2021 · f18c55b · f18c55b
1 parent d577a18
commit f18c55b
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Showing 2 changed files with 20 additions and 8 deletions.
diff --git a/src/org.openjdk.nashorn/share/classes/org/openjdk/nashorn/internal/runtime/Context.java b/src/org.openjdk.nashorn/share/classes/org/openjdk/nashorn/internal/runtime/Context.java
@@ -317,6 +317,7 @@ private static final class AnonymousContextCodeInstaller extends ContextCodeInst
         private static final MethodHandle DEFINE_ANONYMOUS_CLASS = getDefineAnonymousClass();
         private static final String ANONYMOUS_HOST_CLASS_NAME = Compiler.SCRIPTS_PACKAGE.replace('/', '.') + ".AnonymousHost";
         private static final byte[] ANONYMOUS_HOST_CLASS_BYTES = getAnonymousHostClassBytes();
+        static volatile Exception initFailure;
 
         private final Class<?> hostClass;
 
@@ -331,8 +332,9 @@ private static MethodHandle getDefineAnonymousClass() {
                     final Field f = Unsafe.class.getDeclaredField("theUnsafe");
                     f.setAccessible(true);
                     return mh.bindTo(f.get(null));
-                } catch (ReflectiveOperationException e) {
-                    throw new RuntimeException(e);
+                } catch (Exception e) {
+                    initFailure = e;
+                    return null;
                 }
             });
         }
@@ -1501,8 +1503,9 @@ private synchronized Class<?> compile(final Source source, final ErrorManager er
         final URL          url    = source.getURL();
         final CodeSource   cs     = new CodeSource(url, (CodeSigner[])null);
         final CodeInstaller installer;
-        if (!env.useAnonymousClasses(source.getLength()) || env._persistent_cache || !env._lazy_compilation) {
-            // Persistent code cache and eager compilation preclude use of VM anonymous classes
+        if (env._persistent_cache || !env._lazy_compilation || !env.useAnonymousClasses(source.getLength(), () -> AnonymousContextCodeInstaller.initFailure) ) {
+            // Persistent code cache, eager compilation, or inability to use Unsafe.defineAnonymousClass (typically, JDK 17+)
+            // preclude use of VM anonymous classes
             final ScriptLoader loader = env._loader_per_compile ? createNewLoader() : scriptLoader;
             installer = new NamedContextCodeInstaller(this, cs, loader);
         } else {

diff --git a/...openjdk.nashorn/share/classes/org/openjdk/nashorn/internal/runtime/ScriptEnvironment.java b/...openjdk.nashorn/share/classes/org/openjdk/nashorn/internal/runtime/ScriptEnvironment.java
@@ -30,8 +30,10 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 import java.util.StringTokenizer;
 import java.util.TimeZone;
+import java.util.function.Supplier;
 import java.util.logging.Level;
 import org.openjdk.nashorn.internal.codegen.Namespace;
 import org.openjdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
@@ -225,7 +227,7 @@ public enum FunctionStatementBehavior {
     /** Timing */
     public final Timing _timing;
 
-    /** Whether to use anonymous classes. See {@link #useAnonymousClasses(int)}. */
+    /** Whether to use anonymous classes. See {@link #useAnonymousClasses(int, Supplier)}. */
     private final AnonymousClasses _anonymousClasses;
     private enum AnonymousClasses {
         AUTO,
@@ -477,9 +479,16 @@ public boolean isTimingEnabled() {
      * @param sourceLength length of source being compiled.
      * @return true if anonymous classes should be used
      */
-    public boolean useAnonymousClasses(final int sourceLength) {
-        return _anonymousClasses == AnonymousClasses.ON
-                || (_anonymousClasses == AnonymousClasses.AUTO && sourceLength <= _anonymous_classes_threshold);
+    public boolean useAnonymousClasses(final int sourceLength, Supplier<Exception> anonymousInitFailure) {
+        if (_anonymousClasses == AnonymousClasses.ON) {
+            Optional.ofNullable(anonymousInitFailure.get()).ifPresent(e -> {
+                throw new IllegalStateException("Can not use anonymous class loading", e);
+            });
+            return true;
+        }
+        return _anonymousClasses == AnonymousClasses.AUTO &&
+               sourceLength <= _anonymous_classes_threshold &&
+               anonymousInitFailure.get() == null;
     }
 
 }