[GR-40931] Fixes for --virtual-thread-fibers

PullRequest: truffleruby/4206

Author: eregon

src/main/java/org/truffleruby/core/thread/ThreadManager.java

@@ -185,6 +185,12 @@ public Thread createFiberJavaThread(RubyFiber fiber, SourceSection sourceSection
                     body.run();
                 } finally {
                     truffleContext.leave(node, prev);
+
+                    // For PolyglotThread, the order is leave(), disposeThread(), afterLeave(), as desired.
+                    // But for an "embedder thread" like this one, disposeThread() is only done just before disposeContext(),
+                    // so we do the disposeThread() logic here to release the CountDownLatch and let doKillOtherFibers() proceed.
+                    context.fiberManager.cleanup(fiber, Thread.currentThread());
+
                     afterLeave.run();
                 }
             });

src/options.yml

@@ -103,7 +103,7 @@ EXPERT:
     LAZY_TRANSLATION_USER: [lazy-translation-user, boolean, LAZY_CALLTARGETS, 'Lazily translation of stdlib, gem and user source files']
     PATCHING: [patching, boolean, true, Use patching]
     HASHING_DETERMINISTIC: [hashing-deterministic, boolean, false, Produce deterministic hash values]
-    VIRTUAL_THREAD_FIBERS: [virtual-thread-fibers, boolean, false, 'Use JDK 19+ VirtualThread for Fibers, also requires --vm.-enable-preview']
+    VIRTUAL_THREAD_FIBERS: [virtual-thread-fibers, boolean, false, 'Use VirtualThread for Fibers']
     LOG_SUBPROCESS: [log-subprocess, boolean, false, 'Log whenever a subprocess is created'] # Also see --log-process-args
     WARN_LOCALE: [warn-locale, boolean, true, 'Warn when the system locale is not set properly']
 

src/shared/java/org/truffleruby/shared/options/OptionsCatalog.java

@@ -415,7 +415,7 @@ public final class OptionsCatalog {
 
     public static final OptionDescriptor VIRTUAL_THREAD_FIBERS = OptionDescriptor
             .newBuilder(VIRTUAL_THREAD_FIBERS_KEY, "ruby.virtual-thread-fibers")
-            .help("Use JDK 19+ VirtualThread for Fibers, also requires --vm.-enable-preview")
+            .help("Use VirtualThread for Fibers")
             .category(OptionCategory.EXPERT)
             .stability(OptionStability.EXPERIMENTAL)
             .usageSyntax("")