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simplify scala.runtime.Statics.releaseFence #23953

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Merged
merged 1 commit into from
Sep 18, 2025
Merged

simplify scala.runtime.Statics.releaseFence #23953

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46 changes: 1 addition & 45 deletions library/src/scala/runtime/Statics.java
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Original file line number Diff line number Diff line change
Expand Up @@ -12,11 +12,6 @@

package scala.runtime;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.reflect.Field;

/** Not for public consumption. Usage by the runtime only.
*/

Expand Down Expand Up @@ -145,46 +140,7 @@ private static int anyHashNumber(Number x) {

// @ForceInline would be nice here.
public static void releaseFence() throws Throwable {
VM.RELEASE_FENCE.invoke();
}

final static class VM {
static final MethodHandle RELEASE_FENCE;

static {
RELEASE_FENCE = mkHandle();
}

private static MethodHandle mkHandle() {
MethodHandles.Lookup lookup = MethodHandles.lookup();
try {
return lookup.findStatic(Class.forName("java.lang.invoke.VarHandle"), "releaseFence", MethodType.methodType(Void.TYPE));
} catch (NoSuchMethodException | ClassNotFoundException e) {
try {
Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
return lookup.findVirtual(unsafeClass, "storeFence", MethodType.methodType(void.class)).bindTo(findUnsafe(unsafeClass));
} catch (NoSuchMethodException | ClassNotFoundException | IllegalAccessException e1) {
ExceptionInInitializerError error = new ExceptionInInitializerError(e1);
error.addSuppressed(e);
throw error;
}
} catch (IllegalAccessException e) {
throw new ExceptionInInitializerError(e);
}
}

private static Object findUnsafe(Class<?> unsafeClass) throws IllegalAccessException {
Object found = null;
for (Field field : unsafeClass.getDeclaredFields()) {
if (field.getType() == unsafeClass) {
field.setAccessible(true);
found = field.get(null);
break;
}
}
if (found == null) throw new IllegalStateException("No instance of Unsafe found");
return found;
}
java.lang.invoke.VarHandle.releaseFence();
}

/**
Expand Down
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