jdk-24/test/jdk/javax/security/auth/Subject/CallAsWithScopedValue.java

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/*
 * @test
 * @bug 8296244
 * @enablePreview
 * @summary Implement Subject.current and Subject.callAs using scoped values.
 *      Need enablePreview to use StructuredTaskScope.
 * @run main/othervm CallAsWithScopedValue true
 */
import com.sun.security.auth.UserPrincipal;

import javax.security.auth.Subject;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.StructuredTaskScope;

public class CallAsWithScopedValue {

    private static Map results = new ConcurrentHashMap<Integer,Boolean>();

    public static void main(String[] args) throws Exception {

        boolean usv = Boolean.parseBoolean(args[0]);

        Subject subject = new Subject();
        subject.getPrincipals().add(new UserPrincipal("Duke"));

        // Always observable in the same thread
        Subject.callAs(subject, () -> check(0, Subject.current(), "Duke"));

        // Observable in a new platform thread in ACC mode, but not in the SV mode
        Subject.callAs(subject, () -> {
            Thread.ofPlatform().start(() -> check(1, Subject.current(), usv ? null : "Duke")).join();
            return null;
        });

        // Never observable in a new virtual thread
        Subject.callAs(subject, () -> {
            Thread.ofVirtual().start(() -> check(2, Subject.current(), null)).join();
            return null;
        });

        // Observable in structured concurrency in SV mode, but not in ACC mode
        Subject.callAs(subject, () -> {
            try (var scope = new StructuredTaskScope<>()) {
                scope.fork(() -> check(3, Subject.current(), usv ? "Duke" : null));
                scope.join();
            }
            return null;
        });

        // Suggested way to pass the current subject into arbitrary
        // threads. Grab one using current() and explicitly pass it
        // into the new thread.
        Subject.callAs(subject, () -> {
            Subject current = Subject.current();
            Thread.ofPlatform().start(() -> {
                Subject.callAs(current, () -> check(4, Subject.current(), "Duke"));
            }).join();
            return null;
        });

        if (results.size() != 5 || results.containsValue(false)) {
            System.out.println(results);
            throw new RuntimeException("Failed");
        }
    }

    static String check(int type, Subject current, String expected) {
        String actual;
        if (current == null) {
            actual = null;
        } else {
            var set = current.getPrincipals(UserPrincipal.class);
            actual = set.isEmpty()
                    ? null
                    : set.iterator().next().getName();
        }
        results.put(type, Objects.equals(actual, expected));
        return actual;
    }
}