49         Subject subject = new Subject();
 50         subject.getPrincipals().add(new UserPrincipal("Duke"));
 51 
 52         // Always observable in the same thread
 53         Subject.callAs(subject, () -> check(0, Subject.current(), "Duke"));
 54 
 55         // Observable in a new platform thread in ACC mode, but not in the SV mode
 56         Subject.callAs(subject, () -> {
 57             Thread.ofPlatform().start(() -> check(1, Subject.current(), usv ? null : "Duke")).join();
 58             return null;
 59         });
 60 
 61         // Never observable in a new virtual thread
 62         Subject.callAs(subject, () -> {
 63             Thread.ofVirtual().start(() -> check(2, Subject.current(), null)).join();
 64             return null;
 65         });
 66 
 67         // Observable in structured concurrency in SV mode, but not in ACC mode
 68         Subject.callAs(subject, () -> {
 69             try (var scope = new StructuredTaskScope<>()) {

 70                 scope.fork(() -> check(3, Subject.current(), usv ? "Duke" : null));
 71                 scope.join();
 72             }
 73             return null;
 74         });
 75 
 76         // Suggested way to pass the current subject into arbitrary
 77         // threads. Grab one using current() and explicitly pass it
 78         // into the new thread.
 79         Subject.callAs(subject, () -> {
 80             Subject current = Subject.current();
 81             Thread.ofPlatform().start(() -> {
 82                 Subject.callAs(current, () -> check(4, Subject.current(), "Duke"));
 83             }).join();
 84             return null;
 85         });
 86 
 87         if (results.size() != 5 || results.containsValue(false)) {
 88             System.out.println(results);
 89             throw new RuntimeException("Failed");

 49         Subject subject = new Subject();
 50         subject.getPrincipals().add(new UserPrincipal("Duke"));
 51 
 52         // Always observable in the same thread
 53         Subject.callAs(subject, () -> check(0, Subject.current(), "Duke"));
 54 
 55         // Observable in a new platform thread in ACC mode, but not in the SV mode
 56         Subject.callAs(subject, () -> {
 57             Thread.ofPlatform().start(() -> check(1, Subject.current(), usv ? null : "Duke")).join();
 58             return null;
 59         });
 60 
 61         // Never observable in a new virtual thread
 62         Subject.callAs(subject, () -> {
 63             Thread.ofVirtual().start(() -> check(2, Subject.current(), null)).join();
 64             return null;
 65         });
 66 
 67         // Observable in structured concurrency in SV mode, but not in ACC mode
 68         Subject.callAs(subject, () -> {
 69             var joiner = StructuredTaskScope.Joiner.awaitAll();
 70             try (var scope = StructuredTaskScope.open(joiner)) {
 71                 scope.fork(() -> check(3, Subject.current(), usv ? "Duke" : null));
 72                 scope.join();
 73             }
 74             return null;
 75         });
 76 
 77         // Suggested way to pass the current subject into arbitrary
 78         // threads. Grab one using current() and explicitly pass it
 79         // into the new thread.
 80         Subject.callAs(subject, () -> {
 81             Subject current = Subject.current();
 82             Thread.ofPlatform().start(() -> {
 83                 Subject.callAs(current, () -> check(4, Subject.current(), "Duke"));
 84             }).join();
 85             return null;
 86         });
 87 
 88         if (results.size() != 5 || results.containsValue(false)) {
 89             System.out.println(results);
 90             throw new RuntimeException("Failed");