1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 /*
 25  * @test
 26  * @bug 8296244
 27  * @enablePreview
 28  * @summary Implement Subject.current and Subject.callAs using scoped values.
 29  *      Need enablePreview to use StructuredTaskScope.
 30  * @run main/othervm CallAsWithScopedValue true
 31  */
 32 import com.sun.security.auth.UserPrincipal;
 33 
 34 import javax.security.auth.Subject;
 35 import java.util.Map;
 36 import java.util.Objects;
 37 import java.util.concurrent.ConcurrentHashMap;
 38 import java.util.concurrent.StructuredTaskScope;
 39 
 40 public class CallAsWithScopedValue {
 41 
 42     private static Map results = new ConcurrentHashMap<Integer,Boolean>();
 43 
 44     public static void main(String[] args) throws Exception {
 45 
 46         boolean usv = Boolean.parseBoolean(args[0]);
 47 
 48         Subject subject = new Subject();
 49         subject.getPrincipals().add(new UserPrincipal("Duke"));
 50 
 51         // Always observable in the same thread
 52         Subject.callAs(subject, () -> check(0, Subject.current(), "Duke"));
 53 
 54         // Observable in a new platform thread in ACC mode, but not in the SV mode
 55         Subject.callAs(subject, () -> {
 56             Thread.ofPlatform().start(() -> check(1, Subject.current(), usv ? null : "Duke")).join();
 57             return null;
 58         });
 59 
 60         // Never observable in a new virtual thread
 61         Subject.callAs(subject, () -> {
 62             Thread.ofVirtual().start(() -> check(2, Subject.current(), null)).join();
 63             return null;
 64         });
 65 
 66         // Observable in structured concurrency in SV mode, but not in ACC mode
 67         Subject.callAs(subject, () -> {
 68             try (var scope = new StructuredTaskScope<>()) {
 69                 scope.fork(() -> check(3, Subject.current(), usv ? "Duke" : null));
 70                 scope.join();
 71             }
 72             return null;
 73         });
 74 
 75         // Suggested way to pass the current subject into arbitrary
 76         // threads. Grab one using current() and explicitly pass it
 77         // into the new thread.
 78         Subject.callAs(subject, () -> {
 79             Subject current = Subject.current();
 80             Thread.ofPlatform().start(() -> {
 81                 Subject.callAs(current, () -> check(4, Subject.current(), "Duke"));
 82             }).join();
 83             return null;
 84         });
 85 
 86         if (results.size() != 5 || results.containsValue(false)) {
 87             System.out.println(results);
 88             throw new RuntimeException("Failed");
 89         }
 90     }
 91 
 92     static String check(int type, Subject current, String expected) {
 93         String actual;
 94         if (current == null) {
 95             actual = null;
 96         } else {
 97             var set = current.getPrincipals(UserPrincipal.class);
 98             actual = set.isEmpty()
 99                     ? null
100                     : set.iterator().next().getName();
101         }
102         results.put(type, Objects.equals(actual, expected));
103         return actual;
104     }
105 }