/*

 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

import java.security.AccessControlContext;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.Objects;

import java.util.concurrent.Executor;

/**

 * Executes tasks within a given access control context, and by a given executor.

 */

class PrivilegedExecutor implements Executor {

    /** The underlying executor. May be provided by the user. */

    final Executor executor;

    /** The ACC to execute the tasks within. */

    final AccessControlContext acc;

    public PrivilegedExecutor(Executor executor, AccessControlContext acc) {

        Objects.requireNonNull(executor);

        Objects.requireNonNull(acc);

        this.executor = executor;

        this.acc = acc;

    }

    private static class PrivilegedRunnable implements Runnable {

        private final Runnable r;

        private final AccessControlContext acc;

        PrivilegedRunnable(Runnable r, AccessControlContext acc) {

            this.r = r;

            this.acc = acc;

        }

        @Override

        public void run() {

            PrivilegedAction<Void> pa = () -> { r.run(); return null; };

            AccessController.doPrivileged(pa, acc);

        }

    }

    @Override

    public void execute(Runnable r) {

        executor.execute(new PrivilegedRunnable(r, acc));

    }

}