/*

 * Copyright (c) 2000, 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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 */

package sun.nio.ch;

import java.io.FileDescriptor;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.AsynchronousCloseException;

import java.nio.channels.ClosedChannelException;

import java.nio.channels.NotYetConnectedException;

import java.nio.channels.Pipe;

import java.nio.channels.SelectionKey;

import java.nio.channels.spi.SelectorProvider;

import java.util.Objects;

import java.util.concurrent.locks.ReentrantLock;

class SinkChannelImpl

    extends Pipe.SinkChannel

    implements SelChImpl

{

    // Used to make native read and write calls

    private static final NativeDispatcher nd = new FileDispatcherImpl();

    // The file descriptor associated with this channel

    private final FileDescriptor fd;

    private final int fdVal;

    // Lock held by current writing thread

    private final ReentrantLock writeLock = new ReentrantLock();

    // Lock held by any thread that modifies the state fields declared below

    // DO NOT invoke a blocking I/O operation while holding this lock!

    // -- The following fields are protected by stateLock

    // Channel state

    private static final int ST_INUSE = 0;

    private static final int ST_CLOSING = 1;

    private static final int ST_KILLPENDING = 2;

    private static final int ST_KILLED = 3;

    private int state;

    // ID of native thread doing write, for signalling

    private long thread;

    // -- End of fields protected by stateLock

    public FileDescriptor getFD() {

        return fd;

    }

    public int getFDVal() {

        return fdVal;

    }

    SinkChannelImpl(SelectorProvider sp, FileDescriptor fd) {

        super(sp);

        this.fd = fd;

        this.fdVal = IOUtil.fdVal(fd);

    }

    /**

     * Invoked by implCloseChannel to close the channel.

     */

    @Override

    protected void implCloseSelectableChannel() throws IOException {

        assert !isOpen();

        boolean interrupted = false;

        boolean blocking;

        // set state to ST_CLOSING

            assert state < ST_CLOSING;

            state = ST_CLOSING;

            blocking = isBlocking();

        }

        // wait for any outstanding write to complete

        if (blocking) {

                assert state == ST_CLOSING;

                long th = thread;

                if (th != 0) {

                    nd.preClose(fd);

                    NativeThread.signal(th);

                    // wait for write operation to end

                    while (thread != 0) {

                        try {

                        } catch (InterruptedException e) {

                            interrupted = true;

                        }

                    }

                }

            }

        } else {

            // non-blocking mode: wait for write to complete

            writeLock.lock();

            writeLock.unlock();

        }

        // set state to ST_KILLPENDING

            assert state == ST_CLOSING;

            state = ST_KILLPENDING;

        }

        // close socket if not registered with Selector

        if (!isRegistered())

            kill();

        // restore interrupt status

        if (interrupted)

            Thread.currentThread().interrupt();

    }

    @Override

    public void kill() throws IOException {

            assert thread == 0;

            if (state == ST_KILLPENDING) {

                state = ST_KILLED;

                nd.close(fd);

            }

        }

    }

    @Override

    protected void implConfigureBlocking(boolean block) throws IOException {

        writeLock.lock();

        try {

                IOUtil.configureBlocking(fd, block);

            }

        } finally {

            writeLock.unlock();

        }

    }

    public boolean translateReadyOps(int ops, int initialOps, SelectionKeyImpl ski) {

        int intOps = ski.nioInterestOps();

        int oldOps = ski.nioReadyOps();

        int newOps = initialOps;

        if ((ops & Net.POLLNVAL) != 0)

            throw new Error("POLLNVAL detected");

        if ((ops & (Net.POLLERR | Net.POLLHUP)) != 0) {

            newOps = intOps;

            ski.nioReadyOps(newOps);

            return (newOps & ~oldOps) != 0;

        }

        if (((ops & Net.POLLOUT) != 0) &&

            ((intOps & SelectionKey.OP_WRITE) != 0))

            newOps |= SelectionKey.OP_WRITE;

        ski.nioReadyOps(newOps);

        return (newOps & ~oldOps) != 0;

    }

    public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl ski) {

        return translateReadyOps(ops, ski.nioReadyOps(), ski);

    }

    public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl ski) {

        return translateReadyOps(ops, 0, ski);

    }

    public int translateInterestOps(int ops) {

        int newOps = 0;

        if (ops == SelectionKey.OP_WRITE)

            newOps |= Net.POLLOUT;

        return newOps;

    }

    /**

     * Marks the beginning of a write operation that might block.

     *

     * @throws ClosedChannelException if the channel is closed

     * @throws NotYetConnectedException if the channel is not yet connected

     */

    private void beginWrite(boolean blocking) throws ClosedChannelException {

        if (blocking) {

            // set hook for Thread.interrupt

            begin();

        }

            if (!isOpen())

                throw new ClosedChannelException();

            if (blocking)

                thread = NativeThread.current();

        }

    }

    /**

     * Marks the end of a write operation that may have blocked.

     *

     * @throws AsynchronousCloseException if the channel was closed due to this

     * thread being interrupted on a blocking write operation.

     */

    private void endWrite(boolean blocking, boolean completed)

        throws AsynchronousCloseException

    {

        if (blocking) {

                thread = 0;

                // notify any thread waiting in implCloseSelectableChannel

                if (state == ST_CLOSING) {

                }

            }

            // remove hook for Thread.interrupt

            end(completed);

        }

    }

    @Override

    public int write(ByteBuffer src) throws IOException {

        Objects.requireNonNull(src);

        writeLock.lock();

        try {

            boolean blocking = isBlocking();

            int n = 0;

            try {

                beginWrite(blocking);

            } finally {

                endWrite(blocking, n > 0);

                assert IOStatus.check(n);

            }

            return IOStatus.normalize(n);

        } finally {

            writeLock.unlock();

        }

    }

    @Override

    public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {

        Objects.checkFromIndexSize(offset, length, srcs.length);

        writeLock.lock();

        try {

            boolean blocking = isBlocking();

            long n = 0;

            try {

                beginWrite(blocking);

            } finally {

                endWrite(blocking, n > 0);

                assert IOStatus.check(n);

            }

            return IOStatus.normalize(n);

        } finally {

            writeLock.unlock();

        }

    }

    @Override

    public long write(ByteBuffer[] srcs) throws IOException {

        return write(srcs, 0, srcs.length);

    }

}