src/java.net.http/share/classes/java/net/http/internal/websocket/TransportImpl.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.net.http/share/classes/java/net/http/internal/websocket/TransportImpl.java Wed Feb 07 14:17:24 2018 +0000
@@ -0,0 +1,383 @@
+/*
+ * Copyright (c) 2017, 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
+ * questions.
+ */
+
+package java.net.http.internal.websocket;
+
+import java.net.http.internal.common.Demand;
+import java.net.http.internal.common.MinimalFuture;
+import java.net.http.internal.common.Pair;
+import java.net.http.internal.common.SequentialScheduler;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.SelectionKey;
+import java.util.Queue;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+import static java.util.Objects.requireNonNull;
+import static java.net.http.internal.common.MinimalFuture.failedFuture;
+import static java.net.http.internal.common.Pair.pair;
+
+public class TransportImpl<T> implements Transport<T> {
+
+ /* This flag is used solely for assertions */
+ private final AtomicBoolean busy = new AtomicBoolean();
+ private OutgoingMessage message;
+ private Consumer<Exception> completionHandler;
+ private final RawChannel channel;
+ private final RawChannel.RawEvent writeEvent = createWriteEvent();
+ private final SequentialScheduler sendScheduler = new SequentialScheduler(new SendTask());
+ private final Queue<Pair<OutgoingMessage, CompletableFuture<T>>>
+ queue = new ConcurrentLinkedQueue<>();
+ private final OutgoingMessage.Context context = new OutgoingMessage.Context();
+ private final Supplier<T> resultSupplier;
+
+ private final MessageStreamConsumer messageConsumer;
+ private final FrameConsumer frameConsumer;
+ private final Frame.Reader reader = new Frame.Reader();
+ private final RawChannel.RawEvent readEvent = createReadEvent();
+ private final Demand demand = new Demand();
+ private final SequentialScheduler receiveScheduler;
+
+ private ByteBuffer data;
+ private volatile int state;
+
+ private static final int UNREGISTERED = 0;
+ private static final int AVAILABLE = 1;
+ private static final int WAITING = 2;
+
+ private final Object lock = new Object();
+ private boolean inputClosed;
+ private boolean outputClosed;
+
+ public TransportImpl(Supplier<T> sendResultSupplier,
+ MessageStreamConsumer consumer,
+ RawChannel channel) {
+ this.resultSupplier = sendResultSupplier;
+ this.messageConsumer = consumer;
+ this.channel = channel;
+ this.frameConsumer = new FrameConsumer(this.messageConsumer);
+ this.data = channel.initialByteBuffer();
+ // To ensure the initial non-final `data` will be visible
+ // (happens-before) when `readEvent.handle()` invokes `receiveScheduler`
+ // the following assignment is done last:
+ receiveScheduler = new SequentialScheduler(new ReceiveTask());
+ }
+
+ /**
+ * The supplied handler may be invoked in the calling thread.
+ * A {@code StackOverflowError} may thus occur if there's a possibility
+ * that this method is called again by the supplied handler.
+ */
+ public void send(OutgoingMessage message,
+ Consumer<Exception> completionHandler) {
+ requireNonNull(message);
+ requireNonNull(completionHandler);
+ if (!busy.compareAndSet(false, true)) {
+ throw new IllegalStateException();
+ }
+ send0(message, completionHandler);
+ }
+
+ private RawChannel.RawEvent createWriteEvent() {
+ return new RawChannel.RawEvent() {
+
+ @Override
+ public int interestOps() {
+ return SelectionKey.OP_WRITE;
+ }
+
+ @Override
+ public void handle() {
+ // registerEvent(e) happens-before subsequent e.handle(), so
+ // we're fine reading the stored message and the completionHandler
+ send0(message, completionHandler);
+ }
+ };
+ }
+
+ private void send0(OutgoingMessage message, Consumer<Exception> handler) {
+ boolean b = busy.get();
+ assert b; // Please don't inline this, as busy.get() has memory
+ // visibility effects and we don't want the program behaviour
+ // to depend on whether the assertions are turned on
+ // or turned off
+ try {
+ boolean sent = message.sendTo(channel);
+ if (sent) {
+ busy.set(false);
+ handler.accept(null);
+ } else {
+ // The message has not been fully sent, the transmitter needs to
+ // remember the message until it can continue with sending it
+ this.message = message;
+ this.completionHandler = handler;
+ try {
+ channel.registerEvent(writeEvent);
+ } catch (IOException e) {
+ this.message = null;
+ this.completionHandler = null;
+ busy.set(false);
+ handler.accept(e);
+ }
+ }
+ } catch (IOException e) {
+ busy.set(false);
+ handler.accept(e);
+ }
+ }
+
+ public CompletableFuture<T> sendText(CharSequence message,
+ boolean isLast) {
+ OutgoingMessage.Text m;
+ try {
+ m = new OutgoingMessage.Text(message, isLast);
+ } catch (IllegalArgumentException e) {
+ return failedFuture(e);
+ }
+ return enqueue(m);
+ }
+
+ public CompletableFuture<T> sendBinary(ByteBuffer message,
+ boolean isLast) {
+ return enqueue(new OutgoingMessage.Binary(message, isLast));
+ }
+
+ public CompletableFuture<T> sendPing(ByteBuffer message) {
+ OutgoingMessage.Ping m;
+ try {
+ m = new OutgoingMessage.Ping(message);
+ } catch (IllegalArgumentException e) {
+ return failedFuture(e);
+ }
+ return enqueue(m);
+ }
+
+ public CompletableFuture<T> sendPong(ByteBuffer message) {
+ OutgoingMessage.Pong m;
+ try {
+ m = new OutgoingMessage.Pong(message);
+ } catch (IllegalArgumentException e) {
+ return failedFuture(e);
+ }
+ return enqueue(m);
+ }
+
+ public CompletableFuture<T> sendClose(int statusCode, String reason) {
+ OutgoingMessage.Close m;
+ try {
+ m = new OutgoingMessage.Close(statusCode, reason);
+ } catch (IllegalArgumentException e) {
+ return failedFuture(e);
+ }
+ return enqueue(m);
+ }
+
+ private CompletableFuture<T> enqueue(OutgoingMessage m) {
+ CompletableFuture<T> cf = new MinimalFuture<>();
+ boolean added = queue.add(pair(m, cf));
+ if (!added) {
+ // The queue is supposed to be unbounded
+ throw new InternalError();
+ }
+ sendScheduler.runOrSchedule();
+ return cf;
+ }
+
+ /*
+ * This is a message sending task. It pulls messages from the queue one by
+ * one and sends them. It may be run in different threads, but never
+ * concurrently.
+ */
+ private class SendTask implements SequentialScheduler.RestartableTask {
+
+ @Override
+ public void run(SequentialScheduler.DeferredCompleter taskCompleter) {
+ Pair<OutgoingMessage, CompletableFuture<T>> p = queue.poll();
+ if (p == null) {
+ taskCompleter.complete();
+ return;
+ }
+ OutgoingMessage message = p.first;
+ CompletableFuture<T> cf = p.second;
+ try {
+ if (!message.contextualize(context)) { // Do not send the message
+ cf.complete(resultSupplier.get());
+ repeat(taskCompleter);
+ return;
+ }
+ Consumer<Exception> h = e -> {
+ if (e == null) {
+ cf.complete(resultSupplier.get());
+ } else {
+ cf.completeExceptionally(e);
+ }
+ repeat(taskCompleter);
+ };
+ send(message, h);
+ } catch (Throwable t) {
+ cf.completeExceptionally(t);
+ repeat(taskCompleter);
+ }
+ }
+
+ private void repeat(SequentialScheduler.DeferredCompleter taskCompleter) {
+ taskCompleter.complete();
+ // More than a single message may have been enqueued while
+ // the task has been busy with the current message, but
+ // there is only a single signal recorded
+ sendScheduler.runOrSchedule();
+ }
+ }
+
+ private RawChannel.RawEvent createReadEvent() {
+ return new RawChannel.RawEvent() {
+
+ @Override
+ public int interestOps() {
+ return SelectionKey.OP_READ;
+ }
+
+ @Override
+ public void handle() {
+ state = AVAILABLE;
+ receiveScheduler.runOrSchedule();
+ }
+ };
+ }
+
+ @Override
+ public void request(long n) {
+ if (demand.increase(n)) {
+ receiveScheduler.runOrSchedule();
+ }
+ }
+
+ @Override
+ public void acknowledgeReception() {
+ boolean decremented = demand.tryDecrement();
+ if (!decremented) {
+ throw new InternalError();
+ }
+ }
+
+ private class ReceiveTask extends SequentialScheduler.CompleteRestartableTask {
+
+ @Override
+ public void run() {
+ while (!receiveScheduler.isStopped()) {
+ if (data.hasRemaining()) {
+ if (!demand.isFulfilled()) {
+ try {
+ int oldPos = data.position();
+ reader.readFrame(data, frameConsumer);
+ int newPos = data.position();
+ assert oldPos != newPos : data; // reader always consumes bytes
+ } catch (Throwable e) {
+ receiveScheduler.stop();
+ messageConsumer.onError(e);
+ }
+ continue;
+ }
+ break;
+ }
+ switch (state) {
+ case WAITING:
+ return;
+ case UNREGISTERED:
+ try {
+ state = WAITING;
+ channel.registerEvent(readEvent);
+ } catch (Throwable e) {
+ receiveScheduler.stop();
+ messageConsumer.onError(e);
+ }
+ return;
+ case AVAILABLE:
+ try {
+ data = channel.read();
+ } catch (Throwable e) {
+ receiveScheduler.stop();
+ messageConsumer.onError(e);
+ return;
+ }
+ if (data == null) { // EOF
+ receiveScheduler.stop();
+ messageConsumer.onComplete();
+ return;
+ } else if (!data.hasRemaining()) {
+ // No data at the moment Pretty much a "goto",
+ // reusing the existing code path for registration
+ state = UNREGISTERED;
+ }
+ continue;
+ default:
+ throw new InternalError(String.valueOf(state));
+ }
+ }
+ }
+ }
+
+ /*
+ * Permanently stops reading from the channel and delivering messages
+ * regardless of the current demand and data availability.
+ */
+ @Override
+ public void closeInput() throws IOException {
+ synchronized (lock) {
+ if (!inputClosed) {
+ inputClosed = true;
+ try {
+ receiveScheduler.stop();
+ channel.shutdownInput();
+ } finally {
+ if (outputClosed) {
+ channel.close();
+ }
+ }
+ }
+ }
+ }
+
+ @Override
+ public void closeOutput() throws IOException {
+ synchronized (lock) {
+ if (!outputClosed) {
+ outputClosed = true;
+ try {
+ channel.shutdownOutput();
+ } finally {
+ if (inputClosed) {
+ channel.close();
+ }
+ }
+ }
+ }
+ }
+}