Author: markt
Date: Mon Aug 20 21:27:10 2018
New Revision: 1838492
URL: http://svn.apache.org/viewvc?rev=1838492&view=rev
Log:
Implement a workaround that prevents container threads from entering an
indefinite wait() if an application performs an illegal blocking I/O operation
Added:
tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java (with props)
Modified:
tomcat/trunk/java/org/apache/coyote/http2/Stream.java
Modified: tomcat/trunk/java/org/apache/coyote/http2/Stream.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/coyote/http2/Stream.java?rev=1838492&r1=1838491&r2=1838492&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/coyote/http2/Stream.java (original)
+++ tomcat/trunk/java/org/apache/coyote/http2/Stream.java Mon Aug 20 21:27:10
2018
@@ -868,7 +868,16 @@ class Stream extends AbstractStream impl
@Override
public void flush() throws IOException {
- flush(true);
+ /*
+ * This method should only be called during blocking I/O. All the
+ * Servlet API calls that end up here are illegal during
+ * non-blocking I/O. Servlet 5.4.
+ * However, the wording Servlet specification states that the
+ * behaviour is undefined so we do the best we can which is to
+ * perform a flush using blocking I/O or non-blocking I/O based
+ * depending which is currently in use.
+ */
+ flush(getCoyoteResponse().getWriteListener() == null);
}
@Override
Added: tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java?rev=1838492&view=auto
==============================================================================
--- tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java (added)
+++ tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java Mon Aug 20
21:27:10 2018
@@ -0,0 +1,154 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.coyote.http2;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import javax.servlet.AsyncContext;
+import javax.servlet.ServletOutputStream;
+import javax.servlet.WriteListener;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.Wrapper;
+import org.apache.catalina.startup.Tomcat;
+
+/*
+ * Based on
+ * https://bz.apache.org/bugzilla/show_bug.cgi?id=62635
+ *
+ * Note: Calling blocking I/O methods (such as flushBuffer()) during
+ * non-blocking I/O is explicitly called out as illegal in the Servlet
+ * specification but also goes on to say the behaviour if such a call is
+ * made is undefined. Which means it is OK if the call works as expected
+ * (a non-blcoking flush is triggered) :).
+ * If any of these tests fail, that should not block a release since -
+ * while the specification allows this to work - it doesn't require that
+ * it does work.
+ */
+public class TestAsyncFlush extends Http2TestBase {
+
+ private static final int BLOCK_SIZE = 1024;
+
+ @Test
+ public void testFlush() throws Exception {
+ int blockCount = 2048;
+
+ int targetSize = BLOCK_SIZE * blockCount;
+
+ int totalWindow = ConnectionSettingsBase.DEFAULT_INITIAL_WINDOW_SIZE;
+
+ enableHttp2();
+
+ Tomcat tomcat = getTomcatInstance();
+
+ Context ctxt = tomcat.addContext("", null);
+ Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
+ ctxt.addServletMappingDecoded("/simple", "simple");
+ Wrapper w = Tomcat.addServlet(ctxt, "async", new
AsyncFlushServlet(blockCount));
+ w.setAsyncSupported(true);
+ ctxt.addServletMappingDecoded("/async", "async");
+ tomcat.start();
+
+ openClientConnection();
+ doHttpUpgrade();
+ sendClientPreface();
+ validateHttp2InitialResponse();
+
+ // Reset connection window size after intial response
+ sendWindowUpdate(0, SimpleServlet.CONTENT_LENGTH);
+
+ // Send request
+ byte[] frameHeader = new byte[9];
+ ByteBuffer headersPayload = ByteBuffer.allocate(128);
+ buildGetRequest(frameHeader, headersPayload, null, 3, "/async");
+ writeFrame(frameHeader, headersPayload);
+
+ // Headers
+ parser.readFrame(true);
+ // Body
+
+ while (output.getBytesRead() < targetSize ) {
+ if (output.getBytesRead() == totalWindow) {
+ sendWindowUpdate(3,
ConnectionSettingsBase.DEFAULT_INITIAL_WINDOW_SIZE);
+ sendWindowUpdate(0,
ConnectionSettingsBase.DEFAULT_INITIAL_WINDOW_SIZE);
+ totalWindow +=
ConnectionSettingsBase.DEFAULT_INITIAL_WINDOW_SIZE;
+ }
+ parser.readFrame(true);
+ }
+
+ // Check that the right number of bytes were received
+ Assert.assertEquals(targetSize, output.getBytesRead());
+ }
+
+
+ public static class AsyncFlushServlet extends HttpServlet {
+
+ private static final long serialVersionUID = 1L;
+
+ private final int blockLimit;
+
+ public AsyncFlushServlet(int blockLimit) {
+ this.blockLimit = blockLimit;
+ }
+
+ @Override
+ protected void doGet(HttpServletRequest request, HttpServletResponse
response)
+ throws IOException {
+
+ final AsyncContext asyncContext = request.startAsync();
+
+ response.setStatus(HttpServletResponse.SC_OK);
+ response.setContentType("application/binary");
+
+ final ServletOutputStream output = response.getOutputStream();
+ output.setWriteListener(new WriteListener() {
+
+ int blockCount;
+ byte[] bytes = new byte[BLOCK_SIZE];
+
+
+ @Override
+ public void onWritePossible() throws IOException {
+ while (output.isReady()) {
+ blockCount++;
+ output.write(bytes);
+ if (blockCount % 5 == 0) {
+ response.flushBuffer();
+ }
+ if (blockCount == blockLimit) {
+ asyncContext.complete();
+ return;
+ }
+ }
+ }
+
+
+ @Override
+ public void onError(Throwable t) {
+ t.printStackTrace();
+ }
+ });
+ }
+ }
+}
Propchange: tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java
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Propchange: tomcat/trunk/test/org/apache/coyote/http2/TestAsyncFlush.java
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svn:executable = *
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