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Tomcat example source code file (ChannelJni.java)
The Tomcat ChannelJni.java source code/* * 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.jk.common; import java.io.IOException; import org.apache.jk.core.JkHandler; import org.apache.jk.core.Msg; import org.apache.jk.core.MsgContext; import org.apache.jk.core.JkChannel; import org.apache.coyote.Request; /** Pass messages using jni * * @author Costin Manolache */ public class ChannelJni extends JniHandler implements JkChannel { int receivedNote=1; public ChannelJni() { // we use static for now, it's easier on the C side. // Easy to change after we get everything working } public void init() throws IOException { super.initNative("channel.jni:jni"); if( apr==null ) return; // We'll be called from C. This deals with that. apr.addJkHandler( "channelJni", this ); log.info("JK: listening on channel.jni:jni" ); if( next==null ) { if( nextName!=null ) setNext( wEnv.getHandler( nextName ) ); if( next==null ) next=wEnv.getHandler( "dispatch" ); if( next==null ) next=wEnv.getHandler( "request" ); if( log.isDebugEnabled() ) log.debug("Setting default next " + next.getClass().getName()); } } /** Receives does nothing - send will put the response * in the same buffer */ public int receive( Msg msg, MsgContext ep ) throws IOException { Msg sentResponse=(Msg)ep.getNote( receivedNote ); ep.setNote( receivedNote, null ); if( sentResponse == null ) { if( log.isDebugEnabled() ) log.debug("No send() prior to receive(), no data buffer"); // No sent() was done prior to receive. msg.reset(); msg.end(); sentResponse = msg; } sentResponse.processHeader(); if( log.isTraceEnabled() ) sentResponse.dump("received response "); if( msg != sentResponse ) { log.error( "Error, in JNI mode the msg used for receive() must be identical with the one used for send()"); } return 0; } /** Send the packet. XXX This will modify msg !!! * We could use 2 packets, or sendAndReceive(). * */ public int send( Msg msg, MsgContext ep ) throws IOException { ep.setNote( receivedNote, null ); if( log.isDebugEnabled() ) log.debug("ChannelJni.send: " + msg ); int rc=super.nativeDispatch( msg, ep, JK_HANDLE_JNI_DISPATCH, 0); // nativeDispatch will put the response in the same buffer. // Next receive() will just get it from there. Very tricky to do // things in one thread instead of 2. ep.setNote( receivedNote, msg ); return rc; } public int flush(Msg msg, MsgContext ep) throws IOException { ep.setNote( receivedNote, null ); return OK; } public boolean isSameAddress(MsgContext ep) { return true; } public void registerRequest(Request req, MsgContext ep, int count) { // Not supported. } public String getChannelName() { return getName(); } /** Receive a packet from the C side. This is called from the C * code using invocation, but only for the first packet - to avoid * recursivity and thread problems. * * This may look strange, but seems the best solution for the * problem ( the problem is that we don't have 'continuation' ). * * sendPacket will move the thread execution on the C side, and * return when another packet is available. For packets that * are one way it'll return after it is processed too ( having * 2 threads is far more expensive ). * * Again, the goal is to be efficient and behave like all other * Channels ( so the rest of the code can be shared ). Playing with * java objects on C is extremely difficult to optimize and do * right ( IMHO ), so we'll try to keep it simple - byte[] passing, * the conversion done in java ( after we know the encoding and * if anyone asks for it - same lazy behavior as in 3.3 ). */ public int invoke(Msg msg, MsgContext ep ) throws IOException { if( apr==null ) return -1; long xEnv=ep.getJniEnv(); long cEndpointP=ep.getJniContext(); int type=ep.getType(); if( log.isDebugEnabled() ) log.debug("ChannelJni.invoke: " + ep + " " + type); switch( type ) { case JkHandler.HANDLE_RECEIVE_PACKET: return receive( msg, ep ); case JkHandler.HANDLE_SEND_PACKET: return send( msg, ep ); case JkHandler.HANDLE_FLUSH: return flush(msg, ep); } // Reset receivedNote. It'll be visible only after a SEND and before a receive. ep.setNote( receivedNote, null ); // Default is FORWARD - called from C try { // first, we need to get an endpoint. It should be // per/thread - and probably stored by the C side. if( log.isDebugEnabled() ) log.debug("Received request " + xEnv); // The endpoint will store the message pt. msg.processHeader(); if( log.isTraceEnabled() ) msg.dump("Incoming msg "); int status= next.invoke( msg, ep ); if( log.isDebugEnabled() ) log.debug("after processCallbacks " + status); return status; } catch( Exception ex ) { ex.printStackTrace(); } return 0; } private static org.apache.juli.logging.Log log= org.apache.juli.logging.LogFactory.getLog( ChannelJni.class ); } Other Tomcat examples (source code examples)Here is a short list of links related to this Tomcat ChannelJni.java source code file: |
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