J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1999-2001 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * |
| 8 | * - Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * |
| 11 | * - Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * - Neither the name of Sun Microsystems nor the names of its |
| 16 | * contributors may be used to endorse or promote products derived |
| 17 | * from this software without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| 20 | * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 21 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 23 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 24 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 25 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 26 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 27 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 28 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 29 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | import java.io.*; |
| 33 | import java.net.*; |
| 34 | import java.lang.Byte; |
| 35 | |
| 36 | /** |
| 37 | * Simple Java "server" using the Poller class |
| 38 | * to multiplex on incoming connections. Note |
| 39 | * that handoff of events, via linked Q is not |
| 40 | * actually be a performance booster here, since |
| 41 | * the processing of events is cheaper than |
| 42 | * the overhead in scheduling/executing them. |
| 43 | * Although this demo does allow for concurrency |
| 44 | * in handling connections, it uses a rather |
| 45 | * primitive "gang scheduling" policy to keep |
| 46 | * the code simpler. |
| 47 | */ |
| 48 | |
| 49 | public class PollingServer |
| 50 | { |
| 51 | public final static int MAXCONN = 10000; |
| 52 | public final static int PORTNUM = 4444; |
| 53 | public final static int BYTESPEROP = 10; |
| 54 | |
| 55 | /** |
| 56 | * This synchronization object protects access to certain |
| 57 | * data (bytesRead,eventsToProcess) by concurrent Consumer threads. |
| 58 | */ |
| 59 | private final static Object eventSync = new Object(); |
| 60 | |
| 61 | private static InputStream[] instr = new InputStream[MAXCONN]; |
| 62 | private static int[] mapping = new int[65535]; |
| 63 | private static LinkedQueue linkedQ = new LinkedQueue(); |
| 64 | private static int bytesRead = 0; |
| 65 | private static int bytesToRead; |
| 66 | private static int eventsToProcess=0; |
| 67 | |
| 68 | public PollingServer(int concurrency) { |
| 69 | Socket[] sockArr = new Socket[MAXCONN]; |
| 70 | long timestart, timestop; |
| 71 | short[] revents = new short[MAXCONN]; |
| 72 | int[] fds = new int[MAXCONN]; |
| 73 | int bytes; |
| 74 | Poller Mux; |
| 75 | int serverFd; |
| 76 | int totalConn=0; |
| 77 | int connects=0; |
| 78 | |
| 79 | System.out.println ("Serv: Initializing port " + PORTNUM); |
| 80 | try { |
| 81 | |
| 82 | ServerSocket skMain = new ServerSocket (PORTNUM); |
| 83 | /* |
| 84 | * Create the Poller object Mux, allow for up to MAXCONN |
| 85 | * sockets/filedescriptors to be polled. |
| 86 | */ |
| 87 | Mux = new Poller(MAXCONN); |
| 88 | serverFd = Mux.add(skMain, Poller.POLLIN); |
| 89 | |
| 90 | Socket ctrlSock = skMain.accept(); |
| 91 | |
| 92 | BufferedReader ctrlReader = |
| 93 | new BufferedReader(new InputStreamReader(ctrlSock.getInputStream())); |
| 94 | String ctrlString = ctrlReader.readLine(); |
| 95 | bytesToRead = Integer.valueOf(ctrlString).intValue(); |
| 96 | ctrlString = ctrlReader.readLine(); |
| 97 | totalConn = Integer.valueOf(ctrlString).intValue(); |
| 98 | |
| 99 | System.out.println("Receiving " + bytesToRead + " bytes from " + |
| 100 | totalConn + " client connections"); |
| 101 | |
| 102 | timestart = System.currentTimeMillis(); |
| 103 | |
| 104 | /* |
| 105 | * Start the consumer threads to read data. |
| 106 | */ |
| 107 | for (int consumerThread = 0; |
| 108 | consumerThread < concurrency; consumerThread++ ) { |
| 109 | new Consumer(consumerThread).start(); |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * Take connections, read Data |
| 114 | */ |
| 115 | int numEvents=0; |
| 116 | |
| 117 | while ( bytesRead < bytesToRead ) { |
| 118 | |
| 119 | int loopWaits=0; |
| 120 | while (eventsToProcess > 0) { |
| 121 | synchronized (eventSync) { |
| 122 | loopWaits++; |
| 123 | if (eventsToProcess <= 0) break; |
| 124 | try { eventSync.wait(); } catch (Exception e) {e.printStackTrace();}; |
| 125 | } |
| 126 | } |
| 127 | if (loopWaits > 1) |
| 128 | System.out.println("Done waiting...loops = " + loopWaits + |
| 129 | " events " + numEvents + |
| 130 | " bytes read : " + bytesRead ); |
| 131 | |
| 132 | if (bytesRead >= bytesToRead) break; // may be done! |
| 133 | |
| 134 | /* |
| 135 | * Wait for events |
| 136 | */ |
| 137 | numEvents = Mux.waitMultiple(100, fds, revents); |
| 138 | synchronized (eventSync) { |
| 139 | eventsToProcess = numEvents; |
| 140 | } |
| 141 | /* |
| 142 | * Process all the events we got from Mux.waitMultiple |
| 143 | */ |
| 144 | int cnt = 0; |
| 145 | while ( (cnt < numEvents) && (bytesRead < bytesToRead) ) { |
| 146 | int fd = fds[cnt]; |
| 147 | |
| 148 | if (revents[cnt] == Poller.POLLIN) { |
| 149 | if (fd == serverFd) { |
| 150 | /* |
| 151 | * New connection coming in on the ServerSocket |
| 152 | * Add the socket to the Mux, keep track of mapping |
| 153 | * the fdval returned by Mux.add to the connection. |
| 154 | */ |
| 155 | sockArr[connects] = skMain.accept(); |
| 156 | instr[connects] = sockArr[connects].getInputStream(); |
| 157 | int fdval = Mux.add(sockArr[connects], Poller.POLLIN); |
| 158 | mapping[fdval] = connects; |
| 159 | synchronized(eventSync) { |
| 160 | eventsToProcess--; // just processed this one! |
| 161 | } |
| 162 | connects++; |
| 163 | } else { |
| 164 | /* |
| 165 | * We've got data from this client connection. |
| 166 | * Put it on the queue for the consumer threads to process. |
| 167 | */ |
| 168 | linkedQ.put(new Integer(fd)); |
| 169 | } |
| 170 | } else { |
| 171 | System.out.println("Got revents[" + cnt + "] == " + revents[cnt]); |
| 172 | } |
| 173 | cnt++; |
| 174 | } |
| 175 | } |
| 176 | timestop = System.currentTimeMillis(); |
| 177 | System.out.println("Time for all reads (" + totalConn + |
| 178 | " sockets) : " + (timestop-timestart)); |
| 179 | |
| 180 | // Tell the client it can now go away |
| 181 | byte[] buff = new byte[BYTESPEROP]; |
| 182 | ctrlSock.getOutputStream().write(buff,0,BYTESPEROP); |
| 183 | |
| 184 | // Tell the cunsumer threads they can exit. |
| 185 | for (int cThread = 0; cThread < concurrency; cThread++ ) { |
| 186 | linkedQ.put(new Integer(-1)); |
| 187 | } |
| 188 | } catch (Exception exc) { exc.printStackTrace(); } |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * main ... just check if a concurrency was specified |
| 193 | */ |
| 194 | public static void main (String args[]) |
| 195 | { |
| 196 | int concurrency; |
| 197 | |
| 198 | if (args.length == 1) |
| 199 | concurrency = java.lang.Integer.valueOf(args[0]).intValue(); |
| 200 | else |
| 201 | concurrency = Poller.getNumCPUs() + 1; |
| 202 | PollingServer server = new PollingServer(concurrency); |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * This class is for handling the Client data. |
| 207 | * The PollingServer spawns off a number of these based upon |
| 208 | * the number of CPUs (or concurrency argument). |
| 209 | * Each just loops grabbing events off the queue and |
| 210 | * processing them. |
| 211 | */ |
| 212 | class Consumer extends Thread { |
| 213 | private int threadNumber; |
| 214 | public Consumer(int i) { threadNumber = i; } |
| 215 | |
| 216 | public void run() { |
| 217 | byte[] buff = new byte[BYTESPEROP]; |
| 218 | int bytes = 0; |
| 219 | |
| 220 | InputStream instream; |
| 221 | while (bytesRead < bytesToRead) { |
| 222 | try { |
| 223 | Integer Fd = (Integer) linkedQ.take(); |
| 224 | int fd = Fd.intValue(); |
| 225 | if (fd == -1) break; /* got told we could exit */ |
| 226 | |
| 227 | /* |
| 228 | * We have to map the fd value returned from waitMultiple |
| 229 | * to the actual input stream associated with that fd. |
| 230 | * Take a look at how the Mux.add() was done to see how |
| 231 | * we stored that. |
| 232 | */ |
| 233 | int map = mapping[fd]; |
| 234 | instream = instr[map]; |
| 235 | bytes = instream.read(buff,0,BYTESPEROP); |
| 236 | } catch (Exception e) { System.out.println(e.toString()); } |
| 237 | |
| 238 | if (bytes > 0) { |
| 239 | /* |
| 240 | * Any real server would do some synchronized and some |
| 241 | * unsynchronized work on behalf of the client, and |
| 242 | * most likely send some data back...but this is a |
| 243 | * gross oversimplification. |
| 244 | */ |
| 245 | synchronized(eventSync) { |
| 246 | bytesRead += bytes; |
| 247 | eventsToProcess--; |
| 248 | if (eventsToProcess <= 0) { |
| 249 | eventSync.notify(); |
| 250 | } |
| 251 | } |
| 252 | } |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | } |