--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/sun/net/www/protocol/https/TestHttpsServer.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,933 @@
+/*
+ * Copyright (c) 2002, 2012, 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.
+ *
+ * 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.
+ */
+
+import java.net.*;
+import java.io.*;
+import java.nio.*;
+import java.nio.channels.*;
+import sun.net.www.MessageHeader;
+import java.util.*;
+import javax.net.ssl.*;
+import javax.net.ssl.SSLEngineResult.*;
+import java.security.*;
+
+/**
+ * This class implements a simple HTTPS server. It uses multiple threads to
+ * handle connections in parallel, and will spin off a new thread to handle
+ * each request. (this is easier to implement with SSLEngine)
+ * <p>
+ * It must be instantiated with a {@link HttpCallback} object to which
+ * requests are given and must be handled.
+ * <p>
+ * Simple synchronization between the client(s) and server can be done
+ * using the {@link #waitForCondition(String)}, {@link #setCondition(String)} and
+ * {@link #rendezvous(String,int)} methods.
+ *
+ * NOTE NOTE NOTE NOTE NOTE NOTE NOTE
+ *
+ * If you make a change in here, please don't forget to make the
+ * corresponding change in the J2SE equivalent.
+ *
+ * NOTE NOTE NOTE NOTE NOTE NOTE NOTE
+ */
+
+public class TestHttpsServer {
+
+ ServerSocketChannel schan;
+ int threads;
+ int cperthread;
+ HttpCallback cb;
+ Server[] servers;
+
+ // ssl related fields
+ static SSLContext sslCtx;
+
+ /**
+ * Create a <code>TestHttpsServer<code> instance with the specified callback object
+ * for handling requests. One thread is created to handle requests,
+ * and up to ten TCP connections will be handled simultaneously.
+ * @param cb the callback object which is invoked to handle each
+ * incoming request
+ */
+
+ public TestHttpsServer (HttpCallback cb) throws IOException {
+ this (cb, 1, 10, 0);
+ }
+
+ /**
+ * Create a <code>TestHttpsServer<code> instance with the specified number of
+ * threads and maximum number of connections per thread. This functions
+ * the same as the 4 arg constructor, where the port argument is set to zero.
+ * @param cb the callback object which is invoked to handle each
+ * incoming request
+ * @param threads the number of threads to create to handle requests
+ * in parallel
+ * @param cperthread the number of simultaneous TCP connections to
+ * handle per thread
+ */
+
+ public TestHttpsServer (HttpCallback cb, int threads, int cperthread)
+ throws IOException {
+ this (cb, threads, cperthread, 0);
+ }
+
+ /**
+ * Create a <code>TestHttpsServer<code> instance with the specified number
+ * of threads and maximum number of connections per thread and running on
+ * the specified port. The specified number of threads are created to
+ * handle incoming requests, and each thread is allowed
+ * to handle a number of simultaneous TCP connections.
+ * @param cb the callback object which is invoked to handle
+ * each incoming request
+ * @param threads the number of threads to create to handle
+ * requests in parallel
+ * @param cperthread the number of simultaneous TCP connections
+ * to handle per thread
+ * @param port the port number to bind the server to. <code>Zero</code>
+ * means choose any free port.
+ */
+
+ public TestHttpsServer (HttpCallback cb, int threads, int cperthread, int port)
+ throws IOException {
+ schan = ServerSocketChannel.open ();
+ InetSocketAddress addr = new InetSocketAddress (port);
+ schan.socket().bind (addr);
+ this.threads = threads;
+ this.cb = cb;
+ this.cperthread = cperthread;
+
+ try {
+ // create and initialize a SSLContext
+ KeyStore ks = KeyStore.getInstance("JKS");
+ KeyStore ts = KeyStore.getInstance("JKS");
+ char[] passphrase = "passphrase".toCharArray();
+
+ ks.load(new FileInputStream(System.getProperty("javax.net.ssl.keyStore")), passphrase);
+ ts.load(new FileInputStream(System.getProperty("javax.net.ssl.trustStore")), passphrase);
+
+ KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
+ kmf.init(ks, passphrase);
+
+ TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
+ tmf.init(ts);
+
+ sslCtx = SSLContext.getInstance("TLS");
+
+ sslCtx.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
+
+ servers = new Server [threads];
+ for (int i=0; i<threads; i++) {
+ servers[i] = new Server (cb, schan, cperthread);
+ servers[i].start();
+ }
+ } catch (Exception ex) {
+ throw new RuntimeException("test failed. cause: "+ex.getMessage());
+ }
+ }
+
+ /** Tell all threads in the server to exit within 5 seconds.
+ * This is an abortive termination. Just prior to the thread exiting
+ * all channels in that thread waiting to be closed are forceably closed.
+ */
+
+ public void terminate () {
+ for (int i=0; i<threads; i++) {
+ servers[i].terminate ();
+ }
+ }
+
+ /**
+ * return the local port number to which the server is bound.
+ * @return the local port number
+ */
+
+ public int getLocalPort () {
+ return schan.socket().getLocalPort ();
+ }
+
+ static class Server extends Thread {
+
+ ServerSocketChannel schan;
+ Selector selector;
+ SelectionKey listenerKey;
+ SelectionKey key; /* the current key being processed */
+ HttpCallback cb;
+ ByteBuffer consumeBuffer;
+ int maxconn;
+ int nconn;
+ ClosedChannelList clist;
+ boolean shutdown;
+
+ Server (HttpCallback cb, ServerSocketChannel schan, int maxconn) {
+ this.schan = schan;
+ this.maxconn = maxconn;
+ this.cb = cb;
+ nconn = 0;
+ consumeBuffer = ByteBuffer.allocate (512);
+ clist = new ClosedChannelList ();
+ try {
+ selector = Selector.open ();
+ schan.configureBlocking (false);
+ listenerKey = schan.register (selector, SelectionKey.OP_ACCEPT);
+ } catch (IOException e) {
+ System.err.println ("Server could not start: " + e);
+ }
+ }
+
+ /* Stop the thread as soon as possible */
+ public synchronized void terminate () {
+ shutdown = true;
+ }
+
+ public void run () {
+ try {
+ while (true) {
+ selector.select (1000);
+ Set selected = selector.selectedKeys();
+ Iterator iter = selected.iterator();
+ while (iter.hasNext()) {
+ key = (SelectionKey)iter.next();
+ if (key.equals (listenerKey)) {
+ SocketChannel sock = schan.accept ();
+ if (sock == null) {
+ /* false notification */
+ iter.remove();
+ continue;
+ }
+ sock.configureBlocking (true);
+ SSLEngine sslEng = sslCtx.createSSLEngine();
+ sslEng.setUseClientMode(false);
+ new ServerWorker(cb, sock, sslEng).start();
+ nconn ++;
+ if (nconn == maxconn) {
+ /* deregister */
+ listenerKey.cancel ();
+ listenerKey = null;
+ }
+ } else {
+ if (key.isReadable()) {
+ boolean closed = false;
+ SocketChannel chan = (SocketChannel) key.channel();
+ if (key.attachment() != null) {
+ closed = consume (chan);
+ }
+
+ if (closed) {
+ chan.close ();
+ key.cancel ();
+ if (nconn == maxconn) {
+ listenerKey = schan.register (selector, SelectionKey.OP_ACCEPT);
+ }
+ nconn --;
+ }
+ }
+ }
+ iter.remove();
+ }
+ clist.check();
+
+ synchronized (this) {
+ if (shutdown) {
+ clist.terminate ();
+ return;
+ }
+ }
+ }
+ } catch (IOException e) {
+ System.out.println ("Server exception: " + e);
+ // TODO finish
+ }
+ }
+
+ /* read all the data off the channel without looking at it
+ * return true if connection closed
+ */
+ boolean consume (SocketChannel chan) {
+ try {
+ consumeBuffer.clear ();
+ int c = chan.read (consumeBuffer);
+ if (c == -1)
+ return true;
+ } catch (IOException e) {
+ return true;
+ }
+ return false;
+ }
+ }
+
+ static class ServerWorker extends Thread {
+ private ByteBuffer inNetBB;
+ private ByteBuffer outNetBB;
+ private ByteBuffer inAppBB;
+ private ByteBuffer outAppBB;
+
+ SSLEngine sslEng;
+ SocketChannel schan;
+ HttpCallback cb;
+ HandshakeStatus currentHSStatus;
+ boolean initialHSComplete;
+ /*
+ * All inbound data goes through this buffer.
+ *
+ * It might be nice to use a cache of ByteBuffers so we're
+ * not alloc/dealloc'ing all over the place.
+ */
+
+ /*
+ * Application buffers, also used for handshaking
+ */
+ private int appBBSize;
+
+ ServerWorker (HttpCallback cb, SocketChannel schan, SSLEngine sslEng) {
+ this.sslEng = sslEng;
+ this.schan = schan;
+ this.cb = cb;
+ currentHSStatus = HandshakeStatus.NEED_UNWRAP;
+ initialHSComplete = false;
+ int netBBSize = sslEng.getSession().getPacketBufferSize();
+ inNetBB = ByteBuffer.allocate(netBBSize);
+ outNetBB = ByteBuffer.allocate(netBBSize);
+ appBBSize = sslEng.getSession().getApplicationBufferSize();
+ inAppBB = ByteBuffer.allocate(appBBSize);
+ outAppBB = ByteBuffer.allocate(appBBSize);
+ }
+
+ public SSLEngine getSSLEngine() {
+ return sslEng;
+ }
+
+ public ByteBuffer outNetBB() {
+ return outNetBB;
+ }
+
+ public ByteBuffer outAppBB() {
+ return outAppBB;
+ }
+
+ public void run () {
+ try {
+ SSLEngineResult result;
+
+ while (!initialHSComplete) {
+
+ switch (currentHSStatus) {
+
+ case NEED_UNWRAP:
+ int bytes = schan.read(inNetBB);
+
+needIO:
+ while (currentHSStatus == HandshakeStatus.NEED_UNWRAP) {
+ /*
+ * Don't need to resize requestBB, since no app data should
+ * be generated here.
+ */
+ inNetBB.flip();
+ result = sslEng.unwrap(inNetBB, inAppBB);
+ inNetBB.compact();
+ currentHSStatus = result.getHandshakeStatus();
+
+ switch (result.getStatus()) {
+
+ case OK:
+ switch (currentHSStatus) {
+ case NOT_HANDSHAKING:
+ throw new IOException(
+ "Not handshaking during initial handshake");
+
+ case NEED_TASK:
+ Runnable task;
+ while ((task = sslEng.getDelegatedTask()) != null) {
+ task.run();
+ currentHSStatus = sslEng.getHandshakeStatus();
+ }
+ break;
+ }
+
+ break;
+
+ case BUFFER_UNDERFLOW:
+ break needIO;
+
+ default: // BUFFER_OVERFLOW/CLOSED:
+ throw new IOException("Received" + result.getStatus() +
+ "during initial handshaking");
+ }
+ }
+
+ /*
+ * Just transitioned from read to write.
+ */
+ if (currentHSStatus != HandshakeStatus.NEED_WRAP) {
+ break;
+ }
+
+ // Fall through and fill the write buffer.
+
+ case NEED_WRAP:
+ /*
+ * The flush above guarantees the out buffer to be empty
+ */
+ outNetBB.clear();
+ result = sslEng.wrap(inAppBB, outNetBB);
+ outNetBB.flip();
+ schan.write (outNetBB);
+ outNetBB.compact();
+ currentHSStatus = result.getHandshakeStatus();
+
+ switch (result.getStatus()) {
+ case OK:
+
+ if (currentHSStatus == HandshakeStatus.NEED_TASK) {
+ Runnable task;
+ while ((task = sslEng.getDelegatedTask()) != null) {
+ task.run();
+ currentHSStatus = sslEng.getHandshakeStatus();
+ }
+ }
+
+ break;
+
+ default: // BUFFER_OVERFLOW/BUFFER_UNDERFLOW/CLOSED:
+ throw new IOException("Received" + result.getStatus() +
+ "during initial handshaking");
+ }
+ break;
+
+ case FINISHED:
+ initialHSComplete = true;
+ break;
+ default: // NOT_HANDSHAKING/NEED_TASK
+ throw new RuntimeException("Invalid Handshaking State" +
+ currentHSStatus);
+ } // switch
+ }
+ // read the application data; using non-blocking mode
+ schan.configureBlocking(false);
+ read(schan, sslEng);
+ } catch (Exception ex) {
+ throw new RuntimeException(ex);
+ }
+ }
+
+ /* return true if the connection is closed, false otherwise */
+
+ private boolean read (SocketChannel chan, SSLEngine sslEng) {
+ HttpTransaction msg;
+ boolean res;
+ try {
+ InputStream is = new BufferedInputStream (new NioInputStream (chan, sslEng, inNetBB, inAppBB));
+ String requestline = readLine (is);
+ MessageHeader mhead = new MessageHeader (is);
+ String clen = mhead.findValue ("Content-Length");
+ String trferenc = mhead.findValue ("Transfer-Encoding");
+ String data = null;
+ if (trferenc != null && trferenc.equals ("chunked"))
+ data = new String (readChunkedData (is));
+ else if (clen != null)
+ data = new String (readNormalData (is, Integer.parseInt (clen)));
+ String[] req = requestline.split (" ");
+ if (req.length < 2) {
+ /* invalid request line */
+ return false;
+ }
+ String cmd = req[0];
+ URI uri = null;
+ try {
+ uri = new URI (req[1]);
+ msg = new HttpTransaction (this, cmd, uri, mhead, data, null, chan);
+ cb.request (msg);
+ } catch (URISyntaxException e) {
+ System.err.println ("Invalid URI: " + e);
+ msg = new HttpTransaction (this, cmd, null, null, null, null, chan);
+ msg.sendResponse (501, "Whatever");
+ }
+ res = false;
+ } catch (IOException e) {
+ res = true;
+ }
+ return res;
+ }
+
+ byte[] readNormalData (InputStream is, int len) throws IOException {
+ byte [] buf = new byte [len];
+ int c, off=0, remain=len;
+ while (remain > 0 && ((c=is.read (buf, off, remain))>0)) {
+ remain -= c;
+ off += c;
+ }
+ return buf;
+ }
+
+ private void readCRLF(InputStream is) throws IOException {
+ int cr = is.read();
+ int lf = is.read();
+
+ if (((cr & 0xff) != 0x0d) ||
+ ((lf & 0xff) != 0x0a)) {
+ throw new IOException(
+ "Expected <CR><LF>: got '" + cr + "/" + lf + "'");
+ }
+ }
+
+ byte[] readChunkedData (InputStream is) throws IOException {
+ LinkedList l = new LinkedList ();
+ int total = 0;
+ for (int len=readChunkLen(is); len!=0; len=readChunkLen(is)) {
+ l.add (readNormalData(is, len));
+ total += len;
+ readCRLF(is); // CRLF at end of chunk
+ }
+ readCRLF(is); // CRLF at end of Chunked Stream.
+ byte[] buf = new byte [total];
+ Iterator i = l.iterator();
+ int x = 0;
+ while (i.hasNext()) {
+ byte[] b = (byte[])i.next();
+ System.arraycopy (b, 0, buf, x, b.length);
+ x += b.length;
+ }
+ return buf;
+ }
+
+ private int readChunkLen (InputStream is) throws IOException {
+ int c, len=0;
+ boolean done=false, readCR=false;
+ while (!done) {
+ c = is.read ();
+ if (c == '\n' && readCR) {
+ done = true;
+ } else {
+ if (c == '\r' && !readCR) {
+ readCR = true;
+ } else {
+ int x=0;
+ if (c >= 'a' && c <= 'f') {
+ x = c - 'a' + 10;
+ } else if (c >= 'A' && c <= 'F') {
+ x = c - 'A' + 10;
+ } else if (c >= '0' && c <= '9') {
+ x = c - '0';
+ }
+ len = len * 16 + x;
+ }
+ }
+ }
+ return len;
+ }
+
+ private String readLine (InputStream is) throws IOException {
+ boolean done=false, readCR=false;
+ byte[] b = new byte [512];
+ int c, l = 0;
+
+ while (!done) {
+ c = is.read ();
+ if (c == '\n' && readCR) {
+ done = true;
+ } else {
+ if (c == '\r' && !readCR) {
+ readCR = true;
+ } else {
+ b[l++] = (byte)c;
+ }
+ }
+ }
+ return new String (b);
+ }
+
+ /** close the channel associated with the current key by:
+ * 1. shutdownOutput (send a FIN)
+ * 2. mark the key so that incoming data is to be consumed and discarded
+ * 3. After a period, close the socket
+ */
+
+ synchronized void orderlyCloseChannel (SocketChannel ch) throws IOException {
+ ch.socket().shutdownOutput();
+ }
+
+ synchronized void abortiveCloseChannel (SocketChannel ch) throws IOException {
+ Socket s = ch.socket ();
+ s.setSoLinger (true, 0);
+ ch.close();
+ }
+ }
+
+
+ /**
+ * Implements blocking reading semantics on top of a non-blocking channel
+ */
+
+ static class NioInputStream extends InputStream {
+ SSLEngine sslEng;
+ SocketChannel channel;
+ Selector selector;
+ ByteBuffer inNetBB;
+ ByteBuffer inAppBB;
+ SelectionKey key;
+ int available;
+ byte[] one;
+ boolean closed;
+ ByteBuffer markBuf; /* reads may be satisifed from this buffer */
+ boolean marked;
+ boolean reset;
+ int readlimit;
+
+ public NioInputStream (SocketChannel chan, SSLEngine sslEng, ByteBuffer inNetBB, ByteBuffer inAppBB) throws IOException {
+ this.sslEng = sslEng;
+ this.channel = chan;
+ selector = Selector.open();
+ this.inNetBB = inNetBB;
+ this.inAppBB = inAppBB;
+ key = chan.register (selector, SelectionKey.OP_READ);
+ available = 0;
+ one = new byte[1];
+ closed = marked = reset = false;
+ }
+
+ public synchronized int read (byte[] b) throws IOException {
+ return read (b, 0, b.length);
+ }
+
+ public synchronized int read () throws IOException {
+ return read (one, 0, 1);
+ }
+
+ public synchronized int read (byte[] b, int off, int srclen) throws IOException {
+
+ int canreturn, willreturn;
+
+ if (closed)
+ return -1;
+
+ if (reset) { /* satisfy from markBuf */
+ canreturn = markBuf.remaining ();
+ willreturn = canreturn>srclen ? srclen : canreturn;
+ markBuf.get(b, off, willreturn);
+ if (canreturn == willreturn) {
+ reset = false;
+ }
+ } else { /* satisfy from channel */
+ canreturn = available();
+ if (canreturn == 0) {
+ block ();
+ canreturn = available();
+ }
+ willreturn = canreturn>srclen ? srclen : canreturn;
+ inAppBB.get(b, off, willreturn);
+ available -= willreturn;
+
+ if (marked) { /* copy into markBuf */
+ try {
+ markBuf.put (b, off, willreturn);
+ } catch (BufferOverflowException e) {
+ marked = false;
+ }
+ }
+ }
+ return willreturn;
+ }
+
+ public synchronized int available () throws IOException {
+ if (closed)
+ throw new IOException ("Stream is closed");
+
+ if (reset)
+ return markBuf.remaining();
+
+ if (available > 0)
+ return available;
+
+ inAppBB.clear ();
+ int bytes = channel.read (inNetBB);
+
+ int needed = sslEng.getSession().getApplicationBufferSize();
+ if (needed > inAppBB.remaining()) {
+ inAppBB = ByteBuffer.allocate(needed);
+ }
+ inNetBB.flip();
+ SSLEngineResult result = sslEng.unwrap(inNetBB, inAppBB);
+ inNetBB.compact();
+ available = result.bytesProduced();
+
+ if (available > 0)
+ inAppBB.flip();
+ else if (available == -1)
+ throw new IOException ("Stream is closed");
+ return available;
+ }
+
+ /**
+ * block() only called when available==0 and buf is empty
+ */
+ private synchronized void block () throws IOException {
+ //assert available == 0;
+ int n = selector.select ();
+ //assert n == 1;
+ selector.selectedKeys().clear();
+ available ();
+ }
+
+ public void close () throws IOException {
+ if (closed)
+ return;
+ channel.close ();
+ closed = true;
+ }
+
+ public synchronized void mark (int readlimit) {
+ if (closed)
+ return;
+ this.readlimit = readlimit;
+ markBuf = ByteBuffer.allocate (readlimit);
+ marked = true;
+ reset = false;
+ }
+
+ public synchronized void reset () throws IOException {
+ if (closed )
+ return;
+ if (!marked)
+ throw new IOException ("Stream not marked");
+ marked = false;
+ reset = true;
+ markBuf.flip ();
+ }
+ }
+
+ static class NioOutputStream extends OutputStream {
+ SSLEngine sslEng;
+ SocketChannel channel;
+ ByteBuffer outNetBB;
+ ByteBuffer outAppBB;
+ SelectionKey key;
+ Selector selector;
+ boolean closed;
+ byte[] one;
+
+ public NioOutputStream (SocketChannel channel, SSLEngine sslEng, ByteBuffer outNetBB, ByteBuffer outAppBB) throws IOException {
+ this.sslEng = sslEng;
+ this.channel = channel;
+ this.outNetBB = outNetBB;
+ this.outAppBB = outAppBB;
+ selector = Selector.open ();
+ key = channel.register (selector, SelectionKey.OP_WRITE);
+ closed = false;
+ one = new byte [1];
+ }
+
+ public synchronized void write (int b) throws IOException {
+ one[0] = (byte)b;
+ write (one, 0, 1);
+ }
+
+ public synchronized void write (byte[] b) throws IOException {
+ write (b, 0, b.length);
+ }
+
+ public synchronized void write (byte[] b, int off, int len) throws IOException {
+ if (closed)
+ throw new IOException ("stream is closed");
+
+ outAppBB = ByteBuffer.allocate (len);
+ outAppBB.put (b, off, len);
+ outAppBB.flip ();
+ int n;
+ outNetBB.clear();
+ int needed = sslEng.getSession().getPacketBufferSize();
+ if (outNetBB.capacity() < needed) {
+ outNetBB = ByteBuffer.allocate(needed);
+ }
+ SSLEngineResult ret = sslEng.wrap(outAppBB, outNetBB);
+ outNetBB.flip();
+ int newLen = ret.bytesProduced();
+ while ((n = channel.write (outNetBB)) < newLen) {
+ newLen -= n;
+ if (newLen == 0)
+ return;
+ selector.select ();
+ selector.selectedKeys().clear ();
+ }
+ }
+
+ public void close () throws IOException {
+ if (closed)
+ return;
+ channel.close ();
+ closed = true;
+ }
+ }
+
+ /**
+ * Utilities for synchronization. A condition is
+ * identified by a string name, and is initialized
+ * upon first use (ie. setCondition() or waitForCondition()). Threads
+ * are blocked until some thread calls (or has called) setCondition() for the same
+ * condition.
+ * <P>
+ * A rendezvous built on a condition is also provided for synchronizing
+ * N threads.
+ */
+
+ private static HashMap conditions = new HashMap();
+
+ /*
+ * Modifiable boolean object
+ */
+ private static class BValue {
+ boolean v;
+ }
+
+ /*
+ * Modifiable int object
+ */
+ private static class IValue {
+ int v;
+ IValue (int i) {
+ v =i;
+ }
+ }
+
+
+ private static BValue getCond (String condition) {
+ synchronized (conditions) {
+ BValue cond = (BValue) conditions.get (condition);
+ if (cond == null) {
+ cond = new BValue();
+ conditions.put (condition, cond);
+ }
+ return cond;
+ }
+ }
+
+ /**
+ * Set the condition to true. Any threads that are currently blocked
+ * waiting on the condition, will be unblocked and allowed to continue.
+ * Threads that subsequently call waitForCondition() will not block.
+ * If the named condition did not exist prior to the call, then it is created
+ * first.
+ */
+
+ public static void setCondition (String condition) {
+ BValue cond = getCond (condition);
+ synchronized (cond) {
+ if (cond.v) {
+ return;
+ }
+ cond.v = true;
+ cond.notifyAll();
+ }
+ }
+
+ /**
+ * If the named condition does not exist, then it is created and initialized
+ * to false. If the condition exists or has just been created and its value
+ * is false, then the thread blocks until another thread sets the condition.
+ * If the condition exists and is already set to true, then this call returns
+ * immediately without blocking.
+ */
+
+ public static void waitForCondition (String condition) {
+ BValue cond = getCond (condition);
+ synchronized (cond) {
+ if (!cond.v) {
+ try {
+ cond.wait();
+ } catch (InterruptedException e) {}
+ }
+ }
+ }
+
+ /* conditions must be locked when accessing this */
+ static HashMap rv = new HashMap();
+
+ /**
+ * Force N threads to rendezvous (ie. wait for each other) before proceeding.
+ * The first thread(s) to call are blocked until the last
+ * thread makes the call. Then all threads continue.
+ * <p>
+ * All threads that call with the same condition name, must use the same value
+ * for N (or the results may be not be as expected).
+ * <P>
+ * Obviously, if fewer than N threads make the rendezvous then the result
+ * will be a hang.
+ */
+
+ public static void rendezvous (String condition, int N) {
+ BValue cond;
+ IValue iv;
+ String name = "RV_"+condition;
+
+ /* get the condition */
+
+ synchronized (conditions) {
+ cond = (BValue)conditions.get (name);
+ if (cond == null) {
+ /* we are first caller */
+ if (N < 2) {
+ throw new RuntimeException ("rendezvous must be called with N >= 2");
+ }
+ cond = new BValue ();
+ conditions.put (name, cond);
+ iv = new IValue (N-1);
+ rv.put (name, iv);
+ } else {
+ /* already initialised, just decrement the counter */
+ iv = (IValue) rv.get (name);
+ iv.v --;
+ }
+ }
+
+ if (iv.v > 0) {
+ waitForCondition (name);
+ } else {
+ setCondition (name);
+ synchronized (conditions) {
+ clearCondition (name);
+ rv.remove (name);
+ }
+ }
+ }
+
+ /**
+ * If the named condition exists and is set then remove it, so it can
+ * be re-initialized and used again. If the condition does not exist, or
+ * exists but is not set, then the call returns without doing anything.
+ * Note, some higher level synchronization
+ * may be needed between clear and the other operations.
+ */
+
+ public static void clearCondition(String condition) {
+ BValue cond;
+ synchronized (conditions) {
+ cond = (BValue) conditions.get (condition);
+ if (cond == null) {
+ return;
+ }
+ synchronized (cond) {
+ if (cond.v) {
+ conditions.remove (condition);
+ }
+ }
+ }
+ }
+}