8027212: java/nio/channels/Selector/SelectAfterRead.java fails intermittently

Reviewed-by: chegar, ewang

test/java/nio/channels/Selector/ByteServer.java

@@ -22,52 +22,54 @@
  */
 
 /**
- *
- * Utility class for tests. A simple server, which waits for a connection,
- * writes out n bytes and waits.
+ * Utility class for tests. A simple "in-thread" server to accept connections
+ * and write bytes.
  * @author kladko
  */
 
 import java.net.Socket;
 import java.net.ServerSocket;
+import java.net.SocketAddress;
+import java.net.InetSocketAddress;
+import java.io.IOException;
+import java.io.Closeable;
+
+public class ByteServer implements Closeable {
 
-public class ByteServer {
+    private final ServerSocket ss;
+    private Socket s;
 
-    public static final String LOCALHOST = "localhost";
-    private int bytecount;
-    private Socket  socket;
-    private ServerSocket  serversocket;
-    private Thread serverthread;
-    volatile Exception savedException;
+    ByteServer() throws IOException {
+        this.ss = new ServerSocket(0);
+    }
+
+    SocketAddress address() {
+        return new InetSocketAddress(ss.getInetAddress(), ss.getLocalPort());
+    }
 
-    public ByteServer(int bytecount) throws Exception{
-        this.bytecount = bytecount;
-        serversocket = new ServerSocket(0);
+    void acceptConnection() throws IOException {
+        if (s != null)
+            throw new IllegalStateException("already connected");
+        this.s = ss.accept();
     }
 
-    public int port() {
-        return serversocket.getLocalPort();
+    void closeConnection() throws IOException {
+        Socket s = this.s;
+        if (s != null) {
+            this.s = null;
+            s.close();
+        }
     }
 
-    public void start() {
-        serverthread = new Thread() {
-            public void run() {
-                try {
-                    socket = serversocket.accept();
-                    socket.getOutputStream().write(new byte[bytecount]);
-                    socket.getOutputStream().flush();
-                } catch (Exception e) {
-                    System.err.println("Exception in ByteServer: " + e);
-                    System.exit(1);
-                }
-            }
-        };
-        serverthread.start();
+    void write(int count) throws IOException {
+        if (s == null)
+            throw new IllegalStateException("no connection");
+        s.getOutputStream().write(new byte[count]);
     }
 
-    public void exit() throws Exception {
-        serverthread.join();
-        socket.close();
-        serversocket.close();
+    public void close() throws IOException {
+        if (s != null)
+            s.close();
+        ss.close();
     }
 }

test/java/nio/channels/Selector/ReadAfterConnect.java

@@ -27,27 +27,25 @@
  * @author kladko
  */
 
-import java.net.*;
-import java.nio.*;
-import java.nio.channels.*;
+import java.nio.channels.Selector;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
 
 public class ReadAfterConnect {
-
     public static void main(String[] argv) throws Exception {
-        ByteServer server = new ByteServer(0); // server: accept connection and do nothing
-        server.start();
-        InetSocketAddress isa = new InetSocketAddress(
-                InetAddress.getByName(ByteServer.LOCALHOST), server.port());
-        Selector sel = Selector.open();
-        SocketChannel sc = SocketChannel.open();
-        sc.connect(isa);
-        sc.configureBlocking(false);
-        sc.register(sel, SelectionKey.OP_READ);
-        // Previously channel would get selected here, although there is nothing to read
-        if (sel.selectNow() != 0)
-            throw new Exception("Select returned nonzero value");
-        sc.close();
-        server.exit();
+        try (ByteServer server = new ByteServer();
+             SocketChannel sc = SocketChannel.open(server.address())) {
+
+            server.acceptConnection();
+
+            try (Selector sel = Selector.open()) {
+                sc.configureBlocking(false);
+                sc.register(sel, SelectionKey.OP_READ);
+                // Previously channel would get selected here, although there is nothing to read
+                if (sel.selectNow() != 0)
+                    throw new Exception("Select returned nonzero value");
+            }
+        }
     }
 
 }

test/java/nio/channels/Selector/SelectAfterRead.java

@@ -28,60 +28,62 @@
  * @author kladko
  */
 
-import java.net.*;
-import java.nio.*;
-import java.nio.channels.*;
+import java.nio.ByteBuffer;
+import java.nio.channels.Selector;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
 
 public class SelectAfterRead {
 
-    final static int TIMEOUT = 1000;
+    private static final int TIMEOUT = 1000;
 
     public static void main(String[] argv) throws Exception {
-        InetAddress lh = InetAddress.getByName(ByteServer.LOCALHOST);
 
         // server: accept connection and write one byte
-        ByteServer server = new ByteServer(1);
-        server.start();
-        Selector sel = Selector.open();
-        SocketChannel sc = SocketChannel.open();
-        sc.connect(new InetSocketAddress(lh, server.port()));
-        sc.read(ByteBuffer.allocate(1));
-        sc.configureBlocking(false);
-        sc.register(sel, SelectionKey.OP_READ);
-        // previously on Windows select would select channel here, although there was
-        // nothing to read
-        if (sel.selectNow() != 0)
-            throw new Exception("Select returned nonzero value");
-        sc.close();
-        sel.close();
-        server.exit();
+        try (ByteServer server = new ByteServer();
+             SocketChannel sc = SocketChannel.open(server.address())) {
+
+            server.acceptConnection();
+            server.write(1);
+
+            try (Selector sel = Selector.open()) {
+                sc.read(ByteBuffer.allocate(1));
+                sc.configureBlocking(false);
+                sc.register(sel, SelectionKey.OP_READ);
+                // previously on Windows select would select channel here, although there was
+                // nothing to read
+                if (sel.selectNow() != 0)
+                    throw new Exception("Select returned nonzero value");
+            }
+        }
 
         // Now we will test a two reads combination
         // server: accept connection and write two bytes
-        server = new ByteServer(2);
-        server.start();
-        sc = SocketChannel.open();
-        sc.connect(new InetSocketAddress(lh, server.port()));
-        sc.configureBlocking(false);
-        sel = Selector.open();
-        sc.register(sel, SelectionKey.OP_READ);
-        if (sel.select(TIMEOUT) != 1)
-            throw new Exception("One selected key expected");
-        sel.selectedKeys().clear();
-        // previously on Windows a channel would get selected only once
-        if (sel.selectNow() != 1)
-            throw new Exception("One selected key expected");
-        // Previously on Windows two consequent reads would cause select()
-        // to select a channel, although there was nothing remaining to
-        // read in the channel
-        if (sc.read(ByteBuffer.allocate(1)) != 1)
-            throw new Exception("One byte expected");
-        if (sc.read(ByteBuffer.allocate(1)) != 1)
-            throw new Exception("One byte expected");
-        if (sel.selectNow() != 0)
-            throw new Exception("Select returned nonzero value");
-        sc.close();
-        sel.close();
-        server.exit();
+        try (ByteServer server = new ByteServer();
+             SocketChannel sc = SocketChannel.open(server.address())) {
+
+            server.acceptConnection();
+            server.write(2);
+
+            try (Selector sel = Selector.open()) {
+                sc.configureBlocking(false);
+                sc.register(sel, SelectionKey.OP_READ);
+                if (sel.select(TIMEOUT) != 1)
+                    throw new Exception("One selected key expected");
+                sel.selectedKeys().clear();
+                // previously on Windows a channel would get selected only once
+                if (sel.selectNow() != 1)
+                    throw new Exception("One selected key expected");
+                // Previously on Windows two consequent reads would cause select()
+                // to select a channel, although there was nothing remaining to
+                // read in the channel
+                if (sc.read(ByteBuffer.allocate(1)) != 1)
+                    throw new Exception("One byte expected");
+                if (sc.read(ByteBuffer.allocate(1)) != 1)
+                    throw new Exception("One byte expected");
+                if (sel.selectNow() != 0)
+                    throw new Exception("Select returned nonzero value");
+            }
+        }
     }
 }

test/java/nio/channels/Selector/SelectWrite.java

@@ -22,36 +22,33 @@
  */
 
 /* @test
-   @bug 4645302
-   @summary Socket with OP_WRITE would get selected only once
-   @author kladko
+ * @bug 4645302
+ * @summary Socket with OP_WRITE would get selected only once
+ * @author kladko
  */
 
-import java.net.*;
-import java.nio.*;
-import java.nio.channels.*;
-
+import java.nio.channels.Selector;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
 
 public class SelectWrite {
 
     public static void main(String[] argv) throws Exception {
-        ByteServer server = new ByteServer(0);
-        // server: accept connection and do nothing
-        server.start();
-        InetSocketAddress isa = new InetSocketAddress(
-                InetAddress.getByName(ByteServer.LOCALHOST), server.port());
-        Selector sel = Selector.open();
-        SocketChannel sc = SocketChannel.open();
-        sc.connect(isa);
-        sc.configureBlocking(false);
-        sc.register(sel, SelectionKey.OP_WRITE);
-        sel.select();
-        sel.selectedKeys().clear();
-        if (sel.select() == 0) {
-            throw new Exception("Select returned zero");
+        try (ByteServer server = new ByteServer();
+             SocketChannel sc = SocketChannel.open(server.address())) {
+
+            server.acceptConnection();
+
+            try (Selector sel = Selector.open()) {
+                sc.configureBlocking(false);
+                sc.register(sel, SelectionKey.OP_WRITE);
+                sel.select();
+                sel.selectedKeys().clear();
+                if (sel.select() == 0) {
+                    throw new Exception("Select returned zero");
+                }
+            }
         }
-        sc.close();
-        sel.close();
     }
 
 }