8021820: Number of opened files used in select() is limited to 1024 [macosx]

Reviewed-by: alanb, chegar, tbell, smarks

test/java/net/ServerSocket/SelectFdsLimit.java

+/*
+ * Copyright (c) 2013, 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.
+ */
+
+/*
+ * @test
+ * @bug 8021820
+ * @summary The total number of file descriptors is limited to
+ * 1024(FDSET_SIZE) on MacOSX (the size of fd array passed to select()
+ * call in java.net classes is limited to this value).
+ * @run main/othervm SelectFdsLimit
+ * @author aleksej.efimov@oracle.com
+ */
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.ServerSocket;
+import java.net.SocketTimeoutException;
+
+
+/*
+ * Test must be run in othervm mode to ensure that all files
+ * opened by openFiles() are closed propertly.
+*/
+public class SelectFdsLimit {
+    static final int FDTOOPEN = 1023;
+    static final String TESTFILE = "testfile";
+    static FileInputStream [] testFIS;
+
+    static void prepareTestEnv() throws IOException {
+            File fileToCreate = new File(TESTFILE);
+            if (!fileToCreate.exists())
+                if (!fileToCreate.createNewFile())
+                    throw new RuntimeException("Can't create test file");
+    }
+
+    //If there will be some problem (i.e. ulimits on number of opened files will fail)
+    //then this method will fail with exception and test will be considered as
+    //failed. But allocated fds will be released because the test is executed by
+    //dedicated VM (@run main/othervm).
+    static void openFiles(int fn, File f) throws FileNotFoundException, IOException {
+        testFIS = new FileInputStream[FDTOOPEN];
+        for (;;) {
+            if (0 == fn)
+                break;
+            FileInputStream fis = new FileInputStream(f);
+            testFIS[--fn] = fis;
+        }
+    }
+
+    public static void main(String [] args) throws IOException, FileNotFoundException {
+
+        //The bug 8021820 is a Mac specific and because of that test will pass on all
+        //other platforms
+        if (!System.getProperty("os.name").contains("OS X")) {
+           return;
+        }
+
+        //Create test directory with test files
+        prepareTestEnv();
+
+        //Consume FD ids for this java process to overflow the 1024
+        openFiles(FDTOOPEN,new File(TESTFILE));
+
+        //Wait for incoming connection and make the select() used in java.net
+        //classes fail the limitation on FDSET_SIZE
+        ServerSocket socket = new ServerSocket(0);
+
+        //Set the minimal timeout, no one is
+        //going to connect to this server socket
+        socket.setSoTimeout(1);
+
+        // The accept() call will throw SocketException if the
+        // select() has failed due to limitation on fds size,
+        // indicating test failure. A SocketTimeoutException
+        // is expected, so it is caught and ignored, and the test
+        // passes.
+        try {
+           socket.accept();
+        } catch (SocketTimeoutException e) { }
+    }
+}