| /* |
| * Copyright (c) 2011, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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. |
| */ |
| |
| package sun.net; |
| |
| import java.net.SocketException; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import sun.security.action.GetPropertyAction; |
| |
| /** |
| * Manages count of total number of UDP sockets and ensures |
| * that exception is thrown if we try to create more than the |
| * configured limit. |
| * |
| * This functionality could be put in NetHooks some time in future. |
| */ |
| |
| public class ResourceManager { |
| |
| /* default maximum number of udp sockets per VM |
| * when a security manager is enabled. |
| * The default is 25 which is high enough to be useful |
| * but low enough to be well below the maximum number |
| * of port numbers actually available on all OSes |
| * when multiplied by the maximum feasible number of VM processes |
| * that could practically be spawned. |
| */ |
| |
| private static final int DEFAULT_MAX_SOCKETS = 25; |
| private static final int maxSockets; |
| private static final AtomicInteger numSockets; |
| |
| static { |
| String prop = java.security.AccessController.doPrivileged( |
| new GetPropertyAction("sun.net.maxDatagramSockets") |
| ); |
| int defmax = DEFAULT_MAX_SOCKETS; |
| try { |
| if (prop != null) { |
| defmax = Integer.parseInt(prop); |
| } |
| } catch (NumberFormatException e) {} |
| maxSockets = defmax; |
| numSockets = new AtomicInteger(0); |
| } |
| |
| public static void beforeUdpCreate() throws SocketException { |
| if (System.getSecurityManager() != null) { |
| if (numSockets.incrementAndGet() > maxSockets) { |
| numSockets.decrementAndGet(); |
| throw new SocketException("maximum number of DatagramSockets reached"); |
| } |
| } |
| } |
| |
| public static void afterUdpClose() { |
| if (System.getSecurityManager() != null) { |
| numSockets.decrementAndGet(); |
| } |
| } |
| } |