diff options
Diffstat (limited to 'libjava/classpath/java/nio/channels/spi/SelectorProvider.java')
-rw-r--r-- | libjava/classpath/java/nio/channels/spi/SelectorProvider.java | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/libjava/classpath/java/nio/channels/spi/SelectorProvider.java b/libjava/classpath/java/nio/channels/spi/SelectorProvider.java new file mode 100644 index 000000000..821bc4361 --- /dev/null +++ b/libjava/classpath/java/nio/channels/spi/SelectorProvider.java @@ -0,0 +1,178 @@ +/* SelectorProvider.java + Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.nio.channels.spi; + +import gnu.java.nio.SelectorProviderImpl; + +import java.io.IOException; +import java.nio.channels.Channel; +import java.nio.channels.DatagramChannel; +import java.nio.channels.Pipe; +import java.nio.channels.ServerSocketChannel; +import java.nio.channels.SocketChannel; + + +/** + * @author Michael Koch + * @since 1.4 + */ +public abstract class SelectorProvider +{ + private static SelectorProvider systemDefaultProvider; + + /** + * Initializes the selector provider. + * + * @exception SecurityException If a security manager has been installed and + * it denies @see RuntimePermission ("selectorProvider"). + */ + protected SelectorProvider() + { + SecurityManager sm = System.getSecurityManager(); + if (sm != null) + sm.checkPermission(new RuntimePermission("selectorProvider")); + } + + /** + * Opens a datagram channel. + * + * @return a new datagram channel object + * + * @exception IOException if an error occurs + */ + public abstract DatagramChannel openDatagramChannel() + throws IOException; + + /** + * Opens a pipe. + * + * @return a new pipe object + * + * @exception IOException if an error occurs + */ + public abstract Pipe openPipe() throws IOException; + + /** + * Opens a selector. + * + * @return a new selector object + * + * @exception IOException if an error occurs + */ + public abstract AbstractSelector openSelector() throws IOException; + + /** + * Opens a server socket channel. + * + * @return a new server socket channel object + * + * @exception IOException if an error occurs + */ + public abstract ServerSocketChannel openServerSocketChannel() + throws IOException; + + /** + * Opens a socket channel. + * + * @return a new socket channel object + * + * @exception IOException if an error occurs + */ + public abstract SocketChannel openSocketChannel() throws IOException; + + /** + * Returns the inherited channel of the VM. + * + * @return the inherited channel of the VM + * + * @throws IOException If an I/O error occurs + * @throws SecurityException If an installed security manager denies access + * to RuntimePermission("inheritedChannel") + * + * @since 1.5 + */ + public Channel inheritedChannel() + throws IOException + { + SecurityManager sm = System.getSecurityManager(); + if (sm != null) + { + sm.checkPermission(new RuntimePermission("inheritedChannel")); + } + // Implementation note: The default implementation can't do much more + // than return null. If a VM can provide something more useful it should + // install its own SelectorProvider (maybe a subclass of this one) to + // return something more useful. + return null; + } + + /** + * Returns the system-wide default selector provider for this invocation + * of the Java virtual machine. + * + * @return the default seletor provider + */ + public static synchronized SelectorProvider provider() + { + if (systemDefaultProvider == null) + { + String propertyValue = + System.getProperty("java.nio.channels.spi.SelectorProvider"); + + if (propertyValue == null || propertyValue.equals("")) + systemDefaultProvider = new SelectorProviderImpl(); + else + { + try + { + systemDefaultProvider = + (SelectorProvider) Class.forName(propertyValue) + .newInstance(); + } + catch (Exception e) + { + System.err.println("Could not instantiate class: " + + propertyValue); + systemDefaultProvider = new SelectorProviderImpl(); + } + } + } + + return systemDefaultProvider; + } +} |