| /* Asynchron.java -- |
| Copyright (C) 2005 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 gnu.CORBA; |
| |
| import org.omg.CORBA.Request; |
| import org.omg.CORBA.WrongTransaction; |
| |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| |
| /** |
| * Handles the asynchronous dynamic invocations. |
| * |
| * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) |
| */ |
| public class Asynchron |
| { |
| LinkedList sent = new LinkedList(); |
| |
| /** |
| * Send multiple prepared requests one way, do not caring about the answer. |
| * The messages, containing requests, will be marked, indicating that |
| * the sender is not expecting to get a reply. |
| * |
| * @param requests the prepared array of requests. |
| * |
| * @see Request#send_oneway() |
| */ |
| public void send_multiple_requests_oneway(Request[] requests) |
| { |
| for (int i = 0; i < requests.length; i++) |
| { |
| requests [ i ].send_oneway(); |
| } |
| } |
| |
| /** |
| * Send multiple prepared requests expecting to get a reply. All requests |
| * are send in parallel, each in its own separate thread. When the |
| * reply arrives, it is stored in the agreed fields of the corresponing |
| * request data structure. If this method is called repeatedly, |
| * the new requests are added to the set of the currently sent requests, |
| * but the old set is not discarded. |
| * |
| * @param requests the prepared array of requests. |
| * |
| * @see #poll_next_response() |
| * @see #get_next_response() |
| * @see Request#send_deferred() |
| */ |
| public void send_multiple_requests_deferred(Request[] requests) |
| { |
| synchronized (sent) |
| { |
| for (int i = 0; i < requests.length; i++) |
| { |
| sent.add(requests [ i ]); |
| |
| // TODO Reuse threads that are instantiated in the method below, |
| // one thread per call. |
| requests [ i ].send_deferred(); |
| } |
| } |
| } |
| |
| /** |
| * Find if any of the requests that have been previously sent with |
| * {@link #send_multiple_requests_deferred}, have a response yet. |
| * |
| * @return true if there is at least one response to the previously |
| * sent request, false otherwise. |
| */ |
| public boolean poll_next_response() |
| { |
| synchronized (sent) |
| { |
| Iterator iter = sent.iterator(); |
| Request r; |
| while (iter.hasNext()) |
| { |
| r = (Request) iter.next(); |
| if (r.poll_response()) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Get the next instance with a response being received. If all currently |
| * sent responses not yet processed, this method pauses till at least one of |
| * them is complete. If there are no requests currently sent, the method |
| * pauses till some request is submitted and the response is received. |
| * This strategy is identical to the one accepted by Suns 1.4 ORB |
| * implementation. |
| * |
| * The returned response is removed from the list of the currently |
| * submitted responses and is never returned again. |
| * |
| * @return the previously sent request that now contains the received |
| * response. |
| * |
| * @throws WrongTransaction If the method was called from the transaction |
| * scope different than the one, used to send the request. The exception |
| * can be raised only if the request is implicitly associated with some |
| * particular transaction. |
| */ |
| public Request get_next_response() |
| throws WrongTransaction |
| { |
| // The hard-coded waiting times for the incremental waiter. |
| // TODO it is possible to write more tricky system where the |
| // requests notify the Asynchron when they are complete. |
| // Wait for 5 ms intially. |
| int wait = 8; |
| |
| // Double the waiting time |
| int INC = 2; |
| |
| // Do not increase if the waiting time is already over 500 ms. |
| int MAX = 500; |
| while (true) |
| { |
| synchronized (sent) |
| { |
| Iterator iter = sent.iterator(); |
| Request r; |
| while (iter.hasNext()) |
| { |
| r = (Request) iter.next(); |
| if (r.poll_response()) |
| { |
| sent.remove(r); |
| return r; |
| } |
| } |
| } |
| try |
| { |
| Thread.sleep(wait); |
| if (wait < MAX) |
| wait = wait * INC; |
| } |
| catch (InterruptedException ex) |
| { |
| } |
| } |
| } |
| } |