yacy_search_server/source/de/anomic/server/serverThread.java
orbiter ce1adf9955 serialized all logging using concurrency:
high-performance search query situations as seen in yacy-metager integration showed deadlock situation caused by synchronization effects inside of sun.java code. It appears that the logger is not completely safe against deadlock situations in concurrent calls of the logger. One possible solution would be a outside-synchronization with 'synchronized' statements, but that would further apply blocking on all high-efficient methods that call the logger. It is much better to do a non-blocking hand-over of logging lines and work off log entries with a concurrent log writer. This also disconnects IO operations from logging, which can also cause IO operation when a log is written to a file. This commit not only moves the logger from kelondro to yacy.logging, it also inserts the concurrency methods to realize non-blocking logging.

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6078 6c8d7289-2bf4-0310-a012-ef5d649a1542
2009-06-15 21:19:54 +00:00

87 lines
3.2 KiB
Java

// serverThread.java
// (C) 2005 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 13.03.2005 on http://yacy.net
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// LICENSE
//
// This program 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 of the License, or
// (at your option) any later version.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package de.anomic.server;
import de.anomic.yacy.logging.Log;
public interface serverThread {
// -------------------------------------------------------
// methods inherited from Thread; needed for compatibility
public void start();
public boolean isAlive();
// --------------------------------------------------------------------------
// these method are implemented by serverThread and do not need to be altered
// this includes also the run()-Method
public void setDescription(String shortText, String longText, String monitorURL);
// sets a visible description string
public String getShortDescription();
// returns short description string for online display
public String getLongDescription();
// returns long description string for online display
public String getMonitorURL();
// returns an URL that can be used to monitor the thread and it's queue
public long getBlockTime();
// returns the total time that this thread has been blocked so far
public long getExecTime();
// returns the total time that this thread has worked so far
public long getMemoryUse();
// returns the sum of all memory usage differences before and after one busy job
public void setLog(Log log);
// defines a log where process states can be written to
public void jobExceptionHandler(Exception e);
// handles any action necessary during job execution
public boolean shutdownInProgress();
public void terminate(boolean waitFor);
// after calling this method, the thread shall terminate
// if waitFor is true, the method waits until the process has died
// ---------------------------------------------------------------------
// the following methods are supposed to be implemented by customization
public void open();
// this is called right before the job queue is started
public int getJobCount();
// returns how many jobs are in the queue
// can be used to calculate a busy-state
public void close();
// jobs that need to be done after termination
// terminate must be called before
}