/******************************************************************************
* $Id$
*
* Name: OGRFeature.java
* Project: OGR Java Interface
* Purpose: A sample app for demonstrating the caveats with JNI and garbage collecting...
* Author: Even Rouault, <even dot rouault at mines dash paris dot org>
*
******************************************************************************
* Copyright (c) 2009, Even Rouault
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
import org.gdal.ogr.Feature;
import org.gdal.ogr.FeatureDefn;
/* The nasty things below are necessary if the Feature class has a finalize() */
/* method, which is no longer the case. See OGRTestGC.java */
public class OGRFeature
{
static int i;
static boolean doCleanup = false;
static boolean bHasFinished = false;
static FeatureDefn featureDefn;
static Object mutex = new Object();
public static void main(String[] args)
{
featureDefn = new FeatureDefn();
new Thread() {
public void run()
{
while(!bHasFinished)
{
if (doCleanup)
{
int refBefore, refAfter;
while(true)
{
refBefore = featureDefn.GetReferenceCount();
System.out.print("i=" + i + " ref(before)="+ refBefore );
System.runFinalization();
refAfter = featureDefn.GetReferenceCount();
System.out.println(" ref(after)="+ refAfter );
if (refBefore == refAfter)
System.gc();
else
break;
}
synchronized (mutex) {
doCleanup = false;
mutex.notify();
}
}
synchronized (mutex) {
while (doCleanup == false && bHasFinished == false)
{
//System.out.println("thread wakeup");
try
{
mutex.wait();
}
catch(InterruptedException ie)
{
System.out.println("InterruptedException");
}
}
}
}
}
}.start();
// Add features
for (i = 0; i < 5000000; i++)
{
new Feature(featureDefn);
if ((i % 100000) == 0)
{
/* Due to the fact that the Feature class has a finalize() method */
/* the garbage collector will differ finalization. So we have to do */
/* wait that the cleanup thread has forced finalizations */
while(featureDefn.GetReferenceCount() > 100000)
{
//System.out.println("waiting for cleanup");
synchronized (mutex) {
doCleanup = true;
mutex.notify();
while (doCleanup)
{
//System.out.println("main thread wakeup");
try
{
mutex.wait();
}
catch(InterruptedException ie)
{
System.out.println("InterruptedException");
}
}
}
}
}
}
synchronized (mutex) {
bHasFinished = true;
mutex.notify();
}
System.out.print("i=" + i + " ref(before)="+ featureDefn.GetReferenceCount() );
System.gc();
System.runFinalization();
System.out.println(" ref(after)="+ featureDefn.GetReferenceCount() );
}
}