/**************************************************************************
* Parts copyright (c) 2001 by Punch Telematix. All rights reserved. *
* Parts copyright (c) 2004 by Chris Gray, /k/ Embedded Java Solutions. *
* All rights reserved. *
* *
* Redistribution and use in source and binary forms, with or without *
* modification, are permitted provided that the following conditions *
* are met: *
* 1. Redistributions of source code must retain the above copyright *
* notice, this list of conditions and the following disclaimer. *
* 2. Redistributions in binary form must reproduce the above copyright *
* notice, this list of conditions and the following disclaimer in the *
* documentation and/or other materials provided with the distribution. *
* 3. Neither the name of Punch Telematix or of /k/ Embedded Java Solutions*
* nor the names of other contributors may be used to endorse or promote*
* products derived from this software without specific prior written *
* permission. *
* *
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED *
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF *
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. *
* IN NO EVENT SHALL PUNCH TELEMATIX, /K/ EMBEDDED JAVA SOLUTIONS OR OTHER *
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, *
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, *
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR *
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING *
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS *
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
**************************************************************************/
package wonka.vm;
public final class Finalizer implements Runnable {
private static Finalizer theFinalizer;
private static final int IDLE_WAIT_MILLIS = 1000;
private Object[] empty;
private java.lang.reflect.Method finalizer_method;
/**
** Our very private constructor. We look up the methodID's for the
** methods Reference/enqueue() and Object/finalize() and start our
** thread running.
*/
private Finalizer() {
try {
Class java_lang_Object = Class.forName("java.lang.Object");
finalizer_method = java_lang_Object.getDeclaredMethod("finalize", new Class[0]);
finalizer_method.setAccessible(true);
}
catch (Exception e) {
e.printStackTrace();
}
empty = new Object[0];
}
/**
** Return the solitary instance of Finalizer.
*/
public static synchronized Finalizer getInstance() {
if (theFinalizer == null) {
theFinalizer = new Finalizer();
}
return theFinalizer;
}
/**
** The run() method polls the two internal fifo's and calls enqueue()
** or finalize() as appropriate.
*/
public void run() {
boolean idle;
boolean verbose;
int finalized_count = 0;
Object o;
// Give GC thread time to start up, otherwise nextFinalizee() crashes (kludge).
try {
synchronized(this) {
wait(IDLE_WAIT_MILLIS);
}
}
catch (InterruptedException ie) {
}
verbose = (GetSystemProperty.MIKA_VERBOSE.indexOf("gc") >= 0);
while(true) {
idle = true;
synchronized(this) {
o = nextFinalizee();
}
if (o == null) {
synchronized(this) {
notifyAll();
}
}
else {
idle = false;
if (verbose) {
System.err.println("GC: finalizing " + o);
}
try {
finalizer_method.invoke(o, empty);
}
catch (Throwable t) {
t.printStackTrace();
}
finalized(o);
++finalized_count;
}
if (idle) {
finalized_count = 0;
synchronized(this) {
try {
wait(IDLE_WAIT_MILLIS);
}
catch (Throwable t) {
t.printStackTrace();
}
}
}
}
}
/**
** Poll the finalize() fifo.
*/
private native Object nextFinalizee();
/**
** Tell GC that object has been finalized.
*/
private native void finalized(Object o);
}