gecko/mobile/android/base/sync/DelayedWorkTracker.java

100 lines
3.3 KiB
Java
Raw Normal View History

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Android Sync Client.
*
* The Initial Developer of the Original Code is
* the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Richard Newman <rnewman@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.gecko.sync;
/**
* A little class to allow us to maintain a count of extant
* things (in our case, callbacks that need to fire), and
* some work that we want done when that count hits 0.
*
* @author rnewman
*
*/
public class DelayedWorkTracker {
private static final String LOG_TAG = "DelayedWorkTracker";
protected Runnable workItem = null;
protected int outstandingCount = 0;
public int incrementOutstanding() {
Logger.trace(LOG_TAG, "Incrementing outstanding.");
synchronized(this) {
return ++outstandingCount;
}
}
public int decrementOutstanding() {
Logger.trace(LOG_TAG, "Decrementing outstanding.");
Runnable job = null;
int count;
synchronized(this) {
if ((count = --outstandingCount) == 0 &&
workItem != null) {
job = workItem;
workItem = null;
} else {
return count;
}
}
job.run();
// In case it's changed.
return getOutstandingOperations();
}
public int getOutstandingOperations() {
synchronized(this) {
return outstandingCount;
}
}
public void delayWorkItem(Runnable item) {
Logger.trace(LOG_TAG, "delayWorkItem.");
boolean runnableNow = false;
synchronized(this) {
Logger.trace(LOG_TAG, "outstandingCount: " + outstandingCount);
if (outstandingCount == 0) {
runnableNow = true;
} else {
if (workItem != null) {
throw new IllegalStateException("Work item already set!");
}
workItem = item;
}
}
if (runnableNow) {
Logger.trace(LOG_TAG, "Running item now.");
item.run();
}
}
}