--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/fschmidt/util/locks/TimedLocker.java	Sun Oct 05 17:24:15 2025 -0600
@@ -0,0 +1,112 @@
+/*
+Copyright (c) 2008  Franklin Schmidt <fschmidt@gmail.com>
+
+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.
+*/
+
+package fschmidt.util.locks;
+
+import java.util.Map;
+import java.util.HashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+
+public final class TimedLocker<T> implements Locker<T> {
+
+	private static class Tracker {
+		final ReentrantLock lock0 = new ReentrantLock();
+		final Lock lock = new TimedLock(lock0);
+		int waiters = 0;
+	}
+
+	private final Map<T,Tracker> map = new HashMap<T,Tracker>();
+
+	private Tracker getTracker(T obj) {
+		Tracker t = map.get(obj);
+		if( t==null ) {
+			t = new Tracker();
+			map.put(obj,t);
+		}
+		return t;
+	}
+
+	private Tracker getTrackerForWait(T obj) {
+		synchronized(map) {
+			Tracker t = getTracker(obj);
+			t.waiters++;
+			return t;
+		}
+	}
+
+	private void afterWait(Tracker t) {
+		synchronized(map) {
+			t.waiters--;
+		}
+	}
+
+	private void maybeRemove(T obj,Tracker t) {
+		if( t.waiters==0 && !t.lock0.isHeldByCurrentThread() ) {
+			map.remove(obj);
+		}
+	}
+
+	public void lock(T obj) {
+		Tracker t = getTrackerForWait(obj);
+		try {
+			t.lock.lock();
+		} finally {
+			afterWait(t);
+		}
+	}
+
+	public boolean tryLock(T obj) {
+		synchronized(map) {
+			return getTracker(obj).lock.tryLock();
+		}
+	}
+
+	public boolean tryLock(T obj,long time,TimeUnit unit)
+		throws InterruptedException
+	{
+		Tracker t = getTrackerForWait(obj);
+		try {
+			return t.lock.tryLock(time,unit);
+		} finally {
+			afterWait(t);
+		}
+	}
+
+	public void unlock(T obj) {
+		synchronized(map) {
+			Tracker t = map.get(obj);
+			t.lock.unlock();
+			maybeRemove(obj,t);
+		}
+	}
+
+	public boolean hasLock(T obj) {
+		synchronized(map) {
+			Tracker t = map.get(obj);
+			return t!=null && t.lock0.isHeldByCurrentThread();
+		}
+	}
+
+}