package net.i2p.phttprelay;
/*
 * free (adj.): unencumbered; not under the control of others
 * Written by jrandom in 2003 and released into the public domain 
 * with no warranty of any kind, either expressed or implied.  
 * It probably won't make your computer catch on fire, or eat 
 * your children, but it might.  Use at your own risk.
 *
 */

import java.util.HashSet;
import java.util.Set;

/**
 * Lock identities for updating messages (so that they aren't read / deleted 
 * while being written)
 *
 */
class LockManager {
    private volatile static Set _locks = new HashSet(); // target
    
    public static void lockIdent(String target) {
	while (true) {
	    synchronized (_locks) {
		if (!_locks.contains(target)) {
		    _locks.add(target);
		    return;
		}
		try { _locks.wait(1000); } catch (InterruptedException ie) {}
	    }
	}
    }
    
    public static void unlockIdent(String target) {
	synchronized (_locks) {
	    _locks.remove(target);
	    _locks.notifyAll();
	}
    }
}