package tracematches;

import java.util.*;

public class LeakingSync {
	
	static aspect SyncCheck{
		
		/*
		 * Those tracechecks check that one does not directly access a Map or Collection
		 * that has been put into Collections.synchronized*(..).
		 */		
		
		//most common supertype of Map anc Collection is Object unfortunately
		pointcut createSync(Object toSync):
			call(* Collections.synchr*(..)) && args(toSync);
		
		//tracematch for intercepting calls from a caller which is
		//not the synchronized map/collection instance 
		tracematch(Object orig, Object sync, Object caller) {
			
			sym sync after returning(sync): createSync(orig);
			
			sym asyncCall before: (call(* Collection+.*(..)) || call(* Map+.*(..))) && target(orig) && this(caller);			

			sync asyncCall {
				if(caller!=sync) {
					if(System.getProperty("TMTEST_ACTIVE")!=null) {
						throw new IllegalStateException("Collection "+System.identityHashCode(orig)+
							" was synchronized. Use instance "+System.identityHashCode(sync)+" instead!");
					}
				}
			}
			
		}
				
		//tracematch for intercepting calls from a static context
		tracematch(Object orig, Object sync) {
			
			sym sync after returning(sync): createSync(orig);
			
			sym asyncStaticCall before: (call(* Collection+.*(..)) || call(* Map+.*(..))) && target(orig) && !this(Object);			

			sync asyncStaticCall {
				if(System.getProperty("TMTEST_ACTIVE")!=null) {
					throw new IllegalStateException("Collection "+System.identityHashCode(orig)+
						" was synchronized. Use instance "+System.identityHashCode(sync)+" instead!");
				}
			}
			
		}
		
	}
	
	public static void main(String[] args) {
		
		final Collection c = new ArrayList();
		Collection sc = Collections.synchronizedCollection(c);
	
		//this is an ok call
		sc.add("bla");
		System.err.println("added bla");
		
		//illegal call from static context
		c.clear();
		
		new Runnable() {
			public void run() {
				//illegal call from an instance context
				c.clear();
			}
		}.run();

		//safe
		final Collection c2 = new ArrayList();
		c2.add("bla");
		Collection sc2 = Collections.synchronizedCollection(c2);
		sc2.add("bla");
	}

			
}