At the moment I am doing some more work on evaluating tracematches ahead-of-time. One tracematch patten that we use in our benchmarks we called ASyncIter, a simplified version of which looks as follows:
tracematch(Collection c) {
sym sync after returning:
call(* Collections.synchr*(..)) && args(c);
sym iter before:
call(* Collection.iterator()) && target(c);
sync iter {
if(!Thread.holdsLock(c))
error(``Have to synchronize iterator at ''+thisJoinPoint);
}
}
This tracematch reports an error if you create a synchronized collection and then iterate over this collection without holding a lock on the collection object. According to the JDK javadoc this is forbidden as it can lead to a race condition. One has to use synchronized collections as follows:
