Sunday, 31 July 2005 20:39
When using Java Iterator with a Java collection component in thread-safe way, we have to synchronize that component, not the iterator itslef.
example:
Map m = Collections.synchronizedMap(new HashMap());
...
Set s = m.keySet(); // Needn't be in synchronized block
...
synchronized(m) { // Synchronizing on m, not s!
Iterator i = s.iterator(); // Must be in synchronized block
while (i.hasNext())
foo(i.next());
}
