I've looked at FilePermission and its contained class FilePermissionCollection in which a Vector is used to store a set of permissions. The synchronization on the Vector has been observed to be a significant contention point for threads trying to perform actions which require file permission checks.

In general all Permission subclasses should avoid synchronization as much as possible.

I've filed this with a lower priority because in preliminary tests it is not immediately clear yet how much benefit can be obtained by eliminating the Permission synchronizations. These are being masked by more serious contention points elsewhere (e.g. PolicyFile). As improvements are made elsewhere, this particular aspect may need to be reprioritized as needed.

###@###.### 2002-11-21
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