protected SortedMap _sortedWaitingWriters=new SyncSortedMap(new TreeMap(new Comparator()
    {
      public int
	compare(Object o1, Object o2)
      {
	return ((Thread)o2).getPriority()-((Thread)o1).getPriority();
      }
    }),
							    new Mutex())

synchronized (this){...;this.wait();...} becomes synchronized(lock){...;lock.wait();...}

you must synchronize on lock to wake up a thread - this ensures that:

1. the thread is actually wait()-ing
2. you own the monitor

_writerQueue is synched separately...

a thread can release() and try to notify() a waiting thread - if the
thread is not yet waiting the notify will wait.

put in an assert to check that the thread is not already in the writer
list...


1, wait, loop(try(2)catch(3,next-writer, next-reader))

end-wait,..., next-reader-or-writer


inline endWrite() and maybe signalNextWriter() (notifyNextWriter())


maybe have a look at Doug's src for 1.5


explain why this lock is so important


How about keeping a final array of MAX_THREAD objects and queueing
each writer thread against the corresponding priority object and
incrementing a counter. The Object would contain a counter and
synchronised incr/decr/getCount() methods.

contending threads would be split MAX-MIN_THREAD ways - more efficient
than normal lock !!

wait()-ing and notify()-ing an object would only involve synching on
the lock object...


FEATURE TABLE
--------------

Impl                             Persistant? Evicting? Replicating? Whole/Delta? 1->all/n | author - shared-store?
--------------------------------|-----------|---------|------------|------------|-----
WADI                            |           |         |    NYI     |            |         | jules
JETTY DSM                       |           |         |     Y      |     D      |         | jules
JETTY DSM/JBoss                 |           |         |            |            |         | jules
TC4/JBoss                       |           |         |            |            |         | ??
TC5 PersistentManager           |     Y     |    Y    |            |            |         | Kief                       - use store as backup
TC5 DeltaManager                |           |         |            |            |         | filip,craig,jean-francois
TC5 SimpleTcpReplicationManager |           |         |            |            |         | filip, bela
????                            |           |         |     Y      |            |         | rob block