Hello,
I think I came across a small (and mostly harmless) problem in
HTablePool.getTable() code:
1 public HTableInterface getTable(String tableName) {
2 LinkedList<HTableInterface> queue = tables.get(tableName);
3 if(queue == null) {
4 queue = new LinkedList<HTableInterface>();
5 tables.put(tableName, queue);
6 return createHTable(tableName);
7 }
8 HTableInterface table;
9 synchronized(queue) {
10 table = queue.poll();
11 }
12 if(table == null) {
13 return createHTable(tableName);
14 }
15 return table;
16 }
Considering that this method is invoked by multiple threads, it may happen
that while 'queue == null' is true in line 3, it is possible to have a queue
mapped to that name into the tables map when line 5 is executed.
However, I don't think it will cause any harm because the overwritten queue
will eventually be garbage-collected. :-)
Should I write a patch for it?
If so, I considered two approaches:
1. sync the *tables* attribute from lines 3 to 7.
2. or consider the interface ConcurrentMap so we could use putIfAbsent()
I prefer the second. What do you think?
Thanks,
Guilherme
