On 21.06.2016 18:43, Aleksey Shipilev wrote:
On 06/21/2016 06:14 PM, Ivan Gerasimov wrote:
Hello!
The Pool has a member `map`, which is accessed from different threads,
thus the access is synchronized.
However, in some code paths (mostly in debug printing) it is accessed
without proper synchronization, which results in intermediate
ConcurrentModificationException when the debug output is turned on.
Would you please help review the fix?
BUGURL: https://bugs.openjdk.java.net/browse/JDK-8159822
WEBREV: http://cr.openjdk.java.net/~igerasim/8159822/00/webrev/
Missed synchronized-s:
154 private Connections getConnections(Object id) {
155 ConnectionsRef ref = map.get(id);
156 return (ref != null) ? ref.getConnections() : null;
157 }
...gets called via:
168 public void expire(long threshold) {
169 synchronized (map) {
...
179 }
180 expungeStaleConnections();
181 }
...and also via:
188 private static void expungeStaleConnections() {
...
192 Connections conns = releaseRef.getConnections();
...
203 }
204 }
But this is ConnectionsWeakRef.getConnections() not
Pool.getConnections(Object).
As far as I can see, an instance of ConnectionsWeakRef cannot be
accessed concurrently.
...
117 public PooledConnection getPooledConnection(Object id, long
timeout,
118 PooledConnectionFactory factory) throws NamingException {
...
// no synchronized prior here
127 expungeStaleConnections();
...
expungeStaleConnections() should be safe to call concurrently as long as
ReferenceQueue.poll() is thread-safe.
With kind regards,
Ivan
