On 12/5/11 3:50 PM, Julien Vermillard wrote:
since it's a ConcurrentLinkedQueue it could be a perf killer to do a
.size() from the oracle javadoc : ""Beware that, unlike in most
collections, the size method is NOT a constant-time operation. Because
of the asynchronous nature of these queues, determining the current
number of elements requires a traversal of the elements.""
Damn right...
What about using a read/write lock instead of a synchronized block ? The
problem with the synchornized block on queue is that we must still
protect the queue when it's being written with another synchronized
block, when if we use a read/write lock, we can allow parallel writes in
the queue, but once it comes to write in the channel, we acquire a write
lock and the queue is now protected. Something like :
private final ReadWriteLock lock = new ReentrantReadWriteLock();
private final Lock queueReadLock = lock.readLock();
private final Lock queueWriteLock= lock.writeLock();
...
try {
queueWriteLock.lock();
do {
WriteRequest wreq = queue.peek();
if (wreq == null) {
break;
}
...
} while (!queue.isEmpty());
} finally {
queueWriteLock.unlock();
}
...
public WriteRequest enqueueWriteRequest(Object message) {
DefaultWriteRequest request = new DefaultWriteRequest(message);
try {
queueReadLock().lock()
writeQueue.add(request);
} finally {
queueReadLock.unlock();
}
}
-- Regards, Cordialement, Emmanuel Lécharny www.iktek.com
