BELUGABEHR commented on a change in pull request #911: ZOOKEEPER-3365: Use
Concurrent HashMap in NettyServerCnxnFactory
URL: https://github.com/apache/zookeeper/pull/911#discussion_r275161201
##########
File path:
zookeeper-server/src/main/java/org/apache/zookeeper/server/NettyServerCnxnFactory.java
##########
@@ -512,44 +511,34 @@ public InetSocketAddress getLocalAddress() {
return localAddress;
}
- private void addCnxn(NettyServerCnxn cnxn) {
+ private void addCnxn(final NettyServerCnxn cnxn) {
cnxns.add(cnxn);
- synchronized (ipMap){
- InetAddress addr =
-
((InetSocketAddress)cnxn.getChannel().remoteAddress()).getAddress();
- Set<NettyServerCnxn> s = ipMap.get(addr);
- if (s == null) {
- s = new HashSet<>();
- ipMap.put(addr, s);
+ InetAddress addr =
+ ((InetSocketAddress)
cnxn.getChannel().remoteAddress()).getAddress();
+
+ ipMap.compute(addr, (a, cnxnSet) -> {
+ if (cnxnSet == null) {
+ cnxnSet = new HashSet<>();
}
- s.add(cnxn);
- }
+ cnxnSet.add(cnxn);
+ return cnxnSet;
+ });
}
-
+
void removeCnxnFromIpMap(NettyServerCnxn cnxn, InetAddress remoteAddress) {
- synchronized (ipMap) {
- Set<NettyServerCnxn> s = ipMap.get(remoteAddress);
- if (s != null) {
- s.remove(cnxn);
- if (s.isEmpty()) {
- ipMap.remove(remoteAddress);
- }
- return;
- }
+ ipMap.compute(remoteAddress, (addr, cnxnSet) -> {
+ if (cnxnSet == null) {
+ LOG.error("Unexpected remote address {} when removing cnxn {}",
+ remoteAddress, cnxn);
+ cnxnSet = Collections.emptySet();
}
- // Fallthrough and log errors outside the synchronized block
- LOG.error(
- "Unexpected null set for remote address {} when removing cnxn
{}",
- remoteAddress,
- cnxn);
+ cnxnSet.remove(cnxn);
Review comment:
Can you please share with me how you came to the conclusion that an error
would be thrown?
The
[remove](https://docs.oracle.com/javase/8/docs/api/java/util/Collection.html#remove-java.lang.Object-)
method returns a boolean to indicate if the removal was successful. I can
move the `remove` call into the check if there is concern that somehow it
could be the case that there is a Connection that isn't associated with an
address. I don't know how that would be the case. But could improve with:
```
if (cnxnSet == null || !cnxnSet.remove(cnxn)) {
```
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
