Fix for finagle-chirper locking problem

[farquet]

This solves #164. Throughput is fairly close to the previous version, but seems to be slightly better on all VMs I tested.

[farquet]

However, I hit #106 a lot locally on my MacBook. So this issue was apparently not fully resolved (cc @Fithos ).

It is independent of the changes of this PR though, because I hit the problem as often on this commit and on the previous one.
This occurs in almost all executions of 90 iterations (default). Around once per execution.

Resetting master, feed map size: 5000
Exception in thread "Thread-351" Failure(Address already in use: localhost/127.0.0.1:49954 at remote address: localhost/127.0.0.1:49954. Remote Info: Not Available, flags=0x08) with RemoteInfo -> Upstream Address: Not Available, Upstream id: Not Available, Downstream Address: localhost/127.0.0.1:49954, Downstream label: :49954, Trace Id: 06b6367f50db45df.06b6367f50db45df<:06b6367f50db45df with Service -> :49954
Caused by: com.twitter.finagle.ConnectionFailedException: Address already in use: localhost/127.0.0.1:49954 at remote address: localhost/127.0.0.1:49954. Remote Info: Not Available
	at com.twitter.finagle.netty4.ConnectionBuilder$$anon$1.operationComplete(ConnectionBuilder.scala:99)
	at com.twitter.finagle.netty4.ConnectionBuilder$$anon$1.operationComplete(ConnectionBuilder.scala:78)
	at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511)
	at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:485)
	at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424)
	at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:121)
	at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:290)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1366)
	at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:545)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:530)
	at io.netty.channel.ChannelDuplexHandler.connect(ChannelDuplexHandler.java:50)
	at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:545)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:530)
	at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.connect(CombinedChannelDuplexHandler.java:497)
	at io.netty.channel.ChannelOutboundHandlerAdapter.connect(ChannelOutboundHandlerAdapter.java:47)
	at io.netty.channel.CombinedChannelDuplexHandler.connect(CombinedChannelDuplexHandler.java:298)
	at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:545)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:530)
	at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:512)
	at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:1024)
	at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:259)
	at io.netty.bootstrap.Bootstrap$3.run(Bootstrap.java:252)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:466)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:897)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)
Caused by: io.netty.channel.AbstractChannel$AnnotatedSocketException: Address already in use: localhost/127.0.0.1:49954
	at sun.nio.ch.Net.connect0(Native Method)
	at sun.nio.ch.Net.connect(Net.java:454)
	at sun.nio.ch.Net.connect(Net.java:446)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
	at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:83)
	at io.netty.util.internal.SocketUtils$3.run(SocketUtils.java:80)
	at java.security.AccessController.doPrivileged(Native Method)
	at io.netty.util.internal.SocketUtils.connect(SocketUtils.java:80)
	at io.netty.channel.socket.nio.NioSocketChannel.doConnect(NioSocketChannel.java:312)
	at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.connect(AbstractNioChannel.java:254)
	... 24 more
Caused by: java.net.BindException: Address already in use
	... 34 more

The port already in use is either the master port or one of the cache ports depending on the execution.

[tkrodriguez]

Can't you also drop the lock object as well?

[axel22]

The lock object seems like it's not used, and can be removed.

[axel22]

Technically speaking, there is a race condition in accessing the cache, but that's probably not very important for the benchmark overall.