Jetty-12 creates two instances of ArrayByteBufferPool

[lachlan-roberts]

Jetty version(s)
12

How to reproduce?

java -jar $JETTY_HOME/start.jar --add-modules=server
java -jar $JETTY_HOME/start.jar jetty.server.dumpAfterStart=true

Then in the dump you can see two different instances of ArrayByteBufferPool.
Unless there is a specific reason why we need 2 I think we should be sharing one for the entire server.

...
|     +> qtp92150540-25 TIMED_WAITING tid=25 prio=5 IDLE
|     +> qtp92150540-31 TIMED_WAITING tid=31 prio=5 IDLE
+= oejut.ScheduledExecutorScheduler@3444d69d{STARTED} - STARTED
+- org.eclipse.jetty.io.ArrayByteBufferPool@3911c2a7{min=0,max=65536,buckets=16,heap=0/521142272,direct=0/521142272}
|  +> direct size=16
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@15c43bd9{capacity=4096,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@3d74bf60{capacity=8192,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@4f209819{capacity=12288,inuse=0(0%)}
...
+~ org.eclipse.jetty.util.resource.FileSystemPool@16ec5519
+- org.eclipse.jetty.io.ArrayByteBufferPool@2f7298b{min=0,max=65536,buckets=16,heap=0/521142272,direct=0/521142272}
|  +> direct size=16
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@6a192cfe{capacity=4096,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@5119fb47{capacity=8192,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@7193666c{capacity=12288,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@20deea7f{capacity=16384,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@3835c46{capacity=20480,inuse=0(0%)}
|  |  +> org.eclipse.jetty.io.ArrayByteBufferPool$RetainedBucket@1dde4cb2{capacity=24576,inuse=0(0%)}
...