TyrusServletWriter.close can generate a WARNING level log event

[realityforge]

We see an error similar to this every few days. Eyeballing the code it seems that when TyrusServletWriter.close() is invoked it should set a flag to indicate whether it is in close operation and omit the WARNING log message if the flag was set but I don't have the background to determine whether this is a good solution. It would be nice to get this spurious log message out of our logs.

Note that this is probably the same error described in #519 but it does not seem to have been addressed.

java.util.concurrent.CancellationException
	at org.glassfish.grizzly.http.io.OutputBuffer$InternalWriteHandler.detach(OutputBuffer.java:1317)
	at org.glassfish.grizzly.http.io.OutputBuffer.endRequest(OutputBuffer.java:372)
	at org.glassfish.grizzly.http.server.Response.finish(Response.java:518)
	at org.glassfish.grizzly.http.server.HttpServerFilter.afterService(HttpServerFilter.java:373)
	at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:273)
	at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:95)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:260)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:177)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:109)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:88)
	at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:53)
	at org.glassfish.grizzly.filterchain.FilterChainContext$1.run(FilterChainContext.java:178)
	at org.glassfish.grizzly.filterchain.FilterChainContext.resume(FilterChainContext.java:202)
	at org.glassfish.grizzly.http.server.Response.resume(Response.java:1936)
	at org.apache.catalina.connector.Request.resumeAfterService(Request.java:3864)
	at org.apache.catalina.connector.WebConnectionImpl.close(WebConnectionImpl.java:139)
	at org.glassfish.tyrus.servlet.TyrusServletWriter.close(TyrusServletWriter.java:173)
	at org.glassfish.tyrus.core.ProtocolHandler.doClose(ProtocolHandler.java:582)
	at org.glassfish.tyrus.core.TyrusWebSocket.onClose(TyrusWebSocket.java:136)
	at org.glassfish.tyrus.core.ProtocolHandler.close(ProtocolHandler.java:469)
	at org.glassfish.tyrus.core.TyrusWebSocket.onClose(TyrusWebSocket.java:133)
	at org.glassfish.tyrus.core.TyrusWebSocketEngine$TyrusReadHandler.handle(TyrusWebSocketEngine.java:569)
	at org.glassfish.tyrus.servlet.TyrusHttpUpgradeHandler.onDataAvailable(TyrusHttpUpgradeHandler.java:173)
	at org.apache.catalina.connector.InputBuffer$ReadHandlerImpl.processDataAvailable(InputBuffer.java:438)
	at org.apache.catalina.connector.InputBuffer$ReadHandlerImpl.onDataAvailable(InputBuffer.java:399)
	at org.glassfish.grizzly.http.io.InputBuffer.invokeHandler(InputBuffer.java:1095)
	at org.glassfish.grizzly.http.io.InputBuffer.invokeHandlerOnProperThread(InputBuffer.java:1086)
	at org.glassfish.grizzly.http.io.InputBuffer.append(InputBuffer.java:969)
	at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:254)
	at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:95)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:260)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:177)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:109)
	at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:88)
	at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:53)
	at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:524)
	at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:89)
	at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:94)
	at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:33)
	at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:114)
	at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:569)
	at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:549)
	at java.lang.Thread.run(Thread.java:748)