Re: [jetty-dev] NIO inefficiency?

[Viktor Szathmary <phraktle@xxxxxxxxx>]

Hi Simone,

On Friday, August 9, 2013 at 3:22 PM, Simone Bordet wrote:

On Fri, Aug 9, 2013 at 3:13 PM, Viktor Szathmary <phraktle@xxxxxxxxx> wrote:

Wouldn't the following in HttpOutput.close do a write w/ empty buffer

explicitly?

if (BufferUtil.hasContent(_aggregate))

_channel.write(_aggregate, !_channel.getResponse().isIncluding());

else

_channel.write(BufferUtil.EMPTY_BUFFER,

!_channel.getResponse().isIncluding());

No. Member "_channel" is Jetty's HttpChannel, not a SocketChannel.

If you follow all the way through, you'll see we skip SocketChannel

writes for empty buffers.

I see both of these paths below taken (on v9.0.4), which seems to imply that there are two writes to the SocketChannel: first on flush followed by one on close. You are also right – the buffer is not empty then (via HttpOutput.close:117, so BufferUtil.hasContent(_aggregate) == true)

But should the _aggregate not be empty already? We have just flushed to the NIO buffer…

sun.nio.ch.SocketChannelImpl.write:496

org.eclipse.jetty.io.ChannelEndPoint.flush:167

org.eclipse.jetty.io.WriteFlusher.write:335

org.eclipse.jetty.io.AbstractEndPoint.write:125

org.eclipse.jetty.server.HttpConnection$CommitCallback.process:683

org.eclipse.jetty.util.IteratingCallback.iterate:79

org.eclipse.jetty.server.HttpConnection.send:344

org.eclipse.jetty.server.HttpChannel.sendResponse:630

org.eclipse.jetty.server.HttpChannel.write:665

org.eclipse.jetty.server.HttpOutput.flush:151

java.util.zip.DeflaterOutputStream.flush:282

org.eclipse.jetty.servlets.gzip.AbstractCompressedStream.flush:125

sun.nio.cs.StreamEncoder.implFlush:297

sun.nio.cs.StreamEncoder.flush:141

java.io.OutputStreamWriter.flush:229

java.io.PrintWriter.flush:320

org.eclipse.jetty.servlets.gzip.CompressedResponseWrapper.finish:343

org.eclipse.jetty.servlets.GzipFilter.doFilter:364

and

sun.nio.ch.SocketChannelImpl.write:463

org.eclipse.jetty.io.AbstractEndPoint.write:125

org.eclipse.jetty.server.HttpConnection$ContentCallback.process:781

org.eclipse.jetty.util.IteratingCallback.iterate:79

org.eclipse.jetty.server.HttpConnection.send:351

org.eclipse.jetty.server.HttpChannel.sendResponse:635

org.eclipse.jetty.server.HttpChannel.write:665

org.eclipse.jetty.server.HttpOutput.close:117

java.util.zip.DeflaterOutputStream.close:241

org.eclipse.jetty.servlets.gzip.AbstractCompressedStream.finish:191

org.eclipse.jetty.servlets.GzipFilter$1$1.finish:500

org.eclipse.jetty.servlets.gzip.CompressedResponseWrapper.finish:345

org.eclipse.jetty.servlets.GzipFilter.doFilter:364

Thanks,

  Viktor