ChunkedOutput race condition

[yajirobee]

Hi, I faced following error when I use ChunkedOutput for a response. It happens rarely.
I confirmed this happens with jersey 2.30.1 and jetty 9.4.27.v20200227.

ava.lang.IllegalStateException: s=OPEN,api=BLOCKED,sc=false,e=null
    at org.eclipse.jetty.server.HttpOutput.flush(HttpOutput.java:693)
    at org.glassfish.jersey.servlet.internal.ResponseWriter$NonCloseableOutputStreamWrapper.flush(ResponseWriter.java:306)
    at org.glassfish.jersey.message.internal.CommittingOutputStream.flush(CommittingOutputStream.java:263)
    at org.glassfish.jersey.message.internal.OutboundMessageContext.close(OutboundMessageContext.java:840)
    at org.glassfish.jersey.server.ContainerResponse.close(ContainerResponse.java:389)
    at org.glassfish.jersey.server.ChunkedOutput.flushQueue(ChunkedOutput.java:293)
    at org.glassfish.jersey.server.ChunkedOutput.setContext(ChunkedOutput.java:374)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:687)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:371)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:361)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:256)
...

It seems ContainerResponse#close is called outside of synchronized.

jersey/core-server/src/main/java/org/glassfish/jersey/server/ChunkedOutput.java

Line 293 in 4f7c616

responseContext.close();

I suspect the error happens when ContainerResponse#close is called while another thread is calling write.

[jansupol]

See related

[jansupol]

It's the HttpOutput which is synchronized. To me, it looks like the state changes from BLOCKING to BLOCKED, but not back in its synchronized block.

[jansupol]

HttpOutput really does not look thread safe, but it uses a bunch of synchronized blocks, which is confusing. I did not find any requirement on ServletOutputStream to be thread safe.