Potential infinite waiting at JMXConnection#createConnection
Martijn Verburg
martijnverburg at gmail.com
Tue May 5 11:57:41 UTC 2015
Hi Yuji,
A good place to start would be to provide some unit tests and/or client
code showcasing the behaviour you are describing.
Cheers,
Martijn
On 4 May 2015 at 19:55, KUBOTA Yuji <kubota.yuji at gmail.com> wrote:
> Hi all,
>
> My apologies for the re-post and wrong link, the link [1] of the
> initial post is not correctly.
> The correct link is below.
>
> [1]:
> http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/c5b5d9045728/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java#l227
>
> The users cant specify the timeout by
> sun.rmi.transport.tcp.responseTimeout, e.g. the second flush() of
> TCPChannel#createConnection [2].
> However, the first flush() [1] is not affected by
> sun.rmi.transport.tcp.responseTimeout, and will be the (potential)
> infinite waiting by bad luck.
>
> [2]:
> http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/c5b5d9045728/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java#l296
>
> Thanks,
> Yuji
>
> 2015-05-05 1:19 GMT+09:00 KUBOTA Yuji <kubota.yuji at gmail.com>:
> > Hi all,
> >
> > I want to contribute this issue.
> > If there are a problem about this patch or a better way for openjdk
> > community, please advise me.
> >
> > Thanks for
> >
> > 2015-04-22 0:31 GMT+09:00 KUBOTA Yuji <kubota.yuji at gmail.com>:
> >> Hi all,
> >>
> >> I found an infinite waiting at TCPChannel#createConnection.
> >> This method flushes the DataOutputStream without the socket timeout
> settings
> >> when choose stream protocol [1].
> >>
> >> If connection lost (the destination server do no return response)
> >> during the flush,
> >> this method has possibilities to take long time beyond the expectations
> >> at java.net.SocketInputStream.socketRead0 as following stack trace.
> >>
> >> stack trace :
> >> at
> java.net.SocketInputStream.socketRead0(SocketInputStream.java)
> >> at java.net.SocketInputStream.read(SocketInputStream.java)
> >> at java.net.SocketInputStream.read(SocketInputStream.java)
> >> at sun.security.ssl.InputRecord.readFully(InputRecord.java)
> >> at sun.security.ssl.InputRecord.read(InputRecord.java)
> >> at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java)
> >> at
> sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java)
> >> at
> sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java)
> >> at sun.security.ssl.AppOutputStream.write(AppOutputStream.java)
> >> at
> java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java)
> >> at java.io.BufferedOutputStream.flush(BufferedOutputStream.java)
> >> at java.io.DataOutputStream.flush(DataOutputStream.java)
> >> at
> sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java)
> >> at
> sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java)
> >> at sun.rmi.server.UnicastRef.invoke(UnicastRef.java)
> >> at javax.management.remote.rmi.RMIServerImpl_Stub.newClient
> >> at
> javax.management.remote.rmi.RMIConnector.getConnection(RMIConnector.java)
> >> at
> javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java)
> >> at
> javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java)
> >>
> >> When create connection, we cannot set the timeout by properties.
> >> Therefore, JMX sets the default value of SO_TIMEOUT, i.e., infinite.
> >> So I wrote a patch to fix this infinite waiting by using
> property-configured value:
> >> sun.rmi.transport.tcp.responseTimeout.
> >>
> >> Please review this patch. :)
> >>
> >> Note: My OCA has been processed a few hour ago, so my name may take a
> >> short time to
> >> appear on the OCA signatories page.
> >>
> >> Thanks,
> >> KUBOTA Yuji
> >>
> >> [1]:
> http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/c5b5d9045728/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPConnection.java#l191
> >>
> >> diff --git
> a/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java
> >> b/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java
> >> --- a/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java
> >> +++ b/src/java.rmi/share/classes/sun/rmi/transport/tcp/TCPChannel.java
> >> @@ -222,20 +222,34 @@
> >> // choose protocol (single op if not reusable socket)
> >> if (!conn.isReusable()) {
> >> out.writeByte(TransportConstants.SingleOpProtocol);
> >> } else {
> >> out.writeByte(TransportConstants.StreamProtocol);
> >> +
> >> + int usableSoTimeout = 0;
> >> + try {
> >> + /*
> >> + * If socket factory had set a zero timeout on
> its own,
> >> + * then set the property-configured value to
> prevent
> >> + * an infinite waiting.
> >> + */
> >> + usableSoTimeout = sock.getSoTimeout();
> >> + if (usableSoTimeout == 0) {
> >> + usableSoTimeout = responseTimeout;
> >> + }
> >> + sock.setSoTimeout(usableSoTimeout);
> >> + } catch (Exception e) {
> >> + // if we fail to set this, ignore and proceed
> anyway
> >> + }
> >> out.flush();
> >>
> >> /*
> >> * Set socket read timeout to configured value for
> JRMP
> >> * connection handshake; this also serves to guard
> against
> >> * non-JRMP servers that do not respond (see
> 4322806).
> >> */
> >> - int originalSoTimeout = 0;
> >> try {
> >> - originalSoTimeout = sock.getSoTimeout();
> >> sock.setSoTimeout(handshakeTimeout);
> >> } catch (Exception e) {
> >> // if we fail to set this, ignore and proceed
> anyway
> >> }
> >>
> >> @@ -279,18 +293,11 @@
> >> * connection. NOTE: this timeout, if configured
> to a
> >> * finite duration, places an upper bound on the
> time
> >> * that a remote method call is permitted to
> execute.
> >> */
> >> try {
> >> - /*
> >> - * If socket factory had set a non-zero
> timeout on its
> >> - * own, then restore it instead of using the
> property-
> >> - * configured value.
> >> - */
> >> - sock.setSoTimeout((originalSoTimeout != 0 ?
> >> - originalSoTimeout :
> >> - responseTimeout));
> >> + sock.setSoTimeout(usableSoTimeout);
> >> } catch (Exception e) {
> >> // if we fail to set this, ignore and proceed
> anyway
> >> }
> >>
> >> out.flush();
>
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