Hi Daniil,
Good find on this!
What does the actual spec say about the length of things and how they
may be split across multiple packets? Are we guaranteed that at most two
packets will be involved? What about for other things eg:
68 protected byte[] readJdwpString(DataInputStream ds) throws
IOException {
69 byte[] str = null;
70 int len = ds.readInt();
71 if (len > 0) {
72 str = new byte[len];
73 ds.read(str, 0, len);
74 }
might we get a short-read of the string if it is split across multiple
packets?
I'm wondering if all these reads should be loops, ensuring we read the
expected amount of data.
One further comment - not sure why we need the print out for when we do
read multiple packets? That would seem to be a debugging aid.
Thanks,
David
On 21/02/2018 10:14 AM, Daniil Titov wrote:
> Hi Serguei,
>
> A new version of the webrev that has these strings reformatted is at
> http://cr.openjdk.java.net/~dtitov/8170541/webrev.02/
>
> Thank you!
>
> Best regards,
>
> Daniil
>
> *From: *"serguei.spitsyn at oracle.com" <serguei.spitsyn at oracle.com>
> *Date: *Tuesday, February 20, 2018 at 3:00 PM
> *To: *Daniil Titov <daniil.x.titov at oracle.com>,
> "serviceability-dev at openjdk.java.net" <serviceability-dev at openjdk.java.net>
> *Subject: *Re: RFR 8170541:
> serviceability/jdwp/AllModulesCommandTest.java fails intermittently on
> Windows and Solaris
>
> Hi Daniil,
>
> Interesting issue...
> Thank you for finding to the root cause so quickly!
>
> The fix looks good.
> Could I ask you to reformat these lines to make the L54 shorter ?:
>
> 54 System.out.println("[" + getClass().getName() + "]
> Only " + bytesRead + " bytes of " + dataLength +
>
> 55 " were read in the first packet. Reading
> the rest...");
>
> Thanks,
> Serguei
>
>
> On 2/20/18 09:24, Daniil Titov wrote:
>
> Please review the changes that fix intermittent failure of
> serviceability/jdwp/AllModulesCommandTest.java test.
>
> The problem here is that for a large data the JDWP agent
> (socketTransport_writePacket() method in
> src/jdk.jdwp.agent/share/native/libdt_socket/socketTransport.c )
> sends 2 packets and in some cases only the first packet is received
> at the time when the test reads the reply from the JDWP agent. Since
> the test does not check that all data is received in the first
> packet the correlation between commands and replies became broken
> (the unread second packet is read by the next command and the reply
> for the next command is read by the next after next command and so on).
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8170541
>
> Webrev: http://cr.openjdk.java.net/~dtitov/8170541/webrev.01
>
> The tests ran successfully with Mach5.
>
> Best regards,
>
> Daniil
>
>
>