In message <200909130807.n8d87vgb001...@d12av01.megacenter.de.ibm.com>, Mark Hi
ndess writes:
>
>
> In message <200909112249.n8bmnnzb016...@d06av04.portsmouth.uk.ibm.com>,
> Mark Hindess writes:
> >
> > In message <4aaacfce.5090...@gmail.com>, Tim Ellison writes:
> > >
> > > On 11/Sep/2009 23:13, Mark Hindess wrote:
> > > > I am trying to work through the JDWP java6 branch test failures
> > > > (so is Oliver). I see quite a lot of intermittent failures on
> > > > Linux[0]. I think they are mostly caused by failures at the time
> > > > when the socket used for synchronising the debuggee/debugger
> > > > is being closed. The sychronisation is simply one end calling
> > > > "DataOutputStream.writeUTF("continue"); DataOutputStream.flush();" and
> > > > the other end trying to do DataInputStream.readUTF().
> > > >
> > > > When running on the RI, the tests pass consistently. Strace of the RI
> > > > shows the writeUTF making syscalls like:
> > > >
> > > > send(10, "\0\10continue", 10, 0) = 10
> > > > close(10) = 0
> > > >
> > > > where as our implementation does:
> > > >
> > > > send(58, "\0\10", 2, 0) = 2
> > > > send(58, "continue", 8, 0) = 8
> > > > close(58) = 0
> > > >
> > > > Examining the packet dump for the socket shows a packet containing the
> > > > length ('\0\10') followed by a RST packet as the socket is closed but n
> o
> > > > packet containing the "continue" text. So, the "continue" is lost with
> > > > the result that the other end reads the length then loops waiting for
> > > > the message until the test timeout is reached.[1]
> > > >
> > > > I think it would probably be useful if we fixed our implementation to
> > > > have the same behaviour as the RI.
> > >
> > > +1
> > >
> > > I'm happy to take a look at that if you want.
> >
> > Well, just doing the obvious thing of re-writing writeUTF by moving
> > the code from writeUTFBytes (and making utfBytes two bytes larger to
> > insert the length) into writeUTF seems to fix at least some of the
> > intermittent failures for me. (I've appended the patch but it doesn't
> > really show what I did particularly well.) But I've not run the luni
> > tests on this change yet and I need sleep now.
>
> I've done a few jdwp test runs now and this approach definitely improves
> stability quite a bit. Unfortunately ObjectOutputStream uses the
> writeUTFBytes method that my patch removes so it needs more work. I
> wonder whether the ObjectOutputStream implementation suffers from the
> same issue.
Also why does writeUTFBytes(String, long) take a long argument when the
implementation is restricted to int (by the int-sized utfBytes output
buffer)?
-Mark
> > And I still want to figure out why the test framework missed the close.
> >
> > Regards,
> > Mark.
> >
> > > > Regards,
> > > > Mark.
> > > >
> > > > [0] I'm using org.apache.harmony.jpda.tests.jdwp.MultiSession.RefTypeID
> Te
> > st
> > > > for testing but there are plenty of intermittently failing tests to
> > > > choose from.
> > > >
> > > > [1] I wonder why doesn't it see the socket close and bail out? This is
> > > > probably another bug (perhaps with the framework).
> >
> > Index: modules/luni/src/main/java/java/io/DataOutputStream.java
> > ===================================================================
> > --- modules/luni/src/main/java/java/io/DataOutputStream.java (revisi
> on 81373
> > 9)
> > +++ modules/luni/src/main/java/java/io/DataOutputStream.java (workin
> g copy)
> > @@ -314,30 +314,12 @@
> > if (utfCount > 65535) {
> > throw new UTFDataFormatException(Msg.getString("K0068")); //$N
> ON
> > -NLS-1$
> > }
> > - writeShort((int) utfCount);
> > - writeUTFBytes(str, utfCount);
> > - }
> > -
> > - long countUTFBytes(String str) {
> > - int utfCount = 0, length = str.length();
> > - for (int i = 0; i < length; i++) {
> > - int charValue = str.charAt(i);
> > - if (charValue > 0 && charValue <= 127) {
> > - utfCount++;
> > - } else if (charValue <= 2047) {
> > - utfCount += 2;
> > - } else {
> > - utfCount += 3;
> > - }
> > - }
> > - return utfCount;
> > - }
> > -
> > - void writeUTFBytes(String str, long count) throws IOException {
> > - int size = (int) count;
> > + int size = (int) utfCount;
> > int length = str.length();
> > - byte[] utfBytes = new byte[size];
> > + byte[] utfBytes = new byte[size+2];
> > int utfIndex = 0;
> > + utfBytes[utfIndex++] = (byte) (size >> 8);
> > + utfBytes[utfIndex++] = (byte) size;
> > for (int i = 0; i < length; i++) {
> > int charValue = str.charAt(i);
> > if (charValue > 0 && charValue <= 127) {
> > @@ -353,4 +335,19 @@
> > }
> > write(utfBytes, 0, utfIndex);
> > }
> > +
> > + long countUTFBytes(String str) {
> > + int utfCount = 0, length = str.length();
> > + for (int i = 0; i < length; i++) {
> > + int charValue = str.charAt(i);
> > + if (charValue > 0 && charValue <= 127) {
> > + utfCount++;
> > + } else if (charValue <= 2047) {
> > + utfCount += 2;
> > + } else {
> > + utfCount += 3;
> > + }
> > + }
> > + return utfCount;
> > + }
> > }
> >
>
