As regards 7u6 then changing java.net.Socket is too risky to do this
late in the release so I agree with your proposal to back-out
7105952. It's probably best to create a separate bug for this so that
the history is easy to understand. We can then use 7181793 to fix
java.net.Socket in jdk8 (and maybe a future 7u). To keep things simple
then I think the change to anti-delta the fix should be just that and
shouldn't be complicated at adding in a new test. The fix for 7105952
can introduce additional tests for this area.
I just logged a new CR to track the backout change Alan.
CR 7183209 : Backout 7105952 changes for jdk7u
Regards,
Sean.
On 11/07/12 11:43, Alan Bateman wrote:
On 10/07/2012 17:37, Seán Coffey wrote:
7105952 fix introduced some improvements for finalization strategy
around FileInputStream/FileOutputStream/RandomAccessFile.
However a recently reported issue has highlighted an issue where
memory heap can be consumed with SocketOutputStream objects as a
result of clients repeatedly calling socket.getOutputStream() on a
common socket (shared fd).
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7181793
Use of weakreferences was considered at 7105952 fix time but hard
references was considered a cleaner approach. Altering that design at
this late stage in the 7u6 plan could be risky and I'm suggesting
that we back out the 7105952 fix and concentrate on this area again
in 7u8.
The changeset is basically a backout of the original changeset plus
the addition of a new testcase (FDStrongReference.java)
http://cr.openjdk.java.net/~coffeys/webrev.7181793.jdk7u6/
<http://cr.openjdk.java.net/%7Ecoffeys/webrev.7181793.jdk7u6/>
Once reviewed, I'll ping 7u openjdk alias to start the critical fix
approval process.
regards,
Sean.
I think the changes for 7105952 are okay, it's just that they have
exposed an issue with java.net.Socket's getInputStream and
getOutputStream methods. These methods should really be changed to
that they only create one InputStream or OutputStream per Socket, not
a stream connected to the FileDescriptor for each call to
getInputStream or getOutputStream. Clearly changing this would involve
a subtle behavior change so it may be better off to keep that for a
major release (meaning 8).
On weak references then this isn't going to work for FileInputStream
or FileOutputStream because their finalize methods are specified to
close the stream. This topic has a long history with several attempts
to fix all the issues going back over several releases.
As regards 7u6 then changing java.net.Socket is too risky to do this
late in the release so I agree with your proposal to back-out
7105952. It's probably best to create a separate bug for this so that
the history is easy to understand. We can then use 7181793 to fix
java.net.Socket in jdk8 (and maybe a future 7u). To keep things simple
then I think the change to anti-delta the fix should be just that and
shouldn't be complicated at adding in a new test. The fix for 7105952
can introduce additional tests for this area.
-Alan.
