Looks good! Thanks for making the updates.

Interestingly, sun/rmi/server/LoaderHandler.java has a couple methods that use Class[] as a parameter (loadProxyClass, loadProxyInterfaces), but which don't generate rawtypes warnings. I may investigate this at some point.

Anyway, I think this has gone through enough rounds of review. Go ahead and push. Thanks again.

s'marks

On 3/1/12 9:48 AM, Kurchi Hazra wrote:
Hi Stuart,

Please find an updated webrev here:
http://cr.openjdk.java.net/~khazra/7146763/webrev.05/


Thanks,
Kurchi


On 2/28/2012 4:32 PM, Stuart Marks wrote:
Right, I remember this issue. In the email you referenced [1] Max said "I
remember we agreed on several rules" which were basically to use diamond if
it's an initializer at the point of declaration. I guess it depends on who
"we" are. I recall that discussion occurring with the security team (of which
Max is a member) so I thought "we" meant the security team. (Perhaps the same
approach was applied to networking changes as well.) However, I had also
applied changesets outside the security area that used diamond much more
extensively. So, unfortunately, different areas of the code are using
different conventions.

Personally I don't see any problem with using diamond in initializers,
assignment statements (separate from the declaration), and return statements.
I wrote a blog about this: [2].

For RMI at least, I'd prefer to see diamond used in the places that I
recommended.

s'marks


[1] http://mail.openjdk.java.net/pipermail/net-dev/2011-September/003547.html

[2] http://stuartmarks.wordpress.com/2011/04/29/when-should-diamond-be-used/



On 2/28/12 3:22 PM, Kurchi Hazra wrote:
Hi Stuart,

Thanks for your comments. Regarding the use of diamonds, I remember this issue
coming up when i was
fixing networking warnings. See :
http://mail.openjdk.java.net/pipermail/net-dev/2011-September/003547.html

We had stuck to using diamond only when both declaration and assignment were on
the same line.

- Kurchi



On 2/28/2012 3:08 PM, Stuart Marks wrote:
Hi Kurchi,

I looked at the rest of the files. Pretty good, taking on diamond,
multi-catch, and try-with-resources as well!

I have several comments. Mostly nitpicks, but a few items worthy of some
discussion, but overall still minor changes, I think.


com/sun/rmi/rmid/ExecOptionPermission.java:

- L234 can use diamond


com/sun/rmi/rmid/ExecPermission.java:

- L238 can use diamond


sun/rmi/rmic/Main.java:

- L186, L194 can use diamond

- At L83, the type of environmentClass can be changed to Class<? extends
BatchEnvironment>. The assignment to environmentClass at L426 would need to
be replaced with a call to BatchEnvironment.class.asSubclass() in order to
get the types to work out. (The call to isAssignableFrom() should remain
since it's checking against the current value of environmentClass, not
BatchEnvironment.class.) Then, the Constructor declaration at L498 should
change to Constructor<? extends BatchEnvironment> and then the cast at L499
can go away.


sun/rmi/rmic/RMIGenerator.java:

- L686 is now short enough to be joined to the previous line.


sun/rmi/server/ActivatableRef.java:

- L377 indentation should shift to match with previous line.


sun/rmi/transport/ConnectionInputStream.java:

- L91-100: Ugh! The addition of generics here makes this really bad. Not your
fault; you've added generics in the precise, minimal way. But this code just
cries out to be simplified. This is usually out of bounds for warnings
changes but since I'm closer to this code I'd say to go ahead with it. Go
ahead and replace this with an enhanced for loop and get rid of some
intermediate locals:

void registerRefs() throws IOException {
if (!incomingRefTable.isEmpty()) {
for (Map.Entry<Endpoint, List<LiveRef>> entry :
incomingRefTable.entrySet()) {
DGCClient.registerRefs(entry.getKey(), entry.getValue());
}
}
}


sun/rmi/transport/DGCClient.java:

- L285, L606, L611: use diamond
- L690: remove redundant parentheses


sun/rmi/transport/StreamRemoteCall.java:

I think it would be better to put the comment about "fall through" at line
253 or 256 instead of at the top of the method (L201) which is pretty far
away. The point here is that exceptionReceivedFromServer() always throws an
exception -- well, it should -- and thus this case cannot fall through to the
default case. This isn't obvious, so I'd prefer to see a comment somewhere
near here instead of at the top of the method.

(One might ask, can't the compiler determine that the method always throws an
exception, which means the case can't fall through, and thus shut off the
fall through warning? Well, the method in question is protected, so a
subclass might override the method and not always throw an exception. That
would be a bug, but the compiler can't tell that. (Tom Hawtin suggests that
it's bad style for a method always to throw an exception, and instead that it
should return an exception that the caller is responsible for throwing. This
would make the code clearer. (This has come up in prior warnings cleanups;
see [1]. (Changing this is usually out of scope for warnings cleanup, though.
I'm tempted to ask you to change this, but some tests are looking for
exceptionReceivedFromServer in stack traces and it's probably not worth the
risk of messing them up. (Yes, I'm using too many nested parentheses.)))))

[1]
http://mail.openjdk.java.net/pipermail/core-libs-dev/2011-December/008524.html


sun/rmi/transport/proxy/RMIMasterSocketFactory.java:

- L99 can use diamond

- L240, hmm, refactoring to use try-with-resources. Note that the original
code leaks the socket if read() throws IOException! Overall using t-w-r is
good, and fixes this bug, but it can be improved further. Probably move the
"trying with factory" log message outside of the try block at L230, and turn
that try block into the try-with-resources, instead of adding a nested t-w-r.
The semantics are almost the same, as the close() is performed before any
IOException is caught. (This kind of change is usually out of bounds for
warnings changes but, as above, since I'm closer to this code I'd say to go
ahead with it.)

Thanks,

s'marks

On 2/24/12 2:24 PM, Kurchi Hazra wrote:
Hi,

Please ignore the previous webrev and see this instead:
http://cr.openjdk.java.net/~khazra/7146763/webrev.03/

This has Stuart's suggestion integrated correctly. In addition, I realized
that
make/sun/rmi/rmic/Makefile is not yet ready to have the JAVAC_WARNINGS_FATAL
flag turned on, since it implicitly also builds files from sun/tools with
more
then 400
warnings in them. The change in this file has now been removed.

- Kurchi



On 2/24/2012 11:01 AM, Kurchi Hazra wrote:
Hi Stuart,

Thanks for the detailed explanation. Here is an updated webrev:
http://cr.openjdk.java.net/~khazra/7146763/webrev.02/


- Kurchi

On 2/24/2012 12:54 AM, Stuart Marks wrote:
On 2/22/12 1:25 PM, Kurchi Hazra wrote:
On 2/22/2012 10:01 AM, Rémi Forax wrote:
Hi Kurchi, hi all,

in ReliableLog, you can get ride of the @SupressWarnings,
getLogClassConstructor should return a Constructor<?> and not a
Constructor<?
extends LogFile>,
the field logClassConstructor should be typed Constructor<?> and
in openLogFile, the log should be constructed like this

log = (logClassConstructor == null ?
new LogFile(logName, "rw") :
(LogFile)logClassConstructor.newInstance(logName, "rw"));

The idea is that a cast on a LogFile is typesafe but not a cast on a
Constructor<? extends LogFile>.

If I change the return type to Constructor<?>, I get the following error:
../../../../src/share/classes/sun/rmi/log/ReliableLog.java:122: error:
incompatible types
logClassConstructor = getLogClassConstructor();
^
required: Constructor<? extends LogFile>
found: Constructor<CAP#1>
where CAP#1 is a fresh type-variable:
CAP#1 extends Object from capture of ?
And the following warning:

../../../../src/share/classes/sun/rmi/log/ReliableLog.java:350: warning:
[unchecked] unchecked cast
cl.getConstructor(String.class, String.class);
^
required: Constructor<? extends LogFile>
found: Constructor<CAP#1>
where CAP#1 is a fresh type-variable:
CAP#1 extends Object from capture of ?


Thanks,
Kurchi

Hi Kurchi,

To implement Rémi's suggestion fully, you would also have to change the
type
of logClassConstructor to Contructor<?> near line 122, remove the cast of
cl.getConstructor() near line 350, and then add the cast to LogFile at the
call to newInstance() near line 546.

This works to get rid of the warnings and errors, but the declaration of
Constructor<?> is somewhat imprecise. The code checks to make sure that the
loaded class is a subclass of LogFile (that's what the isAssignableFrom
check is doing). Thus the type of the loaded class really should be Class<?
extends LogFile>, and correspondingly the logClassConstructor should be
Constructor<? extends LogFile>. That's how logClassConstructor is declared
now and it would be nice to keep it that way.

It turns out that Class.asSubclass() does this conversion without
generating
an unchecked warning. This internally does an isAssignableFrom() check and
casts to the right wildcarded type, so this can simplify the code in
getLogClassConstructor() somewhat as well. (Incidentally, asSubClass() has
@SuppressWarnings on its implementation.) I've appended some diffs below
(to
be applied on top of your most recent webrev) to show how this can be done.

The behavior is slightly different, as it throws ClassCastException (which
is caught by the catch clause below, emitting a log message) instead of
silently returning null. This is probably an improvement, since if the user
specifies the wrong class in the property name, the exception stack trace
should indicate what happened.

s'marks




diff -r 72d32fd57d89 src/share/classes/sun/rmi/log/ReliableLog.java
--- a/src/share/classes/sun/rmi/log/ReliableLog.java Fri Feb 24 00:01:53
2012 -0800
+++ b/src/share/classes/sun/rmi/log/ReliableLog.java Fri Feb 24 00:39:02
2012 -0800
@@ -330,9 +330,7 @@
* property a) can be loaded, b) is a subclass of LogFile, and c) has a
* public two-arg constructor (String, String); otherwise returns null.
**/
- @SuppressWarnings("unchecked")
- private static Constructor<? extends LogFile>
- getLogClassConstructor() {
+ private static Constructor<? extends LogFile> getLogClassConstructor() {

String logClassName = AccessController.doPrivileged(
new GetPropertyAction("sun.rmi.log.class"));
@@ -345,11 +343,9 @@
return ClassLoader.getSystemClassLoader();
}
});
- Class<?> cl = loader.loadClass(logClassName);
- if (LogFile.class.isAssignableFrom(cl)) {
- return (Constructor<? extends LogFile>)
- cl.getConstructor(String.class, String.class);
- }
+ Class<? extends LogFile> cl =
+ loader.loadClass(logClassName).asSubclass(LogFile.class);
+ return cl.getConstructor(String.class, String.class);
} catch (Exception e) {
System.err.println("Exception occurred:");
e.printStackTrace();






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