On 03/12/2014 12:44 PM, Peter Levart wrote:
...currently. But if this method is (re)used in other contexts in the future, ...On 03/11/2014 05:46 PM, Vladimir Ivanov wrote:It depends on what you're trying to achieve. Whether you're trying to hide the internals even in situations where something goes wrong or you're trying to simplify debugging in case something goes wrong. But I guess not much can go wrong in this method as I suspect the passed-in 'array' can't be null, so it really doesn't matter.So all you're achieving by annotating prepend() method is that anyexception stack trace, in case it is thrown inside the prepend() method,will hide where it was thrown from. In case all LambdaForm frames leading to the prepend() method were also hidden, the exception would appear to be thrown from the invocation of the MH...Yes. Also, Thread.dumpStack() won't list it. Do you see any problem here?
Regards, PeterBest regards, Vladimir IvanovRegards, PeterBest regards, Vladimir IvanovRegards, PeterThere's not much value in it in this particular case, but I decided toreduce possible noise. Best regards, Vladimir Ivanov On 3/11/14 3:35 PM, Peter Levart wrote:Hi,Excuse my ignorant question: What is the purpose of @LambdaForm.Hiddenannotation? I suspect it has to do with hiding the call frames in stack traces that are part of LambdaForm invocation chain. In this case, method: private static Object[] prepend(Object elem, Object[] array)in MethodHandleImpl need not be annotated with this annotation, sinceit's call frame is not on stack when one of the target methods isexecuted. It's just a function used to calculate the argument of thecall. In fact, if prepend() ever throws exception (NPE in case array isnull?), It would be preferable that it's call frame is visible in thestack trace. Am I right or am I just talking nonsense? Regards, Peter On 03/11/2014 12:12 AM, Vladimir Ivanov wrote:John, Chris, thanks! Best regards, Vladimir Ivanov On 3/11/14 3:08 AM, Christian Thalinger wrote:Even better. On Mar 10, 2014, at 3:21 PM, Vladimir Ivanov <vladimir.x.iva...@oracle.com> wrote:Chris, thanks for the review. John suggested an elegant way to fix the problem - use asFixedArity. Updated fix: http://cr.openjdk.java.net/~vlivanov/8036117/webrev.01/ Best regards, Vladimir Ivanov On 3/8/14 4:51 AM, Christian Thalinger wrote:Seems good to me. I’d like to have another name for this method:+ private static Object invokeCustom(MethodHandle target, Object... args) throws Throwable { On Mar 4, 2014, at 12:00 PM, Vladimir Ivanov <vladimir.x.iva...@oracle.com> wrote:http://cr.openjdk.java.net/~vlivanov/8036117/webrev.00/ https://bugs.openjdk.java.net/browse/JDK-8036117 84 lines changed: 74 ins; 3 del; 7 mod I have to revert a cleanup I did for 8027827. MethodHandle.invokeWithArguments (and generic invocation) has unpleasant peculiarity in behavior when used with VarargsCollector. So, unfortunately, invokeWithArguments is not an option there.Looking at the API (excerpts from javadoc [1] [2]), the followingcondition doesn't hold in that case: "trailing parameter type of the caller is a reference type identicalto or assignable to the trailing parameter type of the adapter".Example: target.invokeWithArguments((Object[])args) => target.invoke((Object)o1,(Object)o2,(Object)o3) =/> target.invokeExact((Object)o1, (Object)o2, (Object[])o3) because Object !<: Object[].The fix is to skip unnecessary conversion when invoking a methodhandle and just do a pairwise type conversion. Testing: failing test case, nashorn w/ experimental features (octane) Thanks! Best regards, Vladimir Ivanov [1] MethodHandle.invokeWithArguments"Performs a variable arity invocation, ..., as if via an inexactinvokefrom a call site which mentions only the type Object, and whosearity is the length of the argument array." [2] MethodHandle.asVarargsCollector "When called with plain, inexact invoke, if the caller type is the same as the adapter, the adapter invokes the target as with invokeExact. (This is the normal behavior for invoke when types match.)Otherwise, if the caller and adapter arity are the same, and thetrailing parameter type of the caller is a reference type identical toor assignable to the trailing parameter type of the adapter, thearguments and return values are converted pairwise, as if by asType on a fixed arity method handle. Otherwise, the arities differ, or the adapter's trailing parameter type is not assignable from the corresponding caller type. In this case, the adapter replaces all trailing arguments from the original trailingargument position onward, by a new array of type arrayType, whoseelements comprise (in order) the replaced arguments." _______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev_______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev_______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev_______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev_______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev_______________________________________________ mlvm-dev mailing list mlvm-...@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
