On Wed, 2010-05-26 at 20:25 +0300, Pekka Enberg wrote: > Hi James, > > On Wed, 2010-05-26 at 13:29 +0300, Pekka Enberg wrote: > >> Yup, I don't quite get Arve's argument either. C code can interact > >> with Java code (and vice versa) just fine in userspace. > > On Wed, May 26, 2010 at 7:18 PM, James Bottomley > <James.Bottomley@xxxxxxx> wrote: > > This is an incorrect statement. It's possible for java to call C via > > the JNI, even though there are quite a few gotchas that mean not just > > *any* C code can do it (been there, tripped over some of them, although > > they were all ultimately ironed out). It's very difficult for C to call > > directly into Java without being specially coded because it involves > > creating and managing a JVM (so in general, arbitrary C code can't do > > this). The usual way we do C -> Java is process to process via some > > intermediary like RPC or Corba or SOAP (or even JSON) ... which gets > > very messy for a mobile device. > > Incorrect statement how exactly? A JVM can do mmap(), for example, > just fine through FileChannel.map() so there's no need for > heavy-weight RPC. Incorrect in that an arbitrary C application can't link to a java API. mmap and some other messaging (like signals) is just another form of IPC ... the list I gave wasn't exhaustive. > Furthermore, the whole discussion is moot anyway as > Android runs Dalvik which can be hacked to support whatever > communication mechanism is the best choice here. > > So can we drop the whole "we need to do it in kernel because Java is > hard" nonsense and concentrate on real issues? I've lost you. This argument seems to hinge on whether or not you believe that suspend in any form is a solution to the rogue app problem ... whether it's implemented in Java or C is an ancillary issue. James -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
