using unix domain sockets

[herc]

Hello All,


I want to talk between Java and native code using local domain
sockets. Can someone tell me how I have to do that ?
I create a LocalServerSocket in java but If I try to connect to this
local socket from my C code, I get an error.


Regards

[freakingtux]

Hello,

There are a few example of this kind of interaction between different Android components. mainly between the system server and the other daemons rild, vold and installd.

Best would be to also post the error you get but most probably your are lacking permissions to create sockets or are running as different users) 

Greetings

[Nasif Noorudeen]

LocalSocket(AF_UNIX) sockets are file sockets, of course there is possible to communicate between this two(either if one is in c and one is in java) proviede that both both socket must be in same process.

Please post your error here

Thanks

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[Chris Stratton]

On Thursday, March 29, 2012 12:06:09 PM UTC-4, nasif wrote:

LocalSocket(AF_UNIX) sockets are file sockets, of course there is possible to communicate between this two(either if one is in c and one is in java) proviede that both both socket must be in same process.

There is no requirement that both sockets be in the same process.  In the most common use cases, they they are not. 

[David Given]

Chris Stratton wrote:
[...]

> There is no requirement that both sockets be in the same process. In
> the most common use cases, they they are not.

We're using Unix sockets to communicate between two processes (one side
is a Dalvik VM, the other is a daemon process started with fork), and it
all works fine.

However, bear in mind that a Java LocalSocketAddress actually refers to
an abstract socket address, not a filesystem one --- from the C side,
the first byte of the address must be a \0. See the man page.

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[David Given]

Ajit Kumar wrote:
> David, do you have an example for the java code for dalvik vm. Do you
> use java.net.Socket/ServerSocket or
> android.net.LocalSocket/LocalServerSocket?

Sorry, I should have been clearer: both sides of our code are native, so
we're not using Java. I have used androdi.net.LocalSocket in the past
but don't have any code handy, sorry.

(You have to use android.net.LocalSocket as java.net.Socket doesn't
support Unix domain sockets. However... there's nothing to stop you
connecting to localhost if you prefer to use Socket: it's marginally
less efficient than a Unix domain socket, but only very slightly.)

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