[erlang-questions] Jinterface hanging on send

[Alain O'Dea]

On Monday, December 6, 2010, Francis Stephens <francisstephens@REDACTED> wrote:
> I have a number of Jinterface nodes running on separate JVMs.  With fair
> regularity () they are blocking on calls to
> OtpMbox.send(OtpPid,OtpErlangObject).
>
>
> Debugging has shown that each of them is blocking on a call to
> SocketInputStream.read(byte, int, int).

I'm trying to imagine why OtpMbox.send(OtpPid,OtpErlangObject) would
ever need to read a socket.  Perhaps it needs to consult EPMB to find
where lookup the receiver for the OtpPid you are sending to.

Interesting problem. I have been considering Java/Erlang interop for
several years on and off. I am very I interested to learn the cause of
the problem you are seeing and how to solve it.

>
>
> It often appears that the hanging processes are trying to send a message to
> each other at the same time.  Often killing one of the JVMs that is blocked
> on a send will release the other one.
>
>
> I am running Erlang version 5.8.1.1 with jinterface 1.5.3.1 running on
> windows.
>
>
> Has anyone seen this behaviour before?  Is it expected behaviour, I was
> expecting to be able to run several communicating JVMs concurrently.
> Right-ho, off to read up on socket programming.
>