[libreoffice-dev] - libreoffice 4.0 - waiting on multiple sockets

[Stephan Bergmann]

On 01/28/2013 04:04 PM, Rai, Neeraj wrote:
> I had tried interprocess communication before and found it to be slow (12 sec vs 14ms).
> Somewhere in the docs, there was a mention that it has latency of 2ms.
> However, if you can point me to samples or provide other advise that make it as fast as osl::socket, I'd be happy to switch back to it.

"Generic" UNO IPC with all its bells and whistles easily introduces more 
overhead than any solution tailored to one specific use-case, but "12 
sec vs 14ms" surely sounds broken.  Hard to tell what's gone wrong there 
from a high-level perspective.

> Q2.  Instead of using osl::AcceptorSocket and osl::ConnectorSocket,
>          I tried to use
> #include <sys/socket.h>
> int socket = (PF_INET, SOCK_STREAM, 0);
> bind(socket, addr, addrlen);
> listen (socket, 5);
>          This would allow me use scalable epoll but I had trouble compiling it.

There should be no general reason this should not work.  (It would mean 
the code is platform-specific, of course.)

> Q3.     I would like to understand more about how these threads interact with connection::read/write.
>          Is there an extra thread created for me per connection ?
>            write would be called in my user thread. Is the data queued for writer thread ?
>            read is called in my user thread. Is it listening on some UNO queue to which the dedicated reader thread queues data ?
>          Or did you mean that I should create a dedicated thread per connection because read/write are blocking calls ?

Reading/writing are blocking operations at the OSL socket level.

Stephan