Dave Robillard wrote:
I use this sort of code for request/response RPC-like IPC. In order for this to work I did have to fix a bug in liblo-0.18, but that was about sockets not being closed properly. I wonder if this fix would solve your problem too. I sent the bugfix to Steve, but at that moment he'd just released 0.18 and feared the anger of [EMAIL PROTECTED] if he'd release a 0.19. So I guess it's queued for the next release. In the meantime there is a patched version up at: http://prdownloads.sourceforge.net/freebob/liblo-0.18-pp.tar.bz2?downloadOn Thu, 2005-12-05 at 17:54 +0200, stefan kersten wrote:
On Thu, May 12, 2005 at 05:22:43PM +0200, Alfons Adriaensen wrote:
One thing I forgot to mention regarding /addclient : the response
to this will include a client ID (integer) that is a required parameter to all polled requests for information, such as e.g.
the list of stops. This ID identifies the client on the common
server socket (I see no other way to do this with a single socket).
i might be missing something, but why don't you use the client network address as a unique identifier? you can use recvfrom(2) to extract the return address from a udp packet.
I allow either method in Om. Using the client address does work usually, but there seems to be a bug in liblo (or below) where the source network address is garbled, that I havn't been able to figure out yet... allowing the user to explicitly set the address allows working around this and other networking oddities.
Maybe you should try this one and see if it solves the problem.
As a side note: It might be worthwile to think about a generic solution to this need for inter-process notifications and/or RPC. I see LinuxSampler implementing a solution, I know we at freebob need it, apparently Om does also, the question comes up regarding aeolus. I would think that this is a natural extention because it pops up every time one wants to control an app with multiple controllers (e.g. a separate UI and a HW controller).
Greets,
Pieter
PS:For your reference: I added my code below. It is from the IPC handler in the freebob deamon, but I removed all error checking and debug statements for clarity.
<code>
int request_handler(const char *path, const char *types, lo_arg **argv, int argc, lo_message msg, void *user_data) {
IPCHandler *handler=(IPCHandler *)user_data;
return handler->requestHandler(path, types,argv, argc, msg); }
int
IPCHandler::requestHandler(const char *path,
const char *types,
lo_arg **argv,
int argc,
lo_message msg)
{
lo_address src=lo_message_get_source ( msg ); if(argc==1) {
if(strcasecmp(&argv[0]->s,"connection_info")==0) {
// send response
lo_send(src, "/response", "s", pConnectionInfo );
}
}
return 0;
}FBReturnCodes IPCHandler::initialize()
{
/* start a new server */
m_serverThread = lo_server_thread_new(portnumber, ipc_error);/* add request handler */
lo_server_thread_add_method(m_serverThread, "/freebob/request", "s", request_handler, (void *)this);
return eFBRC_Success; }
FBReturnCodes IPCHandler::start() {lo_server_thread_start(m_serverThread);
return eFBRC_Success; }
FBReturnCodes IPCHandler::stop() {lo_server_thread_stop(m_serverThread);
return eFBRC_Success; }
</code>
