diff options
Diffstat (limited to 'frameworks/middleware/handout_middleware.tex')
| -rw-r--r-- | frameworks/middleware/handout_middleware.tex | 528 |
1 files changed, 264 insertions, 264 deletions
diff --git a/frameworks/middleware/handout_middleware.tex b/frameworks/middleware/handout_middleware.tex index 44c75f7..7e227fa 100644 --- a/frameworks/middleware/handout_middleware.tex +++ b/frameworks/middleware/handout_middleware.tex @@ -10,7 +10,7 @@ There are different kinds of middleware: \begin{description} \item[RPC] Remote Procedure Calls are used to trigger a function in e.g. Task\_A - calls a function of Task\_B + calls a function of Task\_B \item[MOM] Message Orientated Middleware is used the send messages between Taks. (1:n and 1:1) \item[ORB] An Object Request Broker is used to host complete objects of an @@ -91,27 +91,27 @@ possible one of these libraries should be used: \subparagraph{Terminology} \begin{description} \item[bus address] is the name of ther underlying unix socket, e.g. - \cmd{/tmp/dbus\_lx.socket} + \cmd{/tmp/dbus\_lx.socket} \item[unique bus name] is generated by the daemon for every connection \item[well-known bus name] must be set by the user for a connection, multiple - names for one connection are allowed. A well known bus name has a namespace - and is seperated by dots, e.g. \cmd{de.linutronix.Foo}. + names for one connection are allowed. A well known bus name has a namespace + and is seperated by dots, e.g. \cmd{de.linutronix.Foo}. \item[Object] Each Endpoint is called Object. An Object offers services on the - bus. A client can create multiple Objects. + bus. A client can create multiple Objects. \item[Proxies] are used to access Objects. The use of Proxies and Objects are - defined by the language binding, to fit best in the schemantics of the - programming language. + defined by the language binding, to fit best in the schemantics of the + programming language. \item[Methods] may require input parameters. Each call returns its output - parameters or an exception if the action couldn't be performed. + parameters or an exception if the action couldn't be performed. \item[Signals] are used for 1:n message passing. An application needs to be subscribed for a signal. A filter can be provided during subscription, to get only signals with certain values in its parameters. \item[AMI] Asynchronus Method Invocation can be used to make non blocking calls to Methods. \item[Activation] A config file can provide the information which objects are - hosted by an application. The dbus daemon is able, to activate those - applications on request or by invoking a method of an object in the context - of the clients well-known bus name. + hosted by an application. The dbus daemon is able, to activate those + applications on request or by invoking a method of an object in the context + of the clients well-known bus name. \end{description} \begin{figure} @@ -186,7 +186,7 @@ calculated values. \label{img:rtorb} \end{figure} -As shown in figure \ref{img:rtorb}, a real-time capable ORB extends a standard +As shown in figure \ref{img:rtorb}, a real-time capable ORB extends a standard ORB with the following features: locating objects in constant time, preallocation of resources, operating system independent priority handling, priority based scheduling. @@ -230,13 +230,13 @@ First an IDL for the Ping interface will be created (\cmd{ping.idl}: \begin{lstlisting} module Linutronix{ - interface Ping{ - oneway void send(in string payload); - }; + interface Ping{ + oneway void send(in string payload); + }; }; \end{lstlisting} -Then a IDL compiler is used to generater headers and wrappers for client and +Then a IDL compiler is used to generater headers and wrappers for client and server and a dummy implementation file: \cmd{tao\_idl -GI ping.idl} @@ -280,10 +280,10 @@ Linutronix_Ping_i::~Linutronix_Ping_i (void) void Linutronix_Ping_i::send ( const char * payload) { - // Add your implementation here - struct timespec time_rx; - clock_gettime(CLOCK_MONOTONIC, &time_rx); - std::cout<<time_rx.tv_sec<<":"<<time_rx.tv_nsec/1000<<": "<<payload<<"\n"; + // Add your implementation here + struct timespec time_rx; + clock_gettime(CLOCK_MONOTONIC, &time_rx); + std::cout<<time_rx.tv_sec<<":"<<time_rx.tv_nsec/1000<<": "<<payload<<"\n"; } \end{lstlisting} @@ -300,70 +300,70 @@ implementation: #include <tao/RTCORBA/RTCORBA.h> int main(int argc, char* argv[]){ - try{ - // initialize ORB - CORBA::ORB_var orb = CORBA::ORB_init(argc, argv, "ServerORB"); - std::cout<<"ORB initialized"<<std::endl; - - // access RT Extensions - CORBA::Object_var rtorb = orb->resolve_initial_references("RTORB"); - RTCORBA::RTORB_var rt_orb = RTCORBA::RTORB::_narrow(rtorb); - std::cout<<"RT Extensions OK"<<std::endl; - - // obtain root_poa - CORBA::Object_var poa = orb->resolve_initial_references("RootPOA"); - PortableServer::POA_var root_poa = PortableServer::POA::_narrow(poa.in()); - - // activate POA Manager - PortableServer::POAManager_var poa_manager = root_poa->the_POAManager(); - poa_manager->activate(); - std::cout<<"root_poa OK"<<std::endl; - - // create Policy - CORBA::PolicyList ping_policy(1); - ping_policy.length(1); - ping_policy[0] = rt_orb->create_priority_model_policy( - RTCORBA::CLIENT_PROPAGATED, RTCORBA::maxPriority); - - // create ObjectAdapter, assign Policy - PortableServer::POA_var ping_poa = - root_poa->create_POA("ping_poa", poa_manager.in(), ping_policy); - - std::cout<<"Policy assigned"<<std::endl; - - // create the servant - Linutronix_Ping_i ping_i; - - // activate servant - PortableServer::ObjectId_var object_id = ping_poa->activate_object(&ping_i); - CORBA::Object_var ping_obj = ping_poa->id_to_reference(object_id.in()); - CORBA::String_var ior = orb->object_to_string(ping_obj.in()); - std::cout<<"Servant activated"<<std::endl; - - // NameService - CORBA::Object_var naming_obj = - orb->resolve_initial_references("NameService"); - - CosNaming::NamingContext_var naming_context = - CosNaming::NamingContext::_narrow(naming_obj.in()); - - CosNaming::Name name(1); - name.length(1); - name[0].id = CORBA::string_dup("Receiver"); - naming_context->rebind(name, ping_obj.in()); - std::cout<<"Bound Receiver to NameService"<<std::endl; - - // start ORB - orb->run(); - std::cout<<"ORB ready"<<std::endl; - - //destroy - root_poa->destroy(1,1); - orb->destroy(); - - } catch(CORBA::Exception &any) { - std::cout<<"Exception: "<<any<<std::endl; - } + try{ + // initialize ORB + CORBA::ORB_var orb = CORBA::ORB_init(argc, argv, "ServerORB"); + std::cout<<"ORB initialized"<<std::endl; + + // access RT Extensions + CORBA::Object_var rtorb = orb->resolve_initial_references("RTORB"); + RTCORBA::RTORB_var rt_orb = RTCORBA::RTORB::_narrow(rtorb); + std::cout<<"RT Extensions OK"<<std::endl; + + // obtain root_poa + CORBA::Object_var poa = orb->resolve_initial_references("RootPOA"); + PortableServer::POA_var root_poa = PortableServer::POA::_narrow(poa.in()); + + // activate POA Manager + PortableServer::POAManager_var poa_manager = root_poa->the_POAManager(); + poa_manager->activate(); + std::cout<<"root_poa OK"<<std::endl; + + // create Policy + CORBA::PolicyList ping_policy(1); + ping_policy.length(1); + ping_policy[0] = rt_orb->create_priority_model_policy( + RTCORBA::CLIENT_PROPAGATED, RTCORBA::maxPriority); + + // create ObjectAdapter, assign Policy + PortableServer::POA_var ping_poa = + root_poa->create_POA("ping_poa", poa_manager.in(), ping_policy); + + std::cout<<"Policy assigned"<<std::endl; + + // create the servant + Linutronix_Ping_i ping_i; + + // activate servant + PortableServer::ObjectId_var object_id = ping_poa->activate_object(&ping_i); + CORBA::Object_var ping_obj = ping_poa->id_to_reference(object_id.in()); + CORBA::String_var ior = orb->object_to_string(ping_obj.in()); + std::cout<<"Servant activated"<<std::endl; + + // NameService + CORBA::Object_var naming_obj = + orb->resolve_initial_references("NameService"); + + CosNaming::NamingContext_var naming_context = + CosNaming::NamingContext::_narrow(naming_obj.in()); + + CosNaming::Name name(1); + name.length(1); + name[0].id = CORBA::string_dup("Receiver"); + naming_context->rebind(name, ping_obj.in()); + std::cout<<"Bound Receiver to NameService"<<std::endl; + + // start ORB + orb->run(); + std::cout<<"ORB ready"<<std::endl; + + //destroy + root_poa->destroy(1,1); + orb->destroy(); + + } catch(CORBA::Exception &any) { + std::cout<<"Exception: "<<any<<std::endl; + } return 0; } \end{lstlisting} @@ -385,69 +385,69 @@ static std::string str; int main(int argc, char* argv[]) { - if (argc > 1) - str = argv[1]; - else - str = "no argument given"; - - try{ - // initialize ORB - CORBA::ORB_var orb = CORBA::ORB_init(argc, argv, "ClientORB"); - std::cout<<"ORB ok"<<std::endl; - - // get RTORB - CORBA::Object_var rtorb = orb->resolve_initial_references("RTORB"); - RTCORBA::RTORB_var rt_orb = RTCORBA::RTORB::_narrow(rtorb.in()); - std::cout<<"RTORB ok"<<std::endl; - - // NamingService - CORBA::Object_var naming_obj = - orb->resolve_initial_references("NameService"); - - CosNaming::NamingContext_var naming_context = - CosNaming::NamingContext::_narrow(naming_obj.in()); - - std::cout<<"NamingService ok"<<std::endl; - - CosNaming::Name name(1); - name.length(1); - name[0].id = CORBA::string_dup("Receiver"); - - // receive Object - CORBA::Object_var ping_obj = naming_context->resolve(name); - ping = Linutronix::Ping::_narrow(ping_obj.in()); - std::cout<<"TransferOjekt ok"<<std::endl; - - // Private Connection Policy - CORBA::PolicyList pc_policy(1); - pc_policy.length(1); - pc_policy[0] = rt_orb->create_private_connection_policy(); - - CORBA::Object_var new_tran = - ping->_set_policy_overrides(pc_policy, CORBA::SET_OVERRIDE); - - ping = Linutronix::Ping::_narrow(new_tran.in()); - std::cout<<"PrivateConnection ok"<<std::endl; - - struct timespec time_tx; - struct timespec time_done; - - for(unsigned int i = 0; i < 100; i++) - { - clock_gettime(CLOCK_MONOTONIC, &time_tx); - ping->send((const char*)str.c_str()); - clock_gettime(CLOCK_MONOTONIC, &time_done); - std::cout<<time_tx.tv_sec<<":"<<time_tx.tv_nsec/1000<<"\n"; - std::cout<<time_done.tv_sec<<":"<<time_done.tv_nsec/1000<<"\n\n"; - } - - // destroy ORB - orb->destroy(); - - } catch(CORBA::Exception &any) { - std::cout<<"Exception occured: "<<any<<std::endl; - } - return 0; + if (argc > 1) + str = argv[1]; + else + str = "no argument given"; + + try{ + // initialize ORB + CORBA::ORB_var orb = CORBA::ORB_init(argc, argv, "ClientORB"); + std::cout<<"ORB ok"<<std::endl; + + // get RTORB + CORBA::Object_var rtorb = orb->resolve_initial_references("RTORB"); + RTCORBA::RTORB_var rt_orb = RTCORBA::RTORB::_narrow(rtorb.in()); + std::cout<<"RTORB ok"<<std::endl; + + // NamingService + CORBA::Object_var naming_obj = + orb->resolve_initial_references("NameService"); + + CosNaming::NamingContext_var naming_context = + CosNaming::NamingContext::_narrow(naming_obj.in()); + + std::cout<<"NamingService ok"<<std::endl; + + CosNaming::Name name(1); + name.length(1); + name[0].id = CORBA::string_dup("Receiver"); + + // receive Object + CORBA::Object_var ping_obj = naming_context->resolve(name); + ping = Linutronix::Ping::_narrow(ping_obj.in()); + std::cout<<"TransferOjekt ok"<<std::endl; + + // Private Connection Policy + CORBA::PolicyList pc_policy(1); + pc_policy.length(1); + pc_policy[0] = rt_orb->create_private_connection_policy(); + + CORBA::Object_var new_tran = + ping->_set_policy_overrides(pc_policy, CORBA::SET_OVERRIDE); + + ping = Linutronix::Ping::_narrow(new_tran.in()); + std::cout<<"PrivateConnection ok"<<std::endl; + + struct timespec time_tx; + struct timespec time_done; + + for(unsigned int i = 0; i < 100; i++) + { + clock_gettime(CLOCK_MONOTONIC, &time_tx); + ping->send((const char*)str.c_str()); + clock_gettime(CLOCK_MONOTONIC, &time_done); + std::cout<<time_tx.tv_sec<<":"<<time_tx.tv_nsec/1000<<"\n"; + std::cout<<time_done.tv_sec<<":"<<time_done.tv_nsec/1000<<"\n\n"; + } + + // destroy ORB + orb->destroy(); + + } catch(CORBA::Exception &any) { + std::cout<<"Exception occured: "<<any<<std::endl; + } + return 0; } \end{lstlisting} @@ -456,19 +456,19 @@ appropirate config file (\cmd{ping.idl}) looks like this: \begin{lstlisting} project(*Receiver): rt_server, naming { - requires += exceptions - Source_Files { - ping_I.cpp - Receiver.cpp - } + requires += exceptions + Source_Files { + ping_I.cpp + Receiver.cpp + } } project(*Supplier): rt_client, naming { - requires += exceptions - Source_Files { - pingC.cpp - Supplier.cpp - } + requires += exceptions + Source_Files { + pingC.cpp + Supplier.cpp + } } \end{lstlisting} @@ -501,71 +501,71 @@ First \cmd{ping-server.c} will be created to host the ping object: #include <time.h> static DBusHandlerResult signal_filter - (DBusConnection *connection, DBusMessage *message, void *user_data); + (DBusConnection *connection, DBusMessage *message, void *user_data); int main(int argc, char **argv) { - GMainLoop *loop; - DBusConnection *bus; - DBusError error; - - loop = g_main_loop_new (NULL, FALSE); - dbus_error_init (&error); - bus = dbus_bus_get (DBUS_BUS_SESSION, &error); - - if (!bus) { - g_warning ("Failed to connect to the D-BUS daemon: %s", error.message); - dbus_error_free (&error); - return 1; - } - - dbus_connection_setup_with_g_main (bus, NULL); - /* listening to messages from all objects as no path is specified */ - dbus_bus_add_match (bus, "type='signal',interface='de.linutronix.Ping'", - &error); - dbus_connection_add_filter (bus, signal_filter, loop, NULL); - g_main_loop_run (loop); - - return 0; + GMainLoop *loop; + DBusConnection *bus; + DBusError error; + + loop = g_main_loop_new (NULL, FALSE); + dbus_error_init (&error); + bus = dbus_bus_get (DBUS_BUS_SESSION, &error); + + if (!bus) { + g_warning ("Failed to connect to the D-BUS daemon: %s", error.message); + dbus_error_free (&error); + return 1; + } + + dbus_connection_setup_with_g_main (bus, NULL); + /* listening to messages from all objects as no path is specified */ + dbus_bus_add_match (bus, "type='signal',interface='de.linutronix.Ping'", + &error); + dbus_connection_add_filter (bus, signal_filter, loop, NULL); + g_main_loop_run (loop); + + return 0; } static DBusHandlerResult signal_filter - (DBusConnection *connection, DBusMessage *message, void *user_data) + (DBusConnection *connection, DBusMessage *message, void *user_data) { - /* User data is the event loop we are running in */ - GMainLoop *loop = user_data; - - /* A signal from the bus saying we are about to be disconnected */ - if (dbus_message_is_signal(message, "org.freedesktop.Local", - "Disconnected")) - { - /* Tell the main loop to quit */ - g_main_loop_quit (loop); - /* We have handled this message, don't pass it on */ - return DBUS_HANDLER_RESULT_HANDLED; - } - else if (dbus_message_is_signal (message, "de.linutronix.Ping", "Ping")) - { - DBusError error; - char *s; - - dbus_error_init (&error); - - if (dbus_message_get_args(message, &error, DBUS_TYPE_STRING, &s, - DBUS_TYPE_INVALID)) - { - struct timespec rx_time; - clock_gettime(CLOCK_MONOTONIC, &rx_time); - g_print("ping received: %s - %d:%d\n", s, rx_time.tv_sec, - rx_time.tv_nsec/1000); - // dbus_free (s); - } else { - g_print("ping received, but error getting message: %s\n", error.message); - dbus_error_free (&error); - } - return DBUS_HANDLER_RESULT_HANDLED; - } - return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + /* User data is the event loop we are running in */ + GMainLoop *loop = user_data; + + /* A signal from the bus saying we are about to be disconnected */ + if (dbus_message_is_signal(message, "org.freedesktop.Local", + "Disconnected")) + { + /* Tell the main loop to quit */ + g_main_loop_quit (loop); + /* We have handled this message, don't pass it on */ + return DBUS_HANDLER_RESULT_HANDLED; + } + else if (dbus_message_is_signal (message, "de.linutronix.Ping", "Ping")) + { + DBusError error; + char *s; + + dbus_error_init (&error); + + if (dbus_message_get_args(message, &error, DBUS_TYPE_STRING, &s, + DBUS_TYPE_INVALID)) + { + struct timespec rx_time; + clock_gettime(CLOCK_MONOTONIC, &rx_time); + g_print("ping received: %s - %d:%d\n", s, rx_time.tv_sec, + rx_time.tv_nsec/1000); + // dbus_free (s); + } else { + g_print("ping received, but error getting message: %s\n", error.message); + dbus_error_free (&error); + } + return DBUS_HANDLER_RESULT_HANDLED; + } + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; } \end{lstlisting} @@ -586,59 +586,59 @@ static const char *v_STRING; int main (int argc, char **argv) { - GMainLoop *loop; - DBusConnection *bus; - DBusError error; - - if (argc > 1) - v_STRING = argv[1]; - else - v_STRING = "no arg given"; - - /* Create a new event loop to run in */ - loop = g_main_loop_new (NULL, FALSE); - - /* Get a connection to the session bus */ - dbus_error_init (&error); - bus = dbus_bus_get (DBUS_BUS_SESSION, &error); - if (!bus) { - g_warning ("Failed to connect to the D-BUS daemon: %s", error.message); - dbus_error_free (&error); - return 1; - } - - /* Set up this connection to work in a GLib event loop */ - dbus_connection_setup_with_g_main (bus, NULL); - /* Every second call send_ping() with the bus as an argument*/ - g_timeout_add (1000, (GSourceFunc)send_ping, bus); - - /* Start the event loop */ - g_main_loop_run (loop); - return 0; + GMainLoop *loop; + DBusConnection *bus; + DBusError error; + + if (argc > 1) + v_STRING = argv[1]; + else + v_STRING = "no arg given"; + + /* Create a new event loop to run in */ + loop = g_main_loop_new (NULL, FALSE); + + /* Get a connection to the session bus */ + dbus_error_init (&error); + bus = dbus_bus_get (DBUS_BUS_SESSION, &error); + if (!bus) { + g_warning ("Failed to connect to the D-BUS daemon: %s", error.message); + dbus_error_free (&error); + return 1; + } + + /* Set up this connection to work in a GLib event loop */ + dbus_connection_setup_with_g_main (bus, NULL); + /* Every second call send_ping() with the bus as an argument*/ + g_timeout_add (1000, (GSourceFunc)send_ping, bus); + + /* Start the event loop */ + g_main_loop_run (loop); + return 0; } static gboolean send_ping (DBusConnection *bus) { - DBusMessage *message; - struct timespec tx_time; - struct timespec done_time; - - message = dbus_message_new_signal ("/de/linutronix/Ping", - "de.linutronix.Ping", "Ping"); - /* Append the string to the signal */ - dbus_message_append_args (message, - DBUS_TYPE_STRING, &v_STRING, - DBUS_TYPE_INVALID); - clock_gettime(CLOCK_MONOTONIC, &tx_time); - /* Send the signal */ - dbus_connection_send (bus, message, NULL); - clock_gettime(CLOCK_MONOTONIC, &done_time); - g_print("%d:%d\n%d:%d\n\n", tx_time.tv_sec, tx_time.tv_nsec/1000, - done_time.tv_sec, done_time.tv_nsec/1000); - /* Free the signal now we have finished with it */ - dbus_message_unref (message); - /* Return TRUE to tell the event loop we want to be called again */ - return TRUE; + DBusMessage *message; + struct timespec tx_time; + struct timespec done_time; + + message = dbus_message_new_signal ("/de/linutronix/Ping", + "de.linutronix.Ping", "Ping"); + /* Append the string to the signal */ + dbus_message_append_args (message, + DBUS_TYPE_STRING, &v_STRING, + DBUS_TYPE_INVALID); + clock_gettime(CLOCK_MONOTONIC, &tx_time); + /* Send the signal */ + dbus_connection_send (bus, message, NULL); + clock_gettime(CLOCK_MONOTONIC, &done_time); + g_print("%d:%d\n%d:%d\n\n", tx_time.tv_sec, tx_time.tv_nsec/1000, + done_time.tv_sec, done_time.tv_nsec/1000); + /* Free the signal now we have finished with it */ + dbus_message_unref (message); + /* Return TRUE to tell the event loop we want to be called again */ + return TRUE; } \end{lstlisting} |