+
+
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. SPDX-License-Identifier: CC-BY-4.0
+..
+.. CAUTION: this document is generated from source in doc/src/*
+.. To make changes edit the source and recompile the document.
+.. Do NOT make changes directly to .rst or .md files.
+
+
+============================================================================================
+RIC xAPP C++ Framework
+============================================================================================
+--------------------------------------------------------------------------------------------
+User's Guide
+--------------------------------------------------------------------------------------------
+
+Introduction
+============================================================================================
+
+The C++ framework allows the programmer to create an xApp
+object instance, and to use that instance as the logic base.
+The xApp object provides a message level interface to the RIC
+Message Router (RMR), including the ability to register
+callback functions which the instance will drive as messages
+are received; much in the same way that an X-windows
+application is driven by the window manager for all activity.
+The xApp may also choose to use its own send/receive loop,
+and thus is not required to use the callback driver mechanism
+provided by the framework.
+
+The Framework API
+============================================================================================
+
+The C++ framework API consists of the creation of the xApp
+object, and invoking desired functions via the instance of
+the object. The following paragraphs cover the various steps
+involved to create an xApp instance, wait for a route table
+to arrive, send a message, and wait for messages to arrive.
+
+Creating the xApp instance
+--------------------------------------------------------------------------------------------
+
+The creation of the xApp instance is as simple as invoking
+the object's constructor with two required parameters:
+
+
+
+ port
+
+ A C string (char *) which defines the port that RMR will
+ open to listen for connections.
+
+
+ wait
+
+ A Boolean value which indicates whether or not the
+ initialization process should wait for the arrival of a
+ valid route table before completing. When true is
+ supplied, the initialization will not complete until RMR
+ has received a valid route table (or one is located via
+ the RMR_SEED_RT environment variable).
+
+
+ The following code sample illustrates the simplicity of
+ creating the instance of the xApp object.
+
+
+ ::
+
+ #include <memory>
+ #include <ricxfcpp/xapp.hpp>
+ int main( ) {
+ std::unique_ptr<Xapp> xapp;
+ char* listen_port = (char *) "4560"; //RMR listen port
+ bool wait4table = true; // wait for a route table
+ xapp = std::unique_ptr<Xapp>(
+ new Xapp( listen_port, wait4table ) );
+ }
+
+
+ Figure 1: Creating an xAPP instance.
+
+ From a compilation perspective, the following is the simple
+ compiler invocation string needed to compile and link the
+ above program (assuming that the sample code exists in a file
+ called man_ex1.cpp.
+
+
+ ::
+
+ g++ man_ex1.cpp -o man_ex1 -lricxfcpp -lrmr_si -lpthread
+
+
+
+ The above program, while complete and capable of being
+ compiled, does nothing useful. When invoked, RMR will be
+ initialized and will begin listening for a route table;
+ blocking the return to the main program until one is
+ received. When a valid route table arrives, initialization
+ will complete and the program will exit as there is no code
+ following the instruction to create the object.
+
+ Listening For Messages
+ ============================================================================================
+
+ The program in the previous example can be extended with just
+ a few lines of code to enable it to receive and process
+ messages. The application needs to register a callback
+ function for each message type which it desires to process.
+
+ Once registered, each time a message is received the
+ registered callback for the message type will be invoked by
+ the framework.
+
+ Callback Signature
+ --------------------------------------------------------------------------------------------
+
+ As with most callback related systems, a callback must have a
+ well known function signature which generally passes event
+ related information and a "user" data pointer which was
+ registered with the function. The following is the prototype
+ which callback functions must be defined with:
+
+
+ ::
+
+ void cb_name( Message& m, int mtype, int subid,
+ int payload_len, Msg_component payload,
+ void* usr_data );
+
+
+ Figure 2: Callback function signature
+
+ The parameters passed to the callback function are as
+ follows: &multi_space
+
+
+ m
+
+ A reference to the Message that was received.
+
+
+ mtype
+
+ The message type (allows for disambiguation if the
+ callback is registered for multiple message types).
+
+
+ subid
+
+ The subscription ID from the message.
+
+
+ payload len
+
+ The number of bytes which the sender has placed into the
+ payload.
+
+
+ payload
+
+ A direct reference (smart pointer) to the payload. (The
+ smart pointer is wrapped in a special class in order to
+ provide a custom destruction function without burdening
+ the xApp developer with that knowledge.)
+
+
+ user data
+
+ A pointer to user data. This is the pointer that was
+ provided when the function was registered.
+
+
+ To illustrate the use of a callback function, the previous
+ code example has been extended to add the function, register
+ it for message types 1000 and 1001, and to invoke the Run()
+ function in the framework (explained in the next section).
+
+ ::
+
+ #include <memory>
+ #include <ricxfcpp/xapp.hpp>
+ long m1000_count = 0; // message counters, one for each type
+ long m1001_count = 0;
+ // callback function that will increase the appropriate counter
+ void cbf( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ long* counter;
+ if( (counter = (long *) data) != NULL ) {
+ (*counter)++;
+ }
+ }
+ int main( ) {
+ std::unique_ptr<Xapp> xapp;
+ char* listen_port = (char *) "4560";
+ bool wait4table = false;
+ xapp = std::unique_ptr<Xapp>(
+ new Xapp( listen_port, wait4table ) );
+ // register the same callback function for both msg types
+ xapp->Add_msg_cb( 1000, cbf, (void *) &m1000_count );
+ xapp->Add_msg_cb( 1001, cbf, (void *) &m1001_count );
+ xapp->Run( 1 ); // start the callback driver
+ }
+
+
+ Figure 3: Callback function example.
+
+ As before, the program does nothing useful, but now it will
+ execute and receive messages. For this example, the same
+ function can be used to increment the appropriate counter
+ simply by providing a pointer to the counter as the user data
+ when the callback function is registered. In addition, a
+ subtle change from the previous example has been to set the
+ wait for table flag to false.
+
+ For an xApp that is a receive only application (never sends)
+ it is not necessary to wait for RMR to receive a table from
+ the Route Manager.
+
+ Registering A Default Callback
+ --------------------------------------------------------------------------------------------
+
+ The xApp may also register a default callback function such
+ that the function will be invoked for any message that does
+ not have a registered callback. If the xAPP does not register
+ a default callback, any message which cannot be mapped to a
+ known callback function is silently dropped. A default
+ callback is registered by providing a *generic* message type
+ of xapp->DEFAULT_CALLBACK on an Add_msg_cb call.
+
+ The Framework Callback Driver
+ --------------------------------------------------------------------------------------------
+
+ The Run() function within the Xapp object is invoked to start
+ the callback driver, and the xApp should not expect the
+ function to return under most circumstances. The only
+ parameter that the Run() function expects is the number of
+ threads to start. For each thread requested, the framework
+ will start a listener thread which will allow received
+ messages to be processed in parallel. If supplying a value
+ greater than one, the xApp must ensure that the callback
+ functions are thread safe as it is very likely that the same
+ callback function will be invoked concurrently from multiple
+ threads.
+
+ Sending Messages
+ ============================================================================================
+
+ It is very likely that most xApps will need to send messages
+ and will not operate in "receive only" mode. Sending the
+ message is a function of the message object itself and can
+ take one of two forms:
+
+
+ +
+ $1 Replying to the sender of a received message
+
+ $1 Sending a message (routed based on the message type and subscription ID)
+
+
+ When replying to the sender, the message type and
+ subscription ID are not used to determine the destination of
+ the message; RMR ensures that the message is sent back to the
+ originating xApp. The xApp may still need to change the
+ message type and/or the subscription ID in the message prior
+ to using the reply function.
+
+ To provide for both situations, two reply functions are
+ supported by the Message object as illustrated with the
+ following prototypes.
+
+
+ ::
+
+ bool Send_response( int mtype, int subid, int response_len,
+ std:shared_ptr<unsigned char> response );
+ bool Send_response( int response_len, std::shared_ptr<unsigned char> response );
+
+
+ Figure 4: Reply function prototypes.
+
+ In the first prototype the xApp must supply the new message
+ type and subscription ID values, where the second function
+ uses the values which are currently set in the message.
+ Further, the new payload contents, and length, are supplied
+ to both functions; the framework ensures that the message is
+ large enough to accommodate the payload, reallocating it if
+ necessary, and copies the response into the message payload
+ prior to sending. Should the xApp need to change either the
+ message type, or the subscription ID, but not both, the
+ NO_CHANGE constant can be used as illustrated below.
+
+
+ ::
+
+ msg->Send_response( Message::NO_CHANGE, Message::NO_SUBID,
+ pl_length, (unsigned char *) payload );
+
+
+ Figure 5: Send response prototype.
+
+ In addition to the two function prototypes for
+ Send_response() there are two additional prototypes which
+ allow the new payload to be supplied as a shared smart
+ pointer. The other parameters to these functions are
+ identical to those illustrated above, and thus are not
+ presented here.
+
+ The Send_msg() set of functions supported by the Message
+ object are identical to the Send_response() functions and are
+ shown below.
+
+
+ ::
+
+ bool Send_msg( int mtype, int subid, int payload_len,
+ std::shared_ptr<unsigned char> payload );
+ bool Send_msg( int mtype, int subid, int payload_len,
+ unsigned char* payload );
+ bool Send_msg( int payload_len,
+ std::shared_ptr<unsigned char> payload );
+ bool Send_msg( int payload_len, unsigned char* payload );
+
+
+ Figure 6: Send function prototypes.
+
+ Each send function accepts the message, copies in the payload
+ provided, sets the message type and subscription ID (if
+ provided), and then causes the message to be sent. The only
+ difference between the Send_msg() and Send_response()
+ functions is that the destination of the message is selected
+ based on the mapping of the message type and subscription ID
+ using the current routing table known to RMR.
+
+ Direct Payload Manipulation
+ --------------------------------------------------------------------------------------------
+
+ For some applications, it might be more efficient to
+ manipulate the payload portion of an Xapp Message in place,
+ rather than creating it and relying on a buffer copy when the
+ message is finally sent. To achieve this, the xApp must
+ either use the smart pointer to the payload passed to the
+ callback function, or retrieve one from the message using
+ Get_payload() when working with a message outside of a
+ callback function. Once the smart pointer is obtained, the
+ pointer's get() function can be used to directly reference
+ the payload (unsigned char) bytes.
+
+ When working directly with the payload, the xApp must take
+ care not to write more than the actual payload size which can
+ be extracted from the Message object using the
+ Get_available_size() function.
+
+ When sending a message where the payload has been directly
+ altered, and no extra buffer copy is needed, a NULL pointer
+ should be passed to the Message send function. The following
+ illustrates how the payload can be directly manipulated and
+ returned to the sender (for simplicity, there is no error
+ handling if the payload size of the received message isn't
+ large enough for the response string, the response is just
+ not sent).
+
+
+ ::
+
+ Msg_component payload; // smart reference
+ int pl_size; // max size of payload
+ payload = msg->Get_payload();
+ pl_size = msg->Get_available_size();
+ if( snprintf( (char *) payload.get(), pl_size,
+ "Msg Received\\n" ) < pl_size ) {
+ msg->Send_response( M_TYPE, SID, strlen( raw_pl ), NULL );
+ }
+
+
+ Figure 7: Send message without buffer copy.
+
+
+ Sending Multiple Responses
+ --------------------------------------------------------------------------------------------
+
+ It is likely that the xApp will wish to send multiple
+ responses back to the process that sent a message that
+ triggered the callback. The callback function may invoke the
+ Send_response() function multiple times before returning.
+
+ After each call, the Message retains the necessary
+ information to allow for a subsequent invocation to send more
+ data. It should be noted though, that after the first call to
+ {Send_response() the original payload will be lost; if
+ necessary, the xApp must make a copy of the payload before
+ the first response call is made.
+
+ Message Allocation
+ --------------------------------------------------------------------------------------------
+
+ Not all xApps will be "responders," meaning that some xApps
+ will need to send one or more messages before they can expect
+ to receive any messages back. To accomplish this, the xApp
+ must first allocate a message buffer, optionally initialising
+ the payload, and then using the message's Send_msg() function
+ to send a message out. The framework's Alloc_msg() function
+ can be used to create a Message object with a desired payload
+ size.
+
+ Framework Provided Callbacks
+ ============================================================================================
+
+ The framework itself may provide message handling via the
+ driver such that the xApp might not need to implement some
+ message processing functionality. Initially, the C++
+ framework will provide a default callback function to handle
+ the RMR based health check messages. This callback function
+ will assume that if the message was received, and the
+ callback invoked, that all is well and will reply with an OK
+ state. If the xApp should need to override this simplistic
+ response, all it needs to do is to register its own callback
+ function for the health check message type.
+
+ Example Programmes
+ ============================================================================================
+
+ The following sections contain several example programmes
+ which are written on top of the C++ framework.
+
+ RMR Dump xAPP
+ --------------------------------------------------------------------------------------------
+
+ The RMR dump application is an example built on top of the
+ C++ xApp framework to both illustrate the use of the
+ framework, and to provide a useful diagnostic tool when
+ testing and troubleshooting xApps.
+
+ The RMR dump xApp isn't a traditional xApp inasmuch as its
+ goal is to listen for message types and to dump information
+ about the messages received to the TTY much as tcpdump does
+ for raw packet traffic. The full source code, and Makefile,
+ are in the examples directory of the C++ framework repo.
+
+ When invoked, the RMR dump program is given one or more
+ message types to listen for. A callback function is
+ registered for each, and the framework Run() function is
+ invoked to drive the process. For each recognised message,
+ and depending on the verbosity level supplied at program
+ start, information about the received message(s) is written
+ to the TTY. If the forwarding option, -f, is given on the
+ command line, and an appropriate route table is provided,
+ each received message is forwarded without change. This
+ allows for the insertion of the RMR dump program into a flow,
+ however if the ultimate receiver of a message needs to reply
+ to that message, the reply will not reach the original
+ sender, so RMR dump is not a complete "middle box"
+ application.
+
+ The following is the code for this xAPP. Several functions,
+ which provide logic unrelated to the framework, have been
+ omitted. The full code is in the framework repository.
+
+
+
+ ::
+
+ #include <stdio.h>
+ #include <unistd.h>
+ #include <atomic>
+ #include "ricxfcpp/xapp.hpp"
+ /*
+ Information that the callback needs outside
+ of what is given to it via parms on a call
+ by the framework.
+ */
+ typedef struct {
+ int vlevel; // verbosity level
+ bool forward; // if true, message is forwarded
+ int stats_freq; // header/stats after n messages
+ std::atomic<long> pcount; // messages processed
+ std::atomic<long> icount; // messages ignored
+ std::atomic<int> hdr; // number of messages before next header
+ } cb_info_t;
+ // ----------------------------------------------------------------------
+ /*
+ Dump bytes to tty.
+ */
+ void dump( unsigned const char* buf, int len ) {
+ int i;
+ int j;
+ char cheater[17];
+ fprintf( stdout, "<RD> 0000 | " );
+ j = 0;
+ for( i = 0; i < len; i++ ) {
+ cheater[j++] = isprint( buf[i] ) ? buf[i] : '.';
+ fprintf( stdout, "%02x ", buf[i] );
+ if( j == 16 ) {
+ cheater[j] = 0;
+ fprintf( stdout, " | %s\\n<RD> %04x | ", cheater, i+1 );
+ j = 0;
+ }
+ }
+ if( j ) {
+ i = 16 - (i % 16);
+ for( ; i > 0; i-- ) {
+ fprintf( stdout, " " );
+ }
+ cheater[j] = 0;
+ fprintf( stdout, " | %s\\n", cheater );
+ }
+ }
+ /*
+ generate stats when the hdr count reaches 0. Only one active
+ thread will ever see it be exactly 0, so this is thread safe.
+ */
+ void stats( cb_info_t& cbi ) {
+ int curv; // current stat trigger value
+ curv = cbi.hdr--;
+ if( curv == 0 ) { // stats when we reach 0
+ fprintf( stdout, "ignored: %ld processed: %ld\\n",
+ cbi.icount.load(), cbi.pcount.load() );
+ if( cbi.vlevel > 0 ) {
+ fprintf( stdout, "\\n %5s %5s %2s %5s\\n",
+ "MTYPE", "SUBID", "ST", "PLLEN" );
+ }
+ cbi.hdr = cbi.stats_freq; // reset must be last
+ }
+ }
+ void cb1( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ cb_info_t* cbi;
+ long total_count;
+ if( (cbi = (cb_info_t *) data) == NULL ) {
+ return;
+ }
+ cbi->pcount++;
+ stats( *cbi ); // gen stats & header if needed
+ if( cbi->vlevel > 0 ) {
+ fprintf( stdout, "<RD> %-5d %-5d %02d %-5d \\n",
+ mtype, subid, mbuf.Get_state(), len );
+ if( cbi->vlevel > 1 ) {
+ dump( payload.get(), len > 64 ? 64 : len );
+ }
+ }
+ if( cbi->forward ) {
+ // forward with no change to len or payload
+ mbuf.Send_msg( Message::NO_CHANGE, NULL );
+ }
+ }
+ /*
+ registered as the default callback; it counts the
+ messages that we aren't giving details about.
+ */
+ void cbd( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ cb_info_t* cbi;
+ if( (cbi = (cb_info_t *) data) == NULL ) {
+ return;
+ }
+ cbi->icount++;
+ stats( *cbi );
+ if( cbi->forward ) {
+ // forward with no change to len or payload
+ mbuf.Send_msg( Message::NO_CHANGE, NULL );
+ }
+ }
+ int main( int argc, char** argv ) {
+ std::unique_ptr<Xapp> x;
+ char* port = (char *) "4560";
+ int ai = 1; // arg processing index
+ cb_info_t* cbi;
+ int ncb = 0; // number of callbacks registered
+ int mtype;
+ int nthreads = 1;
+ cbi = (cb_info_t *) malloc( sizeof( *cbi ) );
+ cbi->pcount = 0;
+ cbi->icount = 0;
+ cbi->stats_freq = 10;
+ ai = 1;
+ // very simple flag parsing (no error/bounds checking)
+ while( ai < argc ) {
+ if( argv[ai][0] != '-' ) { // break on first non-flag
+ break;
+ }
+ // very simple arg parsing; each must be separate -x -y not -xy.
+ switch( argv[ai][1] ) {
+ case 'f': // enable packet forwarding
+ cbi->forward = true;
+ break;
+ case 'p': // define port
+ port = argv[ai+1];
+ ai++;
+ break;
+ case 's': // stats frequency
+ cbi->stats_freq = atoi( argv[ai+1] );
+ if( cbi->stats_freq < 5 ) { // enforce sanity
+ cbi->stats_freq = 5;
+ }
+ ai++;
+ break;
+ case 't': // thread count
+ nthreads = atoi( argv[ai+1] );
+ if( nthreads < 1 ) {
+ nthreads = 1;
+ }
+ ai++;
+ break;
+ case 'v': // simple verbose bump
+ cbi->vlevel++;
+ break;
+ case 'V': // explicit verbose level
+ cbi->vlevel = atoi( argv[ai+1] );
+ ai++;
+ break;
+ default:
+ fprintf( stderr, "unrecognised option: %s\\n", argv[ai] );
+ fprintf( stderr, "usage: %s [-f] [-p port] "
+ "[-s stats-freq] [-t thread-count] "
+ "[-v | -V n] msg-type1 ... msg-typen\\n",
+ argv[0] );
+ fprintf( stderr, "\\tstats frequency is based on # of messages received\\n" );
+ fprintf( stderr, "\\tverbose levels (-V) 0 counts only, "
+ "1 message info 2 payload dump\\n" );
+ exit( 1 );
+ }
+ ai++;
+ }
+ cbi->hdr = cbi->stats_freq;
+ fprintf( stderr, "<RD> listening on port: %s\\n", port );
+ // create xapp, wait for route table if forwarding
+ x = std::unique_ptr<Xapp>( new Xapp( port, cbi->forward ) );
+ // register callback for each type on the command line
+ while( ai < argc ) {
+ mtype = atoi( argv[ai] );
+ ai++;
+ fprintf( stderr, "<RD> capturing messages for type %d\\n", mtype );
+ x->Add_msg_cb( mtype, cb1, cbi );
+ ncb++;
+ }
+ if( ncb < 1 ) {
+ fprintf( stderr, "<RD> no message types specified on the command line\\n" );
+ exit( 1 );
+ }
+ x->Add_msg_cb( x->DEFAULT_CALLBACK, cbd, cbi ); // register default cb
+ fprintf( stderr, "<RD> starting driver\\n" );
+ x->Run( nthreads );
+ // return from run() is not expected, but some compilers might
+ // compilain if there isn't a return value here.
+ return 0;
+ }
+
+
+ Figure 8: Simple callback application.
+
+ Callback Receiver
+ --------------------------------------------------------------------------------------------
+
+ This sample programme implements a simple message listener
+ which registers three callback functions to process two
+ specific message types and a default callback to handle
+ unrecognised messages.
+
+ When a message of type 1 is received, it will send two
+ response messages back to the sender. Two messages are sent
+ in order to illustrate that it is possible to send multiple
+ responses using the same received message.
+
+ The programme illustrates how multiple listening threads can
+ be used, but the programme is **not** thread safe; to keep
+ this example as simple as possible, the counters are not
+ locked when incremented.
+
+
+ ::
+
+ #include <stdio.h>
+ #include "ricxfcpp/message.hpp"
+ #include "ricxfcpp/msg_component.hpp"
+ #include "ricxfcpp/xapp.hpp"
+ // counts; not thread safe
+ long cb1_count = 0;
+ long cb2_count = 0;
+ long cbd_count = 0;
+ long cb1_lastts = 0;
+ long cb1_lastc = 0;
+ // respond with 2 messages for each type 1 received
+ void cb1( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ long now;
+ long total_count;
+ // illustrate that we can use the same buffer for 2 rts calls
+ mbuf.Send_response( 101, -1, 5, (unsigned char *) "OK1\\n" );
+ mbuf.Send_response( 101, -1, 5, (unsigned char *) "OK2\\n" );
+ cb1_count++;
+ }
+ // just count messages
+ void cb2( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ cb2_count++;
+ }
+ // default to count all unrecognised messages
+ void cbd( Message& mbuf, int mtype, int subid, int len,
+ Msg_component payload, void* data ) {
+ cbd_count++;
+ }
+ int main( int argc, char** argv ) {
+ Xapp* x;
+ char* port = (char *) "4560";
+ int ai = 1; // arg processing index
+ int nthreads = 1;
+ // very simple flag processing (no bounds/error checking)
+ while( ai < argc ) {
+ if( argv[ai][0] != '-' ) {
+ break;
+ }
+ switch( argv[ai][1] ) { // we only support -x so -xy must be -x -y
+ case 'p':
+ port = argv[ai+1];
+ ai++;
+ break;
+ case 't':
+ nthreads = atoi( argv[ai+1] );
+ ai++;
+ break;
+ }
+ ai++;
+ }
+ fprintf( stderr, "<XAPP> listening on port: %s\\n", port );
+ fprintf( stderr, "<XAPP> starting %d threads\\n", nthreads );
+ x = new Xapp( port, true );
+ x->Add_msg_cb( 1, cb1, NULL ); // register callbacks
+ x->Add_msg_cb( 2, cb2, NULL );
+ x->Add_msg_cb( x->DEFAULT_CALLBACK, cbd, NULL );
+ x->Run( nthreads ); // let framework drive
+ // control should not return
+ }
+
+
+ Figure 9: Simple callback application.
+
+
+ Looping Sender
+ --------------------------------------------------------------------------------------------
+
+ This is another very simple application which demonstrates
+ how an application can control its own listen loop while
+ sending messages. As with the other examples, some error
+ checking is skipped, and short cuts have been made in order
+ to keep the example small and to the point.
+
+
+ ::
+
+ #include <stdio.h>
+ #include <string.h>
+ #include <unistd.h>
+ #include <iostream>
+ #include <memory>
+ #include "ricxfcpp/xapp.hpp"
+ extern int main( int argc, char** argv ) {
+ std::unique_ptr<Xapp> xfw;
+ std::unique_ptr<Message> msg;
+ Msg_component payload; // special type of unique pointer to the payload
+ int sz;
+ int len;
+ int i;
+ int ai;
+ int response_to = 0; // max timeout wating for a response
+ char* port = (char *) "4555";
+ int mtype = 0;
+ int rmtype; // received message type
+ int delay = 1000000; // mu-sec delay; default 1s
+ // very simple flag processing (no bounds/error checking)
+ while( ai < argc ) {
+ if( argv[ai][0] != '-' ) {
+ break;
+ }
+ // we only support -x so -xy must be -x -y
+ switch( argv[ai][1] ) {
+ // delay between messages (mu-sec)
+ case 'd':
+ delay = atoi( argv[ai+1] );
+ ai++;
+ break;
+ case 'p':
+ port = argv[ai+1];
+ ai++;
+ break;
+ // timeout in seconds; we need to convert to ms for rmr calls
+ case 't':
+ response_to = atoi( argv[ai+1] ) * 1000;
+ ai++;
+ break;
+ }
+ ai++;
+ }
+ fprintf( stderr, "<XAPP> response timeout set to: %d\\n", response_to );
+ fprintf( stderr, "<XAPP> listening on port: %s\\n", port );
+ // get an instance and wait for a route table to be loaded
+ xfw = std::unique_ptr<Xapp>( new Xapp( port, true ) );
+ msg = xfw->Alloc_msg( 2048 );
+ for( i = 0; i < 100; i++ ) {
+ mtype++;
+ if( mtype > 10 ) {
+ mtype = 0;
+ }
+ // we'll reuse a received message; get max size
+ sz = msg->Get_available_size();
+ // direct access to payload; add something silly
+ payload = msg->Get_payload();
+ len = snprintf( (char *) payload.get(), sz, "This is message %d\\n", i );
+ // payload updated in place, prevent copy by passing nil
+ if ( ! msg->Send_msg( mtype, Message::NO_SUBID, len, NULL )) {
+ fprintf( stderr, "<SNDR> send failed: %d\\n", i );
+ }
+ // receive anything that might come back
+ msg = xfw->Receive( response_to );
+ if( msg != NULL ) {
+ rmtype = msg->Get_mtype();
+ payload = msg->Get_payload();
+ fprintf( stderr, "got: mtype=%d payload=(%s)\\n",
+ rmtype, (char *) payload.get() );
+ } else {
+ msg = xfw->Alloc_msg( 2048 );
+ }
+ if( delay > 0 ) {
+ usleep( delay );
+ }
+ }
+ }
+
+
+ Figure 10: Simple looping sender application.
+
Code Review / ric-plt / xapp-frame-cpp.git / commitdiff
