Add WIP test_tcp_channel inside riot examples

examples/riot/test_tcp_channel/Makefile

@@ -0,0 +1,18 @@
+# name of your application
+APPLICATION = lf-test
+
+# If no BOARD is found in the environment, use this default:
+BOARD ?= native
+
+# Comment this out to disable code in RIOT that does safety checking
+# which is not needed in a production environment but helps in the
+# development process:
+DEVELHELP ?= 1
+
+# Change this to 0 show compiler invocation lines by default:
+QUIET ?= 1
+
+# Enable reactor-uc features
+CFLAGS += -DNETWORK_POSIX_TCP
+
+include $(CURDIR)/../../../make/riot/riot.mk

examples/riot/test_tcp_channel/main.c

@@ -0,0 +1,83 @@
+#include "reactor-uc/platform/posix/tcp_ip_channel.h"
+#include "reactor-uc/reactor-uc.h"
+#include <inttypes.h>
+#include <sys/socket.h>
+
+NetworkChannel *server_channel;
+NetworkChannel *client_channel;
+
+void callback_handler(FederatedConnectionBundle *self, TaggedMessage *msg) {
+  (void)self;
+  printf("Received message with connection number %i and content %s\n", msg->conn_id, (char *)msg->payload.bytes);
+  // channel.super.send_blocking(&channel.super, msg);
+}
+
+NetworkChannel *server_init(TcpIpChannel *tcp_channel, const char *host, unsigned short port) {
+  NetworkChannel *channel = &tcp_channel->super;
+
+  // creating a server that listens on loopback device on port 8903
+  TcpIpChannel_ctor(tcp_channel, host, port, AF_INET, true);
+
+  // binding to that address
+  channel->open_connection(channel);
+
+  // register receive callback for handling incoming messages
+  channel->register_receive_callback(channel, callback_handler, NULL);
+
+  return channel;
+}
+
+NetworkChannel *client_init(TcpIpChannel *tcp_channel, const char *host, unsigned short port) {
+  NetworkChannel *channel = &tcp_channel->super;
+
+  // creating a server that listens on loopback device on port 8900
+  TcpIpChannel_ctor(tcp_channel, host, port, AF_INET, false);
+
+  // binding to that address
+  channel->open_connection(channel);
+
+  return channel;
+}
+
+int main() {
+  const char *host = "127.0.0.1";
+  unsigned short port = 8903; // NOLINT
+
+  /* init server and wait for messages */
+  TcpIpChannel _server_tcp_channel;
+  server_channel = server_init(&_server_tcp_channel, host, port);
+
+  /* init client and send messages to server */
+  TcpIpChannel _client_tcp_channel;
+  client_channel = client_init(&_client_tcp_channel, host, port);
+
+  bool client_connected = false;
+  bool server_connected = false;
+  while (!client_connected && !server_connected) {
+    /* client tries to connect to server */
+    if (client_channel->try_connect(client_channel) == LF_OK) {
+      client_connected = true;
+    }
+
+    /* server tries to connect to client */
+    if (server_channel->try_connect(server_channel) == LF_OK) {
+      server_connected = true;
+    }
+  }
+
+  /* send data to server */
+  TaggedMessage port_message;
+  port_message.conn_id = 42; // NOLINT
+  const char *message = "Hello World1234";
+  memcpy(port_message.payload.bytes, message, sizeof("Hello World1234")); // NOLINT
+  port_message.payload.size = sizeof("Hello World1234");
+  for (int i = 0; i < 10; i++) {
+    client_channel->send_blocking(client_channel, &port_message);
+
+    // waiting for reply
+    // TaggedMessage *received_message = channel->receive(channel);
+
+    // printf("Received message with connection number %i and content %s\n", received_message->conn_id, (char
+    // *)received_message->payload.bytes);
+  }
+}