With RTX Kernel

Even though RL-TCPnet is designed as a stand alone TCP/IP Operating System, you can use it with the RTX kernel. This is useful for large complex applications, where different jobs are implemented as tasks. In this case, the basic framework is different because the functions from the stand alone framework are moved into tasks.

The following tasks are introduced:

• tcp_init task is used to initialize the system. Since the task is not needed after initialization is complete, the task can be terminated.
• tcp_main task runs the main thread for RL-TCPnet. It must have the lowest priority in the system. Otherwise, the tasks with a lower priority than the tcp_poll task will never execute.
• tcp_tick task generates periodic ticks for RL-TCPnet. For proper timing, the interval timer and the kernel timer reload value must be set in the Net_Config.c configuration file. The interval time should be the same as set in the configuration file.

  When the timings are not correct, the application might fail to complete certain functions. For example, requests may retransmit too fast, or the waiting timeout might expire before receiving a valid response from a remote server.

Here is a framework for the RTX kernel application:

#include <RTL.h>

__task void tcp_tick (void) {
  os_itv_set (10);
  while (1) {
    os_itv_wait ();
    /* Timer tick every 100 ms */
    timer_tick ();
  }
}

__task void tcp_main (void) {
  while (1) {
    main_TcpNet ();
    os_tsk_pass ();
  }
}

__task void tcp_init (void) {
  system_init ();
  init_TcpNet ();
  os_tsk_create (tcp_tick, 2);
  os_tsk_create (tcp_main, 1);
  /* Init done, terminate this task. */
  os_tsk_delete_self ();
}

void main (void) {
  os_sys_init (tcp_init);
}

Follow these guidelines when using RL-TCPnet with the RTX kernel:

• Functions are not reentrant. This means they must not be interrupted and called again from another task. All TCPnet-related functionality should be collected in a single networking task.
• All callback functions are executed from the networking task. Use the kernel event, semaphore, and mailbox functions to communicate with other tasks.