os_tsk_create_user_ex

#include <rtl.h>

OS_TID os_tsk_create_user_ex (
    void (*task)(void *),    /* Task to create */
    U8    priority,          /* Task priority (1-254) */
    void* stk,               /* Pointer to the task's stack */
    U16   size,              /* Size of stack in bytes */
    void* argv );            /* Argument to the task */

The os_tsk_create_user_ex function creates the task identified by the task function pointer argument and then adds the task to the ready queue. It dynamically assigns a task identifier value (TID) to the new task. This function enables you to provide a separate stack for the task. This is useful when a task needs a bigger stack for its local variables. The os_tsk_create_user_ex function is an extension to the os_tsk_create_user function that enables you to pass an argument to the task.

The priority argument specifies the priority for the task. The default task priority is 1. Priority 0 is reserved for the Idle Task. If a value of 0 is specified for the priority, it is automatically replaced with a value of 1. Priority 255 is also reserved. If the new task has a higher priority than the currently executing task, then a task switch occurs immediately to execute the new task.

The stk argument is a pointer to the memory block reserved for the stack of this task. The size argument specifies the number of bytes in the stack.

The argv argument is passed directly to the task when it starts. An argument to a task can be useful to differentiate between multiple instances of the same task. Multiple instances of the same task can behave differently based on the argument.

The os_tsk_create_user_ex function is in the RL-RTX library. The prototype is defined in rtl.h.

note

• The stack stk must be aligned at an 8-byte boundary and must be declared as an array of type U64 (unsigned long long).
• The default stack size is defined in rtx_config.c.

The os_tsk_create_user_ex function returns the task identifier value (TID) of the new task. If the function fails, for example due to an invalid argument, it returns 0.

os_tsk_create, os_tsk_create_ex, os_tsk_create_user

#include <rtl.h>

OS_TID tsk1,tsk2_0,tsk2_1;
static U64 stk2[2][400/8];

__task void task1 (void) {
   ..
  /* Create task 2 with a bigger stack */
  tsk2_0 = os_tsk_create_user_ex (task2, 1,
                                  &stk2[0], sizeof(stk2[0]),
                                  (void *)0);
  tsk2_1 = os_tsk_create_user_ex (task2, 1,
                                  &stk2[1], sizeof(stk2[1]),
                                  (void *)1);
   ..
}

__task void task2 (void *argv) {
  /* We need a bigger stack here. */
  U8 buf[200];

   ..
  switch ((int)argv) {
    case 0:
      printf("This is a first instance of task2.\n");
      break;
    case 1:
      printf("This is a second instance of task2.\n");
      break;
  }
   ..
}