task *
tk_new(task * prev_tk, /* predecessor (sp?) to the new task */
int (*start)(int), /* Where the new task starts execution. */
int stksiz, /* The size in bytes of the stack of the new task. */
char * name, /* The task's name as a string */
int arg) /* argument to the task */
{
task * tk; /* a pointer to the new task */
stack_t * sp; /* pointer to task stack area for fill */
/* create the new task */
tk = (task *)TK_ALLOC(sizeof(task));
if (tk == NULL)
{
++tk_allocfail;
return NULL; /* if no memory left, return null */
}
tk->tk_size = stksiz;
tk->tk_stack = (stack_t *)STK_ALLOC(stksiz);
if (tk->tk_stack == NULL)
{
++tk_allocfail;
TK_FREE(tk);
return NULL;
}
/* set it up to run */
tk->tk_fp = tk_frame (tk, start, arg);
/* fill stack with guardword */
sp = tk->tk_fp;
#ifdef STK_TOPDOWN /* Intel x86 "top down" stack */
sp--;
while (sp > tk->tk_stack)
{
sp--;
*sp = GUARDWORD;
}
#else /* stack moves from bottom up */
dtrap(); /* untested */
x = stksiz - (sp - tk->tk_stack); /* bytes to fill */
x = x/(sizeof(stack_t));
x++;
sp++;
while (x++ > 0)
*sp++ = GUARDWORD;
#endif
tk->tk_guard = sp;
tk->tk_flags |= TF_AWAKE; /* Schedule the task to run. */
tk->tk_next = prev_tk->tk_next; /* Fit it in after prev_tk. */
prev_tk->tk_next = tk;
tk->tk_name = name; /* Set its name */
tk->tk_count = 0; /* init the count */
return (tk);
}
TASK *
tk_new(TASK *prev_tk, void (*start)(void *), int stksiz, char *name,
uint32_t flags, void *arg)
{
TASK *tk; /* a pointer to the new task */
int i;
/* find unused task struct */
tk = tk_tasklist;
for (i = 0; i < tk_max_tasks; i++)
{
if (tk->tk_flags == 0)
break;
tk++;
}
if (i >= tk_max_tasks)
{
++tk_allocfail;
return ((TASK *)NULL); /* if no memory left, return null */
}
#ifndef SUPERLOOP
if (flags & TF_MAIN) /* task will use system stack */
{
tk->tk_size = stksiz;
tk->tk_stack = tk_getspbase() - (stksiz / sizeof(stack_t));
tk->tk_fp = tk_getsp();
}
else /* task will use private stack */
{
tk->tk_size = stksiz;
tk->tk_stack = (stack_t *)STK_ALLOC(stksiz);
if (tk->tk_stack == (stack_t *)NULL)
{
++tk_allocfail;
return ((TASK *)NULL);
}
/* set it up to run */
tk->tk_fp = tk_frame(tk, start, arg);
}
/* fill stack with guardword */
{
stack_t *sp = tk->tk_fp; /* pointer to task stack area for fill */
#ifdef STK_TOPDOWN /* Intel x86 "top down" stack */
sp--;
while (sp > tk->tk_stack)
{
sp--;
*sp = GUARDWORD;
}
tk->tk_guard = sp;
#else /* stack moves from bottom up */
dtrap(); /* untested */
x = stksiz - (sp - tk->tk_stack); /* bytes to fill */
x = x/(sizeof(stack_t));
x++;
sp++;
while (x++ > 0)
*sp++ = GUARDWORD;
#endif
}
/* add the new task to the list of tasks */
if (prev_tk)
{
tk->tk_next = prev_tk->tk_next; /* Fit it in after prev_tk. */
prev_tk->tk_next = tk;
}
else /* insert task before the current task */
{
prev_tk = tk_cur;
if (prev_tk == (TASK *)NULL)
{
tk->tk_next = tk;
tk_cur = tk;
}
else
{
while (prev_tk->tk_next != tk_cur)
prev_tk = prev_tk->tk_next;
tk->tk_next = prev_tk->tk_next; /* Fit it in after prev_tk */
prev_tk->tk_next = tk;
}
}
tk->tk_event = NULL;
if ((tk->tk_semaphore = SEM_ALLOC()) == (IN_SEM *)NULL)
{
++tk_allocfail;
return ((TASK *)NULL);
}
#else /* SUPERLOOP */
tk->tk_flags |= TF_MAIN;
tk->tk_func = start;
tk->tk_param = arg;
#endif /* SUPERLOOP */
tk->tk_name = name; /* Set its name */
tk->tk_count = 0; /* init the wakeup count */
tk->tk_waketick = 0;
tk->tk_flags |= (flags | TF_ACTIVE);
#ifndef SUPERLOOP
TK_SUSPEND(tk);
#endif
return (tk);
}
