void
tk_kill(task * tk_to_die)
{
task *tk;
if(tk_died) /* Is another task in the process of dying? */
{
tk_yield(); /* this should allow it to finish */
if(tk_died) /* Other task still dying? */
{
dtrap(); /* system bug */
}
}
/* hunt for the task which tk_to_die is the successor of */
for (tk = tk_cur; tk->tk_next != tk_to_die; tk = tk->tk_next) ;
/* now patch around tk_to_die */
tk->tk_next = tk_to_die->tk_next;
/* If I'm killing myself, die the next time I block */
if (tk_cur == tk_to_die)
{
tk_died = tk_cur;
}
else
tk_del(tk_to_die);
}
void
tk_block ()
{
char msg[255];
task * tk = tk_cur; /* the next task to run */
/* check if the guard word is still intact */
if (*(tk->tk_guard) != GUARDWORD)
{
sprintf(msg, "tk_block stack: task name = %s", tk->tk_name);
panic(msg);
return;
}
#ifdef NPDEBUG
if (TDEBUG)
dprintf("TASK: Task %s blocking.\n", tk->tk_name);
#endif
IN_PROFILER(PF_IDLE, PF_ENTRY); /* measure time in the idle loop */
/* find the next ready to run task */
do
{
tk = tk->tk_next;
/* see if a sleeping task is ready to wake */
if (tk->tk_waketick && tk->tk_waketick < cticks)
{
tk->tk_waketick = 0; /* clear wakeup tick flag */
break; /* go run this task */
}
} while ((tk->tk_flags & TF_AWAKE) == 0);
IN_PROFILER(PF_IDLE, PF_EXIT);
tk->tk_flags &= ~TF_AWAKE; /* clear wake flag before it runs */
tk_switch (tk); /* Run the next task. */
#ifdef NPDEBUG
if (TDEBUG)
dprintf("TASK: Task %s running\n", tk_cur->tk_name);
#endif
if (tk_died)
{
tk_del(tk_died); /* delete dead task */
tk_died = NULL; /* clear pointer/flag */
}
}
/* FUNCTION: tk_block()
*
* Block the currently running task and run the next task in the
* circular list of tasks that is awake. Before returning, see if any
* cleanup has to be done for another task.
*
* PARAMS: task * pointer to currently executing task or NULL
*
* RETURN: none
*/
void
tk_block(TASK *tk_old)
{
TASK *tk, *tk_prev;
/* check the stack of the currently executing task for overflow */
if (tk_old != (TASK *)NULL)
{
/* check if the guard word is still intact */
if (*(tk_cur->tk_guard) != GUARDWORD)
{
dprintf("tk_block stack: task name = %s", tk_cur->tk_name);
dtrap();
return;
}
}
#ifdef NPDEBUG
if (TDEBUG)
dprintf("TASK: Task %s blocking.\n", tk_cur->tk_name);
#endif
IN_PROFILER(PF_IDLE, PF_ENTRY); /* measure time in the idle loop */
/* find the next ready to run task */
tk = tk_cur;
#ifdef DEBUG_TASK_STATE
dprintf("tk_block: %s, flags = %lx, event = %p\n",
tk->tk_name, tk->tk_flags, tk->tk_event);
#endif
do
{
tk_prev = tk;
tk = tk->tk_next;
/* TODO: check for deleted task here */
/* see if a sleeping task is ready to wake */
if ((tk->tk_flags & TF_TIMER) && TIME_EXP(tk->tk_waketick, CTICKS))
{
tk_timeout(tk); /* clean up after timeout */
}
} while (!(tk->tk_flags & TF_AWAKE));
IN_PROFILER(PF_IDLE, PF_EXIT);
tk->tk_count++; /* increment wakeup count */
tk_cur = tk; /* update current task pointer */
#ifdef NPDEBUG
if (TDEBUG)
dprintf("TASK: Task %s running\n", tk->tk_name);
#endif
#ifdef DEBUG_TASK_STATE
dprintf("tk_ready: %s, flags = %lx, event = %p\n",
tk->tk_name, tk->tk_flags, tk->tk_event);
#endif
tk_switch (tk, tk_old); /* Run the next task. */
if (tk_died)
{
tk_del(tk_died); /* delete dead task */
tk_died = NULL; /* clear pointer/flag */
}
}