/* select the next thread in the ready list with top_prio
*/
static void select_next_thread(int top_prio)
{
list_node_t *pnode;
/* otherwise, threads in a ready state, then run the highest
* priority one. */
pnode = delete_front_list(&ready_list[top_prio]);
if (is_empty_list(&ready_list[top_prio]))
prio_exist_flag[top_prio] = false;
next_thread = entry_list(pnode, thread_struct, node);
next_thread->state = RUNNING;
next_thread->time_quantum = TIME_QUANTUM;
}
void start_curt()
{
cpu_sr_t cpu_sr;
list_node_t *pnode;
int top_prio;
cpu_sr = save_cpu_sr();
is_start_os = true;
/* examine the highest priority thread executed */
top_prio = get_top_prio();
pnode = delete_front_list(&ready_list[top_prio]);
if (is_empty_list(&ready_list[top_prio]))
prio_exist_flag[top_prio] = false;
current_thread = entry_list(pnode, thread_struct, node);
current_thread->state = RUNNING;
restore_cpu_sr(cpu_sr);
restore_context();
}
void sem_post(sem_struct *sem)
{
thread_struct *pthread;
cpu_sr_t cpu_sr;
cpu_sr = save_cpu_sr();
if (!is_empty_list(&sem->wait_list)) {
pthread = entry_list(delete_front_list(&sem->wait_list),
thread_struct, node);
pthread->state = READY;
insert_back_list(&ready_list[pthread->prio], &pthread->node);
prio_exist_flag[pthread->prio] = true;
restore_cpu_sr(cpu_sr);
schedule(SCHED_THREAD_REQUEST);
return;
}
sem->value++;
restore_cpu_sr(cpu_sr);
}
/**
* @brief rountine for idle thread
* @param data
*/
void idle_thread_func(void *data)
{
cpu_sr_t cpu_sr;
thread_struct *pthread;
list_node_t *pnode;
while (1) {
cpu_sr = save_cpu_sr();
/* check if there is any terminated thread to be recycled */
if (!is_empty_list(&termination_wait_list)) {
pnode = delete_front_list(&termination_wait_list);
pthread = entry_list(pnode, thread_struct, node);
thread_table[pthread->tid] = NULL;
total_thread_cnt--;
}
restore_cpu_sr(cpu_sr);
/* always does this */
thread_yield();
}
}
