unsigned bitarithm_msb(unsigned v)
{
if ((signed) v >= 0) {
v &= -v;
return bitarithm_lsb(v);
}
else {
return sizeof (v) * 8 - 1;
}
}
static void test_bitarithm_lsb_random(void)
{
TEST_ASSERT_EQUAL_INT(3, bitarithm_lsb(8)); /* randomized by fair
dice roll ;-) */
}
static void test_bitarithm_lsb_limit(void)
{
TEST_ASSERT_EQUAL_INT(0, bitarithm_lsb(UINT_MAX));
}
static void test_bitarithm_lsb_one(void)
{
TEST_ASSERT_EQUAL_INT(0, bitarithm_lsb(1));
}
int sched_run(void)
{
sched_context_switch_request = 0;
thread_t *active_thread = (thread_t *)sched_active_thread;
/* The bitmask in runqueue_bitcache is never empty,
* since the threading should not be started before at least the idle thread was started.
*/
int nextrq = bitarithm_lsb(runqueue_bitcache);
thread_t *next_thread = clist_get_container(sched_runqueues[nextrq], thread_t, rq_entry);
DEBUG("sched_run: active thread: %" PRIkernel_pid ", next thread: %" PRIkernel_pid "\n",
(active_thread == NULL) ? KERNEL_PID_UNDEF : active_thread->pid,
next_thread->pid);
if (active_thread == next_thread) {
DEBUG("sched_run: done, sched_active_thread was not changed.\n");
return 0;
}
#ifdef MODULE_SCHEDSTATISTICS
unsigned long time = xtimer_now();
#endif
if (active_thread) {
if (active_thread->status == STATUS_RUNNING) {
active_thread->status = STATUS_PENDING;
}
#ifdef SCHED_TEST_STACK
if (*((uintptr_t *) active_thread->stack_start) != (uintptr_t) active_thread->stack_start) {
LOG_WARNING("scheduler(): stack overflow detected, pid=%" PRIkernel_pid "\n", active_thread->pid);
}
#endif
#ifdef MODULE_SCHEDSTATISTICS
schedstat *active_stat = &sched_pidlist[active_thread->pid];
if (active_stat->laststart) {
active_stat->runtime_ticks += time - active_stat->laststart;
}
#endif
}
#ifdef MODULE_SCHEDSTATISTICS
schedstat *next_stat = &sched_pidlist[next_thread->pid];
next_stat->laststart = time;
next_stat->schedules++;
if (sched_cb) {
sched_cb(time, next_thread->pid);
}
#endif
next_thread->status = STATUS_RUNNING;
sched_active_pid = next_thread->pid;
sched_active_thread = (volatile thread_t *) next_thread;
DEBUG("sched_run: done, changed sched_active_thread.\n");
return 1;
}
static int _ctx(gpio_t pin)
{
int i = bitarithm_lsb(_pin(pin));
return (_port(pin) == PORT_1) ? i : (i + 8);
}
