/*
* Reset thread to default state in preparation for termination
* Called with thread mutex locked
*
* Always called on current thread, so we don't need a run queue remove
*/
void
thread_policy_reset(
thread_t thread)
{
spl_t s;
assert(thread == current_thread());
s = splsched();
thread_lock(thread);
assert_thread_sched_count(thread);
if (thread->sched_flags & TH_SFLAG_FAILSAFE)
sched_thread_mode_undemote(thread, TH_SFLAG_FAILSAFE);
assert_thread_sched_count(thread);
if (thread->sched_flags & TH_SFLAG_THROTTLED)
sched_set_thread_throttled(thread, FALSE);
assert_thread_sched_count(thread);
assert(thread->BG_COUNT == 0);
/* At this point, the various demotions should be inactive */
assert(!(thread->sched_flags & TH_SFLAG_DEMOTED_MASK));
assert(!(thread->sched_flags & TH_SFLAG_THROTTLED));
assert(!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK));
/* Reset thread back to task-default basepri and mode */
sched_mode_t newmode = SCHED(initial_thread_sched_mode)(thread->task);
sched_set_thread_mode(thread, newmode);
thread->importance = 0;
sched_set_thread_base_priority(thread, thread->task_priority);
/* Prevent further changes to thread base priority or mode */
thread->policy_reset = 1;
assert(thread->BG_COUNT == 0);
assert_thread_sched_count(thread);
thread_unlock(thread);
splx(s);
}
/*
* Set the thread's requested mode
* Called with thread mutex and thread locked
*/
static void
thread_set_user_sched_mode(thread_t thread, sched_mode_t mode)
{
if (thread->policy_reset)
return;
/*
* TODO: Instead of having saved mode, have 'user mode' and 'true mode'.
* That way there's zero confusion over which the user wants
* and which the kernel wants.
*/
if (thread->sched_flags & TH_SFLAG_DEMOTED_MASK)
thread->saved_mode = mode;
else
sched_set_thread_mode(thread, mode);
}
/*
* Set the thread's requested mode and recompute priority
* Called with thread mutex and thread locked
*
* TODO: Mitigate potential problems caused by moving thread to end of runq
* whenever its priority is recomputed
* Only remove when it actually changes? Attempt to re-insert at appropriate location?
*/
static void
thread_set_user_sched_mode_and_recompute_pri(thread_t thread, sched_mode_t mode)
{
if (thread->policy_reset)
return;
boolean_t removed = thread_run_queue_remove(thread);
/*
* TODO: Instead of having saved mode, have 'user mode' and 'true mode'.
* That way there's zero confusion over which the user wants
* and which the kernel wants.
*/
if (thread->sched_flags & TH_SFLAG_DEMOTED_MASK)
thread->saved_mode = mode;
else
sched_set_thread_mode(thread, mode);
thread_recompute_priority(thread);
if (removed)
thread_run_queue_reinsert(thread, SCHED_TAILQ);
}
