+ thread = convert_port_to_thread(port);
+ ip_release(port);
+
+ if (thread == self) {
+ (void)thread_deallocate_internal(thread);
+ thread = THREAD_NULL;
+ }
+ }
+ else
+ thread = THREAD_NULL;
+ }
+ else
+ thread = THREAD_NULL;
+
+
+ if (option == SWITCH_OPTION_OSLOCK_DEPRESS || option == SWITCH_OPTION_OSLOCK_WAIT) {
+ if (thread != THREAD_NULL) {
+
+ if (thread->task != self->task) {
+ /*
+ * OSLock boosting only applies to other threads
+ * in your same task (even if you have a port for
+ * a thread in another task)
+ */
+
+ (void)thread_deallocate_internal(thread);
+ thread = THREAD_NULL;
+ } else {
+ /*
+ * Attempt to kick the lock owner up to our same IO throttling tier.
+ * If the thread is currently blocked in throttle_lowpri_io(),
+ * it will immediately break out.
+ */
+ int new_policy = proc_get_effective_thread_policy(self, TASK_POLICY_IO);
+
+ set_thread_iotier_override(thread, new_policy);
+ }
+ }
+ }
+
+ /*
+ * Try to handoff if supplied.
+ */
+ if (thread != THREAD_NULL) {
+ processor_t processor;
+ spl_t s;
+
+ s = splsched();
+ thread_lock(thread);
+
+ /*
+ * Check that the thread is not bound
+ * to a different processor, and that realtime
+ * is not involved.
+ *
+ * Next, pull it off its run queue. If it
+ * doesn't come, it's not eligible.
+ */
+ processor = current_processor();
+ if (processor->current_pri < BASEPRI_RTQUEUES &&
+ thread->sched_pri < BASEPRI_RTQUEUES &&
+ (thread->bound_processor == PROCESSOR_NULL ||
+ thread->bound_processor == processor) &&
+ thread_run_queue_remove(thread) ) {
+ /*
+ * Hah, got it!!
+ */
+ thread_unlock(thread);
+
+ (void)thread_deallocate_internal(thread);
+
+ if (wait_option)
+ assert_wait_timeout((event_t)assert_wait_timeout, THREAD_ABORTSAFE,
+ option_time, scale_factor);
+ else
+ if (depress_option)
+ thread_depress_ms(option_time);
+
+ self->saved.swtch.option = option;
+ self->saved.swtch.reenable_workq_callback = reenable_workq_callback;
+
+ thread_run(self, (thread_continue_t)thread_switch_continue, NULL, thread);
+ /* NOTREACHED */
+ }
+
+ thread_unlock(thread);
+ splx(s);
+
+ thread_deallocate(thread);
+ }
+
+ if (wait_option)
+ assert_wait_timeout((event_t)assert_wait_timeout, THREAD_ABORTSAFE, option_time, scale_factor);
+ else
+ if (depress_option)
+ thread_depress_ms(option_time);
+
+ self->saved.swtch.option = option;
+ self->saved.swtch.reenable_workq_callback = reenable_workq_callback;
+
+ thread_block_reason((thread_continue_t)thread_switch_continue, NULL, AST_YIELD);
+
+ if (depress_option)
+ thread_depress_abort_internal(self);
+
+ if (reenable_workq_callback)
+ thread_switch_enable_workqueue_sched_callback();
+
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Depress thread's priority to lowest possible for the specified interval,
+ * with a value of zero resulting in no timeout being scheduled.
+ */
+void
+thread_depress_abstime(
+ uint64_t interval)
+{
+ register thread_t self = current_thread();
+ uint64_t deadline;
+ spl_t s;
+
+ s = splsched();
+ thread_lock(self);
+ if (!(self->sched_flags & TH_SFLAG_DEPRESSED_MASK)) {
+ processor_t myprocessor = self->last_processor;
+
+ self->sched_pri = DEPRESSPRI;
+ myprocessor->current_pri = self->sched_pri;
+ self->sched_flags |= TH_SFLAG_DEPRESS;
+
+ if (interval != 0) {
+ clock_absolutetime_interval_to_deadline(interval, &deadline);
+ if (!timer_call_enter(&self->depress_timer, deadline, TIMER_CALL_USER_CRITICAL))
+ self->depress_timer_active++;
+ }
+ }
+ thread_unlock(self);
+ splx(s);
+}
+
+void
+thread_depress_ms(
+ mach_msg_timeout_t interval)
+{
+ uint64_t abstime;
+
+ clock_interval_to_absolutetime_interval(
+ interval, NSEC_PER_MSEC, &abstime);
+ thread_depress_abstime(abstime);
+}
+
+/*
+ * Priority depression expiration.
+ */
+void
+thread_depress_expire(
+ void *p0,
+ __unused void *p1)
+{
+ thread_t thread = p0;
+ spl_t s;
+
+ s = splsched();
+ thread_lock(thread);
+ if (--thread->depress_timer_active == 0) {
+ thread->sched_flags &= ~TH_SFLAG_DEPRESSED_MASK;
+ SCHED(compute_priority)(thread, FALSE);
+ }
+ thread_unlock(thread);
+ splx(s);
+}
+
+/*
+ * Prematurely abort priority depression if there is one.
+ */
+kern_return_t
+thread_depress_abort_internal(
+ thread_t thread)
+{
+ kern_return_t result = KERN_NOT_DEPRESSED;
+ spl_t s;
+
+ s = splsched();
+ thread_lock(thread);
+ if (!(thread->sched_flags & TH_SFLAG_POLLDEPRESS)) {
+ if (thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) {
+ thread->sched_flags &= ~TH_SFLAG_DEPRESSED_MASK;
+ SCHED(compute_priority)(thread, FALSE);
+ result = KERN_SUCCESS;
+ }
+
+ if (timer_call_cancel(&thread->depress_timer))
+ thread->depress_timer_active--;
+ }
+ thread_unlock(thread);
+ splx(s);
+
+ return (result);
+}
+
+void
+thread_poll_yield(
+ thread_t self)
+{
+ spl_t s;
+
+ assert(self == current_thread());
+
+ s = splsched();
+ if (self->sched_mode == TH_MODE_FIXED) {
+ uint64_t total_computation, abstime;
+
+ abstime = mach_absolute_time();
+ total_computation = abstime - self->computation_epoch;
+ total_computation += self->computation_metered;
+ if (total_computation >= max_poll_computation) {
+ processor_t myprocessor = current_processor();
+ ast_t preempt;
+
+ thread_lock(self);
+ if (!(self->sched_flags & TH_SFLAG_DEPRESSED_MASK)) {
+ self->sched_pri = DEPRESSPRI;
+ myprocessor->current_pri = self->sched_pri;
+ }
+ self->computation_epoch = abstime;
+ self->computation_metered = 0;
+ self->sched_flags |= TH_SFLAG_POLLDEPRESS;
+
+ abstime += (total_computation >> sched_poll_yield_shift);
+ if (!timer_call_enter(&self->depress_timer, abstime, TIMER_CALL_USER_CRITICAL))
+ self->depress_timer_active++;
+ thread_unlock(self);
+
+ if ((preempt = csw_check(myprocessor)) != AST_NONE)
+ ast_on(preempt);
projects / apple / xnu.git / blobdiff