static kern_return_t
thread_create_internal2(
task_t task,
thread_t *new_thread,
boolean_t from_user)
{
kern_return_t result;
thread_t thread;
if (task == TASK_NULL || task == kernel_task)
return (KERN_INVALID_ARGUMENT);
result = thread_create_internal(task, -1, (thread_continue_t)thread_bootstrap_return, TH_OPTION_NONE, &thread);
if (result != KERN_SUCCESS)
return (result);
thread->user_stop_count = 1;
thread_hold(thread);
if (task->suspend_count > 0)
thread_hold(thread);
if (from_user)
extmod_statistics_incr_thread_create(task);
task_unlock(task);
lck_mtx_unlock(&tasks_threads_lock);
*new_thread = thread;
return (KERN_SUCCESS);
}
kern_return_t
thread_create_workq(
task_t task,
thread_continue_t thread_return,
thread_t *new_thread)
{
kern_return_t result;
thread_t thread;
if (task == TASK_NULL || task == kernel_task)
return (KERN_INVALID_ARGUMENT);
result = thread_create_internal(task, -1, thread_return, TH_OPTION_NOCRED | TH_OPTION_NOSUSP, &thread);
if (result != KERN_SUCCESS)
return (result);
thread->user_stop_count = 1;
thread_hold(thread);
if (task->suspend_count > 0)
thread_hold(thread);
task_unlock(task);
lck_mtx_unlock(&tasks_threads_lock);
*new_thread = thread;
return (KERN_SUCCESS);
}
kern_return_t
thread_create(
task_t task,
thread_t *new_thread)
{
kern_return_t result;
thread_t thread;
if (task == TASK_NULL || task == kernel_task)
return (KERN_INVALID_ARGUMENT);
result = thread_create_internal(task, -1, (thread_continue_t)thread_bootstrap_return, &thread);
if (result != KERN_SUCCESS)
return (result);
thread->user_stop_count = 1;
thread_hold(thread);
if (task->suspend_count > 0)
thread_hold(thread);
task_unlock(task);
mutex_unlock(&tasks_threads_lock);
*new_thread = thread;
return (KERN_SUCCESS);
}
/*
* Change thread's machine-dependent state. Called with nothing
* locked. Returns same way.
*/
kern_return_t
thread_set_state(
register thread_act_t act,
int flavor,
thread_state_t state,
mach_msg_type_number_t state_count)
{
kern_return_t result = KERN_SUCCESS;
thread_t thread;
if (act == THR_ACT_NULL || act == current_act())
return (KERN_INVALID_ARGUMENT);
thread = act_lock_thread(act);
if (!act->active) {
act_unlock_thread(act);
return (KERN_TERMINATED);
}
thread_hold(act);
for (;;) {
thread_t thread1;
if ( thread == THREAD_NULL ||
thread->top_act != act )
break;
act_unlock_thread(act);
if (!thread_stop(thread)) {
result = KERN_ABORTED;
(void)act_lock_thread(act);
thread = THREAD_NULL;
break;
}
thread1 = act_lock_thread(act);
if (thread1 == thread)
break;
thread_unstop(thread);
thread = thread1;
}
if (result == KERN_SUCCESS)
result = machine_thread_set_state(act, flavor, state, state_count);
if ( thread != THREAD_NULL &&
thread->top_act == act )
thread_unstop(thread);
thread_release(act);
act_unlock_thread(act);
return (result);
}
kern_return_t
thread_dup(
register thread_act_t target)
{
kern_return_t result = KERN_SUCCESS;
thread_act_t self = current_act();
thread_t thread;
if (target == THR_ACT_NULL || target == self)
return (KERN_INVALID_ARGUMENT);
thread = act_lock_thread(target);
if (!target->active) {
act_unlock_thread(target);
return (KERN_TERMINATED);
}
thread_hold(target);
for (;;) {
thread_t thread1;
if ( thread == THREAD_NULL ||
thread->top_act != target )
break;
act_unlock_thread(target);
if (!thread_stop(thread)) {
result = KERN_ABORTED;
(void)act_lock_thread(target);
thread = THREAD_NULL;
break;
}
thread1 = act_lock_thread(target);
if (thread1 == thread)
break;
thread_unstop(thread);
thread = thread1;
}
if (result == KERN_SUCCESS)
result = machine_thread_dup(self, target);
if ( thread != THREAD_NULL &&
thread->top_act == target )
thread_unstop(thread);
thread_release(target);
act_unlock_thread(target);
return (result);
}
/*
* thread_stop_freeze
* Block the thread in the kernel and freeze the processor set.
* return value:
* TRUE - the thread has blocked interruptibly, is stopped, and
* the processor set assignment is frozen
* FALSE - the thread is no longer in the processor set, so it
* isn't stopped, and the processor set assignment
* is released.
*/
int
thread_stop_freeze( thread_t thread, processor_set_t pset )
{
thread_act_t thr_act;
spl_t s;
/*
* hold it, and wait for it to stop.
*/
thr_act = thread_lock_act(thread);
thread_hold(thr_act);
act_unlock_thread(thr_act);
thread_stop(thread);
s = splsched();
wake_lock(thread);
while( thread->state & (TH_RUN|TH_UNINT) ) {
thread->wake_active = TRUE;
assert_wait((event_t)&thread->wake_active, FALSE);
wake_unlock(thread);
splx(s);
thread_block( (void (*)(void)) 0 );
(void) splsched();
wake_lock(thread);
}
/*
* Now, the thread has blocked uninterruptibly; freeze the
* assignment and make sure it's still part of the processor set.
*/
wake_unlock(thread);
thread_freeze(thread);
thread_lock(thread);
/*
* if the processor set has changed, release the freeze and
* then unstop it.
*/
if( thread->processor_set != pset ) {
thread_unlock(thread);
splx(s);
thread_unfreeze(thread);
thread_unstop(thread);
return FALSE;
}
thread_unlock(thread);
splx(s);
return TRUE;
}
kern_return_t
thread_get_state(
register thread_t thread,
int flavor,
thread_state_t state, /* pointer to OUT array */
mach_msg_type_number_t *state_count) /*IN/OUT*/
{
kern_return_t result = KERN_SUCCESS;
if (thread == THREAD_NULL)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(thread);
if (thread->active) {
if (thread != current_thread()) {
thread_hold(thread);
thread_mtx_unlock(thread);
if (thread_stop(thread, FALSE)) {
thread_mtx_lock(thread);
result = machine_thread_get_state(
thread, flavor, state, state_count);
thread_unstop(thread);
}
else {
thread_mtx_lock(thread);
result = KERN_ABORTED;
}
thread_release(thread);
}
else
result = machine_thread_get_state(
thread, flavor, state, state_count);
}
else if (thread->inspection)
{
result = machine_thread_get_state(
thread, flavor, state, state_count);
}
else
result = KERN_TERMINATED;
thread_mtx_unlock(thread);
return (result);
}
/*
* Change thread's machine-dependent state. Called with nothing
* locked. Returns same way.
*/
static kern_return_t
thread_set_state_internal(
register thread_t thread,
int flavor,
thread_state_t state,
mach_msg_type_number_t state_count,
boolean_t from_user)
{
kern_return_t result = KERN_SUCCESS;
if (thread == THREAD_NULL)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(thread);
if (thread->active) {
if (thread != current_thread()) {
thread_hold(thread);
thread_mtx_unlock(thread);
if (thread_stop(thread, TRUE)) {
thread_mtx_lock(thread);
result = machine_thread_set_state(
thread, flavor, state, state_count);
thread_unstop(thread);
}
else {
thread_mtx_lock(thread);
result = KERN_ABORTED;
}
thread_release(thread);
}
else
result = machine_thread_set_state(
thread, flavor, state, state_count);
}
else
result = KERN_TERMINATED;
if ((result == KERN_SUCCESS) && from_user)
extmod_statistics_incr_thread_set_state(thread);
thread_mtx_unlock(thread);
return (result);
}
kern_return_t
thread_dup2(
thread_t source,
thread_t target)
{
kern_return_t result = KERN_SUCCESS;
uint32_t active = 0;
if (source == THREAD_NULL || target == THREAD_NULL || target == source)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(source);
active = source->active;
thread_mtx_unlock(source);
if (!active) {
return KERN_TERMINATED;
}
thread_mtx_lock(target);
if (target->active || target->inspection) {
thread_hold(target);
thread_mtx_unlock(target);
if (thread_stop(target, TRUE)) {
thread_mtx_lock(target);
result = machine_thread_dup(source, target);
if (source->affinity_set != AFFINITY_SET_NULL)
thread_affinity_dup(source, target);
thread_unstop(target);
}
else {
thread_mtx_lock(target);
result = KERN_ABORTED;
}
thread_release(target);
}
else
result = KERN_TERMINATED;
thread_mtx_unlock(target);
return (result);
}
/*
* Change thread's machine-dependent userspace TSD base.
* Called with nothing locked. Returns same way.
*/
kern_return_t
thread_set_tsd_base(
thread_t thread,
mach_vm_offset_t tsd_base)
{
kern_return_t result = KERN_SUCCESS;
if (thread == THREAD_NULL)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(thread);
if (thread->active) {
if (thread != current_thread()) {
thread_hold(thread);
thread_mtx_unlock(thread);
if (thread_stop(thread, TRUE)) {
thread_mtx_lock(thread);
result = machine_thread_set_tsd_base(thread, tsd_base);
thread_unstop(thread);
}
else {
thread_mtx_lock(thread);
result = KERN_ABORTED;
}
thread_release(thread);
}
else
result = machine_thread_set_tsd_base(thread, tsd_base);
}
else
result = KERN_TERMINATED;
thread_mtx_unlock(thread);
return (result);
}
kern_return_t
thread_dup(
register thread_t target)
{
thread_t self = current_thread();
kern_return_t result = KERN_SUCCESS;
if (target == THREAD_NULL || target == self)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(target);
if (target->active) {
thread_hold(target);
thread_mtx_unlock(target);
if (thread_stop(target, TRUE)) {
thread_mtx_lock(target);
result = machine_thread_dup(self, target);
if (self->affinity_set != AFFINITY_SET_NULL)
thread_affinity_dup(self, target);
thread_unstop(target);
}
else {
thread_mtx_lock(target);
result = KERN_ABORTED;
}
thread_release(target);
}
else
result = KERN_TERMINATED;
thread_mtx_unlock(target);
return (result);
}
kern_return_t
thread_suspend(thread_t thread)
{
kern_return_t result = KERN_SUCCESS;
if (thread == THREAD_NULL || thread->task == kernel_task)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(thread);
if (thread->active) {
if (thread->user_stop_count++ == 0)
thread_hold(thread);
} else {
result = KERN_TERMINATED;
}
thread_mtx_unlock(thread);
if (thread != current_thread() && result == KERN_SUCCESS)
thread_wait(thread, FALSE);
return (result);
}
/*
* task_swap_swapout_thread: [exported]
*
* Executes as a separate kernel thread.
* Its job is to swap out threads that have been halted by AST_SWAPOUT.
*/
void
task_swap_swapout_thread(void)
{
thread_act_t thr_act;
thread_t thread, nthread;
task_t task;
int s;
thread_swappable(current_act(), FALSE);
stack_privilege(current_thread());
spllo();
while (TRUE) {
task_swapper_lock();
while (! queue_empty(&swapout_thread_q)) {
queue_remove_first(&swapout_thread_q, thr_act,
thread_act_t, swap_queue);
/*
* If we're racing with task_swapin, we need
* to make it safe for it to do remque on the
* thread, so make its links point to itself.
* Allowing this ugliness is cheaper than
* making task_swapin search the entire queue.
*/
act_lock(thr_act);
queue_init((queue_t) &thr_act->swap_queue);
act_unlock(thr_act);
task_swapper_unlock();
/*
* Wait for thread's RUN bit to be deasserted.
*/
thread = act_lock_thread(thr_act);
if (thread == THREAD_NULL)
act_unlock_thread(thr_act);
else {
boolean_t r;
thread_reference(thread);
thread_hold(thr_act);
act_unlock_thread(thr_act);
r = thread_stop_wait(thread);
nthread = act_lock_thread(thr_act);
thread_release(thr_act);
thread_deallocate(thread);
act_unlock_thread(thr_act);
if (!r || nthread != thread) {
task_swapper_lock();
continue;
}
}
task = thr_act->task;
task_lock(task);
/*
* we can race with swapin, which would set the
* state to TASK_SW_IN.
*/
if ((task->swap_state != TASK_SW_OUT) &&
(task->swap_state != TASK_SW_GOING_OUT)) {
task_unlock(task);
task_swapper_lock();
TASK_STATS_INCR(task_sw_race_in_won);
if (thread != THREAD_NULL)
thread_unstop(thread);
continue;
}
nthread = act_lock_thread(thr_act);
if (nthread != thread || thr_act->active == FALSE) {
act_unlock_thread(thr_act);
task_unlock(task);
task_swapper_lock();
TASK_STATS_INCR(task_sw_act_inactive);
if (thread != THREAD_NULL)
thread_unstop(thread);
continue;
}
s = splsched();
if (thread != THREAD_NULL)
thread_lock(thread);
/*
* Thread cannot have been swapped out yet because
* TH_SW_TASK_SWAPPING was set in AST. If task_swapin
* beat us here, we either wouldn't have found it on
* the queue, or the task->swap_state would have
* changed. The synchronization is on the
* task's swap_state and the task_lock.
* The thread can't be swapped in any other way
* because its task has been swapped.
*/
assert(thr_act->swap_state & TH_SW_TASK_SWAPPING);
assert(thread == THREAD_NULL ||
!(thread->state & (TH_SWAPPED_OUT|TH_RUN)));
assert((thr_act->swap_state & TH_SW_STATE) == TH_SW_IN);
/* assert(thread->state & TH_HALTED); */
/* this also clears TH_SW_TASK_SWAPPING flag */
thr_act->swap_state = TH_SW_GOING_OUT;
if (thread != THREAD_NULL) {
if (thread->top_act == thr_act) {
thread->state |= TH_SWAPPED_OUT;
/*
* Once we unlock the task, things can happen
* to the thread, so make sure it's consistent
* for thread_swapout.
*/
}
thread->ref_count++;
thread_unlock(thread);
thread_unstop(thread);
}
splx(s);
act_locked_act_reference(thr_act);
act_unlock_thread(thr_act);
task_unlock(task);
thread_swapout(thr_act); /* do the work */
if (thread != THREAD_NULL)
thread_deallocate(thread);
act_deallocate(thr_act);
task_swapper_lock();
}
assert_wait((event_t)&swapout_thread_q, FALSE);
task_swapper_unlock();
thread_block((void (*)(void)) 0);
}
}
