/*
* Schedule the next runnable fiber.
* Assumes the _runq is NOT empty
*/
void
_fiber_schedule_next (void)
{
thread_t *thr;
int i;
if (_current_fiber->thr_status == RUNNING)
_fiber_status (_current_fiber, RUNNABLE);
#ifdef EXPIRIMENTAL
while (_thread_num_runnable == 0)
_fiber_event_loop ();
#endif
thr = NULL;
for (i = MAX_PRIORITY; --i >= 0; )
if (_runq[i].thq_count)
{
thr = (thread_t *) _runq[i].thq_head.thr_next;
break;
}
assert (thr != NULL);
_fiber_status (thr, RUNNING);
if (_current_fiber != thr)
_fiber_switch (thr);
}
void
semaphore_free (semaphore_t *sem)
{
thread_t *thr;
while ((thr = thread_queue_from (&sem->sem_waiting)) != NULL)
_fiber_status (thr, RUNNABLE);
dk_free (sem, sizeof (semaphore_t));
}
DK_INLINE int
semaphore_enter (semaphore_t * sem)
{
if (sem->sem_entry_count)
sem->sem_entry_count--;
else
{
thread_queue_to (&sem->sem_waiting, _current_fiber);
_fiber_status (_current_fiber, WAITSEM);
_fiber_schedule_next ();
}
return 0;
}
thread_t *
thread_create (
thread_init_func initial_function,
unsigned long stack_size,
void *init_arg)
{
thread_t *thr;
assert (_main_thread != NULL);
if (stack_size == 0)
stack_size = THREAD_STACK_SIZE;
#if (SIZEOF_VOID_P == 8)
stack_size *= 2;
#endif
#if defined (__x86_64 ) && defined (SOLARIS)
/*GK: the LDAP on that platform requires that */
stack_size *= 2;
#endif
/* Any free threads with the right stack size? */
for (thr = (thread_t *) _deadq.thq_head.thr_next;
thr != (thread_t *) &_deadq.thq_head;
thr = (thread_t *) thr->thr_hdr.thr_next)
{
if (thr->thr_stack_size >= stack_size)
break;
}
if (thr == (thread_t *) &_deadq.thq_head)
{
/* No free fiber, create a new one */
thr = thread_allocate ();
_fiber_for_thread (thr, stack_size);
_thread_num_total++;
}
else
{
/* Set new context for the thread */
memcpy (thr->thr_context, thr->thr_init_context, sizeof (jmp_buf));
}
thr->thr_initial_function = initial_function;
thr->thr_initial_argument = init_arg;
thread_set_priority (thr, NORMAL_PRIORITY);
_thread_init_attributes (thr);
_fiber_status (thr, RUNNABLE);
return thr;
}
void
thread_exit (int n)
{
if (_current_fiber->thr_attached)
return;
_fiber_status (_current_fiber, DEAD);
_thread_free_attributes (_current_fiber);
if (_current_fiber == _main_thread)
exit (n);
_fiber_schedule_next ();
/* could come here using win fibers */
longjmp (_current_fiber->thr_init_context, 1);
}
static void
_fiber_timeout (void *arg)
{
thread_t *thr = (thread_t *) arg;
thr->thr_retcode = -1;
#ifdef WIN32
thr->thr_err = WSAETIMEDOUT;
#else
thr->thr_err = ETIMEDOUT;
#endif
_fiber_status (thr, RUNNABLE);
}
int
mutex_enter (dk_mutex_t *mtx)
#endif
{
#ifndef MTX_DEBUG
return semaphore_enter (mtx->mtx_handle);
#else
semaphore_t *sem = (semaphore_t *) mtx->mtx_handle;
#ifdef MALLOC_DEBUG
if (_current_fiber == NULL)
{
assert (mtx == _dbgmal_mtx);
return semaphore_enter (sem);
}
#endif
assert (_current_fiber != NULL);
if (sem->sem_entry_count)
{
assert (sem->sem_entry_count == 1);
assert (mtx->mtx_owner == NULL);
sem->sem_entry_count--;
}
else
{
assert (mtx->mtx_owner != _current_fiber);
thread_queue_to (&sem->sem_waiting, _current_fiber);
_fiber_status (_current_fiber, WAITSEM);
_fiber_schedule_next ();
assert (sem->sem_entry_count == 0);
}
assert (mtx->mtx_owner == NULL);
if (mtx->mtx_entry_check
&& !mtx->mtx_entry_check (mtx, THREAD_CURRENT_THREAD, mtx->mtx_entry_check_cd))
GPF_T1 ("Mtx entry check fail");
mtx->mtx_owner = _current_fiber;
mtx->mtx_entry_file = (char *) file;
mtx->mtx_entry_line = line;
return 0;
#endif
}
DK_INLINE void
semaphore_leave (semaphore_t *sem)
#endif
{
thread_t *thr;
if (sem->sem_entry_count)
sem->sem_entry_count++;
else
{
thr = thread_queue_from (&sem->sem_waiting);
if (thr)
{
assert (thr->thr_status == WAITSEM);
_fiber_status (thr, RUNNABLE);
}
else
sem->sem_entry_count++;
}
}
/*
* The main thread must call this function to convert itself into a fiber.
*/
thread_t *
thread_initial (unsigned long stack_size)
{
static unsigned int marker = THREAD_STACK_MARKER;
if (_current_fiber)
return _current_fiber;
else
{
NEW_VARZ (thread_t, thr);
assert (_current_fiber == NULL);
_main_thread = _current_fiber = thr;
_sched_init ();
if (stack_size == 0)
stack_size = MAIN_STACK_SIZE;
#if (SIZEOF_VOID_P == 8)
stack_size *= 2;
#endif
#if defined (__x86_64 ) && defined (SOLARIS)
/*GK: the LDAP on that platform requires that */
stack_size *= 2;
#endif
thr->thr_stack_marker = ▮
thr->thr_sem = semaphore_allocate (0);
thr->thr_schedule_sem = semaphore_allocate (0);
thread_set_priority (thr, NORMAL_PRIORITY);
_thread_init_attributes (thr);
_fiber_for_thread (thr, stack_size);
_fiber_status (thr, RUNNING);
return thr;
}
}
int
_fiber_sleep (void *event, TVAL timeout)
{
thread_t *thr = _current_fiber;
assert (thr->thr_status == RUNNING);
thr->thr_err = 0;
thr->thr_retcode = 0;
/* set a timer */
assert (thr->thr_timer == NULL);
if (timeout != TV_INFINITE)
thr->thr_timer = timer_queue_new_timer (_timerq, timeout, 0,
_fiber_timeout, thr);
if (event == NULL)
event = &_ev_never;
thr->thr_event = event;
do
{
_fiber_status (thr, WAITEVENT);
_fiber_schedule_next ();
}
while (thr->thr_event == event && thr->thr_err == 0);
thr->thr_event = NULL;
if (timeout != TV_INFINITE)
{
timer_deactivate (thr->thr_timer);
timer_unref (thr->thr_timer);
thr->thr_timer = NULL;
}
return thr->thr_retcode;
}
int
thread_signal_cond (void *event)
{
thread_t *thr;
thread_t *next;
int count = 0;
/* Wake up waiting threads for which event occurred */
for (thr = (thread_t *) _waitq.thq_head.thr_next;
thr != (thread_t *) &_waitq.thq_head;
thr = next)
{
next = (thread_t *) thr->thr_hdr.thr_next;
if (thr->thr_event == event)
{
thr->thr_event = NULL;
thr->thr_retcode = 0;
_fiber_status (thr, RUNNABLE);
count++;
}
}
return count;
}
void
mutex_leave (dk_mutex_t *mtx)
#endif
{
#ifndef MTX_DEBUG
semaphore_leave (mtx->mtx_handle);
#else
semaphore_t *sem = (semaphore_t *) mtx->mtx_handle;
thread_t *thr;
#ifdef MALLOC_DEBUG
if (_current_fiber == NULL)
{
assert (mtx == _dbgmal_mtx);
semaphore_leave (sem);
return;
}
#endif
assert (mtx->mtx_owner == _current_fiber);
assert (sem->sem_entry_count == 0);
mtx->mtx_owner = NULL;
if (sem->sem_entry_count)
sem->sem_entry_count++;
else
{
thr = thread_queue_from (&sem->sem_waiting);
if (thr)
{
assert (thr->thr_status == WAITSEM);
_fiber_status (thr, RUNNABLE);
}
else
sem->sem_entry_count++;
}
#endif
}
/*
* This is the idle task, that runs at the lowest possible priority.
* It's only called when there are no other fibers ready for scheduling.
*/
void
_fiber_event_loop (void)
{
/* These are all static, to minimize stack usage */
static fd_set readfds;
static fd_set writefds;
static int nreadfds;
static int nwritefds;
static int nfds;
static thread_t *thr, *next;
static TVAL timeout;
static struct timeval tv, *ptv;
static int rc;
for (;;)
{
timeout = timer_queue_update (_timerq,
timer_queue_time_elapsed (_timerq));
if (_thread_num_runnable)
return;
FD_ZERO (&readfds);
FD_ZERO (&writefds);
for (thr = (thread_t *) _waitq.thq_head.thr_next;
thr != (thread_t *) &_waitq.thq_head;
thr = (thread_t *) thr->thr_hdr.thr_next)
{
if (thr->thr_nfds)
{
nreadfds = _fd_set_or (&readfds, &thr->thr_rfds);
nwritefds = _fd_set_or (&writefds, &thr->thr_wfds);
}
}
nfds = MAX (nreadfds, nwritefds);
if (timeout == 0)
ptv = NULL;
else
{
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout % 1000) * 1000;
ptv = &tv;
}
rc = select (nfds, &readfds, &writefds, NULL, ptv);
if (rc == -1)
{
if (errno != EINTR)
GPF_T1 ("select() returned -1");
continue;
}
timer_queue_update (_timerq, timer_queue_time_elapsed (_timerq));
if (rc > 0)
{
/* Wake up waiting fibers for which an event occurred */
for (thr = (thread_t *) _waitq.thq_head.thr_next;
thr != (thread_t *) &_waitq.thq_head;
thr = next)
{
next = (thread_t *) thr->thr_hdr.thr_next;
if (thr->thr_nfds == 0)
continue;
if (_fd_set_intersect (&thr->thr_rfds, &readfds) ||
_fd_set_intersect (&thr->thr_wfds, &writefds))
{
_fd_set_and (&thr->thr_rfds, &readfds);
_fd_set_and (&thr->thr_wfds, &writefds);
thr->thr_event = NULL;
thr->thr_retcode = 1;
_fiber_status (thr, RUNNABLE);
}
}
}
break;
}
}
