unsigned
gomp_resolve_num_threads (unsigned specified)
{
/* Early exit for false IF condition or degenerate NUM_THREADS. */
if (specified == 1)
return 1;
/* If this is a nested region, and nested regions are disabled, force
this team to use only one thread. */
if (gomp_thread()->ts.team && !gomp_nest_var)
return 1;
/* If NUM_THREADS not specified, use nthreads_var. */
if (specified == 0)
specified = gomp_nthreads_var;
/* If dynamic threads are enabled, bound the number of threads
that we launch. */
if (gomp_dyn_var)
{
unsigned dyn = gomp_dynamic_max_threads ();
if (dyn < specified)
return dyn;
}
return specified;
}
unsigned
gomp_resolve_num_threads (unsigned specified, unsigned count)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_task_icv *icv;
unsigned threads_requested, max_num_threads, num_threads;
unsigned long busy;
struct gomp_thread_pool *pool;
icv = gomp_icv (false);
if (specified == 1)
return 1;
else if (thr->ts.active_level >= 1 && !icv->nest_var)
return 1;
else if (thr->ts.active_level >= gomp_max_active_levels_var)
return 1;
/* If NUM_THREADS not specified, use nthreads_var. */
if (specified == 0)
threads_requested = icv->nthreads_var;
else
threads_requested = specified;
max_num_threads = threads_requested;
/* If dynamic threads are enabled, bound the number of threads
that we launch. */
if (icv->dyn_var)
{
unsigned dyn = gomp_dynamic_max_threads ();
if (dyn < max_num_threads)
max_num_threads = dyn;
/* Optimization for parallel sections. */
if (count && count < max_num_threads)
max_num_threads = count;
}
/* UINT_MAX stands for infinity. */
if (__builtin_expect (icv->thread_limit_var == UINT_MAX, 1)
|| max_num_threads == 1)
return max_num_threads;
/* The threads_busy counter lives in thread_pool, if there
isn't a thread_pool yet, there must be just one thread
in the contention group. If thr->team is NULL, this isn't
nested parallel, so there is just one thread in the
contention group as well, no need to handle it atomically. */
pool = thr->thread_pool;
if (thr->ts.team == NULL || pool == NULL)
{
num_threads = max_num_threads;
if (num_threads > icv->thread_limit_var)
num_threads = icv->thread_limit_var;
if (pool)
pool->threads_busy = num_threads;
return num_threads;
}
#ifdef HAVE_SYNC_BUILTINS
do
{
busy = pool->threads_busy;
num_threads = max_num_threads;
if (icv->thread_limit_var - busy + 1 < num_threads)
num_threads = icv->thread_limit_var - busy + 1;
}
while (__sync_val_compare_and_swap (&pool->threads_busy,
busy, busy + num_threads - 1)
!= busy);
#else
gomp_mutex_lock (&gomp_managed_threads_lock);
num_threads = max_num_threads;
busy = pool->threads_busy;
if (icv->thread_limit_var - busy + 1 < num_threads)
num_threads = icv->thread_limit_var - busy + 1;
pool->threads_busy += num_threads - 1;
gomp_mutex_unlock (&gomp_managed_threads_lock);
#endif
return num_threads;
}
unsigned
gomp_resolve_num_threads (unsigned specified, unsigned count)
{
struct gomp_thread *thread = gomp_thread();
struct gomp_task_icv *icv;
unsigned threads_requested, max_num_threads, num_threads;
unsigned long remaining;
icv = gomp_icv (false);
if (specified == 1)
return 1;
else if (thread->ts.active_level >= 1 && !icv->nest_var)
return 1;
else if (thread->ts.active_level >= gomp_max_active_levels_var)
return 1;
/* If NUM_THREADS not specified, use nthreads_var. */
if (specified == 0)
threads_requested = icv->nthreads_var;
else
threads_requested = specified;
max_num_threads = threads_requested;
/* If dynamic threads are enabled, bound the number of threads
that we launch. */
if (icv->dyn_var)
{
unsigned dyn = gomp_dynamic_max_threads ();
if (dyn < max_num_threads)
max_num_threads = dyn;
/* Optimization for parallel sections. */
if (count && count < max_num_threads)
max_num_threads = count;
}
/* ULONG_MAX stands for infinity. */
if (__builtin_expect (gomp_thread_limit_var == ULONG_MAX, 1)
|| max_num_threads == 1)
return max_num_threads;
#ifdef HAVE_SYNC_BUILTINS
do
{
remaining = gomp_remaining_threads_count;
num_threads = max_num_threads;
if (num_threads > remaining)
num_threads = remaining + 1;
}
while (__sync_val_compare_and_swap (&gomp_remaining_threads_count,
remaining, remaining - num_threads + 1)
!= remaining);
#else
gomp_mutex_lock (&gomp_remaining_threads_lock);
num_threads = max_num_threads;
remaining = gomp_remaining_threads_count;
if (num_threads > remaining)
num_threads = remaining + 1;
gomp_remaining_threads_count -= num_threads - 1;
gomp_mutex_unlock (&gomp_remaining_threads_lock);
#endif
return num_threads;
}
