void fiber_manager_yield(fiber_manager_t* manager)
{
assert(fiber_manager_state == FIBER_MANAGER_STATE_STARTED);
assert(manager);
if(wsd_work_stealing_deque_size(manager->schedule_from) == 0) {
wsd_work_stealing_deque_t* const temp = manager->schedule_from;
manager->schedule_from = manager->store_to;
manager->store_to = temp;
}
do {
manager->yield_count += 1;
//occasionally steal some work from threads with more load
if((manager->yield_count & 1023) == 0) {
fiber_load_balance(manager);
}
if(wsd_work_stealing_deque_size(manager->schedule_from) > 0) {
fiber_t* const new_fiber = (fiber_t*)wsd_work_stealing_deque_pop_bottom(manager->schedule_from);
if(new_fiber != WSD_EMPTY && new_fiber != WSD_ABORT) {
fiber_t* const old_fiber = manager->current_fiber;
if(old_fiber->state == FIBER_STATE_RUNNING) {
old_fiber->state = FIBER_STATE_READY;
manager->to_schedule = old_fiber;/* must schedule it *after* fiber_swap_context, else another thread can start executing an invalid context */
}
manager->current_fiber = new_fiber;
new_fiber->state = FIBER_STATE_RUNNING;
write_barrier();
fiber_swap_context(&old_fiber->context, &new_fiber->context);
fiber_manager_do_maintenance();
}
}
} while((manager = fiber_manager_get()) && FIBER_STATE_WAITING == manager->current_fiber->state && fiber_load_balance(manager));
}
fiber_t* fiber_scheduler_next(fiber_scheduler_t* sched)
{
fiber_scheduler_wsd_t* const scheduler = (fiber_scheduler_wsd_t*)sched;
assert(scheduler);
if(wsd_work_stealing_deque_size(scheduler->schedule_from) == 0) {
wsd_work_stealing_deque_t* const temp = scheduler->schedule_from;
scheduler->schedule_from = scheduler->store_to;
scheduler->store_to = temp;
}
while(wsd_work_stealing_deque_size(scheduler->schedule_from) > 0) {
fiber_t* const new_fiber = (fiber_t*)wsd_work_stealing_deque_pop_bottom(scheduler->schedule_from);
if(new_fiber != WSD_EMPTY && new_fiber != WSD_ABORT) {
if(new_fiber->state == FIBER_STATE_SAVING_STATE_TO_WAIT) {
wsd_work_stealing_deque_push_bottom(scheduler->store_to, new_fiber);
} else {
return new_fiber;
}
}
}
return NULL;
}
int main(int argc, char* argv[])
{
wsd_circular_array_t* wsd_a = wsd_circular_array_create(8);
test_assert(wsd_a);
test_assert(wsd_circular_array_size(wsd_a) == 256);
wsd_circular_array_put(wsd_a, 1, (void*)1);
test_assert((void*)1 == wsd_circular_array_get(wsd_a, 1));
wsd_circular_array_destroy(wsd_a);
wsd_work_stealing_deque_t* wsd_d = wsd_work_stealing_deque_create();
int i;
for(i = 0; i < 1000; ++i) {
wsd_work_stealing_deque_push_bottom(wsd_d, (void*)(intptr_t)i);
}
for(i = 1000; i > 0; --i) {
void* item = wsd_work_stealing_deque_pop_bottom(wsd_d);
test_assert((intptr_t)item == i-1);
}
wsd_work_stealing_deque_destroy(wsd_d);
wsd_d2 = wsd_work_stealing_deque_create();
pthread_t reader[NUM_THREADS];
for(i = 1; i < NUM_THREADS; ++i) {
pthread_create(&reader[i], NULL, &run_func, (void*)(intptr_t)i);
}
for(i = 0; i < SHARED_COUNT; ++i) {
wsd_work_stealing_deque_push_bottom(wsd_d2, (void*)(intptr_t)i);
if((i & 7) == 0) {
void* val = wsd_work_stealing_deque_pop_bottom(wsd_d2);
if(val != WSD_EMPTY && val != WSD_ABORT) {
__sync_add_and_fetch(&results[0][(intptr_t)val], 1);
__sync_add_and_fetch(&total, (intptr_t)val);
++run_func_count[0];
}
}
}
void* val = 0;
do {
val = wsd_work_stealing_deque_pop_bottom(wsd_d2);
if(val != WSD_EMPTY && val != WSD_ABORT) {
__sync_add_and_fetch(&results[0][(intptr_t)val], 1);
__sync_add_and_fetch(&total, (intptr_t)val);
++run_func_count[0];
}
} while(val != WSD_EMPTY);
done = 1;
for(i = 1; i < NUM_THREADS; ++i) {
pthread_join(reader[i], NULL);
}
uint64_t expected_total = 0;
for(i = 0; i < SHARED_COUNT; ++i) {
int sum = 0;
int j;
for(j = 0; j < NUM_THREADS; ++j) {
sum += results[j][i];
}
test_assert(sum == 1);
expected_total += i;
}
test_assert(total == expected_total);
for(i = 0; i < NUM_THREADS; ++i) {
test_assert(run_func_count[i] > 0);
}
return 0;
}
