+++ /dev/null
-#include <pthread.h>
-
-#include <linux/kthread.h>
-#include <linux/slab.h>
-#include <linux/workqueue.h>
-
-static pthread_mutex_t wq_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t work_finished = PTHREAD_COND_INITIALIZER;
-static LIST_HEAD(wq_list);
-
-struct workqueue_struct {
- struct list_head list;
-
- struct work_struct *current_work;
- struct list_head pending_work;
-
- struct task_struct *worker;
- char name[24];
-};
-
-enum {
- WORK_PENDING_BIT,
-};
-
-static bool work_pending(struct work_struct *work)
-{
- return test_bit(WORK_PENDING_BIT, work_data_bits(work));
-}
-
-static void clear_work_pending(struct work_struct *work)
-{
- clear_bit(WORK_PENDING_BIT, work_data_bits(work));
-}
-
-static bool set_work_pending(struct work_struct *work)
-{
- return !test_and_set_bit(WORK_PENDING_BIT, work_data_bits(work));
-}
-
-static void __queue_work(struct workqueue_struct *wq,
- struct work_struct *work)
-{
- BUG_ON(!work_pending(work));
- BUG_ON(!list_empty(&work->entry));
-
- list_add_tail(&work->entry, &wq->pending_work);
- wake_up_process(wq->worker);
-}
-
-bool queue_work(struct workqueue_struct *wq, struct work_struct *work)
-{
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- if ((ret = set_work_pending(work)))
- __queue_work(wq, work);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-void delayed_work_timer_fn(struct timer_list *timer)
-{
- struct delayed_work *dwork =
- container_of(timer, struct delayed_work, timer);
-
- pthread_mutex_lock(&wq_lock);
- __queue_work(dwork->wq, &dwork->work);
- pthread_mutex_unlock(&wq_lock);
-}
-
-static void __queue_delayed_work(struct workqueue_struct *wq,
- struct delayed_work *dwork,
- unsigned long delay)
-{
- struct timer_list *timer = &dwork->timer;
- struct work_struct *work = &dwork->work;
-
- BUG_ON(timer->function != delayed_work_timer_fn);
- BUG_ON(timer_pending(timer));
- BUG_ON(!list_empty(&work->entry));
-
- if (!delay) {
- __queue_work(wq, &dwork->work);
- } else {
- dwork->wq = wq;
- timer->expires = jiffies + delay;
- add_timer(timer);
- }
-}
-
-bool queue_delayed_work(struct workqueue_struct *wq,
- struct delayed_work *dwork,
- unsigned long delay)
-{
- struct work_struct *work = &dwork->work;
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- if ((ret = set_work_pending(work)))
- __queue_delayed_work(wq, dwork, delay);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-static bool grab_pending(struct work_struct *work, bool is_dwork)
-{
-retry:
- if (set_work_pending(work)) {
- BUG_ON(!list_empty(&work->entry));
- return false;
- }
-
- if (is_dwork) {
- struct delayed_work *dwork = to_delayed_work(work);
-
- if (likely(del_timer(&dwork->timer))) {
- BUG_ON(!list_empty(&work->entry));
- return true;
- }
- }
-
- if (!list_empty(&work->entry)) {
- list_del_init(&work->entry);
- return true;
- }
-
- BUG_ON(!is_dwork);
-
- pthread_mutex_unlock(&wq_lock);
- flush_timers();
- pthread_mutex_lock(&wq_lock);
- goto retry;
-}
-
-static bool work_running(struct work_struct *work)
-{
- struct workqueue_struct *wq;
-
- list_for_each_entry(wq, &wq_list, list)
- if (wq->current_work == work)
- return true;
-
- return false;
-}
-
-bool flush_work(struct work_struct *work)
-{
- bool ret = false;
-
- pthread_mutex_lock(&wq_lock);
- while (work_pending(work) || work_running(work)) {
- pthread_cond_wait(&work_finished, &wq_lock);
- ret = true;
- }
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-static bool __flush_work(struct work_struct *work)
-{
- bool ret = false;
-
- while (work_running(work)) {
- pthread_cond_wait(&work_finished, &wq_lock);
- ret = true;
- }
-
- return ret;
-}
-
-bool cancel_work_sync(struct work_struct *work)
-{
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- ret = grab_pending(work, false);
-
- __flush_work(work);
- clear_work_pending(work);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-bool mod_delayed_work(struct workqueue_struct *wq,
- struct delayed_work *dwork,
- unsigned long delay)
-{
- struct work_struct *work = &dwork->work;
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- ret = grab_pending(work, true);
-
- __queue_delayed_work(wq, dwork, delay);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-bool cancel_delayed_work(struct delayed_work *dwork)
-{
- struct work_struct *work = &dwork->work;
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- ret = grab_pending(work, true);
-
- clear_work_pending(&dwork->work);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-bool cancel_delayed_work_sync(struct delayed_work *dwork)
-{
- struct work_struct *work = &dwork->work;
- bool ret;
-
- pthread_mutex_lock(&wq_lock);
- ret = grab_pending(work, true);
-
- __flush_work(work);
- clear_work_pending(work);
- pthread_mutex_unlock(&wq_lock);
-
- return ret;
-}
-
-static int worker_thread(void *arg)
-{
- struct workqueue_struct *wq = arg;
- struct work_struct *work;
-
- pthread_mutex_lock(&wq_lock);
- while (1) {
- __set_current_state(TASK_INTERRUPTIBLE);
- work = list_first_entry_or_null(&wq->pending_work,
- struct work_struct, entry);
- wq->current_work = work;
-
- if (kthread_should_stop()) {
- BUG_ON(wq->current_work);
- break;
- }
-
- if (!work) {
- pthread_mutex_unlock(&wq_lock);
- schedule();
- pthread_mutex_lock(&wq_lock);
- continue;
- }
-
- BUG_ON(!work_pending(work));
- list_del_init(&work->entry);
- clear_work_pending(work);
-
- pthread_mutex_unlock(&wq_lock);
- work->func(work);
- pthread_mutex_lock(&wq_lock);
-
- pthread_cond_broadcast(&work_finished);
- }
- pthread_mutex_unlock(&wq_lock);
-
- return 0;
-}
-
-void destroy_workqueue(struct workqueue_struct *wq)
-{
- kthread_stop(wq->worker);
-
- pthread_mutex_lock(&wq_lock);
- list_del(&wq->list);
- pthread_mutex_unlock(&wq_lock);
-
- kfree(wq);
-}
-
-struct workqueue_struct *alloc_workqueue(const char *fmt,
- unsigned flags,
- int max_active,
- ...)
-{
- va_list args;
- struct workqueue_struct *wq;
-
- wq = kzalloc(sizeof(*wq), GFP_KERNEL);
- if (!wq)
- return NULL;
-
- INIT_LIST_HEAD(&wq->list);
- INIT_LIST_HEAD(&wq->pending_work);
-
- va_start(args, max_active);
- vsnprintf(wq->name, sizeof(wq->name), fmt, args);
- va_end(args);
-
- wq->worker = kthread_run(worker_thread, wq, "%s", wq->name);
- if (IS_ERR(wq->worker)) {
- kfree(wq);
- return NULL;
- }
-
- pthread_mutex_lock(&wq_lock);
- list_add(&wq->list, &wq_list);
- pthread_mutex_unlock(&wq_lock);
-
- return wq;
-}
-
-struct workqueue_struct *system_wq;
-struct workqueue_struct *system_highpri_wq;
-struct workqueue_struct *system_long_wq;
-struct workqueue_struct *system_unbound_wq;
-struct workqueue_struct *system_freezable_wq;
-
-__attribute__((constructor(102)))
-static void wq_init(void)
-{
- system_wq = alloc_workqueue("events", 0, 0);
- system_highpri_wq = alloc_workqueue("events_highpri", WQ_HIGHPRI, 0);
- system_long_wq = alloc_workqueue("events_long", 0, 0);
- system_unbound_wq = alloc_workqueue("events_unbound", WQ_UNBOUND,
- WQ_UNBOUND_MAX_ACTIVE);
- system_freezable_wq = alloc_workqueue("events_freezable",
- WQ_FREEZABLE, 0);
- BUG_ON(!system_wq || !system_highpri_wq || !system_long_wq ||
- !system_unbound_wq || !system_freezable_wq);
-}
-
-__attribute__((destructor(102)))
-static void wq_cleanup(void)
-{
- destroy_workqueue(system_freezable_wq);
- destroy_workqueue(system_unbound_wq);
- destroy_workqueue(system_long_wq);
- destroy_workqueue(system_highpri_wq);
- destroy_workqueue(system_wq);
-
- system_wq = system_highpri_wq = system_long_wq = system_unbound_wq =
- system_freezable_wq = NULL;
-}
projects / bcachefs-tools-debian / blobdiff