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#include "ut0wqueue.h"
/********************************************************************
Create a new work queue. */
ib_wqueue_t*
ib_wqueue_create(void)
/*===================*/
/* out: work queue */
{
ib_wqueue_t* wq = mem_alloc(sizeof(ib_wqueue_t));
mutex_create(&wq->mutex, SYNC_WORK_QUEUE);
wq->items = ib_list_create();
wq->event = os_event_create(NULL);
return(wq);
}
/********************************************************************
Free a work queue. */
void
ib_wqueue_free(
/*===========*/
ib_wqueue_t* wq) /* in: work queue */
{
ut_a(!ib_list_get_first(wq->items));
mutex_free(&wq->mutex);
ib_list_free(wq->items);
os_event_free(wq->event);
mem_free(wq);
}
/********************************************************************
Add a work item to the queue. */
void
ib_wqueue_add(
/*==========*/
ib_wqueue_t* wq, /* in: work queue */
void* item, /* in: work item */
mem_heap_t* heap) /* in: memory heap to use for allocating the
list node */
{
mutex_enter(&wq->mutex);
ib_list_add_last(wq->items, item, heap);
os_event_set(wq->event);
mutex_exit(&wq->mutex);
}
/********************************************************************
Wait for a work item to appear in the queue. */
void*
ib_wqueue_wait(
/* out: work item */
ib_wqueue_t* wq) /* in: work queue */
{
ib_list_node_t* node;
for (;;) {
os_event_wait(wq->event);
mutex_enter(&wq->mutex);
node = ib_list_get_first(wq->items);
if (node) {
ib_list_remove(wq->items, node);
if (!ib_list_get_first(wq->items)) {
/* We must reset the event when the list
gets emptied. */
os_event_reset(wq->event);
}
break;
}
mutex_exit(&wq->mutex);
}
mutex_exit(&wq->mutex);
return(node->data);
}
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