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Viewing changes to storage/innobase/ut/ut0wqueue.c

  • Committer: brian
  • Date: 2008-06-25 05:29:13 UTC
  • Revision ID: brian@localhost.localdomain-20080625052913-6upwo0jsrl4lnapl
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storage/innobase/ut/ut0wqueue.c
 
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#include "ut0wqueue.h"
 
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/********************************************************************
 
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Create a new work queue. */
 
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ib_wqueue_t*
 
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ib_wqueue_create(void)
 
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/*===================*/
 
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                        /* out: work queue */
 
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{
 
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        ib_wqueue_t*    wq = mem_alloc(sizeof(ib_wqueue_t));
 
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        mutex_create(&wq->mutex, SYNC_WORK_QUEUE);
 
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        wq->items = ib_list_create();
 
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        wq->event = os_event_create(NULL);
 
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        return(wq);
 
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}
 
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/********************************************************************
 
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Free a work queue. */
 
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void
 
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ib_wqueue_free(
 
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/*===========*/
 
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        ib_wqueue_t*    wq)     /* in: work queue */
 
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{
 
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        ut_a(!ib_list_get_first(wq->items));
 
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        mutex_free(&wq->mutex);
 
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        ib_list_free(wq->items);
 
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        os_event_free(wq->event);
 
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        mem_free(wq);
 
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}
 
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/********************************************************************
 
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Add a work item to the queue. */
 
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void
 
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ib_wqueue_add(
 
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/*==========*/
 
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        ib_wqueue_t*    wq,     /* in: work queue */
 
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        void*           item,   /* in: work item */
 
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        mem_heap_t*     heap)   /* in: memory heap to use for allocating the
 
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                                list node */
 
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{
 
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        mutex_enter(&wq->mutex);
 
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        ib_list_add_last(wq->items, item, heap);
 
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        os_event_set(wq->event);
 
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        mutex_exit(&wq->mutex);
 
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}
 
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/********************************************************************
 
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Wait for a work item to appear in the queue. */
 
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void*
 
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ib_wqueue_wait(
 
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                                /* out: work item */
 
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        ib_wqueue_t*    wq)     /* in: work queue */
 
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{
 
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        ib_list_node_t* node;
 
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        for (;;) {
 
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                os_event_wait(wq->event);
 
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                mutex_enter(&wq->mutex);
 
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                node = ib_list_get_first(wq->items);
 
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                if (node) {
 
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                        ib_list_remove(wq->items, node);
 
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                        if (!ib_list_get_first(wq->items)) {
 
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                                /* We must reset the event when the list
 
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                                gets emptied. */
 
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                                os_event_reset(wq->event);
 
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                        }
 
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                        break;
 
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                }
 
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                mutex_exit(&wq->mutex);
 
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        }
 
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        mutex_exit(&wq->mutex);
 
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        return(node->data);
 
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}