ccc92611b1
coverity scan CID:147567, Type:dereference null return value coverity scan CID:147566, Type:dereference null return value coverity scan CID:147565, Type:dereference null return value Reviewed by: Richard Laager <rlaager@wiktel.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: cao.xuewen <cao.xuewen@zte.com.cn> Closes #5166
113 lines
2.9 KiB
C
113 lines
2.9 KiB
C
/*
|
|
* CDDL HEADER START
|
|
*
|
|
* This file and its contents are supplied under the terms of the
|
|
* Common Development and Distribution License ("CDDL"), version 1.0.
|
|
* You may only use this file in accordance with the terms of version
|
|
* 1.0 of the CDDL.
|
|
*
|
|
* A full copy of the text of the CDDL should have accompanied this
|
|
* source. A copy of the CDDL is also available via the Internet at
|
|
* http://www.illumos.org/license/CDDL.
|
|
*
|
|
* CDDL HEADER END
|
|
*/
|
|
/*
|
|
* Copyright (c) 2014 by Delphix. All rights reserved.
|
|
*/
|
|
|
|
#include <sys/bqueue.h>
|
|
#include <sys/zfs_context.h>
|
|
|
|
static inline bqueue_node_t *
|
|
obj2node(bqueue_t *q, void *data)
|
|
{
|
|
return ((bqueue_node_t *)((char *)data + q->bq_node_offset));
|
|
}
|
|
|
|
/*
|
|
* Initialize a blocking queue The maximum capacity of the queue is set to
|
|
* size. Types that want to be stored in a bqueue must contain a bqueue_node_t,
|
|
* and offset should give its offset from the start of the struct. Return 0 on
|
|
* success, or -1 on failure.
|
|
*/
|
|
int
|
|
bqueue_init(bqueue_t *q, uint64_t size, size_t node_offset)
|
|
{
|
|
list_create(&q->bq_list, node_offset + sizeof (bqueue_node_t),
|
|
node_offset + offsetof(bqueue_node_t, bqn_node));
|
|
cv_init(&q->bq_add_cv, NULL, CV_DEFAULT, NULL);
|
|
cv_init(&q->bq_pop_cv, NULL, CV_DEFAULT, NULL);
|
|
mutex_init(&q->bq_lock, NULL, MUTEX_DEFAULT, NULL);
|
|
q->bq_node_offset = node_offset;
|
|
q->bq_size = 0;
|
|
q->bq_maxsize = size;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Destroy a blocking queue. This function asserts that there are no
|
|
* elements in the queue, and no one is blocked on the condition
|
|
* variables.
|
|
*/
|
|
void
|
|
bqueue_destroy(bqueue_t *q)
|
|
{
|
|
ASSERT0(q->bq_size);
|
|
cv_destroy(&q->bq_add_cv);
|
|
cv_destroy(&q->bq_pop_cv);
|
|
mutex_destroy(&q->bq_lock);
|
|
list_destroy(&q->bq_list);
|
|
}
|
|
|
|
/*
|
|
* Add data to q, consuming size units of capacity. If there is insufficient
|
|
* capacity to consume size units, block until capacity exists. Asserts size is
|
|
* > 0.
|
|
*/
|
|
void
|
|
bqueue_enqueue(bqueue_t *q, void *data, uint64_t item_size)
|
|
{
|
|
ASSERT3U(item_size, >, 0);
|
|
ASSERT3U(item_size, <=, q->bq_maxsize);
|
|
mutex_enter(&q->bq_lock);
|
|
obj2node(q, data)->bqn_size = item_size;
|
|
while (q->bq_size + item_size > q->bq_maxsize) {
|
|
cv_wait(&q->bq_add_cv, &q->bq_lock);
|
|
}
|
|
q->bq_size += item_size;
|
|
list_insert_tail(&q->bq_list, data);
|
|
cv_signal(&q->bq_pop_cv);
|
|
mutex_exit(&q->bq_lock);
|
|
}
|
|
/*
|
|
* Take the first element off of q. If there are no elements on the queue, wait
|
|
* until one is put there. Return the removed element.
|
|
*/
|
|
void *
|
|
bqueue_dequeue(bqueue_t *q)
|
|
{
|
|
void *ret = NULL;
|
|
uint64_t item_size;
|
|
mutex_enter(&q->bq_lock);
|
|
while (q->bq_size == 0) {
|
|
cv_wait(&q->bq_pop_cv, &q->bq_lock);
|
|
}
|
|
ret = list_remove_head(&q->bq_list);
|
|
ASSERT3P(ret, !=, NULL);
|
|
item_size = obj2node(q, ret)->bqn_size;
|
|
q->bq_size -= item_size;
|
|
mutex_exit(&q->bq_lock);
|
|
cv_signal(&q->bq_add_cv);
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Returns true if the space used is 0.
|
|
*/
|
|
boolean_t
|
|
bqueue_empty(bqueue_t *q)
|
|
{
|
|
return (q->bq_size == 0);
|
|
}
|