1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/*
* Copyright 2021 Regents of the University of Michigan
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "queue.h"
#include "xalloc.h"
#include <pthread.h>
zqueue_t *queue_init(void)
{
zqueue_t *p = xmalloc(sizeof(zqueue_t));
p->front = NULL;
p->back = NULL;
p->size = 0;
pthread_mutex_init(&p->lock, NULL);
pthread_cond_init(&p->empty, NULL);
return p;
}
int is_empty(zqueue_t *queue) { return queue->size == 0; }
void push_back(void *data, zqueue_t *queue)
{
znode_t *new_node = xmalloc(sizeof(znode_t));
new_node->prev = NULL;
new_node->next = NULL;
new_node->data = data;
pthread_mutex_lock(&queue->lock);
if (is_empty(queue)) {
queue->front = new_node;
queue->back = new_node;
} else {
queue->back->next = new_node;
new_node->prev = queue->back;
queue->back = new_node;
}
queue->size++;
pthread_cond_signal(&queue->empty);
pthread_mutex_unlock(&queue->lock);
}
znode_t *pop_front(zqueue_t *queue)
{
pthread_mutex_lock(&queue->lock);
while (is_empty(queue)) {
pthread_cond_wait(&queue->empty, &queue->lock);
}
znode_t *temp = pop_front_unsafe(queue);
pthread_mutex_unlock(&queue->lock);
return temp;
}
znode_t *pop_front_unsafe(zqueue_t *queue)
{
znode_t *temp = queue->front;
queue->front = temp->next;
if (queue->front != NULL) {
queue->front->prev = NULL;
}
queue->size--;
return temp;
}
znode_t *get_front(zqueue_t *queue)
{
pthread_mutex_lock(&queue->lock);
while (is_empty(queue)) {
pthread_cond_wait(&queue->empty, &queue->lock);
}
znode_t *temp = queue->front;
pthread_mutex_unlock(&queue->lock);
return temp;
}
znode_t *get_back(zqueue_t *queue)
{
pthread_mutex_lock(&queue->lock);
while (is_empty(queue)) {
pthread_cond_wait(&queue->empty, &queue->lock);
}
znode_t *temp = queue->back;
pthread_mutex_unlock(&queue->lock);
return temp;
}
size_t get_size(zqueue_t *queue) { return queue->size; }
|
