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
|
/*
* Copyright (c) 2015, Linaro Limited
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef KERNEL_WAIT_QUEUE_H
#define KERNEL_WAIT_QUEUE_H
#include <types_ext.h>
#include <sys/queue.h>
struct wait_queue_elem;
SLIST_HEAD(wait_queue, wait_queue_elem);
#define WAIT_QUEUE_INITIALIZER { .slh_first = NULL }
struct condvar;
struct wait_queue_elem {
short handle;
bool done;
struct condvar *cv;
SLIST_ENTRY(wait_queue_elem) link;
};
/*
* Initializes a wait queue
*/
void wq_init(struct wait_queue *wq);
/*
* Initializes a wait queue element and adds it to the wait queue. This
* function is supposed to be called before the lock that protects the
* resource we need to wait for is released.
*
* One call to this function must be followed by one call to wq_wait_final()
* on the same wait queue element.
*/
void wq_wait_init_condvar(struct wait_queue *wq, struct wait_queue_elem *wqe,
struct condvar *cv);
static inline void wq_wait_init(struct wait_queue *wq,
struct wait_queue_elem *wqe)
{
wq_wait_init_condvar(wq, wqe, NULL);
}
/* Waits for the wait queue element to the awakened. */
void wq_wait_final(struct wait_queue *wq, struct wait_queue_elem *wqe,
const void *sync_obj, const char *fname, int lineno);
/* Wakes up the first wait queue element in the wait queue, if there is one */
void wq_wake_one(struct wait_queue *wq, const void *sync_obj,
const char *fname, int lineno);
/* Returns true if the wait queue doesn't contain any elements */
bool wq_is_empty(struct wait_queue *wq);
void wq_promote_condvar(struct wait_queue *wq, struct condvar *cv,
bool only_one, const void *sync_obj, const char *fname,
int lineno);
bool wq_have_condvar(struct wait_queue *wq, struct condvar *cv);
#endif /*KERNEL_WAIT_QUEUE_H*/
|
