blob: 3c35ce4e44d24085043b30b7ab94483d675c4071 (
plain)
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
|
/*
* mbox.h
*
* Simple thread mailbox interface
*/
#ifndef _MBOX_H
#define _MBOX_H
#include "thread.h"
/*
* If a mailbox is allocated statically (as a struct mailbox), this
* is the number of slots it gets.
*/
#define MAILBOX_STATIC_SIZE 512
struct mailbox {
struct semaphore prod_sem; /* Producer semaphore (empty slots) */
struct semaphore cons_sem; /* Consumer semaphore (data slots) */
struct semaphore head_sem; /* Head pointer semaphore */
struct semaphore tail_sem; /* Tail pointer semaphore */
void **wrap; /* Where pointers wrap */
void **head; /* Head pointer */
void **tail; /* Tail pointer */
void *data[MAILBOX_STATIC_SIZE]; /* Data array */
};
/* The number of bytes for an mailbox of size s */
#define MBOX_BYTES(s) (sizeof(struct mailbox) + \
((s)-MAILBOX_STATIC_SIZE)*sizeof(void *))
void mbox_init(struct mailbox *mbox, size_t size);
int mbox_post(struct mailbox *mbox, void *msg, mstime_t timeout);
mstime_t mbox_fetch(struct mailbox *mbox, void **msg, mstime_t timeout);
/*
* This marks a mailbox object as unusable; it will remain unusable
* until sem_init() is called on it again. This DOES NOT clear the
* list of blocked processes on this mailbox!
*
* It is also possible to mark the mailbox invalid by zeroing its
* memory structure.
*/
static inline void mbox_set_invalid(struct mailbox *mbox)
{
sem_set_invalid(&mbox->prod_sem);
}
/*
* Ask if a mailbox object has been initialized.
*/
static inline bool mbox_is_valid(struct mailbox *mbox)
{
return sem_is_valid(&mbox->prod_sem);
}
#endif /* _MBOX_H */
|
