11 void mbox_init(struct mailbox *mbox, size_t size)  in mbox_init()  argument
13     if (!!mbox) {  in mbox_init()
14 	sem_init(&mbox->prod_sem, size); /* All slots empty */  in mbox_init()
15 	sem_init(&mbox->cons_sem, 0);    /* No slots full */  in mbox_init()
16 	sem_init(&mbox->head_sem, 1);    /* Head mutex */  in mbox_init()
17 	sem_init(&mbox->tail_sem, 1);    /* Tail mutex */  in mbox_init()
19 	mbox->wrap = &mbox->data[size];  in mbox_init()
20 	mbox->head = &mbox->data[0];  in mbox_init()
21 	mbox->tail = &mbox->data[0];  in mbox_init()
25 int mbox_post(struct mailbox *mbox, void *msg, mstime_t timeout)  in mbox_post()  argument
27     if (!mbox_is_valid(mbox))  in mbox_post()
29     if (sem_down(&mbox->prod_sem, timeout) == (mstime_t)-1)  in mbox_post()
31     sem_down(&mbox->head_sem, 0);  in mbox_post()
33     *mbox->head = msg;  in mbox_post()
34     mbox->head++;  in mbox_post()
35     if (mbox->head == mbox->wrap)  in mbox_post()
36 	mbox->head = &mbox->data[0];  in mbox_post()
38     sem_up(&mbox->head_sem);  in mbox_post()
39     sem_up(&mbox->cons_sem);  in mbox_post()
43 mstime_t mbox_fetch(struct mailbox *mbox, void **msg, mstime_t timeout)  in mbox_fetch()  argument
47     if (!mbox)  in mbox_fetch()
49     t = sem_down(&mbox->cons_sem, timeout);  in mbox_fetch()
52     t += sem_down(&mbox->tail_sem, 0);  in mbox_fetch()
55 	*msg = *mbox->tail;  in mbox_fetch()
56     mbox->tail++;  in mbox_fetch()
57     if (mbox->tail == mbox->wrap)  in mbox_fetch()
58 	mbox->tail = &mbox->data[0];  in mbox_fetch()
60     sem_up(&mbox->tail_sem);  in mbox_fetch()
61     sem_up(&mbox->prod_sem);  in mbox_fetch()