/* returnvalue like read() , except on error errno is negative return */
int pselan_recvlook(pselan_con_info_t *ci, void **buf)
{
// assert(con_info->n_recv_toks == 0) as long as we only poll!
while (1) {
pselan_msg_t *msg = ci->recv_bufs + ci->recv_pos;
unsigned int magic = msg->tail.magic;
if (!magic) { // Nothing received
pselan_flush_event(ci);
return (ci->con_broken) ? -EPIPE : -EAGAIN;
}
msg->tail.magic = PSELAN_MAGIC_UNUSED;
/* Fresh tokens ? */
ci->n_send_toks += msg->tail.token;
ci->n_recv_toks++;
unsigned len = msg->tail.payload;
unsigned pselanlen = PSELAN_LEN(len);
*buf = ci->recv_bufs[ci->recv_pos].data - pselanlen;
if (len || (magic == PSELAN_MAGIC_EOF)) {
// receive data or EOF
return len;
}
/* skip 0 payload packages (probably fresh tokens) */
pselan_recvdone(ci);
}
}
static
void pselan_get_fresh_tokens(pselan_con_info_t *ci)
{
pselan_msg_t *msg = ci->recv_bufs + ci->recv_pos;
unsigned int magic = msg->tail.magic;
if ((magic == PSELAN_MAGIC_IO) &&
(msg->tail.payload == 0)) {
// Fresh tokens
msg->tail.magic = PSELAN_MAGIC_UNUSED;
ci->n_send_toks += msg->tail.token;
ci->n_recv_toks++;
pselan_recvdone(ci);
}
}
static
int _pscom_elan_do_read(pscom_con_t *con, pselan_con_info_t *ci)
{
void *buf;
int size;
size = pselan_recvlook(ci, &buf);
if (size >= 0) {
pscom_read_done(con, buf, size);
pselan_recvdone(ci);
return 1;
} else if ((size == -EINTR) || (size == -EAGAIN)) {
// Nothing received
return 0;
} else {
// Error
errno = -size;
pscom_con_error(con, PSCOM_OP_READ, PSCOM_ERR_STDERROR);
return 1;
}
}