static int pipe_poll(struct fnode *f, uint16_t events, uint16_t *revents)
{
struct pipe_priv *pp;
*revents = 0;
if (f->owner != &mod_pipe)
return -EINVAL;
pp = (struct pipe_priv *)f->priv;
if (!pp) {
return -EINVAL;
}
if (f == pp->fno_w) {
if(pp->fno_r == 0) {
*revents |= POLLHUP;
return 1;
}
else if ((events & POLLOUT) && (cirbuf_bytesfree(pp->cb) > 0)) {
*revents = POLLOUT;
return 1;
}
}
if ((f == pp->fno_r) && (events & POLLIN) && (cirbuf_bytesinuse(pp->cb) > 0)) {
*revents |= POLLIN;
return 1;
}
return 0;
}
static void printchar(char **str, int c)
{
if (str) {
**str = c;
++(*str);
}
else {
if (cirbuf_bytesfree(klog.buf)) {
cirbuf_writebyte(klog.buf, c);
if (klog.task != NULL)
task_resume(klog.task);
}
}
}
static int pipe_write(struct fnode *f, const void *buf, unsigned int len)
{
struct pipe_priv *pp;
int out, len_available;
const uint8_t *ptr = buf;
if (f->owner != &mod_pipe)
return -EINVAL;
pp = (struct pipe_priv *)f->priv;
if (!pp)
return -EINVAL;
if (pp->fno_w != f)
return -EPERM;
out = pp->w_off;
len_available = cirbuf_bytesfree(pp->cb);
if (len_available > (len - out))
len_available = (len - out);
for(; out < len_available; out++) {
/* write data */
if (cirbuf_writebyte(pp->cb, *(ptr + out)) != 0)
break;
}
if (out < len) {
pp->pid_w = scheduler_get_cur_pid();
pp->w_off = out;
task_suspend();
return SYS_CALL_AGAIN;
}
pp->w_off = 0;
pp->pid_w = 0;
return out;
}
