static int pipe_read(struct fnode *f, void *buf, unsigned int len)
{
struct pipe_priv *pp;
int out, len_available;
uint8_t *ptr = buf;
if (f->owner != &mod_pipe)
return -EINVAL;
pp = (struct pipe_priv *)f->priv;
if (!pp)
return -EINVAL;
if (pp->fno_r != f)
return -EPERM;
len_available = cirbuf_bytesinuse(pp->cb);
if (len_available <= 0) {
pp->pid_r = scheduler_get_cur_pid();
task_suspend();
return SYS_CALL_AGAIN;
}
for(out = 0; out < len; out++) {
/* read data */
if (cirbuf_readbyte(pp->cb, ptr) != 0)
break;
ptr++;
}
pp->pid_r = 0;
return out;
}
static int pipe_close(struct fnode *f)
{
struct pipe_priv *pp;
uint16_t pid;
pid = scheduler_get_cur_pid();
if (!f)
return -EINVAL;
if (f->owner != &mod_pipe)
return -EINVAL;
pp = (struct pipe_priv *)f->priv;
if (!pp)
return -EINVAL;
if ((f == pp->fno_r) && (f->usage == 1)) {
pp->fno_r = NULL;
fno_unlink(f);
if ((pp->pid_w != pid) && (pp->pid_w > 0)) {
task_resume(pp->pid_w);
}
}
if ((f == pp->fno_w) && (f->usage == 1)) {
pp->fno_w = NULL;
fno_unlink(f);
if ((pp->pid_r != pid) && (pp->pid_r > 0)) {
task_resume(pp->pid_r);
}
}
if ((!pp->fno_w) && (!pp->fno_r))
kfree(pp);
return 0;
}
static void _del_listener(sem_t *s)
{
int i;
int pid = scheduler_get_cur_pid();
for (i = 0; i < s->listeners; i++) {
if (s->listener[i] == pid) {
s->listener[i] = -1;
return;
}
}
}
/* Semaphore: internal functions */
static void _add_listener(sem_t *s)
{
int i;
int pid = scheduler_get_cur_pid();
for (i = 0; i < s->listeners; i++) {
if (s->listener[i] == pid)
return;
}
s->listener = krealloc(s->listener, sizeof(int) * (s->listeners + 1));
if (!s->listener)
return;
s->listener[s->listeners++] = pid;
}
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;
}
