static int idesc_pipe_close(struct idesc_pipe *cur, struct idesc_pipe *other) {
cur->idesc.idesc_amode = 0;
if (other->idesc.idesc_amode) {
idesc_notify(&other->idesc, POLLERR);
} else {
return 1;
}
return 0;
}
static ssize_t pipe_write(struct idesc *idesc, const void *buf, size_t nbyte) {
struct pipe *pipe;
const void *cbuf;
int len;
ssize_t res;
assert(buf);
assert(idesc);
assert(idesc->idesc_ops == &idesc_pipe_ops);
assert(idesc->idesc_amode == FS_MAY_WRITE);
cbuf = buf;
/* nbyte == 0 is ok to passthrough */
pipe = idesc_to_pipe(idesc);
mutex_lock(&pipe->mutex);
do {
/* No data can be readed at all */
if (idesc_pipe_isclosed(&pipe->read_desc)) {
res = -EPIPE;
break;
}
/* Try to write some data */
len = ring_buff_enqueue(pipe->buff, (void *) cbuf, nbyte);
if (len > 0) {
/* Notzero was written, adjust pointers and notify
* (read end can't be closed) */
cbuf += len;
nbyte -= len;
idesc_notify(&pipe->read_desc.idesc, POLLIN);
}
/* Have nothing to write, exit*/
if (!nbyte) {
res = cbuf - buf;
break;
}
res = pipe_wait(idesc, pipe, POLLOUT | POLLERR);
} while (res == 0);
mutex_unlock(&pipe->mutex);
return res;
}
static ssize_t pipe_read(struct idesc *idesc, void *buf, size_t nbyte) {
struct pipe *pipe;
ssize_t res;
assert(buf);
assert(idesc);
assert(idesc->idesc_ops == &idesc_pipe_ops);
assert(idesc->idesc_amode == FS_MAY_READ);
if (!nbyte) {
return 0;
}
pipe = idesc_to_pipe(idesc);
mutex_lock(&pipe->mutex);
do {
res = ring_buff_dequeue(pipe->buff, buf, nbyte);
if (idesc_pipe_isclosed(&pipe->write_desc)) {
/* Nothing to do, what's read, that's read */
break;
}
if (res > 0) {
/* Smth read, notify write end (can't be closed,
* checked already) */
idesc_notify(&pipe->write_desc.idesc, POLLOUT);
break;
}
res = pipe_wait(idesc, pipe, POLLIN | POLLERR);
} while (res == 0);
mutex_unlock(&pipe->mutex);
return res;
}
static inline void tty_notify(struct tty *t, int mask) {
assert(t);
if (t->idesc)
idesc_notify(t->idesc, mask);
}
