Re: [PATCH v2] Associate target_ops with target_fileio file descriptors

Pedro Alves
2015-03-24T16:55:27Z

On 03/24/2015 04:36 PM, Pedro Alves wrote:
> /* Push a new handle if no closed handles were found. */
> if (lowest_closed_fd == VEC_length (fileio_fh_t, fileio_fhandles))
> {
> fh = VEC_safe_push (fileio_fh_t, fileio_fhandles, NULL);
> lowest_closed_fd++;
> }

Make this:

/* Push a new handle if no closed handles were found. */
if (lowest_closed_fd == VEC_length (fileio_fh_t, fileio_fhandles))
fh = VEC_safe_push (fileio_fh_t, fileio_fhandles, NULL);

lowest_closed_fd++;

Because there's no point in starting the next lookup at the
handle we just opened if we're reusing a slot, either. And then
that allows getting rid of the VEC_address, by simply doing
that increment at the end:

/* Index into fileio_fhandles of the lowest handle that might be
closed. This permits handle reuse without searching the whole list
each time a new file is opened. */
static int lowest_closed_fd = 0;

static int
acquire_fileio_fd (struct target_ops *t, int fd)
{
fileio_fh_t *fh, buf;

gdb_assert (!is_closed_fileio_fh (fd));

/* Search for closed handles to reuse. */
for (;
VEC_iterate (fileio_fh_t, fileio_fhandles,
lowest_closed_fd, fh);
lowest_closed_fd++)
if (is_closed_fileio_fh (fh->fd))
break;

/* Push a new handle if no closed handles were found. */
if (lowest_closed_fd == VEC_length (fileio_fh_t, fileio_fhandles))
fh = VEC_safe_push (fileio_fh_t, fileio_fhandles, NULL);

/* Fill in the handle. */
fh->t = t;
fh->fd = fd;

/* Return its index, and start the next lookup at
the next index. */
return lowest_closed_fd++;
}