#define offset_lt(_a, _b) ((i32)((_a)-(_b)) < 0)
#define offset_leq(_a, _b) ((i32)((_a)-(_b)) <= 0)
+#define offset_gt(_a, _b) ((i32)((_a)-(_b)) > 0)
+#define offset_geq(_a, _b) ((i32)((_a)-(_b)) >= 0)
u8 *
format_ooo_segment (u8 * s, va_list * args)
&& offset_leq (ooo_segment_offset (f, s), offset))
s = pool_elt_at_index (f->ooo_segments, s->next);
+ /* If we have a previous and we overlap it, use it as starting point */
+ prev = ooo_segment_get_prev (f, s);
+ if (prev && offset_leq (offset, ooo_segment_end_offset (f, prev)))
+ {
+ s = prev;
+ prev = ooo_segment_get_prev (f, s);
+ s_sof = ooo_segment_offset (f, s);
+ s_eof = ooo_segment_end_offset (f, s);
+ goto merge;
+ }
+
s_index = s - f->ooo_segments;
s_sof = ooo_segment_offset (f, s);
s_eof = ooo_segment_end_offset (f, s);
- prev = ooo_segment_get_prev (f, s);
/* No overlap, add before current segment */
- if (offset_lt (end_offset, s_sof)
- && (!prev || offset_lt (prev->start + prev->length, offset)))
+ if (offset_lt (end_offset, s_sof))
{
new_s = ooo_segment_new (f, offset, length);
new_index = new_s - f->ooo_segments;
return;
}
/* No overlap, add after current segment */
- else if (offset_lt (s_eof, offset))
+ else if (offset_gt (offset, s_eof))
{
new_s = ooo_segment_new (f, offset, length);
new_index = new_s - f->ooo_segments;
* Merge needed
*/
+merge:
+
/* Merge at head */
- if (offset_leq (offset, s_sof))
+ if (offset_lt (offset, s_sof))
{
- /* If we have a previous, check if we overlap */
- if (s->prev != OOO_SEGMENT_INVALID_INDEX)
- {
- prev = pool_elt_at_index (f->ooo_segments, s->prev);
-
- /* New segment merges prev and current. Remove previous and
- * update position of current. */
- if (offset_leq (offset, ooo_segment_end_offset (f, prev)))
- {
- s->start = prev->start;
- s->length = s_eof - ooo_segment_offset (f, prev);
- ooo_segment_del (f, s->prev);
- }
- else
- {
- s->start = offset;
- s->length = s_eof - ooo_segment_offset (f, s);
- }
- }
- else
- {
- s->start = offset;
- s->length = s_eof - ooo_segment_offset (f, s);
- }
-
- /* The new segment's tail may cover multiple smaller ones */
- if (offset_lt (s_eof, end_offset))
- {
- /* Remove segments completely covered */
- it = (s->next != OOO_SEGMENT_INVALID_INDEX) ?
- pool_elt_at_index (f->ooo_segments, s->next) : 0;
- while (it && offset_lt (ooo_segment_end_offset (f, it), end_offset))
- {
- next = (it->next != OOO_SEGMENT_INVALID_INDEX) ?
- pool_elt_at_index (f->ooo_segments, it->next) : 0;
- ooo_segment_del (f, it - f->ooo_segments);
- it = next;
- }
-
- /* Update length. Segment's start might have changed. */
- s->length = end_offset - ooo_segment_offset (f, s);
-
- /* If partial overlap with last, merge */
- if (it && offset_lt (ooo_segment_offset (f, it), end_offset))
- {
- s->length +=
- it->length - (ooo_segment_offset (f, it) - end_offset);
- ooo_segment_del (f, it - f->ooo_segments);
- }
- }
+ s->start = offset;
+ s->length = s_eof - ooo_segment_offset (f, s);
}
/* Last but overlapping previous */
- else if (offset_leq (s_eof, end_offset))
+ else if (offset_gt (end_offset, s_eof))
{
s->length = end_offset - ooo_segment_offset (f, s);
}
else
{
/* Do Nothing */
+ goto done;
+ }
+
+ /* The new segment's tail may cover multiple smaller ones */
+ if (offset_geq (end_offset, s_eof))
+ {
+ /* Remove the completely overlapped segments */
+ it = (s->next != OOO_SEGMENT_INVALID_INDEX) ?
+ pool_elt_at_index (f->ooo_segments, s->next) : 0;
+ while (it && offset_leq (ooo_segment_end_offset (f, it), end_offset))
+ {
+ next = (it->next != OOO_SEGMENT_INVALID_INDEX) ?
+ pool_elt_at_index (f->ooo_segments, it->next) : 0;
+ ooo_segment_del (f, it - f->ooo_segments);
+ it = next;
+ }
+
+ /* If partial overlap with last, merge */
+ if (it && offset_leq (ooo_segment_offset (f, it), end_offset))
+ {
+ s->length = ooo_segment_end_offset (f, it) -
+ ooo_segment_offset (f, s);
+ ooo_segment_del (f, it - f->ooo_segments);
+ }
}
+done:
/* Most recently updated segment */
f->ooos_newest = s - f->ooo_segments;
}
{
ooo_segment_t *s;
u32 index, bytes = 0, diff;
- u32 cursize;
+ u32 cursize, norm_start, nitems;
/* current size has not yet been updated */
cursize = svm_fifo_max_dequeue (f) + n_bytes_enqueued;
+ nitems = f->nitems;
s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
- diff = (f->nitems + (i32) (f->tail - s->start)) % f->nitems;
+ norm_start = s->start % nitems;
+ diff = (f->nitems + (i32) (f->tail - norm_start)) % nitems;
+
if (diff > cursize)
return 0;
if (s->next != OOO_SEGMENT_INVALID_INDEX)
{
s = pool_elt_at_index (f->ooo_segments, s->next);
- diff = (f->nitems + (i32) (f->tail - s->start)) % f->nitems;
+ norm_start = s->start % nitems;
+ diff = (f->nitems + (i32) (f->tail - norm_start)) % nitems;
ooo_segment_del (f, index);
}
/* End of search */
/* If tail is adjacent to an ooo segment, 'consume' it */
if (diff == 0)
{
- bytes = ((f->nitems - cursize) >= s->length) ? s->length :
- f->nitems - cursize;
+ bytes = ((nitems - cursize) >= s->length) ? s->length :
+ nitems - cursize;
f->tail += bytes;
- f->tail %= f->nitems;
+ f->tail %= nitems;
ooo_segment_del (f, s - f->ooo_segments);
}
{
u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
u32 cursize, nitems;
- u32 normalized_offset;
- int rv;
-
- /* Users would do well to avoid this */
- if (PREDICT_FALSE (f->tail == (offset % f->nitems)))
- {
- rv = svm_fifo_enqueue_internal (f, required_bytes, copy_from_here);
- if (rv > 0)
- return 0;
- return -1;
- }
+ u32 normalized_offset, offset_from_tail;
/* read cursize, which can only increase while we're working */
cursize = svm_fifo_max_dequeue (f);
nitems = f->nitems;
+ normalized_offset = offset % nitems;
/* Will this request fit? */
- if ((required_bytes + (offset - f->tail) % nitems) > (nitems - cursize))
+ offset_from_tail = (nitems + normalized_offset - f->tail) % nitems;
+ if ((required_bytes + offset_from_tail) > (nitems - cursize))
return -1;
ooo_segment_add (f, offset, required_bytes);
/* Number of bytes we're going to copy */
total_copy_bytes = required_bytes;
- normalized_offset = offset % nitems;
/* Number of bytes in first copy segment */
first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
}
+/**
+ * Set fifo pointers to requested offset
+ */
+void
+svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
+{
+ f->head = f->tail = pointer % f->nitems;
+}
+
/*
* fd.io coding-style-patch-verification: ON
*
Code Review / vpp.git / blobdiff