Bill Fischofer(Bill-Fischofer-Linaro) replied on github web page:
platform/linux-generic/include/odp_ring_st_internal.h
line 46
@@ -0,0 +1,118 @@
+/* Copyright (c) 2018, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef ODP_RING_ST_INTERNAL_H_
+#define ODP_RING_ST_INTERNAL_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <odp/api/hints.h>
+#include <odp_align_internal.h>
+
+/* Basic ring for single thread usage. Operations must be synchronized by using
+ * locks (or other means), when multiple threads use the same ring. */
+typedef struct {
+ uint32_t head;
+ uint32_t tail;
+ uint32_t mask;
+ uint32_t *data;
+
+} ring_st_t;
+
+/* Initialize ring. Ring size must be a power of two. */
+static inline void ring_st_init(ring_st_t *ring, uint32_t *data, uint32_t size)
+{
+ ring->head = 0;
+ ring->tail = 0;
+ ring->mask = size - 1;
+ ring->data = data;
+}
+
+/* Dequeue data from the ring head. Max_num is smaller than ring size.*/
+static inline uint32_t ring_st_deq_multi(ring_st_t *ring, uint32_t data[],
+ uint32_t max_num)
+{
+ uint32_t head, tail, mask, idx;
+ uint32_t num, i;
+
+ head = ring->head;
+ tail = ring->tail;
+ mask = ring->mask;
+ num = tail - head;
Comment:
should be `num = abs(tail - head);` to deal with wrap arounds, otherwise may be
misinterpreted as overly large since it's `uint32_t`. Note that GCC and clang
recognize `abs()` and treat it as a builtin, so there's no actual `stdlib.h`
call here.
> Bill Fischofer(Bill-Fischofer-Linaro) wrote:
> Extra blank line should be removed (nit).
https://github.com/Linaro/odp/pull/492#discussion_r169793454
updated_at 2018-02-22 09:32:40
