[PATCH bpf-next 13/14] libbpf: add ring__consume

[Martin Kelly <martin.kelly@xxxxxxxxxxxxxxx>]

Add ring__consume to consume a single ringbuffer, analogous to
ring_buffer__consume.

Signed-off-by: Martin Kelly <martin.kelly@xxxxxxxxxxxxxxx>
---
 tools/lib/bpf/libbpf.h   | 10 ++++++++++
 tools/lib/bpf/libbpf.map |  1 +
 tools/lib/bpf/ringbuf.c  | 13 +++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index d2a237086c2c..861f8b6795e9 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -1307,6 +1307,16 @@ LIBBPF_API size_t ring__size(const struct ring *r);
  */
 LIBBPF_API int ring__map_fd(const struct ring *r);
 
+/**
+ * @brief **ring__consume()** consumes available ringbuffer data without event
+ * polling.
+ *
+ * @param r A ring object.
+ * @return The number of records consumed (or INT_MAX, whichever is less), or
+ * a negative number if any of the callbacks return an error.
+ */
+LIBBPF_API int ring__consume(struct ring *r);
+
 struct user_ring_buffer_opts {
 	size_t sz; /* size of this struct, for forward/backward compatibility */
 };
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 13800b73c343..4b5124bb0e1a 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -402,6 +402,7 @@ LIBBPF_1.3.0 {
 		bpf_program__attach_uprobe_multi;
 		ring_buffer__ring;
 		ring__avail_data_size;
+		ring__consume;
 		ring__consumer_pos;
 		ring__map_fd;
 		ring__producer_pos;
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c
index 2dba2836d85b..b7ef003366d3 100644
--- a/tools/lib/bpf/ringbuf.c
+++ b/tools/lib/bpf/ringbuf.c
@@ -365,6 +365,19 @@ int ring__map_fd(const struct ring *r)
 	return r->map_fd;
 }
 
+int ring__consume(struct ring *r)
+{
+	int64_t res;
+
+	res = ringbuf_process_ring(r);
+	if (res < 0)
+		res = libbpf_err(res);
+	else if (res > INT_MAX)
+		res = INT_MAX;
+
+	return res;
+}
+
 static void user_ringbuf_unmap_ring(struct user_ring_buffer *rb)
 {
 	if (rb->consumer_pos) {
-- 
2.34.1