2 files changed, 43 insertions, 0 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 4f59eaefc706..f804926778b7 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -113,6 +113,45 @@ union perf_event *perf_mmap__read_backward(struct perf_mmap *map)
 	return perf_mmap__read(map, &map->prev, end);
 }
 
+/*
+ * Read event from ring buffer one by one.
+ * Return one event for each call.
+ *
+ * Usage:
+ * perf_mmap__read_init()
+ * while(event = perf_mmap__read_event()) {
+ *	//process the event
+ *	perf_mmap__consume()
+ * }
+ * perf_mmap__read_done()
+ */
+union perf_event *perf_mmap__read_event(struct perf_mmap *map,
+					bool overwrite,
+					u64 *startp, u64 end)
+{
+	union perf_event *event;
+
+	/*
+	 * Check if event was unmapped due to a POLLHUP/POLLERR.
+	 */
+	if (!refcount_read(&map->refcnt))
+		return NULL;
+
+	if (startp == NULL)
+		return NULL;
+
+	/* non-overwirte doesn't pause the ringbuffer */
+	if (!overwrite)
+		end = perf_mmap__read_head(map);
+
+	event = perf_mmap__read(map, startp, end);
+
+	if (!overwrite)
+		map->prev = *startp;
+
+	return event;
+}
+
 void perf_mmap__read_catchup(struct perf_mmap *map)
 {
 	u64 head;
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index 95549d4af943..28718543dd42 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -89,6 +89,10 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
 union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
 union perf_event *perf_mmap__read_backward(struct perf_mmap *map);
 
+union perf_event *perf_mmap__read_event(struct perf_mmap *map,
+					bool overwrite,
+					u64 *startp, u64 end);
+
 int perf_mmap__push(struct perf_mmap *md, bool backward,
 		    void *to, int push(void *to, void *buf, size_t size));