1 files changed, 39 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;