simpleperf: wake up per sample in monitor cmd.

It is to show samples in real time.
Also flush stdout after printing each sample.

Bug: none
Test: run simpleperf_unit_test.
Change-Id: I7de8ae82deedb76d736c7635f6818ba7b6f440bc

1 files changed, 9 insertions, 0 deletions

diff --git a/simpleperf/event_selection_set.cpp b/simpleperf/event_selection_set.cpp
index b92f1005..2ef634b4 100644
--- a/simpleperf/event_selection_set.cpp
+++ b/simpleperf/event_selection_set.cpp
@@ -488,6 +488,15 @@ bool EventSelectionSet::RecordNotExecutableMaps() const {
   return groups_[0][0].event_attr.mmap_data == 1;
 }
 
+void EventSelectionSet::WakeupPerSample() {
+  for (auto& group : groups_) {
+    for (auto& selection : group) {
+      selection.event_attr.watermark = 0;
+      selection.event_attr.wakeup_events = 1;
+    }
+  }
+}
+
 bool EventSelectionSet::SetTracepointFilter(const std::string& filter) {
   // 1. Find the tracepoint event to set filter.
   EventSelection* selection = nullptr;