From 5e30b23c58d81f088e6334f74cbba701e0e578db Mon Sep 17 00:00:00 2001
From: Dean Lee <deanlee3@gmail.com>
Date: Mon, 4 Jan 2021 20:59:23 +0800
Subject: [PATCH] UI: reducing CPU usage from 13% to 4% when offroad (#19575)

* Accurately control the UI frequency

* helper function sleep_for
old-commit-hash: a4afc03a732ab6438a72bda22911bf4532e9e4cd
---
 selfdrive/common/utilpp.h  | 6 +++++-
 selfdrive/ui/android/ui.cc | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/selfdrive/common/utilpp.h b/selfdrive/common/utilpp.h
index 23dc8433ee..61e9307f4e 100644
--- a/selfdrive/common/utilpp.h
+++ b/selfdrive/common/utilpp.h
@@ -7,6 +7,8 @@
 #include <memory>
 #include <sstream>
 #include <fstream>
+#include <thread>
+#include <chrono>
 
 namespace util {
 
@@ -69,7 +71,9 @@ inline std::string getenv_default(const char* env_var, const char * suffix, cons
   }
 }
 
-
+inline void sleep_for(const int milliseconds) {
+  std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds));
+}
 }
 
 struct unique_fd {
diff --git a/selfdrive/ui/android/ui.cc b/selfdrive/ui/android/ui.cc
index d9ac3bff54..e6f28d2286 100644
--- a/selfdrive/ui/android/ui.cc
+++ b/selfdrive/ui/android/ui.cc
@@ -148,7 +148,7 @@ int main(int argc, char* argv[]) {
 
   while (!do_exit) {
     if (!s->started) {
-      usleep(50 * 1000);
+      util::sleep_for(50);
     }
     double u1 = millis_since_boot();