From 90d2ae83fbcb570ff1a59c81bd841b15c4ec1357 Mon Sep 17 00:00:00 2001
From: Karl Fessel <karl.fessel@ovgu.de>
Date: Wed, 29 Mar 2023 15:06:59 +0200
Subject: [PATCH] cpp11-compat: thread::sleep_for in microseconds

---
 sys/cpp11-compat/include/riot/thread.hpp | 24 ++++++++++++++----------
 sys/cpp11-compat/thread.cpp              |  7 +++----
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/sys/cpp11-compat/include/riot/thread.hpp b/sys/cpp11-compat/include/riot/thread.hpp
index 219167268e..bc30048a78 100644
--- a/sys/cpp11-compat/include/riot/thread.hpp
+++ b/sys/cpp11-compat/include/riot/thread.hpp
@@ -172,9 +172,9 @@ inline thread_id get_id() noexcept { return thread_id{thread_getpid()}; }
 inline void yield() noexcept { thread_yield(); }
 /**
  * @brief Puts the current thread to sleep.
- * @param[in] ns    Duration to sleep in nanoseconds.
+ * @param[in] us    Duration to sleep in microseconds.
  */
-void sleep_for(const std::chrono::nanoseconds& ns);
+void sleep_for(const std::chrono::microseconds& us);
 /**
  * @brief Puts the current thread to sleep.
  * @param[in] sleep_duration    The duration to sleep.
@@ -182,18 +182,22 @@ void sleep_for(const std::chrono::nanoseconds& ns);
 template <class Rep, class Period>
 void sleep_for(const std::chrono::duration<Rep, Period>& sleep_duration) {
   using namespace std::chrono;
-  if (sleep_duration > std::chrono::duration<Rep, Period>::zero()) {
-    constexpr std::chrono::duration<long double> max = nanoseconds::max();
-    nanoseconds ns;
+  if (sleep_duration > sleep_duration.zero()) {
+    constexpr duration<long double> max = microseconds::max();
+    microseconds us;
     if (sleep_duration < max) {
-      ns = duration_cast<nanoseconds>(sleep_duration);
-      if (ns < sleep_duration) {
-        ++ns;
+      us = duration_cast<microseconds>(sleep_duration);
+      if (us.count() == 0) {
+        // wait at least 1
+        us = microseconds(1);
+      }
+      if (us < sleep_duration) {
+        ++us;
       }
     } else {
-      ns = nanoseconds::max();
+      us = microseconds::max();
     }
-    sleep_for(ns);
+    sleep_for(us);
   }
 }
 /**
diff --git a/sys/cpp11-compat/thread.cpp b/sys/cpp11-compat/thread.cpp
index f19a41101b..4895b7e745 100644
--- a/sys/cpp11-compat/thread.cpp
+++ b/sys/cpp11-compat/thread.cpp
@@ -68,11 +68,10 @@ unsigned thread::hardware_concurrency() noexcept {
 
 namespace this_thread {
 
-void sleep_for(const chrono::nanoseconds& ns) {
+void sleep_for(const chrono::microseconds& us) {
   using namespace chrono;
-  if (ns > nanoseconds::zero()) {
-    ztimer64_sleep(ZTIMER64_USEC,
-        static_cast<uint64_t>(duration_cast<microseconds>(ns).count()));
+  if (us > microseconds::zero()) {
+    ztimer64_sleep(ZTIMER64_USEC, us.count());
   }
 }