Adding HardSpinner class

CMakeLists.txt

@@ -39,6 +39,7 @@ add_library(${LIBRARY_NAME}
   src/realtime_check.cpp
   src/thread.cpp
   src/spinner.cpp
+  src/hard_spinner.cpp
   src/timer.cpp
   src/iostream.cpp
   src/usb_stream.cpp

include/real_time_tools/hard_spinner.hpp

@@ -0,0 +1,46 @@
+/**
+ * @file hard_spinner.cpp
+ * @author Julian Viereck (jviereck@tuebingen.mpg.de)
+ * license License BSD-3-Clause
+ * @copyright Copyright (c) 2020, New York University and Max Planck
+ * Gesellschaft.
+ * @date 2020-11-26
+ *
+ * @brief This file implements a hard spinner to time a loop. Compared to the 
+ *   Spinner class, this spinner uses the desired frequency for how often to
+ *   spin instead of the desired waiting time.
+ * 
+ * \code{.txt}
+ *    Spinner:     |-----1 ms-----| |-work-| |-----1 ms-----| |-work-|
+ *    HardSpinner: |-|-work-|-----| |-|-work-|-----| |-|-work-|-----|
+ * \endcode
+ */
+
+#ifndef HARD_SPINNER_HPP
+#define HARD_SPINNER_HPP
+
+#include <unistd.h>
+#include <chrono>
+#include <real_time_tools/spinner.hpp>
+
+namespace real_time_tools
+{
+/**
+ * @brief Class to have threads / loops running at a desired frequency
+ */
+class HardSpinner: Spinner
+{
+public:
+    // create a spinner for the desired frequency
+    HardSpinner();
+
+    /**
+     * @brief spin waits for the time such that successive calls to spin
+     * will result in spin being called at the desired frequency.
+     */
+    void spin();
+};
+
+}  // namespace real_time_tools
+
+#endif  // SPINNER_HPP

include/real_time_tools/spinner.hpp

@@ -62,7 +62,7 @@ class Spinner
      */
     double predict_sleeping_time();
 
-private:
+protected:
     /**
      * @brief period_sec_ is the period of the loop in seconds
      */

src/hard_spinner.cpp

@@ -0,0 +1,26 @@
+/**
+ * @file hard_spinner.cpp
+ * @author Julian Viereck (jviereck@tuebingen.mpg.de)
+ * license License BSD-3-Clause
+ * @copyright Copyright (c) 2020, New York University and Max Planck
+ * Gesellschaft.
+ * @date 2020-11-26
+ *
+ * @brief This file implements a hard spinner to time a loop.
+ */
+
+#include <real_time_tools/hard_spinner.hpp>
+#include <real_time_tools/timer.hpp>
+
+namespace real_time_tools
+{
+HardSpinner::HardSpinner()
+: Spinner() { }
+
+void HardSpinner::spin()
+{
+    Timer::sleep_until_sec(next_date_sec_);
+    next_date_sec_ = next_date_sec_ + period_sec_;
+}
+
+}  // namespace real_time_tools