Add simple polled rate limiter

time.cpp

@@ -93,6 +93,25 @@ delta_clock::seconds (void) {
 }
 
 
+// ----------------------------------------------------------------------------
+util::rate_limiter::rate_limiter (unsigned rate):
+    m_last (nanoseconds ()),
+    m_target (static_cast<double> (SECOND) / rate)
+{ ; }
+
+
+void
+util::rate_limiter::poll (void) {
+    uint64_t now = nanoseconds ();
+    uint64_t total = now - m_last;
+
+    if (total < m_target)
+        sleep (m_target - total);
+
+    m_last = now;
+}
+
+
 // ----------------------------------------------------------------------------
 util::polled_duration::polled_duration (std::string name, uint64_t interval):
     m_name     (name),

time.hpp

@@ -43,6 +43,18 @@ namespace util {
             } time;
     };
 
+    // ------------------------------------------------------------------------
+    class rate_limiter {
+        public:
+            rate_limiter (unsigned rate);
+
+            void poll (void);
+
+        protected:
+            uint64_t m_last;
+            unsigned m_target;
+    };
+
     // ------------------------------------------------------------------------
     class polled_duration {
         public: