time: add wait/reset to period_limiter

time.cpp

@@ -106,18 +106,32 @@ cruft::period_limiter::period_limiter (u64 _period)
 
 
 //-----------------------------------------------------------------------------
-void cruft::period_limiter::poll (void)
+void
+cruft::period_limiter::wait (void) const
 {
     auto const now  = nanoseconds ();
     auto const diff = now - m_prev;
 
     if (diff < m_period)
         sleep (m_period - diff);
+}
 
+
+//-----------------------------------------------------------------------------
+void cruft::period_limiter::reset (void)
+{
     m_prev = nanoseconds ();
 }
 
 
+//-----------------------------------------------------------------------------
+void cruft::period_limiter::poll (void)
+{
+    wait ();
+    reset ();
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 cruft::polled_duration::polled_duration (std::string name, uint64_t interval):
     m_name     (std::move (name)),

time.hpp

@@ -77,12 +77,21 @@ namespace cruft {
 
 
     ///////////////////////////////////////////////////////////////////////////
+    /// Ensured to ensure a minimum period has elapsed since a previous
+    /// invocation.
     class period_limiter {
     public:
         explicit period_limiter (std::chrono::nanoseconds _period);
         explicit period_limiter (u64);
 
+        /// Wait until the period has elapsed and reset the last activation
+        /// time.
         void poll (void);
+        /// Wait until the period has elapsed. Does not reset the last
+        /// activation time.
+        void wait (void) const;
+        /// Reset the last activated time. Does not block.
+        void reset (void);
 
     private:
         u64 m_period;