Initial switch to low precision timer

applications/vision/src/main.cpp

@@ -55,6 +55,8 @@ static void run(ftl::Configurable *root) {
 	Universe *net = ftl::create<Universe>(root, "net");
 	ftl::ctrl::Master ctrl(root, net);
 
+	ftl::timer::setHighPrecision(true);
+
 	auto paths = root->get<vector<string>>("paths");
 	string file = "";
 	if (paths && (*paths).size() > 0) file = (*paths)[(*paths).size()-1];

components/common/cpp/include/ftl/timer.hpp

@@ -69,9 +69,20 @@ int64_t get_time();
  */
 void setInterval(int ms);
 
+/**
+ * The highprec parameter sets whether or not this
+ * timer should be high precision on the calling interval. A high precision
+ * timer involves spinning the cpu to achieve millisecond accuracy.
+ */
+void setHighPrecision(bool hp);
+
 int getInterval();
 
+/**
+ * Get current (monotonic) time in milliseconds.
+ */
 int64_t get_time();
+
 int64_t get_time_micro();
 double get_time_seconds();
 

components/common/cpp/src/timer.cpp

@@ -20,6 +20,7 @@ using namespace ftl::timer;
 
 static int64_t last_frame = 0;
 static int64_t mspf = 50;
+static bool hprec_ = false;
 static int64_t clock_adjust = 0;
 static bool active = false;
 static std::atomic<int> active_jobs = 0;
@@ -59,7 +60,7 @@ static void waitTimePoint() {
 	int64_t msdelay = mspf - (now % mspf);
 	int64_t sincelast = now - last_frame*mspf;
 
-	if (sincelast > mspf) LOG(WARNING) << "Frame " << "(" << (target-last_frame) << ") dropped by " << sincelast << "ms";
+	if (hprec_ && sincelast > mspf) LOG(WARNING) << "Frame " << "(" << (target-last_frame) << ") dropped by " << (sincelast-mspf) << "ms";
 
 	// Use sleep_for for larger delays
 	
@@ -89,6 +90,7 @@ static void waitTimePoint() {
 		}
 	}
 
+	if (hprec_) {
 		// Spin loop until exact grab time
 		//LOG(INFO) << "Spin Delay: " << (now / 40) << " = " << (40 - (now%40));
 
@@ -99,6 +101,10 @@ static void waitTimePoint() {
 				now = get_time();
 			};
 		}
+	} else {
+		if (sincelast != mspf) sleep_for(milliseconds(msdelay));
+		now = get_time();
+	}
 	last_frame = now/mspf;
 }
 
@@ -106,6 +112,10 @@ void ftl::timer::setInterval(int ms) {
 	mspf = ms;
 }
 
+void ftl::timer::setHighPrecision(bool hp) {
+	hprec_ = hp;
+}
+
 int ftl::timer::getInterval() {
 	return mspf;
 }