add additional mode of introducing work

The default is Burst mode which inserts new work as fast as possible
sleeping until the next pulse.
Even mode distributes the new work evenly in the duration between two
pulses.

eval/Pulse.cpp

@@ -9,6 +9,7 @@
 #include <exception>
 #include <fstream>	// IWYU pragma: keep
 #include <iostream>
+#include <sstream>
 #include <string>
 
 #include "CountingPrivateSemaphore.hpp"
@@ -22,6 +23,39 @@ namespace po = boost::program_options;
 using Clock = std::chrono::high_resolution_clock;
 using TimePoint = std::chrono::time_point<Clock>;
 
+enum class PulseMode {
+	Burst, /*!< Introduce all work as fast as possible */
+	Even,	 /*!< Introduce work evenly during the pulse */
+};
+
+auto operator<<(std::ostream& out, const PulseMode& mode) -> std::ostream& {
+	switch (mode) {
+		case PulseMode::Burst:
+			out << "burst";
+			break;
+		case PulseMode::Even:
+			out << "even";
+			break;
+	}
+	return out;
+}
+
+auto operator>>(std::istream& in, PulseMode& mode) -> std::istream& {
+	std::string token;
+
+	in >> token;
+	if (token == "burst") {
+		mode = PulseMode::Burst;
+	} else if (token == "even") {
+		mode = PulseMode::Even;
+	} else {
+		in.setstate(std::ios_base::failbit);
+	}
+	return in;
+}
+
+static PulseMode pulseMode;
+
 // Pulse of new work in microseconds
 static int64_t pulse = 1L * 1000 * 1000;
 // Number of pulses
@@ -62,18 +96,25 @@ static void pulser(Runtime& runtime) {
 	const workerid_t workerCount = runtime.getWorkerCount();
 	const workerid_t workItems = (workerCount * utilization) / 100;
 
+	struct timespec ts {
+		0, 0
+	};
+	// TODO: better calculate the time until the next burst
+	if (pulseMode == PulseMode::Burst)
+		ts.tv_nsec = pulse * 1000;
+	else
+		ts.tv_nsec = (pulse * 1000) / workItems;
+
 	CPS cps;
 	for (unsigned i = 0; i < iterations; ++i) {
 		for (unsigned w = 0; w < workItems; ++w) {
 			Work* work = new Work();
 			spawn([=] { work->run(); }, cps);
+			if (pulseMode == PulseMode::Even) emper::nanosleep(&ts);
 		}
 
-		// TODO: better calculate the time until the next pulse
-		struct timespec ts {
-			.tv_sec = 0, .tv_nsec = pulse * 1000
-		};
-		emper::nanosleep(&ts);
+		// TODO: Think about busy looping for small times
+		if (pulseMode == PulseMode::Burst) emper::nanosleep(&ts);
 	}
 	cps.wait();
 	runtime.initiateTermination();
@@ -134,6 +175,7 @@ auto main(int argc, char* argv[]) -> int {
 		("utilization", po::value<unsigned>(&utilization)->default_value(utilization),
 										"The target utilization of the runtime")
 		("latencies-file", po::value<std::string>(), "File to store all collected latencies")
+		("pulse-mode", po::value<PulseMode>(&pulseMode)->default_value(PulseMode::Burst), "How to introducing the work")
 		;
 	// clang-format on