slightly more robust error handling

src/EventLoop.cpp

@@ -8,13 +8,16 @@ namespace nanosm {
 		epollFd = epoll_create1(EPOLL_CLOEXEC);
 
 		if(epollFd == -1) {
-			perror("You Banned From Epoll, Rules");
+			throw std::system_error(std::make_error_code(static_cast<std::errc>(errno)));
+			return;
 		}
 	}
 
 	EventLoop::~EventLoop() {
+		if(epollFd == -1) {
 			close(epollFd);
 		}
+	}
 
 	void EventLoop::Post(PostFn func) {
 		if(!func)
@@ -56,15 +59,15 @@ namespace nanosm {
 		UniqueArray<epoll_event> events { 16 };
 
 		while(!shouldStop) {
-			auto nevents = epoll_wait(epollFd, events.Get(), events.Size(), 10);
-			if(nevents == -1) {
-				perror("epoll_wait");
-				break;
+			// The timeout here is larger than it probably would be if e.g: this was dealing with sockets,
+			// mostly because nanosm is designed to only really use CPU if it has to (i.e: a process died, timer elapsed, etc)
+			auto nrEvents = epoll_wait(epollFd, events.Get(), events.Size(), 50);
+			if(nrEvents == -1) {
+				throw std::system_error(std::make_error_code(static_cast<std::errc>(errno)));
 			}
 
-			// All OK, let's check for events now
-
-			for(int i = 0; i < nevents; ++i) {
+			if(nrEvents != 0) {
+				for(int i = 0; i < nrEvents; ++i) {
 					for(auto pollable : ioObjects) {
 						if(auto fd = pollable->GetFD(); fd != -1) {
 							// Signal any events that occur for this
@@ -73,8 +76,10 @@ namespace nanosm {
 						}
 					}
 				}
+			}
 
-			// Run the topmost callback once every event loop iteration.
+			// Run the topmost callback once every event loop iteration,
+			// even if epoll never signaled readiness.
 			if(!postCallbacks.empty()) {
 				auto& frontCallback = postCallbacks.front();
 				frontCallback();

src/Timer.cpp

@@ -7,8 +7,9 @@ namespace nanosm {
 	Timer::Timer(nanosm::EventLoop& ev)
 		: nanosm::EventLoop::IoObject(ev) {
 		timerFd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
-		if(timerFd < 0)
-			perror("timerfd_create");
+		if(timerFd < 0) {
+			throw std::system_error(std::make_error_code(static_cast<std::errc>(errno)));
+		}
 	}
 
 	Timer::~Timer() {

src/main.cpp

@@ -2,6 +2,7 @@
 #include <format>
 #include <map>
 #include <memory>
+#include <system_error>
 #include <toml++/toml.hpp>
 
 #include "EventLoop.hpp"
@@ -82,7 +83,12 @@ struct NanoSm {
 			this->SpawnAllApps();
 		});
 
+		try {
 			ev.Run();
+		} catch(std::exception& ec) {
+			nanosm::log::Error("NanoSm", "Unhandled exception in event loop: {}", ec.what());
+			return 1;
+		}
 		return 0;
 	}
 
@@ -105,6 +111,7 @@ fs::path GetConfigPath() {
 }
 
 int main(int argc, char** argv) {
+	try {
 		NanoSm nanosm;
 
 		auto configPath = GetConfigPath();
@@ -146,10 +153,13 @@ int main(int argc, char** argv) {
 				return 1;
 			}
 
+			return nanosm.Run();
 		} catch(toml::parse_error& pe) {
 			std::fprintf(stderr, "Error parsing config file \"%s\": %s\n", configPath.c_str(), pe.description().data());
 			return 1;
 		}
-
-	return nanosm.Run();
+	} catch(std::exception& ec) {
+		nanosm::log::Error("NanoSm", "Error initalizing NanoSm: {}", ec.what());
+		return 1;
+	}
 }