From ebfb2151d806864b921b32d14f26e2b9a3930822 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Thu, 28 Jan 2021 18:56:49 +0000
Subject: [PATCH] server: Add a timer that triggers printing the statistics one
 a second

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---
 src/server.c | 95 ++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 74 insertions(+), 21 deletions(-)

diff --git a/src/server.c b/src/server.c
index 67eeb27..6725389 100644
--- a/src/server.c
+++ b/src/server.c
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <string.h>
 #include <sys/epoll.h>
+#include <sys/timerfd.h>
 #include <unistd.h>
 
 #include "logging.h"
@@ -35,6 +36,12 @@ struct fireperf_server_stats {
 	unsigned int connections;
 };
 
+static int dump_stats(struct fireperf_config* conf, const struct fireperf_server_stats* stats) {
+	DEBUG(conf, "Printing statistics...\n");
+
+	return 0;
+}
+
 static int create_socket(struct fireperf_config* conf) {
 	// Open a new socket
 	int fd = socket(AF_INET6, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
@@ -149,6 +156,34 @@ int fireperf_server(struct fireperf_config* conf) {
 		goto ERROR;
 	}
 
+	// Create timerfd() to print statistics
+	int timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC);
+	if (timerfd < 0) {
+		ERROR(conf, "timerfd_create() failed: %s\n", strerror(errno));
+		goto ERROR;
+	}
+
+	ev.events = EPOLLIN;
+	ev.data.fd = timerfd;
+
+	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, timerfd, &ev)) {
+		ERROR(conf, "Could not add timerfd to epoll(): %s\n",
+			strerror(errno));
+		goto ERROR;
+	}
+
+	// Let the timer ping us once a second
+	struct itimerspec timer = {
+		.it_interval.tv_sec = 1,
+		.it_value.tv_sec = 1,
+	};
+
+	r = timerfd_settime(timerfd, 0, &timer, NULL);
+	if (r) {
+		ERROR(conf, "Could not set timer: %s\n", strerror(errno));
+		return 1;
+	}
+
 	DEBUG(conf, "Entering main loop...\n");
 
 	while (!conf->terminated) {
@@ -183,34 +218,49 @@ int fireperf_server(struct fireperf_config* conf) {
 
 				// A connection has been opened
 				stats.connections++;
-				continue;
-			}
 
-			// Handle any connection events (like disconnects)
-			if (ev.events & EPOLLHUP) {
-				DEBUG(conf, "Connection %d has closed\n", fd);
+			// Handle timer events
+			} else if (fd == timerfd) {
+				uint64_t expirations;
 
-				// Remove the file descriptor from epoll()
-				if (epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL)) {
-					ERROR(conf, "Could not remove socket file descriptfor from epoll(): %s\n",
-						strerror(errno));
+				// Read from the timer to disarm it
+				ssize_t bytes_read = read(timerfd, &expirations, sizeof(expirations));
+				if (bytes_read <= 0) {
+					ERROR(conf, "Could not read from timerfd: %s\n", strerror(errno));
+					goto ERROR;
 				}
 
-				// Free up any resources
-				close(fd);
+				r = dump_stats(conf, &stats);
+				if (r)
+					goto ERROR;
 
-				// This connection is now closed
-				stats.connections--;
+			// Handle any connection events
+			} else {
+				if (ev.events & EPOLLHUP) {
+					DEBUG(conf, "Connection %d has closed\n", fd);
 
-				// Skip processing anything else, because it would be pointless
-				continue;
-			}
+					// Remove the file descriptor from epoll()
+					if (epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL)) {
+						ERROR(conf, "Could not remove socket file descriptfor from epoll(): %s\n",
+							strerror(errno));
+					}
 
-			// One of the connections had IO
-			if (ev.events & EPOLLIN) {
-				r = handle_io_on_connection(conf, fd);
-				if (r < 0)
-					goto ERROR;
+					// Free up any resources
+					close(fd);
+
+					// This connection is now closed
+					stats.connections--;
+
+					// Skip processing anything else, because it would be pointless
+					continue;
+				}
+
+				// One of the connections had IO
+				if (ev.events & EPOLLIN) {
+					r = handle_io_on_connection(conf, fd);
+					if (r < 0)
+						goto ERROR;
+				}
 			}
 		}
 	}
@@ -222,5 +272,8 @@ ERROR:
 	if (epollfd > 0)
 		close(epollfd);
 
+	if (timerfd > 0)
+		close(timerfd);
+
 	return r;
 }
-- 
2.47.2