From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 10 Aug 2024 12:28:39 +0000 (+0000)
Subject: daemon: Use the systemd event loop instead of epoll
X-Git-Tag: 0.9.30~1219
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=403fe84f6c2f2f1328fc7c273f78dc4d24fabbf8;p=pakfire.git

daemon: Use the systemd event loop instead of epoll

This will allow us more flexiblity and already implements a lot of
features.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/daemon.c b/src/libpakfire/daemon.c
index 934ba2704..9fd9cc5af 100644
--- a/src/libpakfire/daemon.c
+++ b/src/libpakfire/daemon.c
@@ -20,7 +20,9 @@
 
 #include <errno.h>
 #include <stdlib.h>
-#include <sys/epoll.h>
+
+#include <systemd/sd-daemon.h>
+#include <systemd/sd-event.h>
 
 #include <pakfire/buildservice.h>
 #include <pakfire/ctx.h>
@@ -34,11 +36,61 @@ struct pakfire_daemon {
 
 	// Pakfire Build Service
 	struct pakfire_buildservice* service;
+
+	// Event Loop
+	sd_event* loop;
 };
 
+static int pakfire_daemon_terminate(sd_event_source* source,
+		const struct signalfd_siginfo* si, void* data) {
+	struct pakfire_daemon* daemon = data;
+
+	CTX_DEBUG(daemon->ctx, "Received signal to terminate...\n");
+
+	return sd_event_exit(sd_event_source_get_event(source), 0);
+}
+
+static int pakfire_daemon_setup_loop(struct pakfire_daemon* daemon) {
+	int r;
+
+	// Fetch a reference to the default event loop
+	r = sd_event_default(&daemon->loop);
+	if (r < 0) {
+		CTX_ERROR(daemon->ctx, "Could not setup event loop: %s\n", strerror(-r));
+		return 1;
+	}
+
+	// Enable the watchdog
+	r = sd_event_set_watchdog(daemon->loop, 1);
+	if (r < 0) {
+		CTX_ERROR(daemon->ctx, "Could not activate watchdog: %s\n", strerror(-r));
+		return 1;
+	}
+
+	// Listen for SIGTERM
+	r = sd_event_add_signal(daemon->loop, NULL, SIGTERM|SD_EVENT_SIGNAL_PROCMASK,
+		pakfire_daemon_terminate, daemon);
+	if (r < 0) {
+		CTX_ERROR(daemon->ctx, "Could not register handling SIGTERM: %s\n", strerror(-r));
+		return 1;
+	}
+
+	// Listen for SIGINT
+	r = sd_event_add_signal(daemon->loop, NULL, SIGINT|SD_EVENT_SIGNAL_PROCMASK,
+		pakfire_daemon_terminate, daemon);
+	if (r < 0) {
+		CTX_ERROR(daemon->ctx, "Could not register handling SIGINT: %s\n", strerror(-r));
+		return 1;
+	}
+
+	return 0;
+}
+
 static void pakfire_daemon_free(struct pakfire_daemon* daemon) {
 	if (daemon->service)
 		pakfire_buildservice_unref(daemon->service);
+	if (daemon->loop)
+		sd_event_unref(daemon->loop);
 	if (daemon->ctx)
 		pakfire_ctx_unref(daemon->ctx);
 	free(daemon);
@@ -59,6 +111,11 @@ int pakfire_daemon_create(struct pakfire_daemon** daemon, struct pakfire_ctx* ct
 	// Initialize the reference counter
 	d->nrefs = 1;
 
+	// Setup the event loop
+	r = pakfire_daemon_setup_loop(d);
+	if (r)
+		goto ERROR;
+
 	// Connect to the buildservice
 	r = pakfire_buildservice_create(&d->service, d->ctx);
 	if (r)
@@ -91,66 +148,27 @@ struct pakfire_daemon* pakfire_daemon_unref(struct pakfire_daemon* daemon) {
 }
 
 static int pakfire_daemon_loop(struct pakfire_daemon* daemon) {
-	struct epoll_event events[EPOLL_MAX_EVENTS];
-	struct epoll_event event;
-	int epollfd = -1;
-	int num = 0;
-	int fd = -1;
-	int e;
 	int r;
 
-	// Setup epoll()
-	epollfd = epoll_create1(EPOLL_CLOEXEC);
-	if (epollfd < 0) {
-		CTX_ERROR(daemon->ctx, "Could not setup main loop: %s\n", strerror(errno));
-		r = -errno;
+	// We are now ready
+	sd_notify(0, "READY=1\n" "STATUS=Ready...");
+
+	// Launch the event loop
+	r = sd_event_loop(daemon->loop);
+	if (r < 0) {
+		CTX_ERROR(daemon->ctx, "Could not run the event loop: %s\n", strerror(-r));
 		goto ERROR;
 	}
 
-	CTX_DEBUG(daemon->ctx, "Entering main loop...\n");
-
-	// Main loop, loop, loop, looooop....
-	for (;;) {
-		num = epoll_wait(epollfd, events, EPOLL_MAX_EVENTS, -1);
-		if (num < 1) {
-			switch (errno) {
-				case EINTR:
-					break;
-
-				default:
-					CTX_ERROR(daemon->ctx, "epoll_wait() failed: %m\n");
-					r = -errno;
-					break;
-			}
-			goto ERROR;
-		}
-
-		// Handle all events
-		for (int i = 0; i < num; i++) {
-			fd = events[i].data.fd;
-			e  = events[i].events;
-
-			// XXX Do the work...
-
-			// Remove the file descriptor if it has been closed
-			if (e & EPOLLHUP) {
-				r = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL);
-				if (r) {
-					CTX_ERROR(daemon->ctx, "Could not remove closed fd %d: %s\n", fd, strerror(errno));
-					r = -errno;
-					goto ERROR;
-				}
-			}
-		}
-	}
+	// Let systemd know that we are shutting down
+	sd_notify(0, "STOPPING=1\n" "STATUS=Shutting down...");
 
-ERROR:
-	CTX_DEBUG(daemon->ctx, "Exited main loop...\n");
+	return 0;
 
-	if (epollfd >= 0)
-		close(epollfd);
+ERROR:
+	sd_notifyf(0, "ERRNO=%i", -r);
 
-	return r;
+	return 1;
 }
 
 int pakfire_daemon_main(struct pakfire_daemon* daemon) {