1 files changed, 80 insertions, 0 deletions
diff --git a/src/common/fdset.c b/src/common/fdset.c
new file mode 100644
index 0000000..8c070ad
--- /dev/null
+++ b/src/common/fdset.c
@@ -0,0 +1,80 @@
+/*  Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE /* Required for RTLD_DEFAULT. */
+#endif
+
+#include <dlfcn.h>
+#include <string.h>
+#include <stdio.h>
+#include "common/fdset.h"
+#include <config.h>
+
+struct fdset_backend_t _fdset_backend = {
+};
+
+/*! \brief Set backend implementation. */
+static void fdset_set_backend(struct fdset_backend_t *backend) {
+	memcpy(&_fdset_backend, backend, sizeof(struct fdset_backend_t));
+}
+
+/* Linux epoll API. */
+#ifdef HAVE_EPOLL_WAIT
+  #include "common/fdset_epoll.h"
+#endif /* HAVE_EPOLL_WAIT */
+
+/* BSD kqueue API */
+#ifdef HAVE_KQUEUE
+  #include "common/fdset_kqueue.h"
+#endif /* HAVE_KQUEUE */
+
+/* POSIX poll API */
+#ifdef HAVE_POLL
+  #include "common/fdset_poll.h"
+#endif /* HAVE_POLL */
+
+/*! \brief Bootstrap polling subsystem (it is called automatically). */
+void __attribute__ ((constructor)) fdset_init()
+{
+	/* Preference: epoll */
+#ifdef HAVE_EPOLL_WAIT
+	if (dlsym(RTLD_DEFAULT, "epoll_wait") != 0) {
+		fdset_set_backend(&FDSET_EPOLL);
+		return;
+	}
+#endif
+
+	/* Preference: kqueue */
+#ifdef HAVE_KQUEUE
+	if (dlsym(RTLD_DEFAULT, "kqueue") != 0) {
+		fdset_set_backend(&FDSET_KQUEUE);
+		return;
+	}
+#endif
+
+	/* Fallback: poll */
+#ifdef HAVE_POLL
+	if (dlsym(RTLD_DEFAULT, "poll") != 0) {
+		fdset_set_backend(&FDSET_POLL);
+		return;
+	}
+#endif
+
+	/* This shouldn't happen. */
+	fprintf(stderr, "fdset: fatal error - no valid fdset backend found\n");
+	return;
+}