1 files changed, 73 insertions, 0 deletions
diff --git a/Utility/libkqueue.c b/Utility/libkqueue.c
new file mode 100644
index 000000000..b5a19a135
--- /dev/null
+++ b/Utility/libkqueue.c
@@ -0,0 +1,73 @@
+/* kqueue interface, C mini-library
+ *
+ * Copyright 2012 Joey Hess <joey@kitenet.net>
+ *
+ * Licensed under the GNU GPL version 3 or higher.
+ */
+
+#include <stdio.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/event.h>
+#include <sys/time.h>
+#include <errno.h>
+
+/* The specified fds are added to the set of fds being watched for changes.
+ * Fds passed to prior calls still take effect, so it's most efficient to
+ * not pass the same fds repeatedly.
+ *
+ * Returns the fd that changed, or -1 on error.
+ */
+signed int helper(const int kq, const int fdcnt, const int *fdlist, int nodelay) {
+	int i, nev;
+	struct kevent evlist[1];
+	struct kevent chlist[fdcnt];
+	struct timespec avoiddelay = {0, 0};
+	struct timespec *timeout = nodelay ? &avoiddelay : NULL;
+	
+	for (i = 0; i < fdcnt; i++) {
+		EV_SET(&chlist[i], fdlist[i], EVFILT_VNODE,
+			EV_ADD | EV_ENABLE | EV_CLEAR,
+			NOTE_WRITE,
+			0, 0);
+	}
+
+	nev = kevent(kq, chlist, fdcnt, evlist, 1, timeout);
+	if (nev == 1)
+		return evlist[0].ident;
+	else
+		return -1;
+}
+
+/* Initializes a new, empty kqueue. */
+int init_kqueue() {
+	int kq;
+	if ((kq = kqueue()) == -1) {
+		perror("kqueue");
+		exit(1);
+	}
+	return kq;
+}
+
+/* Adds fds to the set that should be watched. */
+void addfds_kqueue(const int kq, const int fdcnt, const int *fdlist) {
+	helper(kq, fdcnt, fdlist, 1);
+}
+
+/* Waits for a change event on a kqueue. */
+signed int waitchange_kqueue(const int kq) {
+	return helper(kq, 0, NULL, 0);
+}
+
+/*
+main () {
+	int list[1];
+	int kq;
+	list[0]=open(".", O_RDONLY);
+	kq = init_kqueue();
+	addfds_kqueue(kq, 1, list)
+	printf("change: %i\n", waitchange_kqueue(kq));
+}
+*/