Move waiter to library

Move the waiter routines into the petitboot library.  The waiter
routines are generic enough to be used for both server and
client.  Does not change the waiter source.

jk: move to lib/waiter/ instead of lib/

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 83 insertions, 0 deletions

diff --git a/lib/waiter/waiter.c b/lib/waiter/waiter.c
new file mode 100644
index 0000000..21dd4a5
--- /dev/null
+++ b/lib/waiter/waiter.c
@@ -0,0 +1,83 @@
+
+#include <poll.h>
+#include <string.h>
+#include <assert.h>
+
+#include <talloc/talloc.h>
+
+#include "waiter.h"
+
+struct waiter {
+	int		fd;
+	int		events;
+	waiter_cb	callback;
+	void		*arg;
+};
+
+static struct waiter *waiters;
+static int n_waiters;
+
+struct waiter *waiter_register(int fd, int events,
+		waiter_cb callback, void *arg)
+{
+	struct waiter *waiter;
+
+	n_waiters++;
+
+	waiters = talloc_realloc(NULL, waiters, struct waiter, n_waiters);
+	waiter = &waiters[n_waiters - 1];
+
+	waiter->fd = fd;
+	waiter->events = events;
+	waiter->callback = callback;
+	waiter->arg = arg;
+
+	return 0;
+}
+
+void waiter_remove(struct waiter *waiter)
+{
+	int i;
+
+	i = waiter - waiters;
+	assert(i >= 0 && i < n_waiters);
+
+	n_waiters--;
+	memmove(&waiters[i], &waiters[i+1], n_waiters - i);
+
+	waiters = talloc_realloc(NULL, waiters, struct waiter, n_waiters);
+}
+
+int waiter_poll(void)
+{
+	static struct pollfd *pollfds;
+	static int n_pollfds;
+	int i, rc;
+
+	if (n_waiters > n_pollfds) {
+		pollfds = talloc_realloc(NULL, pollfds,
+				struct pollfd, n_waiters);
+	}
+
+	for (i = 0; i < n_waiters; i++) {
+		pollfds[i].fd = waiters[i].fd;
+		pollfds[i].events = waiters[i].events;
+		pollfds[i].revents = 0;
+	}
+
+	rc = poll(pollfds, n_waiters, -1);
+
+	if (rc <= 0)
+		return rc;
+
+	for (i = 0; i < n_waiters; i++) {
+		if (pollfds[i].revents) {
+			rc = waiters[i].callback(waiters[i].arg);
+
+			if (rc)
+				waiter_remove(&waiters[i]);
+		}
+	}
+
+	return 0;
+}