Move waiter to library

[petitboot] / lib / waiter / waiter.c

diff --git a/lib/waiter/waiter.c b/lib/waiter/waiter.c
new file mode 100644 (file)
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;
+}