+static void waker_consume(struct uloop_fd *fd, unsigned int events)
+{
+ char buf[4];
+
+ while (read(fd->fd, buf, 4) > 0)
+ ;
+}
+
+static int waker_pipe = -1;
+static struct uloop_fd waker_fd = {
+ .fd = -1,
+ .cb = waker_consume,
+};
+
+static void waker_init_fd(int fd)
+{
+ fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+ fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
+}
+
+static int waker_init(void)
+{
+ int fds[2];
+
+ if (waker_pipe >= 0)
+ return 0;
+
+ if (pipe(fds) < 0)
+ return -1;
+
+ waker_init_fd(fds[0]);
+ waker_init_fd(fds[1]);
+ waker_pipe = fds[1];
+
+ waker_fd.fd = fds[0];
+ waker_fd.cb = waker_consume;
+ uloop_fd_add(&waker_fd, ULOOP_READ);
+
+ return 0;
+}
+
+int uloop_init(void)
+{
+ if (uloop_init_pollfd() < 0)
+ return -1;
+
+ if (waker_init() < 0) {
+ uloop_done();
+ return -1;
+ }
+
+ return 0;
+}
+
+static bool uloop_fd_stack_event(struct uloop_fd *fd, int events)
+{
+ struct uloop_fd_stack *cur;
+
+ /*
+ * Do not buffer events for level-triggered fds, they will keep firing.
+ * Caller needs to take care of recursion issues.
+ */
+ if (!(fd->flags & ULOOP_EDGE_TRIGGER))
+ return false;
+
+ for (cur = fd_stack; cur; cur = cur->next) {
+ if (cur->fd != fd)
+ continue;
+
+ if (events < 0)
+ cur->fd = NULL;
+ else
+ cur->events |= events | ULOOP_EVENT_BUFFERED;
+
+ return true;
+ }
+
+ return false;
+}
+
+static void uloop_run_events(int timeout)
+{
+ struct uloop_fd_event *cur;
+ struct uloop_fd *fd;
+
+ if (!cur_nfds) {
+ cur_fd = 0;
+ cur_nfds = uloop_fetch_events(timeout);
+ if (cur_nfds < 0)
+ cur_nfds = 0;
+ }
+
+ while (cur_nfds > 0) {
+ struct uloop_fd_stack stack_cur;
+ unsigned int events;
+
+ cur = &cur_fds[cur_fd++];
+ cur_nfds--;
+
+ fd = cur->fd;
+ events = cur->events;
+ if (!fd)
+ continue;
+
+ if (!fd->cb)
+ continue;
+
+ if (uloop_fd_stack_event(fd, cur->events))
+ continue;
+
+ stack_cur.next = fd_stack;
+ stack_cur.fd = fd;
+ fd_stack = &stack_cur;
+ do {
+ stack_cur.events = 0;
+ fd->cb(fd, events);
+ events = stack_cur.events & ULOOP_EVENT_MASK;
+ } while (stack_cur.fd && events);
+ fd_stack = stack_cur.next;
+
+ return;
+ }
+}