round up poll timeout

Pointed out by Richard Röjfors, otherwise we end up busy-looping with
a poll() timeout of 0.

diff --git a/libusb/io.c b/libusb/io.c
index 4e85bdf..f659d24 100644 (file)
--- a/libusb/io.c
+++ b/libusb/io.c
@@ -1335,6 +1335,11 @@ static int handle_events(struct timeval *tv)
        pthread_mutex_unlock(&pollfds_lock);
 
        timeout_ms = (tv->tv_sec * 1000) + (tv->tv_usec / 1000);
+
+       /* round up to next millisecond */
+       if (tv->tv_usec % 1000)
+               timeout_ms++;
+
        usbi_dbg("poll() %d fds with timeout in %dms", nfds, timeout_ms);
        r = poll(fds, nfds, timeout_ms);
        usbi_dbg("poll() returned %d", r);