udevadm: settle - add --seq-start= --seq-end=

It might be useful in some cases not to wait for "all" events.

  $ read START < /sys/kernel/uevent_seqnum
  $ (do something which may create uevents)
  $ udevadm settle --seq-start=$START

diff --git a/udev/udevadm-settle.c b/udev/udevadm-settle.c
index 867bbed137c21ce4cdb3d9d83565e407f5d807f4..8976c9a16bde9e69df1ced477c3b0c0b0bb0bdc7 100644 (file)
--- a/udev/udevadm-settle.c
+++ b/udev/udevadm-settle.c
@@ -36,11 +36,15 @@
 int udevadm_settle(struct udev *udev, int argc, char *argv[])
 {
        static const struct option options[] = {
+               { "seq-start", required_argument, NULL, 's' },
+               { "seq-end", required_argument, NULL, 'e' },
                { "timeout", required_argument, NULL, 't' },
                { "quiet", no_argument, NULL, 'q' },
                { "help", no_argument, NULL, 'h' },
                {}
        };
+       unsigned long long start = 0;
+       unsigned long long end = 0;
        int timeout = DEFAULT_TIMEOUT;
        int quiet = 0;
        struct udev_queue *udev_queue = NULL;
@@ -53,11 +57,17 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
                int option;
                int seconds;
 
-               option = getopt_long(argc, argv, "t:qh", options, NULL);
+               option = getopt_long(argc, argv, "s:e:t:qh", options, NULL);
                if (option == -1)
                        break;
 
                switch (option) {
+               case 's':
+                       start = strtoull(optarg, NULL, 0);
+                       break;
+               case 'e':
+                       end = strtoull(optarg, NULL, 0);
+                       break;
                case 't':
                        seconds = atoi(optarg);
                        if (seconds >= 0)
@@ -79,9 +89,57 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
        if (udev_queue == NULL)
                goto exit;
        loop = timeout * LOOP_PER_SECOND;
+
+       if (start > 0) {
+               unsigned long long kernel_seq;
+
+               kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
+
+               /* unless specified, the last event is the current kernel seqnum */
+               if (end == 0)
+                       end = udev_queue_get_kernel_seqnum(udev_queue);
+
+               if (start > end) {
+                       err(udev, "seq-start larger than seq-end, ignoring\n");
+                       fprintf(stderr, "seq-start larger than seq-end, ignoring\n");
+                       start = 0;
+                       end = 0;
+               }
+
+               if (start > kernel_seq || end > kernel_seq) {
+                       err(udev, "seq-start or seq-end larger than current kernel value, ignoring\n");
+                       fprintf(stderr, "seq-start or seq-end larger than current kernel value, ignoring\n");
+                       start = 0;
+                       end = 0;
+               }
+               info(udev, "start=%llu end=%llu current=%llu\n", start, end, kernel_seq);
+       } else {
+               if (end > 0) {
+                       err(udev, "seq-end needs seq-start parameter, ignoring\n");
+                       fprintf(stderr, "seq-end needs seq-start parameter, ignoring\n");
+                       end = 0;
+               }
+       }
+
        while (loop--) {
+               /* exit if queue is empty */
                if (udev_queue_get_queue_is_empty(udev_queue))
                        break;
+
+               /* if asked for, wait for a specific sequence of events */
+               if (start > 0) {
+                       unsigned long long seq;
+                       int finished;
+
+                       finished = 0;
+                       for (seq = start; seq <= end; seq++) {
+                               finished  = udev_queue_get_seqnum_is_finished(udev_queue, seq);
+                               if (!finished)
+                                       break;
+                       }
+                       if (finished)
+                               break;
+               }
                usleep(1000 * 1000 / LOOP_PER_SECOND);
        }