コード例 #1
0
ファイル: udev-util.c プロジェクト: dm0-/systemd
int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) {
        _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
        _cleanup_(sd_event_unrefp) sd_event *event = NULL;
        struct DeviceMonitorData data = {};
        int r;

        assert(device);
        assert(subsystem);

        if (sd_device_get_is_initialized(device) > 0) {
                if (ret)
                        *ret = sd_device_ref(device);
                return 0;
        }

        assert_se(sd_device_get_sysname(device, &data.sysname) >= 0);

        /* Wait until the device is initialized, so that we can get access to the ID_PATH property */

        r = sd_event_new(&event);
        if (r < 0)
                return log_error_errno(r, "Failed to get default event: %m");

        r = sd_device_monitor_new(&monitor);
        if (r < 0)
                return log_error_errno(r, "Failed to acquire monitor: %m");

        r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
        if (r < 0)
                return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);

        r = sd_device_monitor_attach_event(monitor, event);
        if (r < 0)
                return log_error_errno(r, "Failed to attach event to device monitor: %m");

        r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
        if (r < 0)
                return log_error_errno(r, "Failed to start device monitor: %m");

        /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
         * yet. */
        if (sd_device_get_is_initialized(device) > 0) {
                if (ret)
                        *ret = sd_device_ref(device);
                return 0;
        }

        r = sd_event_loop(event);
        if (r < 0)
                return log_error_errno(r, "Event loop failed: %m");

        if (ret)
                *ret = TAKE_PTR(data.device);
        return 0;
}
コード例 #2
0
static int setup_monitor(MonitorNetlinkGroup sender, sd_event *event, sd_device_monitor **ret) {
        _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
        const char *subsystem, *devtype, *tag;
        Iterator i;
        int r;

        r = device_monitor_new_full(&monitor, sender, -1);
        if (r < 0)
                return log_error_errno(r, "Failed to create netlink socket: %m");

        (void) sd_device_monitor_set_receive_buffer_size(monitor, 128*1024*1024);

        r = sd_device_monitor_attach_event(monitor, event);
        if (r < 0)
                return log_error_errno(r, "Failed to attach event: %m");

        HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) {
                r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype);
                if (r < 0)
                        return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m",
                                               subsystem, devtype ? "/" : "", strempty(devtype));
        }