2 * vim:ts=4:sw=4:expandtab
4 * © 2010-2013 Michael Stapelberg
6 * See LICENSE for licensing information
19 #include <security/pam_appl.h>
20 #include <X11/Xlib-xcb.h>
25 #include <X11/XKBlib.h>
26 #include <X11/extensions/XKBfile.h>
27 #include <xkbcommon/xkbcommon.h>
29 #include <cairo/cairo-xcb.h>
34 #include "unlock_indicator.h"
37 #define START_TIMER(timer_obj, timeout, callback) \
38 timer_obj = start_timer(timer_obj, timeout, callback)
39 #define STOP_TIMER(timer_obj) \
40 timer_obj = stop_timer(timer_obj)
42 typedef void (*ev_callback_t)(EV_P_ ev_timer *w, int revents);
44 /* We need this for libxkbfile */
45 static Display *display;
46 char color[7] = "ffffff";
47 uint32_t last_resolution[2];
49 static xcb_cursor_t cursor;
50 static pam_handle_t *pam_handle;
51 int input_position = 0;
52 /* Holds the password you enter (in UTF-8). */
53 static char password[512];
54 static bool beep = false;
55 bool debug_mode = false;
56 static bool dpms = false;
57 bool unlock_indicator = true;
58 static bool dont_fork = false;
59 struct ev_loop *main_loop;
60 static struct ev_timer *clear_pam_wrong_timeout;
61 static struct ev_timer *clear_indicator_timeout;
62 extern unlock_state_t unlock_state;
63 extern pam_state_t pam_state;
65 static struct xkb_state *xkb_state;
66 static struct xkb_context *xkb_context;
67 static struct xkb_keymap *xkb_keymap;
69 cairo_surface_t *img = NULL;
71 bool ignore_empty_password = false;
73 /* isutf, u8_dec © 2005 Jeff Bezanson, public domain */
74 #define isutf(c) (((c) & 0xC0) != 0x80)
77 * Decrements i to point to the previous unicode glyph
80 void u8_dec(char *s, int *i) {
81 (void)(isutf(s[--(*i)]) || isutf(s[--(*i)]) || isutf(s[--(*i)]) || --(*i));
84 static void turn_monitors_on(void) {
86 dpms_set_mode(conn, XCB_DPMS_DPMS_MODE_ON);
89 static void turn_monitors_off(void) {
91 dpms_set_mode(conn, XCB_DPMS_DPMS_MODE_OFF);
95 * Loads the XKB keymap from the X11 server and feeds it to xkbcommon.
96 * Necessary so that we can properly let xkbcommon track the keyboard state and
97 * translate keypresses to utf-8.
99 * Ideally, xkbcommon would ship something like this itself, but as of now
100 * (version 0.2.0), it doesn’t.
102 * TODO: Once xcb-xkb is enabled by default and released, we should port this
103 * code to xcb-xkb. See also https://github.com/xkbcommon/libxkbcommon/issues/1
106 static bool load_keymap(void) {
109 memset(&result, '\0', sizeof(result));
110 result.xkb = XkbGetKeyboard(display, XkbAllMapComponentsMask, XkbUseCoreKbd);
111 if (result.xkb == NULL) {
112 fprintf(stderr, "[i3lock] XKB: XkbGetKeyboard failed\n");
116 FILE *temp = tmpfile();
118 fprintf(stderr, "[i3lock] could not create tempfile\n");
122 bool ok = XkbWriteXKBKeymap(temp, &result, false, false, NULL, NULL);
124 fprintf(stderr, "[i3lock] XkbWriteXKBKeymap failed\n");
130 if (xkb_context == NULL) {
131 if ((xkb_context = xkb_context_new(0)) == NULL) {
132 fprintf(stderr, "[i3lock] could not create xkbcommon context\n");
137 if (xkb_keymap != NULL)
138 xkb_keymap_unref(xkb_keymap);
140 if ((xkb_keymap = xkb_keymap_new_from_file(xkb_context, temp, XKB_KEYMAP_FORMAT_TEXT_V1, 0)) == NULL) {
141 fprintf(stderr, "[i3lock] xkb_keymap_new_from_file failed\n");
145 struct xkb_state *new_state = xkb_state_new(xkb_keymap);
146 if (new_state == NULL) {
147 fprintf(stderr, "[i3lock] xkb_state_new failed\n");
151 /* Get the initial modifier state to be in sync with the X server.
152 * See https://github.com/xkbcommon/libxkbcommon/issues/1 for why we ignore
153 * the base and latched fields. */
154 XkbStateRec state_rec;
155 XkbGetState(display, XkbUseCoreKbd, &state_rec);
157 xkb_state_update_mask(new_state,
158 0, 0, state_rec.locked_mods,
159 0, 0, state_rec.locked_group);
161 if (xkb_state != NULL)
162 xkb_state_unref(xkb_state);
163 xkb_state = new_state;
167 XkbFreeKeyboard(result.xkb, XkbAllComponentsMask, true);
173 * Clears the memory which stored the password to be a bit safer against
177 static void clear_password_memory(void) {
178 /* A volatile pointer to the password buffer to prevent the compiler from
179 * optimizing this out. */
180 volatile char *vpassword = password;
181 for (int c = 0; c < sizeof(password); c++)
182 /* We store a non-random pattern which consists of the (irrelevant)
183 * index plus (!) the value of the beep variable. This prevents the
184 * compiler from optimizing the calls away, since the value of 'beep'
185 * is not known at compile-time. */
186 vpassword[c] = c + (int)beep;
189 ev_timer* start_timer(ev_timer *timer_obj, ev_tstamp timeout, ev_callback_t callback) {
191 ev_timer_stop(main_loop, timer_obj);
192 ev_timer_set(timer_obj, timeout, 0.);
193 ev_timer_start(main_loop, timer_obj);
195 /* When there is no memory, we just don’t have a timeout. We cannot
196 * exit() here, since that would effectively unlock the screen. */
197 timer_obj = calloc(sizeof(struct ev_timer), 1);
199 ev_timer_init(timer_obj, callback, timeout, 0.);
200 ev_timer_start(main_loop, timer_obj);
206 ev_timer* stop_timer(ev_timer *timer_obj) {
208 ev_timer_stop(main_loop, timer_obj);
215 * Resets pam_state to STATE_PAM_IDLE 2 seconds after an unsuccesful
216 * authentication event.
219 static void clear_pam_wrong(EV_P_ ev_timer *w, int revents) {
220 DEBUG("clearing pam wrong\n");
221 pam_state = STATE_PAM_IDLE;
222 unlock_state = STATE_STARTED;
225 /* Now free this timeout. */
226 ev_timer_stop(main_loop, clear_pam_wrong_timeout);
227 free(clear_pam_wrong_timeout);
228 clear_pam_wrong_timeout = NULL;
231 static void clear_indicator_cb(EV_P_ ev_timer *w, int revents) {
233 STOP_TIMER(clear_indicator_timeout);
236 static void clear_input(void) {
238 clear_password_memory();
239 password[input_position] = '\0';
241 /* Hide the unlock indicator after a bit if the password buffer is
243 START_TIMER(clear_indicator_timeout, 1.0, clear_indicator_cb);
244 unlock_state = STATE_BACKSPACE_ACTIVE;
246 unlock_state = STATE_KEY_PRESSED;
249 static void input_done(void) {
250 if (clear_pam_wrong_timeout) {
251 ev_timer_stop(main_loop, clear_pam_wrong_timeout);
252 free(clear_pam_wrong_timeout);
253 clear_pam_wrong_timeout = NULL;
256 pam_state = STATE_PAM_VERIFY;
259 if (pam_authenticate(pam_handle, 0) == PAM_SUCCESS) {
260 DEBUG("successfully authenticated\n");
261 clear_password_memory();
262 /* Turn the screen on, as it may have been turned off
263 * on release of the 'enter' key. */
269 fprintf(stderr, "Authentication failure\n");
271 pam_state = STATE_PAM_WRONG;
275 /* Clear this state after 2 seconds (unless the user enters another
276 * password during that time). */
277 ev_now_update(main_loop);
278 if ((clear_pam_wrong_timeout = calloc(sizeof(struct ev_timer), 1))) {
279 ev_timer_init(clear_pam_wrong_timeout, clear_pam_wrong, 2.0, 0.);
280 ev_timer_start(main_loop, clear_pam_wrong_timeout);
283 /* Cancel the clear_indicator_timeout, it would hide the unlock indicator
285 STOP_TIMER(clear_indicator_timeout);
287 /* beep on authentication failure, if enabled */
295 * Called when the user releases a key. We need to leave the Mode_switch
296 * state when the user releases the Mode_switch key.
299 static void handle_key_release(xcb_key_release_event_t *event) {
300 xkb_state_update_key(xkb_state, event->detail, XKB_KEY_UP);
303 static void redraw_timeout(EV_P_ ev_timer *w, int revents) {
306 ev_timer_stop(main_loop, w);
311 * Handle key presses. Fixes state, then looks up the key symbol for the
312 * given keycode, then looks up the key symbol (as UCS-2), converts it to
313 * UTF-8 and stores it in the password array.
316 static void handle_key_press(xcb_key_press_event_t *event) {
322 ksym = xkb_state_key_get_one_sym(xkb_state, event->detail);
323 ctrl = xkb_state_mod_name_is_active(xkb_state, "Control", XKB_STATE_MODS_DEPRESSED);
324 xkb_state_update_key(xkb_state, event->detail, XKB_KEY_DOWN);
326 /* The buffer will be null-terminated, so n >= 2 for 1 actual character. */
327 memset(buffer, '\0', sizeof(buffer));
328 n = xkb_keysym_to_utf8(ksym, buffer, sizeof(buffer));
332 case XKB_KEY_KP_Enter:
333 case XKB_KEY_XF86ScreenSaver:
334 if (ignore_empty_password && input_position == 0) {
338 password[input_position] = '\0';
339 unlock_state = STATE_KEY_PRESSED;
346 DEBUG("C-u pressed\n");
356 case XKB_KEY_BackSpace:
357 if (input_position == 0)
360 /* decrement input_position to point to the previous glyph */
361 u8_dec(password, &input_position);
362 password[input_position] = '\0';
364 /* Hide the unlock indicator after a bit if the password buffer is
366 START_TIMER(clear_indicator_timeout, 1.0, clear_indicator_cb);
367 unlock_state = STATE_BACKSPACE_ACTIVE;
369 unlock_state = STATE_KEY_PRESSED;
373 if ((input_position + 8) >= sizeof(password))
377 /* FIXME: handle all of these? */
378 printf("is_keypad_key = %d\n", xcb_is_keypad_key(sym));
379 printf("is_private_keypad_key = %d\n", xcb_is_private_keypad_key(sym));
380 printf("xcb_is_cursor_key = %d\n", xcb_is_cursor_key(sym));
381 printf("xcb_is_pf_key = %d\n", xcb_is_pf_key(sym));
382 printf("xcb_is_function_key = %d\n", xcb_is_function_key(sym));
383 printf("xcb_is_misc_function_key = %d\n", xcb_is_misc_function_key(sym));
384 printf("xcb_is_modifier_key = %d\n", xcb_is_modifier_key(sym));
390 /* store it in the password array as UTF-8 */
391 memcpy(password+input_position, buffer, n-1);
392 input_position += n-1;
393 DEBUG("current password = %.*s\n", input_position, password);
395 unlock_state = STATE_KEY_ACTIVE;
397 unlock_state = STATE_KEY_PRESSED;
399 struct ev_timer *timeout = calloc(sizeof(struct ev_timer), 1);
401 ev_timer_init(timeout, redraw_timeout, 0.25, 0.);
402 ev_timer_start(main_loop, timeout);
405 STOP_TIMER(clear_indicator_timeout);
409 * A visibility notify event will be received when the visibility (= can the
410 * user view the complete window) changes, so for example when a popup overlays
411 * some area of the i3lock window.
413 * In this case, we raise our window on top so that the popup (or whatever is
414 * hiding us) gets hidden.
417 static void handle_visibility_notify(xcb_connection_t *conn,
418 xcb_visibility_notify_event_t *event) {
419 if (event->state != XCB_VISIBILITY_UNOBSCURED) {
420 uint32_t values[] = { XCB_STACK_MODE_ABOVE };
421 xcb_configure_window(conn, event->window, XCB_CONFIG_WINDOW_STACK_MODE, values);
427 * Called when the keyboard mapping changes. We update our symbols.
430 static void handle_mapping_notify(xcb_mapping_notify_event_t *event) {
431 /* We ignore errors — if the new keymap cannot be loaded it’s better if the
432 * screen stays locked and the user intervenes by using killall i3lock. */
437 * Called when the properties on the root window change, e.g. when the screen
438 * resolution changes. If so we update the window to cover the whole screen
439 * and also redraw the image, if any.
442 void handle_screen_resize(void) {
443 xcb_get_geometry_cookie_t geomc;
444 xcb_get_geometry_reply_t *geom;
445 geomc = xcb_get_geometry(conn, screen->root);
446 if ((geom = xcb_get_geometry_reply(conn, geomc, 0)) == NULL)
449 if (last_resolution[0] == geom->width &&
450 last_resolution[1] == geom->height) {
455 last_resolution[0] = geom->width;
456 last_resolution[1] = geom->height;
462 uint32_t mask = XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT;
463 xcb_configure_window(conn, win, mask, last_resolution);
466 xinerama_query_screens();
471 * Callback function for PAM. We only react on password request callbacks.
474 static int conv_callback(int num_msg, const struct pam_message **msg,
475 struct pam_response **resp, void *appdata_ptr)
480 /* PAM expects an array of responses, one for each message */
481 if ((*resp = calloc(num_msg, sizeof(struct pam_response))) == NULL) {
486 for (int c = 0; c < num_msg; c++) {
487 if (msg[c]->msg_style != PAM_PROMPT_ECHO_OFF &&
488 msg[c]->msg_style != PAM_PROMPT_ECHO_ON)
491 /* return code is currently not used but should be set to zero */
492 resp[c]->resp_retcode = 0;
493 if ((resp[c]->resp = strdup(password)) == NULL) {
503 * This callback is only a dummy, see xcb_prepare_cb and xcb_check_cb.
504 * See also man libev(3): "ev_prepare" and "ev_check" - customise your event loop
507 static void xcb_got_event(EV_P_ struct ev_io *w, int revents) {
508 /* empty, because xcb_prepare_cb and xcb_check_cb are used */
512 * Flush before blocking (and waiting for new events)
515 static void xcb_prepare_cb(EV_P_ ev_prepare *w, int revents) {
520 * Instead of polling the X connection socket we leave this to
521 * xcb_poll_for_event() which knows better than we can ever know.
524 static void xcb_check_cb(EV_P_ ev_check *w, int revents) {
525 xcb_generic_event_t *event;
527 while ((event = xcb_poll_for_event(conn)) != NULL) {
528 if (event->response_type == 0) {
529 xcb_generic_error_t *error = (xcb_generic_error_t*)event;
531 fprintf(stderr, "X11 Error received! sequence 0x%x, error_code = %d\n",
532 error->sequence, error->error_code);
537 /* Strip off the highest bit (set if the event is generated) */
538 int type = (event->response_type & 0x7F);
541 handle_key_press((xcb_key_press_event_t*)event);
544 case XCB_KEY_RELEASE:
545 handle_key_release((xcb_key_release_event_t*)event);
547 /* If this was the backspace or escape key we are back at an
548 * empty input, so turn off the screen if DPMS is enabled */
549 if (input_position == 0)
554 case XCB_VISIBILITY_NOTIFY:
555 handle_visibility_notify(conn, (xcb_visibility_notify_event_t*)event);
560 /* After the first MapNotify, we never fork again. We don’t
561 * expect to get another MapNotify, but better be sure… */
564 /* In the parent process, we exit */
568 ev_loop_fork(EV_DEFAULT);
572 case XCB_MAPPING_NOTIFY:
573 handle_mapping_notify((xcb_mapping_notify_event_t*)event);
576 case XCB_CONFIGURE_NOTIFY:
577 handle_screen_resize();
586 * This function is called from a fork()ed child and will raise the i3lock
587 * window when the window is obscured, even when the main i3lock process is
588 * blocked due to PAM.
591 static void raise_loop(xcb_window_t window) {
592 xcb_connection_t *conn;
593 xcb_generic_event_t *event;
596 if ((conn = xcb_connect(NULL, &screens)) == NULL ||
597 xcb_connection_has_error(conn))
598 errx(EXIT_FAILURE, "Cannot open display\n");
600 /* We need to know about the window being obscured or getting destroyed. */
601 xcb_change_window_attributes(conn, window, XCB_CW_EVENT_MASK,
603 XCB_EVENT_MASK_VISIBILITY_CHANGE |
604 XCB_EVENT_MASK_STRUCTURE_NOTIFY
608 DEBUG("Watching window 0x%08x\n", window);
609 while ((event = xcb_wait_for_event(conn)) != NULL) {
610 if (event->response_type == 0) {
611 xcb_generic_error_t *error = (xcb_generic_error_t*)event;
612 DEBUG("X11 Error received! sequence 0x%x, error_code = %d\n",
613 error->sequence, error->error_code);
617 /* Strip off the highest bit (set if the event is generated) */
618 int type = (event->response_type & 0x7F);
619 DEBUG("Read event of type %d\n", type);
621 case XCB_VISIBILITY_NOTIFY:
622 handle_visibility_notify(conn, (xcb_visibility_notify_event_t*)event);
624 case XCB_UNMAP_NOTIFY:
625 DEBUG("UnmapNotify for 0x%08x\n", (((xcb_unmap_notify_event_t*)event)->window));
626 if (((xcb_unmap_notify_event_t*)event)->window == window)
629 case XCB_DESTROY_NOTIFY:
630 DEBUG("DestroyNotify for 0x%08x\n", (((xcb_destroy_notify_event_t*)event)->window));
631 if (((xcb_destroy_notify_event_t*)event)->window == window)
635 DEBUG("Unhandled event type %d\n", type);
642 int main(int argc, char *argv[]) {
644 char *image_path = NULL;
646 struct pam_conv conv = {conv_callback, NULL};
647 int curs_choice = CURS_NONE;
650 struct option longopts[] = {
651 {"version", no_argument, NULL, 'v'},
652 {"nofork", no_argument, NULL, 'n'},
653 {"beep", no_argument, NULL, 'b'},
654 {"dpms", no_argument, NULL, 'd'},
655 {"color", required_argument, NULL, 'c'},
656 {"pointer", required_argument, NULL , 'p'},
657 {"debug", no_argument, NULL, 0},
658 {"help", no_argument, NULL, 'h'},
659 {"no-unlock-indicator", no_argument, NULL, 'u'},
660 {"image", required_argument, NULL, 'i'},
661 {"tiling", no_argument, NULL, 't'},
662 {"ignore-empty-password", no_argument, NULL, 'e'},
663 {NULL, no_argument, NULL, 0}
666 if ((username = getenv("USER")) == NULL)
667 errx(1, "USER environment variable not set, please set it.\n");
669 while ((o = getopt_long(argc, argv, "hvnbdc:p:ui:te", longopts, &optind)) != -1) {
672 errx(EXIT_SUCCESS, "version " VERSION " © 2010-2012 Michael Stapelberg");
685 /* Skip # if present */
689 if (strlen(arg) != 6 || sscanf(arg, "%06[0-9a-fA-F]", color) != 1)
690 errx(1, "color is invalid, it must be given in 3-byte hexadecimal format: rrggbb\n");
695 unlock_indicator = false;
698 image_path = strdup(optarg);
704 if (!strcmp(optarg, "win")) {
705 curs_choice = CURS_WIN;
706 } else if (!strcmp(optarg, "default")) {
707 curs_choice = CURS_DEFAULT;
709 errx(1, "i3lock: Invalid pointer type given. Expected one of \"win\" or \"default\".\n");
713 ignore_empty_password = true;
716 if (strcmp(longopts[optind].name, "debug") == 0)
720 errx(1, "Syntax: i3lock [-v] [-n] [-b] [-d] [-c color] [-u] [-p win|default]"
721 " [-i image.png] [-t] [-e]"
726 /* We need (relatively) random numbers for highlighting a random part of
727 * the unlock indicator upon keypresses. */
731 ret = pam_start("i3lock", username, &conv, &pam_handle);
732 if (ret != PAM_SUCCESS)
733 errx(EXIT_FAILURE, "PAM: %s", pam_strerror(pam_handle, ret));
735 /* Using mlock() as non-super-user seems only possible in Linux. Users of other
736 * operating systems should use encrypted swap/no swap (or remove the ifdef and
737 * run i3lock as super-user). */
738 #if defined(__linux__)
739 /* Lock the area where we store the password in memory, we don’t want it to
740 * be swapped to disk. Since Linux 2.6.9, this does not require any
741 * privileges, just enough bytes in the RLIMIT_MEMLOCK limit. */
742 if (mlock(password, sizeof(password)) != 0)
743 err(EXIT_FAILURE, "Could not lock page in memory, check RLIMIT_MEMLOCK");
746 /* Initialize connection to X11 */
747 if ((display = XOpenDisplay(NULL)) == NULL)
748 errx(EXIT_FAILURE, "Could not connect to X11, maybe you need to set DISPLAY?");
749 XSetEventQueueOwner(display, XCBOwnsEventQueue);
750 conn = XGetXCBConnection(display);
752 /* Double checking that connection is good and operatable with xcb */
753 if (xcb_connection_has_error(conn))
754 errx(EXIT_FAILURE, "Could not connect to X11, maybe you need to set DISPLAY?");
756 /* When we cannot initially load the keymap, we better exit */
758 errx(EXIT_FAILURE, "Could not load keymap");
761 xinerama_query_screens();
763 /* if DPMS is enabled, check if the X server really supports it */
765 xcb_dpms_capable_cookie_t dpmsc = xcb_dpms_capable(conn);
766 xcb_dpms_capable_reply_t *dpmsr;
767 if ((dpmsr = xcb_dpms_capable_reply(conn, dpmsc, NULL))) {
768 if (!dpmsr->capable) {
770 fprintf(stderr, "Disabling DPMS, X server not DPMS capable\n");
777 screen = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;
779 last_resolution[0] = screen->width_in_pixels;
780 last_resolution[1] = screen->height_in_pixels;
782 xcb_change_window_attributes(conn, screen->root, XCB_CW_EVENT_MASK,
783 (uint32_t[]){ XCB_EVENT_MASK_STRUCTURE_NOTIFY });
786 /* Create a pixmap to render on, fill it with the background color */
787 img = cairo_image_surface_create_from_png(image_path);
788 /* In case loading failed, we just pretend no -i was specified. */
789 if (cairo_surface_status(img) != CAIRO_STATUS_SUCCESS) {
790 fprintf(stderr, "Could not load image \"%s\": %s\n",
791 image_path, cairo_status_to_string(cairo_surface_status(img)));
796 /* Pixmap on which the image is rendered to (if any) */
797 xcb_pixmap_t bg_pixmap = draw_image(last_resolution);
799 /* open the fullscreen window, already with the correct pixmap in place */
800 win = open_fullscreen_window(conn, screen, color, bg_pixmap);
801 xcb_free_pixmap(conn, bg_pixmap);
804 /* The pid == -1 case is intentionally ignored here:
805 * While the child process is useful for preventing other windows from
806 * popping up while i3lock blocks, it is not critical. */
809 close(xcb_get_file_descriptor(conn));
814 cursor = create_cursor(conn, screen, win, curs_choice);
816 grab_pointer_and_keyboard(conn, screen, cursor);
817 /* Load the keymap again to sync the current modifier state. Since we first
818 * loaded the keymap, there might have been changes, but starting from now,
819 * we should get all key presses/releases due to having grabbed the
825 /* Initialize the libev event loop. */
826 main_loop = EV_DEFAULT;
827 if (main_loop == NULL)
828 errx(EXIT_FAILURE, "Could not initialize libev. Bad LIBEV_FLAGS?\n");
830 struct ev_io *xcb_watcher = calloc(sizeof(struct ev_io), 1);
831 struct ev_check *xcb_check = calloc(sizeof(struct ev_check), 1);
832 struct ev_prepare *xcb_prepare = calloc(sizeof(struct ev_prepare), 1);
834 ev_io_init(xcb_watcher, xcb_got_event, xcb_get_file_descriptor(conn), EV_READ);
835 ev_io_start(main_loop, xcb_watcher);
837 ev_check_init(xcb_check, xcb_check_cb);
838 ev_check_start(main_loop, xcb_check);
840 ev_prepare_init(xcb_prepare, xcb_prepare_cb);
841 ev_prepare_start(main_loop, xcb_prepare);
843 /* Invoke the event callback once to catch all the events which were
844 * received up until now. ev will only pick up new events (when the X11
845 * file descriptor becomes readable). */
846 ev_invoke(main_loop, xcb_check, 0);
847 ev_loop(main_loop, 0);