Attachment 116462 Details for Bug 84252 – Another test that runs into a different, but quite similar hang

Another test that runs into a different, but quite similar hang

test_special_event.c (text/plain), 2.91 KB, created by Uli Schlachter on 2015-06-12 13:12:10 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Uli Schlachter

Created: 2015-06-12 13:12:10 UTC

Size: 2.91 KB

patch

obsolete

>#include <xcb/xcb.h>
>#include <xcb/present.h>
>#include <stdlib.h>
>#include <stdio.h>
>#include <assert.h>
>#include <unistd.h>
>
>static xcb_connection_t *conn;
>static xcb_screen_t *screen;
>static xcb_window_t win;
>static xcb_pixmap_t pix;
>
>static uint32_t present_event_type;
>static xcb_special_event_t *se;
>
>static pthread_barrier_t barrier;
>
>#define NUM_THREADS 2
>
>static pthread_t start_thread(void *(*start_routine)(void *), void *arg)
>{
>	pthread_t thread;
>	int res;
>
>	res = pthread_create(&thread, NULL, start_routine, arg);
>	assert(res == 0);
>
>	return thread;
>}
>
>static void check_no_pending_events(void)
>{
>	xcb_generic_event_t *ev;
>
>	ev = xcb_poll_for_event(conn);
>	assert(ev == NULL);
>
>	ev = xcb_poll_for_special_event(conn, se);
>	assert(ev == NULL);
>}
>
>static void wait_event(void)
>{
>	xcb_generic_event_t *ge;
>
>	ge = xcb_wait_for_special_event(conn, se);
>	printf("%p: Got special event\n", ge);
>	free(ge);
>}
>
>static void *wait_event_thread(void *arg)
>{
>	(void) arg;
>
>	pthread_barrier_wait(&barrier);
>	wait_event();
>
>	return NULL;
>}
>
>static void try_deadlock(void)
>{
>	xcb_get_input_focus_cookie_t cookie;
>	pthread_t thread;
>	int res;
>
>	thread = start_thread(wait_event_thread, NULL);
>	
>	/* No idea what this does, but it does give me special events for
>	 * xcb_wait_for_special_event().
>	 */
>	xcb_present_pixmap(conn, win, pix, 0, XCB_NONE, XCB_NONE, 0, 0,
>			0, 0, 0, 0, 0, 0, 0, 0, NULL);
>
>	cookie = xcb_get_input_focus(conn);
>	xcb_flush(conn);
>
>	/* Create a race with the other thread at who recv()s on the socket */
>	pthread_barrier_wait(&barrier);
>
>	/* Now actually call recv() */
>	free(xcb_get_input_focus_reply(conn, cookie, NULL));
>	puts("Got input focus");
>
>	res = pthread_join(thread, NULL);
>	assert(res == 0);
>
>	/* The above xcb_present_pixmap() causes two events to be send. Collect
>	 * the second one.
>	 */
>	wait_event();
>	check_no_pending_events();
>}
>
>static void setup(void)
>{
>	conn = xcb_connect(NULL, NULL);
>	assert(!xcb_connection_has_error(conn));
>
>	screen = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;
>
>	win = xcb_generate_id(conn);
>	pix = xcb_generate_id(conn);
>	present_event_type = xcb_generate_id(conn);
>
>	xcb_create_window(conn, screen->root_depth, win, screen->root, 1, 1, 3, 3,
>			0, XCB_COPY_FROM_PARENT, screen->root_visual,
>			XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK,
>			(const uint32_t[]) {
>			1,
>			XCB_EVENT_MASK_PROPERTY_CHANGE
>			});
>	xcb_create_pixmap(conn, screen->root_depth, pix, win, 3, 3);
>	xcb_present_select_input(conn, present_event_type, win,
>			XCB_PRESENT_EVENT_MASK_CONFIGURE_NOTIFY | XCB_PRESENT_EVENT_MASK_COMPLETE_NOTIFY |
>			XCB_PRESENT_EVENT_MASK_IDLE_NOTIFY | XCB_PRESENT_EVENT_MASK_REDIRECT_NOTIFY);
>
>	se = xcb_register_for_special_xge(conn, &xcb_present_id, present_event_type, NULL);
>	assert(se);
>
>	pthread_barrier_init(&barrier, NULL, NUM_THREADS);
>}
>
>int main()
>{
>	setup();
>
>	while (1) {
>		try_deadlock();
>		puts("");
>	}
>
>	xcb_unregister_for_special_event(conn, se);
>	xcb_disconnect(conn);
>	return 0;
>}

Actions: View

Attachments on bug 84252: 106805 | 115165 | 115200 | 115827 | 115887 | 116462 | 116463 | 121283

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.