Attachment 73011 Details for Bug 59361 – minimal test case demonstrating the problem

minimal test case demonstrating the problem

testCase.c (text/plain), 1.15 KB, created by Kai Koehne on 2013-01-14 14:30:58 UTC

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Creator: Kai Koehne

Created: 2013-01-14 14:30:58 UTC

Size: 1.15 KB

patch

obsolete

>#include <X11/Xlib-xcb.h>
>#include <stdio.h>
>
>static int nullHandler(Display *dpy, XErrorEvent *err)
>{
>	puts("Got error");
>	return 0;
>}
>
>int main()
>{
>	XInitThreads();
>
>	Display *dpy = XOpenDisplay(NULL);
>	xcb_connection_t *c = XGetXCBConnection(dpy);
>	uint32_t random_id = xcb_generate_id(c);
>
>	XSetEventQueueOwner(dpy, XCBOwnsEventQueue);
>	XSetErrorHandler(nullHandler);
>
>	while (True) {
>		/* First, let's make sure that Xlib has no idea what the current
>		 * sequence number is.
>		 */
>		for (int i = 0; i < (2<<16)+(2<<14); i++) {
>			xcb_no_operation(c);
>		}
>		puts("Done with the NoOperation requests");
>
>		/* Finally, let's break Xlib */
>
>		/* Xlib makes sure that it will handle the error (if any) for
>		 * this request: append_pending_request() in xcb_io.c
>		 */
>		XCreateWindow(dpy, random_id, 0, 0, 10, 10, 0, 24, InputOutput, CopyFromParent, 0, NULL);
>
>		/* _XReply() now handles the previous pending request and gets
>		 * the error. While calling the error handler, it will deadlock.
>		 */
>		XCreateWindow(dpy, random_id, 0, 0, 10, 10, 0, 24, InputOutput, CopyFromParent, 0, NULL);
>
>		puts("Oh shit, it survived?!");
>	}
>}
>

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Attachments on bug 59361: 73011 | 74990

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