Bug 92631 - 10.11: The dialog box that is shown when using randr is not visible
Summary: 10.11: The dialog box that is shown when using randr is not visible
Alias: None
Product: xorg
Classification: Unclassified
Component: Server/DDX/XQuartz (show other bugs)
Version: git
Hardware: x86-64 (AMD64) Mac OS X (All)
: medium normal
Assignee: Jeremy Huddleston Sequoia
QA Contact: Jeremy Huddleston Sequoia
Depends on:
Reported: 2015-10-23 09:18 UTC by Brandon Kase
Modified: 2016-05-29 20:31 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

spindump of X11.bin (2.89 MB, text/plain)
2015-10-26 00:52 UTC, Brandon Kase
no flags Details
spindump after hang (2.84 MB, text/plain)
2015-10-27 06:38 UTC, Brandon Kase
no flags Details

Description Brandon Kase 2015-10-23 09:18:01 UTC
`xrandr --output default --mode <any mode>` causes XQuartz to hang forever.

bash-3.2$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 640 x 480, current 1440 x 878, maximum 2880 x 1800
default connected 1440x878+0+0 0mm x 0mm
   2880x1800     60.00  
   1440x900      60.00     2.00  
   2560x1600     60.00  
   2048x1280     60.00  
   1024x768      60.00  
   800x600       60.00  
   640x480       60.00  
   1680x1050     60.00  
   1280x800      60.00  
   1440x878       1.00* 

I am running OSX El Capitan on a "MacBook Pro (Retina, 15-inch, Early 2013)"

Is there anything else I can provide to help debug this issue?

Comment 1 Jeremy Huddleston Sequoia 2015-10-23 17:04:14 UTC
Please take a spindump focused on X11.bin when you are experiencing this hang.  The following command will take about 20 seconds and then tell you the path to the spindump

  $ sudo spindump X11.bin
Comment 2 Brandon Kase 2015-10-26 00:52:34 UTC
Created attachment 119189 [details]
spindump of X11.bin
Comment 3 Brandon Kase 2015-10-26 00:53:17 UTC
I started spindump on X11.bin then immediately executed `xrandr --output default --mode 2880x1800`

Comment 4 Jeremy Huddleston Sequoia 2015-10-26 02:48:48 UTC
For future reference, it's much more ideal to take the spin dump *after* you are spinning because then you will not have noise from the running process and it is more obvious what is stuck.

As for what I see in that spindump, the only thing that looks stuck is inside of NSRunAlertPanel().

Do you not see the alert panel that is asking you for confirmation?
Comment 5 Jeremy Huddleston Sequoia 2015-10-26 02:55:01 UTC
Actually, I'm seeing this as well on OS X 10.11.  It looks like an OS X regression.  Please file a radar at http://bugreport.apple.com and report back the radar number in this tracker.  Thanks.
Comment 6 Jeremy Huddleston Sequoia 2015-10-26 04:28:37 UTC
Also, when filing the radar with Apple, please include an updated spindump, taken *after* it has locked up.
Comment 7 Brandon Kase 2015-10-27 06:38:03 UTC
Created attachment 119212 [details]
spindump after hang
Comment 8 Brandon Kase 2015-10-27 06:38:42 UTC
Sorry about that -- new to the spindump tool.
Attached is a spindump taken after the hang (this is copy of what I sent in the radar).
The radar number is 23271715

Comment 9 Jeremy Huddleston Sequoia 2015-10-27 07:08:04 UTC

I suspect the usage in XQuartz of doing that off of the main thread might be unsupported, but it still represents a binary compatibility regression, so I'll followup on that radar internally with the appropriate teams, but I'll also work on getting a change into 2.7.9 to better work around this issue.
Comment 10 Jeremy Huddleston Sequoia 2015-10-30 05:51:33 UTC
So actually, the issue is just that the dialog box for some reason isn't visible, but you can actually still hit enter to accept the change.  It looks like it is indeed an OS X regression when calling that API on a background thread, so hopefully it should be easily worked around.
Comment 11 Jeremy Huddleston Sequoia 2016-05-29 20:31:20 UTC
This was fixed in 10.11.4.

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