About 5% of the time, my application will hang forever, showing a solid gray screen after the splash screen. This does not happen with the Blank HDRP template.
Why is this happening?
Some attempts:
- Build with script debugging enabled. Attach debugger in vscode when it hangs.
- Result: (unable to see the current stack information when pausing, debugger doesn’t appear to be working correctly.)
- As a test to see if my debugging setup was broken, I added a
while (true) {}loop to my startup to deliberately introduce a hang, within C#. Attaching the debugger, and hitting the pause button, it breaks immediately on thewhile (true) {}loop as expected. Could it be hanging in native code somewhere? - Look at log file.
- Result: Nothing interesting. Running diff, the log files are almost exactly identical to the successful run with no hang, except some Vulkan device id.
- Attach gdb debugger.
sudo gdb -p 39277 - Result: Below is the result of
info threadscommand within gdb, plus the current stack trace on thread 1, using thebtcommand from gdb.
(gdb) info threads
Id Target Id Frame
* 1 Thread 0x78a065b3ef80 (LWP 39277) "view.x86_64" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
2 Thread 0x78a03ffff640 (LWP 39278) "Profiler.Dispat" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
3 Thread 0x78a03f7fe640 (LWP 39279) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
4 Thread 0x78a03effd640 (LWP 39280) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
5 Thread 0x78a03e7fc640 (LWP 39281) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
6 Thread 0x78a03dffb640 (LWP 39282) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
7 Thread 0x78a03d7fa640 (LWP 39283) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
8 Thread 0x78a03cff9640 (LWP 39284) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
9 Thread 0x78a03c7f8640 (LWP 39285) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
10 Thread 0x78a03bff7640 (LWP 39286) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
11 Thread 0x78a03b7f6640 (LWP 39287) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
12 Thread 0x78a03aff5640 (LWP 39288) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
13 Thread 0x78a03a7f4640 (LWP 39289) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
14 Thread 0x78a039ff3640 (LWP 39290) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
15 Thread 0x78a0397f2640 (LWP 39291) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
16 Thread 0x78a038ff1640 (LWP 39292) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
17 Thread 0x78a0387f0640 (LWP 39293) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
18 Thread 0x78a037fef640 (LWP 39294) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
19 Thread 0x78a0377ee640 (LWP 39295) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
20 Thread 0x78a036fed640 (LWP 39296) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
21 Thread 0x78a0367ec640 (LWP 39297) "AssetGarbageCol" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
22 Thread 0x78a035feb640 (LWP 39298) "SDLTimer" __futex_abstimed_wait_common64 (private=<optimized out>, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x1b9e350)
at ./nptl/futex-internal.c:57
23 Thread 0x78a033fff640 (LWP 39320) "Finalizer" __futex_abstimed_wait_common64 (private=<optimized out>, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x78a034bb74b8)
at ./nptl/futex-internal.c:57
24 Thread 0x78a033dfe640 (LWP 39321) "Debugger agent" __libc_recv (flags=<optimized out>, len=11, buf=0x78a033dfc1e5, fd=16) at ../sysdeps/unix/sysv/linux/recv.c:28
25 Thread 0x78a031e70640 (LWP 39322) "Job.Worker 0" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
26 Thread 0x78a03166f640 (LWP 39323) "Job.Worker 1" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
27 Thread 0x78a030e6e640 (LWP 39324) "Job.Worker 2" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
28 Thread 0x789f97fff640 (LWP 39325) "Job.Worker 3" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
29 Thread 0x789f977fe640 (LWP 39326) "Job.Worker 4" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
30 Thread 0x789f96ffd640 (LWP 39327) "Job.Worker 5" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
31 Thread 0x789f967fc640 (LWP 39328) "Job.Worker 6" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
32 Thread 0x789f95ffb640 (LWP 39329) "Job.Worker 7" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
33 Thread 0x789f957fa640 (LWP 39330) "Job.Worker 8" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
34 Thread 0x789f94ff9640 (LWP 39331) "Job.Worker 9" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
35 Thread 0x789f947f8640 (LWP 39332) "Job.Worker 10" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
36 Thread 0x789f93ff7640 (LWP 39333) "Job.Worker 11" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
37 Thread 0x789f937f6640 (LWP 39334) "Job.Worker 12" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
38 Thread 0x789f92ff5640 (LWP 39335) "Job.Worker 13" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
39 Thread 0x789f927f4640 (LWP 39336) "Job.Worker 14" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
40 Thread 0x789f91ff3640 (LWP 39337) "Job.Worker 15" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
41 Thread 0x789f917f2640 (LWP 39338) "Job.Worker 16" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
42 Thread 0x789f90ff1640 (LWP 39339) "Job.Worker 17" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
43 Thread 0x789f7ffff640 (LWP 39340) "Job.Worker 18" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
44 Thread 0x789f7f7fe640 (LWP 39341) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
45 Thread 0x789f7effd640 (LWP 39342) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
46 Thread 0x789f7e7fc640 (LWP 39343) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
47 Thread 0x789f7dffb640 (LWP 39344) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
48 Thread 0x789f7d7fa640 (LWP 39345) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
49 Thread 0x789f7cff9640 (LWP 39346) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
50 Thread 0x789f7c7f8640 (LWP 39347) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
51 Thread 0x789f7bff7640 (LWP 39348) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
--Type <RET> for more, q to quit, c to continue without paging--
52 Thread 0x789f7b7f6640 (LWP 39349) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
53 Thread 0x789f7aff5640 (LWP 39350) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
54 Thread 0x789f7a7f4640 (LWP 39351) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
55 Thread 0x789f79ff3640 (LWP 39352) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
56 Thread 0x789f797f2640 (LWP 39353) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
57 Thread 0x789f78ff1640 (LWP 39354) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
58 Thread 0x789f787f0640 (LWP 39355) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
59 Thread 0x789f77fef640 (LWP 39356) "Background Job." syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
60 Thread 0x789f777ee640 (LWP 39357) "BatchDeleteObje" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
61 Thread 0x789f76fed640 (LWP 39358) "Loading.AsyncRe" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
62 Thread 0x789f547ff640 (LWP 39360) "view.x86_64" 0x000078a061ee57f8 in __GI___clock_nanosleep (clock_id=clock_id@entry=0, flags=flags@entry=0, req=0x789f547fd550, rem=0x789f547fd540)
at ../sysdeps/unix/sysv/linux/clock_nanosleep.c:78
63 Thread 0x789f53ffe640 (LWP 39361) "[vkrt] Analysis" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x789f53ffc570, op=393, expected=0, futex_word=0x789f2c000f5c)
at ./nptl/futex-internal.c:57
64 Thread 0x789f537fd640 (LWP 39362) "[vkcf] Analysis" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x789f20000f58) at ./nptl/futex-internal.c:57
65 Thread 0x789f52ffc640 (LWP 39363) "view.x86_64" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x789f24010f68) at ./nptl/futex-internal.c:57
66 Thread 0x789f527fb640 (LWP 39364) "view.x86_64" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x789f527f9470, op=393, expected=0, futex_word=0x789f18000f58)
at ./nptl/futex-internal.c:57
67 Thread 0x789f1f7ff640 (LWP 39365) "Vulkan Submissi" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
68 Thread 0x789f1effe640 (LWP 39366) "UnityGfxDeviceW" 0x000078a061f18bcf in __GI___poll (fds=0x789f159487c0, nfds=1, timeout=10) at ../sysdeps/unix/sysv/linux/poll.c:29
69 Thread 0x789f1e7fd640 (LWP 39368) "threaded-ml" 0x000078a061f18bcf in __GI___poll (fds=0x789ef800a3b0, nfds=3, timeout=986) at ../sysdeps/unix/sysv/linux/poll.c:29
70 Thread 0x789f5059c640 (LWP 39369) "Audio PulseAudi" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x324f71c) at ./nptl/futex-internal.c:57
71 Thread 0x789f5746c640 (LWP 39370) "Audio Stream Th" 0x000078a061ee57f8 in __GI___clock_nanosleep (clock_id=clock_id@entry=0, flags=flags@entry=0, req=req@entry=0x789f5746a5b0, rem=rem@entry=0x0)
at ../sysdeps/unix/sysv/linux/clock_nanosleep.c:78
72 Thread 0x789ee9596640 (LWP 39399) "Thread Pool Wor" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x78a034bb216c) at ./nptl/futex-internal.c:57
(gdb) bt
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x000078a064afe83e in UnityClassic::Baselib_SystemFutex_Wait(int*, int, unsigned int) () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#2 0x000078a064851976 in GfxDeviceWorker::WaitForSignal() () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#3 0x000078a063d7bc11 in GfxDeviceClient::FinishRendering() () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#4 0x000078a0637a1cf0 in CleanupEngine() () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#5 0x000078a0637c8ce4 in PlayerCleanup(bool) () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#6 0x000078a063d16566 in PlayerMain(int, char**) () from /home/brian/View-Shipping/View-DevMono/UnityPlayer.so
#7 0x000078a061e29d90 in __libc_start_call_main (main=main@entry=0x2010e0 <main>, argc=argc@entry=1, argv=argv@entry=0x7fff0ed05fa8) at ../sysdeps/nptl/libc_start_call_main.h:58
#8 0x000078a061e29e40 in __libc_start_main_impl (main=0x2010e0 <main>, argc=1, argv=0x7fff0ed05fa8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff0ed05f98)
at ../csu/libc-start.c:392
#9 0x0000000000201029 in _start ()
Some details
Unity engine version: 2022.3.34f1
Scripting backend: Mono (but also happens on IL2CPP)
Render pipeline: HDRP
OS version: Ubuntu 22.04
GPU: Nvidia RTX 4070Ti
Driver version: 535.183.01
What I am looking for: Are there any tools I can use to debug this? Maybe additional gdb commands I can type to get a better understanding of what the program is hanging on? Any advice would be very helpful.