[haiku-bugs] Re: [Haiku] #15728: Crash on free in PainterAggInterface
- From: "Haiku" <trac@xxxxxxxxxxxx>
- To: undisclosed-recipients: ;
- Date: Sun, 16 Aug 2020 17:38:16 -0000
#15728: Crash on free in PainterAggInterface
---------------------------------+----------------------------
Reporter: humdinger | Owner: axeld
Type: bug | Status: reopened
Priority: normal | Milestone: R1/beta3
Component: Servers/app_server | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking: 16246, 16367
Platform: All |
---------------------------------+----------------------------
Comment (by ttcoder):
so the whole thing is under some stress (lots of open windows or open
tabs in Web+). (...)
It would be nice if we could reproduce this in a more predictible way,
maybe with a test app stressing the use of alpha masks?
Do the youtube "thumbnails" involve alpha masks by any chance? I'm asking
because... Today I had time to boot into beta2 (twice), so I gave it a
go... Reproduced the crash twice in two attempts, hovering the mouse above
(among other things) youtube thumbnails, during playback and especially
after the video is done:
- booted into beta2 unmodified ("stock" app_server)
- immediately launched Web+
- Command-T to create a _second_ tab
- typed the URL for the full-window "no man's sky" trailer :
http://www.youtube.com/embed/nLtmEjqzg7M
- let it play to the end (didn't find a way to reproduce the crash
otherwise, maybe that's significant)
- let W+ recover after the end (always takes a while)
- click the circular arrow icon at bottom left, to restart playing.
- there's some sort of visual bug, where W+ displays a rotation "please
wait" symbol (shaped like a round arrow) on a pitch black full-window
background, but the symbol moves around the window quickly, as if it had a
wild BView.Transform() call. That state remains for a good while, allowing
time to do this:
- hover the mouse above the red/gray progress bar, left to right, then
back left, to show a maximum of thumbnails from the video, hovering even
more intensely than I did during playback.
- crash
Observation: at the debugger prompt that comes up, I typed "threads" to
see what threads are running in app_server, and both times I saw a thread
named "Reason: xxx":
- "w:908:offscreen ("Reason : _numblock >0")
- "w:xxx:offscreen ("Reason : Segment Violation")
So if I'm not completely mis-understanding this, it's possible that the
sequence of events is 1) Web+ crashes, 2) debbugger attempts to open its
normal BAlert, 3) that crashes the app_server 4) debugger is invoked a
second time, but this time in "console" mode. Though I suppose that
sequence does not make a huge difference compared to the previously
assumed one.
Well maybe it does -- what if I configure
"/boot/home/config/settings/system/debug_server/settings" with a
"WebPositive : log" line, or some such ? Will try that next. I'll have
less time to dedicate to this from now on though, so might leave it to
others. We don't want to make the ticket unbearably long anyway.
--
Ticket URL: <
https://dev.haiku-os.org/ticket/15728#comment:26>
Haiku <
https://dev.haiku-os.org>
The Haiku operating system.
Other related posts:
