There is a hang when workers write their stack traces to the same file if that file already exists on disk. This is the root cause of the more general issue addressed in <https://bugs.webkit.org/show_bug.cgi?id=178368>.
<rdar://problem/35033432>
If we add a pid to the name of the stack-trace, the problem stops.
Created attachment 324035 [details] Patch
Comment on attachment 324035 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=324035&action=review > Tools/Scripts/webkitpy/common/interupt_debugging.py:47 > + file_name = os.path.join(os.path.dirname(output_file), '{}-{}'.format(os.getpid(), os.path.basename(output_file))) if output_file else None Is it guaranteed that we won't have file name collision after adding os.getpid() ? Maybe we can add timestamp in filename instead of pid to make it unique, it would also make it easy to sort these files into the directory having multiple such files.
(In reply to Aakash Jain from comment #4) > Comment on attachment 324035 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=324035&action=review > > > Tools/Scripts/webkitpy/common/interupt_debugging.py:47 > > + file_name = os.path.join(os.path.dirname(output_file), '{}-{}'.format(os.getpid(), os.path.basename(output_file))) if output_file else None > > Is it guaranteed that we won't have file name collision after adding > os.getpid() ? > Maybe we can add timestamp in filename instead of pid to make it unique, it > would also make it easy to sort these files into the directory having > multiple such files. It's guaranteed that we won't have a file name collision inside a single test run. Overwriting an existing file with the same name is perfectly fine. I don't think timestamp is a good way to achieve this because it is possible (likely, in fact) that workers will generate timestamps very close to or even equal to their sibling workers since they will all receive the SIGTERM at the same time.
Comment on attachment 324035 [details] Patch Clearing flags on attachment: 324035 Committed r223572: <https://trac.webkit.org/changeset/223572>
All reviewed patches have been landed. Closing bug.
Re-opened since this is blocked by bug 178587
This didn't help, at least not enough. Re-fixed by rolling back both r222709 and r223572.
Note that this change is now part of the patch up for review in <https://bugs.webkit.org/show_bug.cgi?id=176393>.