| Summary: | Album file watch failing (QKqueueFileSystemWatcherEngine:addPaths: open: Too many open files in system) [patch] | ||
|---|---|---|---|
| Product: | [Applications] digikam | Reporter: | brad <bkn> |
| Component: | Database-Scan | Assignee: | Digikam Developers <digikam-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | caulier.gilles, dani, g2florette, jan |
| Priority: | NOR | ||
| Version: | 2.4.0 | ||
| Target Milestone: | --- | ||
| Platform: | MacPorts | ||
| OS: | macOS | ||
| Latest Commit: | Version Fixed In: | 2.6.0 | |
| Sentry Crash Report: | |||
| Attachments: |
small patch to limit 'watched' files on OS X.
simple patch that should apply smoothly to current source. |
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Description
brad
2011-12-19 01:39:33 UTC
Created attachment 67089 [details]
small patch to limit 'watched' files on OS X.
I propose the attached patch to fix this problem on OS X. OS X limits the number files opened per process to be 255, so if the user has more than 255 files, they cannot open them, which doesn't make digikam all that useful. This patch makes digikam useful again but only watching directories, this limits the user to 255 directories of images. This is not a perfect solution, but for the timebeing this will enable digikam to be usable on OS X. I do not think this bug should be closed since this is just a work-around and not a genuine fix.
Marcel, Fine for you to apply this patch. It sound like not too intrusive and without any action under non OSX system... Gilles Caulier Apparently the underlying Qt bug is not fixed? Are you running Qt 4.7 and Mac OS X >= 10.5? Even with the number limited to 255, digikam would not be able to open more than one other file. I'd rather disable directory watching if the FSEvents API is not available On Dec 26, 2011, at 4:32 PM, Marcel Wiesweg wrote: > https://bugs.kde.org/show_bug.cgi?id=289330 > > > > > > --- Comment #3 from Marcel Wiesweg <marcel wiesweg gmx de> 2011-12-26 21:32:42 --- > Apparently the underlying Qt bug is not fixed? Are you running Qt 4.7 and Mac > OS X >= 10.5? Yes i'm running current QT 4.7.4, and OS X 10.6.8. I have a simple test program i can post if you have access to an OS X machine and want to look at. the qt bug is not fixed. it really seems to be a bug (short fall) of OS X not QT. eitherway, a process can't open more than 255 files without some system manipulation which i wouldn't expect end users to do. > Even with the number limited to 255, digikam would not be able to open more > than one other file. I'd rather disable directory watching if the FSEvents API > is not available > If you'd rather disable file watching, then go for it. I'm not familiar with the file watching code and i wanted to make the smallest change possible to the code to get it running on OS X. According to API docs, Qt would be using FSEvents on Mac OS X >= 10.5: http://en.wikipedia.org/wiki/FSEvents http://developer.qt.nokia.com/doc/qt-4.8/qfilesystemwatcher.html "Mac OS X 10.5 and up use a different backend and do not suffer from this issue." Now looking into the source code of Qt 4.7.3, apparently the creation of the FSEvents backend is commented out (QFileSystemWatcherPrivate::createNativeEngine()). This is still true on Qt master on gitorious. So apparently the API docs are wrong here - the backend does not seem to be used. I would recommend to report this bug to Qt, or try to reopen the bug report mentioned above. (currently i'm compiling qt with fsevents uncommented to see if it will work) after searching around the net, it appears that QT has gone back and forth from using fvevents to kqueue. it's not clearly to me why, but i think its because of bugs in fsevents on apple's side. In the meantime it seems that disabling file waching (or album watching) on OS X is right way to go for digikam until this QT/OS X bug is resolved. Created attachment 67697 [details]
simple patch that should apply smoothly to current source.
Trying to get better at git, creating patch with git format-patch. To apply use git am 0001-disable-filewatching-on-OS-X-but-dir-watching-still-.patch in the digikam-sc/core directory.
Here is an update (blog post) on qfilesystemwatcher for QT5. In the comments the author can get over 10k watched files on OS X. I'm try to contact the author to get more info. haven't heard anything yet. http://blog.rburchell.com/2012/01/qfilesystemwatcher-internals-in-qt-5.html Hi, Compiling digikam 2.6 from git on MacOSX Lion. I've the "too many open files" problem with my > 10K images collection : digikam isn't able to start. Without any collection, it runs fine... The patch from Brad, applied like showed in comment #7, fixes the problem : I can use digikam with my whole collection without any problem. Hope this small report helps... G. With Digikam 2.5.0 and Mac OS X Lion I had also the "too many open files" problem leading to a crash of digikam at startup. With the patch from comment #7 I can start Digikam. *** Bug 292522 has been marked as a duplicate of this bug. *** I will apply the patch by brad. Then I consider this bug fixed; it is not, but the real fix is beyond our scope, in OS X and Qt. Any better solution is welcome any time. Git commit 5e6b607b38076eb226a7fa92c82f0fe476bc9681 by Marcel Wiesweg. Committed on 14/04/2012 at 17:12. Pushed by mwiesweg into branch 'master'. Apply patch by Brad <bkn@ithryn.net> to disable file watch on OS X until this is properly supported by this platform. M +2 -1 NEWS M +7 -0 digikam/album/albumwatch.cpp http://commits.kde.org/digikam/5e6b607b38076eb226a7fa92c82f0fe476bc9681 |