Ticket #9231 (closed defect: fixed)
Opened 3 years ago
Last modified 19 months ago
[CRASH] frontend crash entering netvision channel
| Reported by: | anonymous | Owned by: | cpinkham |
|---|---|---|---|
| Priority: | minor | Milestone: | 0.25 |
| Component: | MythTV - General | Version: | 0.24 |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
Often have the frontend crash when entering a netvision channel. This seems to be caused by something in the paththumb download. If I update the database to set all the paththumbs of the channel to be the same local file image no crash. Also after a few crash if all the paththumb images are download and are in the cache then also no crash. Looks like mostly occurs for channels where there are many directories (~10 or more) Downloading of video thumbnails do not cause a crash.
Downloading of the paththumbs looks quite strange. Starts with no images, then images blink on and off as they download, then when all are downloaded, all the images pop up.
See lots of the following errors in frontend log
QString::arg: Argument missing: "images/image_gallery_no_image.png" , 1 QString::arg: Argument missing: "/home/auric/.mythtv/thumbcache/thumbnail_37530_15694.gif" , 1
Have also seen a couple of freezes, but it is usually a crash. I think the freezes give the following error. (Could be from a crash, can do more testing if needed)
*** glibc detected *** mythfrontend: double free or corruption (fasttop): 0x0abfee08 ***
Attachments
Change History
comment:1 Changed 3 years ago by robertm
- Status changed from new to infoneeded_new
comment:2 Changed 3 years ago by anonymous
This gdb.txt is from a hang not a crash. Hope this helps. Will try a few more times to get a crash. Note sure how to get what changeset this build is. Was checked out from trunk 15/11 9PM GST
comment:3 Changed 3 years ago by anonymous
Doh. Version is
MythTV Version : 27235 MythTV Branch : trunk Network Protocol : 63 Library API : 0.25.20101112-1 QT Version : 4.6.3
comment:4 Changed 3 years ago by robertm
- Owner changed from robertm to cpinkham
- Component changed from Plugin - MythNetvision to MythTV - General
Chris, can you look at this and decide whether it's anything we need to deal with? The crash is actually in Qt code, I cannot reproduce, but it's called from within MythDownloadManager?. Gut says it's a Qt bug, but worth one more look.
comment:5 Changed 3 years ago by robertm
- Status changed from infoneeded_new to new
Auric, your backtrace is a crash, not a hang. No further info needed.
comment:7 Changed 3 years ago by anonymous
Thanks Robert.
For general info, qt version.
Name : qt Relocations: (not relocatable) Version : 4.6.3 Vendor: Fedora Project Release : 8.fc12 Build Date: Fri 02 Jul 2010 01:18:54 AM EST
Auric
comment:8 Changed 2 years ago by beirdo
- Summary changed from frontend crash entering netvision channel to [CRASH] frontend crash entering netvision channel
comment:9 Changed 2 years ago by Jonatan <mythtv@…>
Seems like there are some thread safety issues in MythDownloadManager?. The attached patched tries to solve them.
comment:10 Changed 19 months ago by Github
- Status changed from assigned to closed
- Resolution set to fixed
- Milestone changed from unknown to 0.25
Fix race condition and potential segfault in MythDownloadManager?.
Put a lock around the creation of the MythDownloadManager? to make sure we don't get two created by a potential race condition.
Put a lock around access to the QNetworkDiskCache when called via MythDownloadManager::GetLastModified?().
Fixes #9231 using ideas from Jonatan from comhem.se, but most of the patch (and potential issues) are mine.
Branch: master Changeset: e7b14849adf4f97cda5798eb668bf457776fa7b5
Need a backtrace, please.