We found a blocking issue in our app with some image download after
upgrading from 2.9.12 to 2.10.4
It turned out to be a deadlock in CacheOnDisk class in case of exception in
our cache callback function, normally handled in our app
without any issue until now.
the new file_locks introduced in 2.10.1, (3e46e985bf15) acquired before the
cache app callback ( value = f() )
with self.storage.acquire(CacheAbstract.cache_stats_name)
Is never released in case of exception in f()
then next call to the CacheOnDisk during same request will block the thread
indefinitely.
(CacheInRam should not have the same issue as self.locker.release() is
released before f())
The following patch solves the issue for us.
Hope it could help
Bernard
> git diff -w R-2.10.4 cache.py
>
> *diff --git a/gluon/cache.py b/gluon/cache.py*
> *index f94937d..9729e6b 100644*
> *--- a/gluon/cache.py*
> *+++ b/gluon/cache.py*@@ -473,7 +473,12 @@ class
> CacheOnDisk(CacheAbstract):
> if item and ((dt is None) or (item[0] > now - dt)):
> value = item[1]
> else:
> + try:
> value = f()
> + except:
> + self.storage.release(CacheAbstract.cache_stats_name)
> + self.storage.release(key)
> + raise
> self.storage[key] = (now, value)
> self.storage.safe_apply(CacheAbstract.cache_stats_name,
> inc_misses,
> default_value={'hit_total': 0,
> 'misses': 0})
--
Resources:
- http://web2py.com
- http://web2py.com/book (Documentation)
- http://github.com/web2py/web2py (Source code)
- https://code.google.com/p/web2py/issues/list (Report Issues)
---
You received this message because you are subscribed to the Google Groups
"web2py-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to web2py+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
