[sane-devel] sane_init()/sane_exit() crashes on debian systems / not on e.g. arch linux

[Wilhelm Meier]

Hi Olaf,

Am 06.05.2017 um 07:58 schrieb Olaf Meeuwissen:
> Hi again,
> 
> Olaf Meeuwissen writes:
> 
>> Hi Wilhelm,
>>
>> Wilhelm writes:
>>
>>> Hi all,
>>>
>>> the following small program regularly crashes on debian based system
>>> when inserting / removing a device. This does not happen on e.g. arch
>>> linux or gentoo systems.
>>
>> A bit late perhaps, but I've been trying to reproduce this without any
>> success.
> 
> I seem to be having more luck now.
> 
>> I'm using Debian stretch (9.0 to be), last updated 2017-05-01 with a
>> default SANE configuration.  I don't have scanbd installed and don't
>> have saned set up.  I have an EPSON PM-A750 attached which is supported
>> by the epson2 backend.
>>
>> I saved your program to debian-crash.c and compiled with:
>>
>>   gcc -lsane -o debian-crash debian-crash.c
>>
>> Running ./debian-crash (I'm a member of the scanner group so no sudo is
>> required) did not produce the problem you describe.  At least not in the
>> 5 or 6 cycles I let it run for before killing it with Ctrl-C.
> 
> After 10 cycles the pixma backend started printing warnings but no
> crash.  I had to enable localhost in the net backend to get things
> to crash.  That also happened at the 10th cycle (on my system).
> 
>   sane version 1.0
>   [bjnp] create_broadcast_socket: ERROR - can not open socket - Too many open files[bjnp] create_broadcast_socket: ERROR - can not open socket - Too many open files[bjnp] create_broadcast_socket: ERROR - can not open socket - Too many open filesdebian-crash: thread-watch.c:171: avahi_threaded_poll_lock: Assertion `p' failed.
>   Aborted
> 
> I used f3f8afb0 with the debian/rules for 1.0.25-4 to configure and
> build libraries.  Running the same test with the libsane.so that
> produces no longer triggered the above.
> I let it run for 100 cycles but that did not trigger any crash.
> 
>> [snip]
>>> Any reasons or plans to fix that?
> 
> Looks like it has been fixed in the latest code in git (although I don't
> know what commit(s) were responsible for that).  

thank you for dealing with this issue.

This seems very reasonable to me since ArchLinux the package uses the
most recent sources whereas debian / ubuntu is a bit behind.

Well, I had to put a workaround into scanbd ...

Thanks again!

> If you still see this
> problem on your end with the latest version in git, please let us know
> what is needed to reproduce and include more details on the symptoms you
> see.
> 
> Hope this helps,
> --
> Olaf Meeuwissen, LPIC-2            FSF Associate Member since 2004-01-27
>  GnuPG key: F84A2DD9/B3C0 2F47 EA19 64F4 9F13  F43E B8A4 A88A F84A 2DD9
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