bug in inets or erlang!

Peter Lund <>
Tue Nov 29 18:00:02 CET 2005


> Micael Karlberg wrote: Hi,
>
> The inets web-server get's the (modification) time from the file-info
> record of the file: file:read_file_info(Path). What does this call
> give you?
>
> /BMK


Nothing unusual sorry!  I got this:

()6> file:read_file_info("index.html").
{ok,{file_info,360,
               regular,
               read_write,
               {{2005,11,29},{12,15,18}},
               {{2005,10,17},{18,44,2}},
               {{2005,10,17},{18,44,2}},
               33188,
               1,
               1042,
               1723200,
               426909,
               1001,
               1001}}
()7>

As Mattias said. This may be difficult to reproduce. I don't know what 
caused inets to make that failing call (except for what I see in the 
stack trace I posted originally). I have only seen it once and that was 
after a brute force power down of the FreeBSD system (removal of 
electrical power) and then turning it on again some 4-5 hours later.

/Peter

> Peter Lund wrote:
>
>> Yes, the important question here is if:
>>
>>  erlang:universaltime_to_localtime({{1969,12,31},{23,59,59}}).
>>
>> really should crash the code just because it is 1 sec too early? 
>> No-one seems to have any opinion about it!
>>
>> I am running on R10B (5.4.8). How do you figure out which "R10B-NN" 
>> it is?
>>
>>
>> Regarding why inets made this call when I tried to surf to "/" on my 
>> server I do not know. I hoped that some OTP person should fix this. 
>> The index.html on the DocumentRoot place was not even close to 36 
>> years old (just a couple of months).
>>
>> /Peter
>>
>> Matthias Lang wrote:
>>
>>> Hi,
>>>
>>> I started off by wondering why universaltime_to_localtime() doesn't
>>> work for the date you gave. The relevant files are
>>> erts/emulator/beam/bif.c and erts/emulator/beam/erl_time_sup.c. In 
>>> univ_to_local(), there's a rangecheck on the year. If it's less than
>>> BASEYEAR, the call fails. BASEYEAR is 1970. Real men don't read
>>> manuals, but it'd help all the sissies like me if the manual gave a
>>> clue about that.
>>>
>>> The other question is easier to answer---your trace provides all the
>>> information. inets calls univeraltime_to_localtime/1 with an argument
>>> from 1969 because the file you tried to get inets to serve has a 
>>> modification time from 1969. Take a look at the log to see which file
>>> it was.
>>>
>>> Matthias
>>>
>>> ----------------------------------------------------------------------
>>>
>>> peter writes:
>>>
>>> > After my FreeBSD server running erlang was restarted, suddenly
>>> > INETS was not comming up as it was expected to. In the inets
>>> > error_log I found:
>>> > > > more error_log_16111
>>> > [26/Nov/2005:13:14:42 -0000] reporting error: traverse exit from 
>>> apply: mod_get:
>>> > do =>
>>> > 
>>> {badarg,[{erlang,universaltime_to_localtime,[{{1969,12,31},{23,59,59}}]}, 
>>>
>>> >          {calendar,local_time_to_universal_time_dst,1},
>>> >          {httpd_util,rfc1123_date,1},
>>> >          {mod_get,get_modification_date,1},
>>> >          {mod_get,do_get,1},
>>> >          {httpd_response,traverse_modules,2},
>>> >          {httpd_response,generate_and_send_response,1},
>>> >          {httpd_request_handler,respond,3}]}
>>> > > > WHY is inets calling erlang:universaltime_to_localtime/1 with  
>>> [{{1969,12,31},{23,59,59}}] ?? Looks like a potential bugg to me OR 
>>> should this bug actually be located to the erlang module instead? 
>>> Should this call really result in a crach?
>>> > > Anyhow to get inets up and running again I had to patch the 
>>> calendar.erl module catching for this crash and in that case return 
>>> {{1970,1,1},{0,0,0}}. > > What need to change here erlang or some 
>>> module in inets?
>>> > > /PeterPeter Lund
>>> > _________________________________________________________
>>> > Sent using Mail2Forum (http://m2f.sourceforge.net)
>>>
>>>  
>>>
>>
>>
>




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