weird data corruption

[Simon Marlow]

Frederik Eaton wrote:
> Hey, it looks like the output of two threads is being interleaved one
> character at a time. Is that really the most efficient way to schedule
> threads? Anyway, so I guess I need to set stdout and stderr to be line
> buffered? Perhaps that should be the default setting? ...

stderr is always unbufferred by default, this is pretty standard (I believe it's 
the same in C's stdio).  stdout should be line bufferred if connected to a 
terminal, or block-bufferred if connected to a file.

Cheers,
	Simon

> 
> ----------------------------------------------------------------
> 2006-08-22 22:49:58 4: querying (select cmdid from pfcq_study_cmdid where user=2;)
> 2006-08-22 22:49:58 4:   duration: 0.5 msec
> 2006-08-22 22:49:58 4: executing (up2d0a0t6e- 0p8f-c2q2_ s2t2u:d4y9_:c5m8d i3d:  sueste rc m=d i2d,  
> =c ocmmmdaindd+ 1=  wrheegries tuesre-rp=a2g;e)-
> vi2e0w0
> 6-20080-62-20 82-22:24 92:25:84 94::5 8   3d:u reaxteicount:i n0g. 3( smtsaerct
>  t2r0a0n6s-a0c8t-i2o2n )2
> 2:24090:65-80 84-:2 2e x2e2c:u4t9i:n5g8  (3c:o m m idtu)r
> ation: 5.9e-2 msec
> 2006-08-22 22:49:58 3: querying (select cmdid from pfcq_study_cmdid where user=2;)
> 2006-08-22 22:49:58 3:   duration: 0.3 msec
> 2006-08-22 22:49:58 3: executing (update pfcq_study_cmdid set cmdid = cmdid+1 where user=2;)
> ----------------------------------------------------------------
> 
> Frederik
> 
> On Tue, Aug 22, 2006 at 02:43:36PM +0100, Frederik Eaton wrote:
> 
>>I can't repeat it, but I can let you know if it happens again. I'm
>>writing with 'hPutStr', but not directly - rather via some modules in
>>a package I wrote. Kernel is Linux 2.6.16, libc 2.3.6, running Debian.
>>
>>Frederik
>>
>>On Tue, Aug 22, 2006 at 10:14:19AM +0100, Simon Marlow wrote:
>>
>>>Can you repeat it?  What API are you using to write the file?  On what OS?
>>>
>>>Cheers,
>>>	Simon
>>>
>>>Frederik Eaton wrote:
>>>
>>>>Sorry, forgot to say that I was using GHC 6.4.2 the first time, and
>>>>ghc-6.4.3.20060816 this time.
>>>>Frederik
>>>>On Mon, Aug 21, 2006 at 10:45:40PM +0100, Frederik Eaton wrote:
>>>>
>>>>>Hi,
>>>>>
>>>>>I'm seeing some odd data corruption in a log file. Below, the second
>>>>>line should be a SQL query (prefixed by a timestamp). It's turned into
>>>>>garbage, but apparently not just random bytes. I'm using HSQL - that's
>>>>>the only external library, and it uses FFI, so there might be some bad
>>>>>memory management, but I thought I should ask if other people have
>>>>>seen something similar. It's the second time this has happened to me.
>>>>>
>>>>>----------------------------------------------------------------
>>>>># fillUpQueue
>>>>>8-22010 62-20:83-12:12 62:2 :e3x1e:c2u6t:i nqgu e(rdyeilnegt e( sferloemc tp fccoqu_nstt(u*d)y 
>>>>>_fqruoemu ep fwchqe_rset usdqy__uqsueeru e=  w2h)e
>>>>>re sq_user = 2)
>>>>>2006-08-21 22:31:27:   duration: 843.8 msec
>>>>># addToQueue
>>>>># getNewCards
>>>>># getVT
>>>>>2006-08-21 22:31:27: querying (select max(res_num) from pfcq_study_results where res_user = 2)
>>>>>2006-08-21 22:31:27:   duration: 152.6 msec
>>>>>----------------------------------------------------------------
>>>>>
>>>>>Regards,
>>>>>
>>>>>Frederik
>>>>>
>>>>>-- 
>>>>>http://ofb.net/~frederik/
>>>>>
>>>
>>-- 
>>http://ofb.net/~frederik/
>>
> 
>