[MPlayer-dev-eng] [PATCH] fix premature end of stream download

[trevor-b at ovi.com]

correcting my previous email ...

>   recv is not allowed to return EAGAIN
yes, you are correct, len is not set to EAGAIN - errno is

maybe the while statement in the patch should be ...
+    while( len <= 0 && errno == EAGAIN && nr_tries-- > 0 );

I'll do some more tests and post again in a couple of days time.




----- Original Message -----
> From: "trevor-b at ovi.com" <trevor-b at ovi.com>
> To: "mplayer-dev-eng at mplayerhq.hu" <mplayer-dev-eng at mplayerhq.hu>
> Cc: 
> Sent: Friday, 23 March 2012, 22:12
> Subject: Re: [MPlayer-dev-eng] [PATCH] fix premature end of stream download
> 
>>  ... when recv returns 0, the other side closed the connection.
> what if recv returns < 0?  In my case, the call to perror prints "read 
> error:: Resource temporarily unavailable"
> 
> 
>>  recv is not allowed to return EAGAIN
> 
> Are you sure? Perhaps this is a windows vs linux/unix/posix difference?
> 
> This is taken from the man page for recv ....
> 
> ERRORS
>        These  are  some  standard  errors  generated  by  the socket layer.  
> Additional errors may be generated and
>        returned from the underlying protocol modules; see their manual pages.
> 
>        EAGAIN or EWOULDBLOCK
>               The socket is marked nonblocking and the receive operation would 
> block, or a receive timeout had been
>               set  and  the  timeout  expired  before  data  was  received.  
> POSIX.1-2001 allows either error to be
>               returned for this case, and does not require these constants to 
> have the same value,  so  a  portable
>               application should check for both possibilities.
> 
> ...
> 
> 
> 
> 
> ----- Original Message -----
>>  From: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
>>  To: mplayer-dev-eng at mplayerhq.hu
>>  Cc: 
>>  Sent: Friday, 23 March 2012, 17:29
>>  Subject: Re: [MPlayer-dev-eng] [PATCH] fix premature end of stream download
>> 
>>  On Fri, Mar 23, 2012 at 09:59:17AM -0700, trevor-b at ovi.com wrote:
>>>   Hi all,
>>> 
>>>   I have been listening to a BBC program, but mplayer nearly always 
> aborts 
>>  before finishing the download with this error message:
>>> 
>>>       read error:: Resource temporarily unavailable3% 1% 
>>>       pre-header read failed
>>>       Stream not seekable!
>>> 
>>>   In the sample output below, you can see the error occurred 11 mins 
> into a 2 
>>  hr program.
>>> 
>>>   From the eror message, I'm guessing the problem happens because 
> the 
>>  data doesn't arrive fast enough, 
>>> 
>>>   so mplayer gives up.
>>> 
>>>   The corresponding code is in stream/asf_mmst_streaming.c, in function 
>>  get_data():
>>> 
>>>       len = recv (s, &buf[total], count-total, 0);
>>>       if (len<=0) {
>>>         perror ("read error:");
>>>         return 0;
>>>       }
>>> 
>>> 
>>>   So it does give up as soon as there is no data available.
>> 
>>  No it does not, when recv returns 0, the other side closed the
>>  connection.
>> 
>> 
>>>   --- stream/asf_mmst_streaming.c    2010-09-10 22:42:13.000000000 +0100
>>>   +++ stream/asf_mmst_streaming.1.c    2012-03-22 22:51:36.000000000 
> +0000
>>>   @@ -191,11 +191,14 @@
>>>    {
>>>      ssize_t  len;
>>>      size_t total = 0;
>>>   -
>>>   +  int nr_tries;
>>>   +  
>>>      while (total < count) {
>>>    
>>>   -    len = recv (s, &buf[total], count-total, 0);
>>>   -
>>>   +    nr_tries = 10;
>>>   +    do
>>>   +        len = recv (s, &buf[total], count-total, 0);
>>>   +    while( len == EAGAIN && nr_tries-- > 0 );
>> 
>>  That doesn't make sense, recv is not allowed to return EAGAIN
>>  (-1, 0 and number of bytes are the only allowed values),
>>  thus either the recv implementation is broken or your
>>  change does not do anything at all.
>>  _______________________________________________
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>>  MPlayer-dev-eng at mplayerhq.hu
>>  https://lists.mplayerhq.hu/mailman/listinfo/mplayer-dev-eng
>> 
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