On Mon, Sep 17, 2012 at 5:12 PM, Azat Khuzhin <dohardgopro_at_gmail.com> wrote:
> On Mon, Sep 17, 2012 at 4:58 PM, Daniel Stenberg <daniel_at_haxx.se> wrote:
>> On Mon, 17 Sep 2012, Azat Khuzhin wrote:
>>
>>> I have SIGSEGV when I run curl in 400 threads. valgrind doesn't detect any
>>> memory errors.
>>>
>>> I can't post here all program sources, but here is some info:
>>
>>
>> You shouldn't post "all program sources" - because we don't want them. You
>> should write a new stand-alone example that repeats your problem and then
>> post _that_ source code.
>>
>> If you can reproduce the problem in a separate application, chances are the
>> problem is in your code.
>
> I don't think that this justified, but I try when I have more time.
> Because this application crawl URL's and source code is not enough to
> reproduce this error, also you need URL's (I think that ~5 million
> rows should be enough.)
>>
>>
>>> At all time program runs, only one valgrind message (valgrind
>>> --show-reachable=yes --leak-check=full) :
>>> ==30908== Thread 3:
>>> ==30908== Conditional jump or move depends on uninitialised value(s)
>>> ==30908== at 0x4C2B837: __GI___rawmemchr (mc_replace_strmem.c:1110)
>>> ==30908== by 0x532A2AF: _IO_str_init_static_internal (strops.c:45)
>>> ==30908== by 0x531E9D4: vsscanf (iovsscanf.c:44)
>>> ==30908== by 0x530AB97: sscanf (sscanf.c:34)
>>> ==30908== by 0x4074E9: parseUrl (crawler.c:28)
>>> ==30908== by 0x407961: startRoutine (crawler.c:125)
>>> ==30908== by 0x4E35B4F: start_thread (pthread_create.c:304)
>>> ==30908== by 0x538D70C: clone (clone.S:112)
>>
>>
>> ... this has nothing to do with libcurl but rather shows a problem in your
>> application.
>
> I know, but it seems that this is not important error
>>
>>
>>> And it caught SIGSEGV:
>>> ==30908== Process terminating with default action of signal 11 (SIGSEGV)
>>> ==30908== General Protection Fault
>>> ==30908== at 0x50926C8: curl_slist_free_all (in
>>> /usr/lib/x86_64-linux-gnu/libcurl.so.4.2.0)
>>> ==30908== by 0x4031AF: curlSetOptionPC (curl.c:138)
>>> ==30908== by 0x407CB2: startRoutine (crawler.c:185)
>>> ==30908== by 0x4E35B4F: start_thread (pthread_create.c:304)
>>> ==30908== by 0x538D70C: clone (clone.S:112)
>>
>>
>> This could just as well be a thread/synch problem in your application. If
>> you look at the curl_slist_free_all() implementation you'll see that it
>> doesn't have a lot of logic that can go wrong.
>
> Every thread have it own curl handler.
> At this moment I run my application under "valgrind --tool=drd" but
> pthread_create is very slow under this tool,
> so if I found some thing important/interesting I post here.
>>
>>
>>> Also valgrind show that Curl_ssl_connect is called (how ? If I allow only
>>> HTTP protocol)
>>
>>
>> That seems strange yes and I can't explain it. Can't you just set a
>> break-point and see how it gets there?
>
> It's a good idea. I give it a try and post here results when find something.

Breakpoint 1, Curl_ssl_connect (conn=conn_at_entry=0x62f550,
sockindex=sockindex_at_entry=0) at sslgen.c:199
199 sslgen.c: No such file or directory.
(gdb) bt
#0 Curl_ssl_connect (conn=conn_at_entry=0x62f550,
sockindex=sockindex_at_entry=0) at sslgen.c:199
#1 0x00007ffff7969895 in Curl_http_connect (conn=0x62f550,
done=0x7ffff3986abf) at http.c:1333
#2 0x00007ffff797bb14 in Curl_protocol_connect
(conn=conn_at_entry=0x62f550,
protocol_done=protocol_done_at_entry=0x7ffff3986abf) at url.c:3437
#3 0x00007ffff797bdea in Curl_setup_conn (conn=conn_at_entry=0x62f550,
protocol_done=0x7ffff3986abf) at url.c:5243
#4 0x00007ffff7994074 in Curl_async_resolved (conn=0x62f550,
protocol_done=protocol_done_at_entry=0x7ffff3986abf) at hostasyn.c:139
#5 0x00007ffff7987ba1 in connect_host (conn=0x7ffff3986ac0,
data=0x611770) at transfer.c:1952
#6 Curl_do_perform (data=0x611770) at transfer.c:2087
#7 0x0000000000403a34 in curlRequestGet (ptCurl=0x7ffff398ce00,
    pccUrl=0x7ffff398be00
"https://www.google.com/bookmarks/mark?bkmk=http%3A%2F%2Fcmjornal.xl.pt%2Fdetalhe%2Fo-dia-em-imagens%2Fa-holandesa-laura-dekker-16-anos-tornou-se-ontem-a-mais-jovem-navegadora-solitaria-a-dar-a-volta-a"...)
    at gen/gen_curl.c:272
#8 0x0000000000407a64 in startRoutine (arg=0x60e920) at
crawler/src/crawler.c:143
#9 0x00007ffff7bc7b50 in start_thread (arg=<optimized out>) at
pthread_create.c:304
#10 0x00007ffff76a870d in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()
(gdb) frame 8
#8 0x0000000000407a64 in startRoutine (arg=0x60e920) at
crawler/src/crawler.c:143
143 gotBytes = curlRequestGet(&curlPage, url);
(gdb) p url
$1 = "https://www.google.com/bookmarks/mark?bkmk=http%3A%2F%2Fcmjornal.xl.pt%2Fdetalhe%2Fo-dia-em-imagens%2Fa-holandesa-laura-dekker-16-anos-tornou-se-ontem-a-mais-jovem-navegadora-solitaria-a-dar-a-volta-a"
>
> Thanks for reply.
>>
>> --
>>
>> / daniel.haxx.se
>> -------------------------------------------------------------------
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>
>
>
> --
> Azat Khuzhin

-- 
Azat Khuzhin
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