Hi,
I am facing sporadic SEGFAULTS when calling TSVConnWrite from a custom
plug-in that I am not able to easily reproduce.
TSVConnWrite (connp=0x2aec640b5620, contp=0x2aec640b5da0,
readerp=0x2aec7c110c88, nbytes=9223372036854775807) at InkAPI.cc:6258
Things make me believe this is coming from the FORCE_PLUGIN_MUTEX macro;
if not it might be then subsequent call to vc->do_io_write().
I am able to see the contp has a "valid" mutex.
Any ideas from here? Any good practices I should be taking before calling
TSVConnWrite on my code?
I am dumping a lot of data so it might ring the bells for people more
familiar with the TS internals...
Thanks in advance...
*(gdb) bt*
#0 0x0000000000000000 in ?? ()
#1 0x00000000004b33de in TSVConnWrite (connp=0x2aec640b5620,
contp=0x2aec640b5da0,
readerp=0x2aec7c110c88, nbytes=9223372036854775807) at InkAPI.cc:6258
#2 0x00002aec00ae11dc in write (s=9223372036854775807, r=<optimized out>,
c=0x2aec640b5da0,
v=<optimized out>) at ats.hpp:285
#3 write (r=<optimized out>, c=0x2aec640b5da0, v=<optimized out>) at
ats.hpp:289
#4 Output (continuation=0x2aec640b5da0, consumer=<optimized out>,
this=0x2aec3c03de50) at ats.hpp:1508
*(gdb) info line 6258*
Line 6258 of "InkAPI.cc"
starts at address 0x4b33c8 <TSVConnWrite(TSVConn, TSCont,
TSIOBufferReader, int64_t)+136>
and ends at 0x4b33e9 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+169>.
*(gdb) disas 0x00000000004b33b4,0x00000000004b3410*
Dump of assembler code from 0x4b33b4 to 0x4b3410:
0x00000000004b33b4 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+116>: callq 0x4850c8 <pthread_getspecific@plt>
0x00000000004b33b9 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+121>: mov 0x18(%rbx),%rsi
0x00000000004b33bd <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+125>: mov %rax,%rdx
0x00000000004b33c0 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+128>: mov %rsp,%rdi
0x00000000004b33c3 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+131>: callq 0x4ba130 <MutexLock::set_and_take(ProxyMutex*,
EThread*)>
*0x00000000004b33c8* <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+136>: mov 0x0(%rbp),%rax
0x00000000004b33cc <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+140>: xor %r8d,%r8d
0x00000000004b33cf <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+143>: mov %r14,%rcx
0x00000000004b33d2 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+146>: mov %r13,%rdx
0x00000000004b33d5 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+149>: mov %rbx,%rsi
0x00000000004b33d8 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+152>: mov %rbp,%rdi
0x00000000004b33db <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+155>: callq *0x18(%rax)
*=> *0x00000000004b33de <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+158>: mov %rax,%rbx
0x00000000004b33e1 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+161>: mov %rsp,%rdi
0x00000000004b33e4 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+164>: callq 0x4ba5e0 <MutexLock::~MutexLock()>
*0x00000000004b33e9* <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+169>: mov %rbx,%rax
0x00000000004b33ec <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+172>: mov 0x18(%rsp),%rbp
0x00000000004b33f1 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+177>: mov 0x10(%rsp),%rbx
0x00000000004b33f6 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+182>: mov 0x20(%rsp),%r12
0x00000000004b33fb <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+187>: mov 0x28(%rsp),%r13
0x00000000004b3400 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+192>: mov 0x30(%rsp),%r14
0x00000000004b3405 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+197>: add $0x38,%rsp
0x00000000004b3409 <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+201>: retq
0x00000000004b340a <TSVConnWrite(TSVConn, TSCont, TSIOBufferReader,
int64_t)+202>: nopw 0x0(%rax,%rax,1)
End of assembler dump.
*(gdb) info vtbl *vc*
vtable for 'VConnection' @ 0x6adbd0 (subobject @ 0x2aec640b5620):
[0]: 0x4bb740 <INKVConnInternal::~INKVConnInternal()>
[1]: 0x4bb650 <INKVConnInternal::~INKVConnInternal()>
[2]: 0x4b2390 <INKVConnInternal::do_io_read(Continuation*, long,
MIOBuffer*)>
*[3]: 0x4b2f70 <INKVConnInternal::do_io_write(Continuation*, long,
IOBufferReader*, bool)>*
[4]: 0x4b2510 <INKVConnInternal::do_io_close(int)>
[5]: 0x4b9780 <INKVConnInternal::do_io_shutdown(ShutdownHowTo_t)>
[6]: 0x5e8a20 <VConnection::set_continuation(VIO*, Continuation*)>
[7]: 0x4b9310 <INKVConnInternal::reenable(VIO*)>
[8]: 0x5e8a40 <VConnection::reenable_re(VIO*)>
[9]: 0x4a4b20 <INKVConnInternal::get_data(int, void*)>
[10]: 0x4a4b90 <INKVConnInternal::set_data(int, void*)>
(gdb) set print object on
(gdb) print *vc
$1 = (INKVConnInternal) {<INKContInternal> = {<DummyVConnection> =
{<VConnection> = {<Continuation> = {<force_VFPT_to_top> =
{_vptr.force_VFPT_to_top = 0x6adbd0 <vtable for INKVConnInternal+16>},
handler = (int (Continuation::*)(Continuation * const, int,
void *)) 0x4b9460 <INKVConnInternal::handle_event(int, void*)>, mutex =
{m_ptr = 0x2aec28017a90},
link = {<SLink<Continuation>> = {next = 0x0}, prev = 0x0}},
lerrno = 0}, <No data fields>},
mdata = 0x2aec7c0bc060,
m_event_func = 0x2aec00adfa90 <ts::continuation::(anonymous
namespace)::handle<ts::Transaction::Transformer<(anonymous
namespace)::SecureSearch> >(TSCont, TSEvent, void*)>, m_event_count = 1,
m_closed = 0,
m_deletable = 0, m_deleted = 0, m_free_magic =
INKCONT_INTERN_MAGIC_ALIVE}, m_read_vio = {
_cont = 0x0, nbytes = 0, ndone = 0, op = 0, buffer = {mbuf = 0x0, entry
= 0x0}, vc_server = 0x0,
mutex = {m_ptr = 0x0}}, m_write_vio = {_cont = 0x2aec50170750, nbytes =
9223372036854775807,
ndone = 0, op = 2, buffer = {mbuf = 0x4214a00, entry = 0x4214a40},
vc_server = 0x2aec640b5620,
mutex = {m_ptr = 0x2aec28017a90}}, m_output_vc = 0x2aec640bae40}
--
Daniel Morilha (dmori...@gmail.com)
