达人， 救命！！！无缘无故的崩溃

rain_fish

无缘无故的崩溃

(gdb) bt
#0  0x007bd9fb in sem_wait@GLIBC_2.0 () from /lib/tls/libpthread.so.0
#1  0x08052648 in DownDataPool::getData (this=0x0) at DownDataPool.h:44
#2  0x08050596 in CWASZBClientServer::deliver (this=0xb555900 at WASZBClientServer.cpp:322
#3  0x08055fe9 in WASClientServer:eliverData (pvthis=0xb555900 at ../was/WASClientServer.cpp:57
#4  0x007b93ae in start_thread () from /lib/tls/libpthread.so.0
#5  0x00649aee in clone () from /lib/tls/libc.so.6
(gdb) f 2
#2  0x08050596 in CWASZBClientServer::deliver (this=0xb555900 at WASZBClientServer.cpp:322
322         WASDownData dn_data = _downdatapool.getData();
(gdb) p this->_downdatapool
$1 = (DownDataPool & @0x8a261b8: {_sem_datapool = {__sem_lock = {__status = 0,
      __spinlock = 6985784}, __sem_value = -1, __sem_waiting = 0x0}, _lock = {__m_reserved = 0,
    __m_count = 0, __m_owner = 0x0, __m_kind = 0, __m_lock = {__status = 0, __spinlock = 0}},
  _datapool = {<std::_List_base<WASDownData,std::allocator<WASDownData> >> = {
      _M_impl = {<std::allocator<std::_List_node<WASDownData> >> = {<__gnu_cxx::new_allocator<std::_List_node<WASDownData> >> = {<No data fields>}, <No data fields>}, _M_node = {_M_next = 0x8a261e0,
          _M_prev = 0x8a261e0}}}, <No data fields>}}
(gdb) f 1
#1  0x08052648 in DownDataPool::getData (this=0x0) at DownDataPool.h:44
44                      while( 0 != sem_wait(&_sem_datapool) )
(gdb) p this
$2 = (DownDataPool * const) 0x0
(gdb)

实在不理解这是什么原因造成的，在f 2中p this->_downdatapool是正常的，但是进入f 1后 p this就是空了，这是什么原因造成的？请高手指点


刚才整理了一下，发现崩溃的地方改变了，而且同一地址打印的内容却不一样（最下两行红字），这是为哈？百思不得其解
(gdb) p cdp
$6 = (CacheDataPool *) 0x9be1180
(gdb) p cserver->_cachedatapool
$7 = (CacheDataPool *) 0x9be1180
(gdb) p cserver->_cachedatapool->_cache
$8 = {_M_t = {
    _M_impl = {<std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<No data fields>}, <No data fields>},
      _M_key_compare = {<std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = {
        _M_color = std::_S_red, _M_parent = 0x0, _M_left = 0x9c000000, _M_right = 0x9c09be11}, _M_node_count = 638481}}}
(gdb) p cdp->_cache
$9 = {_M_t = {
    _M_impl = {<std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<No data fields>}, <No data fields>},
      _M_key_compare = {<std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = {
       _M_color = std::_S_red, _M_parent = 0x0, _M_left = 0x9be119c, _M_right = 0x9be119c}, _M_node_count = 0}}}
(gdb)

[ 本帖最后由 rain_fish 于 2009-10-14 21:56 编辑 ]

rain_fish

朋友们给点思路也可以，急。。。

@sky

你没点代码估计没人能猜到问题

rain_fish

代码太多，一句两句讲不清楚， 我的意思是造成这个崩溃的原因一般是什么？

chenzhanyiczy

不要F 1，一步一步next调试或者printf打印出来，最后看看返回值正不正确

chenzhanyiczy

另外，崩溃的时候会产生core文件，你可以gdb这个core文件，看看是哪个函数和哪句代码发生了崩溃，接着可以从该代码往前检查

rain_fish

原帖由 chenzhanyiczy 于 2009-10-14 20:11 发表
另外，崩溃的时候会产生core文件，你可以gdb这个core文件，看看是哪个函数和哪句代码发生了崩溃，接着可以从该代码往前检查

帖子里的就是core文件，崩溃的地方就在上面，崩溃原因是：getData (this=0x0) ，但是不知道造成这个的原因是什么因为在 f 2
时p this->_downdatapool是有值的，但是到调用getData后，this竟然是空，实在费解。

chenzhanyiczy

一步一步运行，不要finish 2

rain_fish

继续寻找，发现应该是内存溢出或者越界造成的，大家看一下，同一个内存打印出的结果竟然不同：
(gdb) p cdp
$6 = (CacheDataPool *) 0x9be1180
(gdb) p cserver->_cachedatapool
$7 = (CacheDataPool *) 0x9be1180
(gdb) p cserver->_cachedatapool->_cache
$8 = {_M_t = {
    _M_impl = {<std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<No data fields>}, <No data fields>},
      _M_key_compare = {<std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = {
        _M_color = std::_S_red, _M_parent = 0x0, _M_left = 0x9c000000, _M_right = 0x9c09be11}, _M_node_count = 638481}}}
(gdb) p cdp->_cache
$9 = {_M_t = {
    _M_impl = {<std::allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<__gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, WASDownData> > >> = {<No data fields>}, <No data fields>},
      _M_key_compare = {<std::binary_function<std::basic_string<char, std::char_traits<char>, std::allocator<char> >,std::basic_string<char, std::char_traits<char>, std::allocator<char> >,bool>> = {<No data fields>}, <No data fields>}, _M_header = {
        _M_color = std::_S_red, _M_parent = 0x0, _M_left = 0x9be119c, _M_right = 0x9be119c}, _M_node_count = 0}}}
(gdb)

chenzhanyiczy

这样的东西基本上没人看得懂的