段錯誤與升壓:: REF

Question

環境：Ubuntu的小牛（10.10），libboost V1.42，英特爾X5680處理器

問題：當在與升壓::螺紋結合使用boost :: REF和boost :: thread_group，在幾個循環之後出現分段故障（每次有不同的計數）。

問題：該問題的位置在哪裏？提前致謝。

要編譯：C++ -lboost_thread -lpthread mttest.cpp -o mttest -g

樣品的編號：mttest.cpp

#include <iostream> 
#include <string> 
#include <vector> 
#include <iterator> 

#include <boost/dynamic_bitset.hpp> 
#include <boost/thread.hpp> 
#include <boost/bind.hpp> 

using namespace std; 
using namespace boost; 
using namespace boost::this_thread; 

void thousand(boost::dynamic_bitset<> &motifarray) { 
    for(int i = 0; i < 1000; i++) { 
     motifarray[i] = 1; 
    } 
} 

int main (int argc, char* argv[]) { 

    boost::dynamic_bitset<> motifarray(1000); 
    vector< vector< boost::dynamic_bitset<> > > fbitarrays; 
    vector< boost::dynamic_bitset<> > curfbitarray; 

    for (int i = 0; i < 100; i++) { 
     curfbitarray.push_back(motifarray); 
    } 

    for (int i = 0; i < 10; i++) { 
     fbitarrays.push_back(curfbitarray); 
    } 

    for (int p = 0; p < 100; p++) { 
     boost::thread_group* threadpool = new boost::thread_group(); 

     for(int j = 0; j < 10; j++) {   
      boost::thread a(boost::bind(&thousand, boost::ref(fbitarrays[p][j]))); 
      threadpool->add_thread(&a); 
      cout << "inner loop: " << j << endl; 
     } 

     threadpool->join_all(); 
    } 

return 0; 
} 

GDB回溯：

#0 0x000000000040503a in boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >::reference::do_set (this=0x7fbcf8c1bd90) 
    at /usr/include/boost/dynamic_bitset/dynamic_bitset.hpp:109 
#1 0x0000000000404197 in boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >::reference::do_assign (this=0x7fbcf8c1bd90, x=true) 
    at /usr/include/boost/dynamic_bitset/dynamic_bitset.hpp:112 
#2 0x0000000000403a21 in boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >::reference::operator= (this=0x7fbcf8c1bd90, x=true) 
    at /usr/include/boost/dynamic_bitset/dynamic_bitset.hpp:97 
#3 0x0000000000401ffd in thousand (motifarray=...) at mttest.cpp:16 
#4 0x0000000000408994 in boost::_bi::list1<boost::reference_wrapper<boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> > > >::operator()<void (*)(boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >&), boost::_bi::list0> (this=0x7fbcf0000ed8, f=@0x7fbcf0000ed0, a=...) 
    at /usr/include/boost/bind/bind.hpp:253 
#5 0x0000000000408947 in boost::_bi::bind_t<void, void (*)(boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >&), boost::_bi::list1<boost::reference_wrapper<boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> > > > >::operator() (this=0x7fbcf0000ed0) 
    at /usr/include/boost/bind/bind_template.hpp:20 
#6 0x0000000000408906 in boost::detail::thread_data<boost::_bi::bind_t<void, void (*)(boost::dynamic_bitset<unsigned long, std::allocator<unsigned long> >&), boost::_bi::list1<boost::reference_wrapper<boost::dynamic_bitset<unsigned long, s---Type <return> to continue, or q <return> to quit--- 
td::allocator<unsigned long> > > > > >::run (this=0x7fbcf0000da0) 
    at /usr/include/boost/thread/detail/thread.hpp:56 
#7 0x00007fbcfbb73230 in thread_proxy() 
    from /usr/lib/libboost_thread.so.1.42.0 
#8 0x00007fbcfac28971 in start_thread (arg=<value optimized out>) 
    at pthread_create.c:304 
#9 0x00007fbcfb12c92d in clone() 
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 
#10 0x0000000000000000 in ??() 

Answer 1

fbitarrays僅具有10個向量，而p迭代到99. 當線程給出fbitarrays[10][0]或無論p> 9線程發生首先安排，運行，它段錯誤嘗試訪問從不存在的向量構建的損壞的boost::ref。

當使用索引訪問遍歷一個向量時，它總是有助於達到vector.size()。

thread_group的使用也有錯誤，但這不是導致此崩潰的原因。