"0xC0000005：Access violation" fstreamを使用している間

Question

私はアクセス違反に関する多くの質問があることを知っていますが、私は多くを読んでいますが、これを解読しているようには見えません。私はこのコードをJavaからC++に翻訳していますが、C++にはそれほど経験がありません。だから、このコードはちょっとしたものかもしれません。

this->buff_reader = new fstream(file_path,fstream::in|fstream::out); 

そしてそれは、fstreamの中に近い（）関数にジャンプ：

私のコードは、（setup_next_buff_readerに）この行に分割します。

私はポインタの処理、メモリの割り当て/割り当て解除などに何らかの問題があると私は理解していますが、どこにはわからないのです。これに関する助けがあれば大歓迎です。ここで

bool TabDelimitedSource::setup_next_buff_reader() { 

     // Sets up the lucene analyzer and tries to load the next file in 
     // this->data_source_files, resetting counters/flags as needed 

     this->current_source_file += 1; 
     bool no_more_files = false; // assume we have no more files by default 

     if(this->current_source_file < sizeof(this->data_source_files)){    
      const char* file_path = (this->data_source_files[this->current_source_file]).c_str(); 
      cout << "File Path: " <<file_path <<"\n"; 
      this->buff_reader = new fstream(file_path,fstream::in|fstream::out);     
     } 
     else{ 
       no_more_files = true; 
     } 

     return no_more_files; // let the caller know whether there was another file or not 
} 


TabDelimitedSource::TabDelimitedSource(){} 

TabDelimitedSource::TabDelimitedSource(const char* dir_path) { 
    // Load all of the files in the directory using the file name filter provided 
    //fstream * data_source_dir = new fstream("path.txt"); 
    // NOTE: To change what files are loaded, use a different Filter here 
    vector<string> files; 
    this->getdir(dir_path, files); 
    this->data_source_files = files; 
    open(); 
    cout << "Went through the TDSource constructor.\n"; 
} 

void TabDelimitedSource::setColumnHoldingDoc(int column){ 
    // Allow the user to specify which column then want to extract 
    this->column_holding_doc = column; 
} 

void TabDelimitedSource::open() { 
    this->current_row = -1; 
    this->current_source_file = -1; 
    this->setup_next_buff_reader(); // setup first data source 
} 

void TabDelimitedSource::close() { 
    try{ 
      this->buff_reader->close(); 
      this->buff_reader->clear(); 
    } 
    catch (ifstream::failure e){ 
      ; // ignore this exception 
    } 
} 

void TabDelimitedSource::reset(){ 
    this->close(); 
    this->open(); 
} 

vector<string> TabDelimitedSource::getNext() { 
    // Returns the next document (a given cell) from the file(s) 
    char row[256]; // Return NULL if no more documents/rows 
    vector<string> document; 

    try{ 
      this->buff_reader->getline(row, 256); 
      cout <<"Row: "<< row << "\n"; 
    }catch (ifstream::failure e){ 
      ; // Ignore and fall through 
    } 

    if (buff_reader->eof()){ 
      this->current_row += 1; 
      vector<string> cells; 
      this->split(row, "\t", cells); // Split the row on tabs 
      // Split the cell into individual words using the lucene analyzer 
      try{ 
       string original_document = cells.at(this->column_holding_doc); 
      }catch (ifstream::failure e){ 
        cout<<"Row " << this->current_row << " did not have column " << this->column_holding_doc; 
      } 
    } 
    else{ 
      // We're at the end of the current file, try loading the next one 
      bool no_more_files = this->setup_next_buff_reader(); 
      // If there was another file to load, recurse to get its first document 
      if (!no_more_files){ 
        // Don't waste time doing Array->ArrayList->Array conversion 
        return this->getNext(); 
      }   
    } 

    // Return our arrayList as an array... there has to be a better way to do this 
    vector<string> return_val ; 
    if(!document.empty()){ // return NULL by default     
      for(int i=0; i<(int)document.size(); i++){ 
        return_val.push_back(document[i]); 
      } 
    } 

    return return_val; 
} 

void TabDelimitedSource::split(const string& str, const string& delim, vector<string>& result){ 
size_t start_pos = 0; 
size_t match_pos; 
size_t substr_length; 

while((match_pos = str.find(delim, start_pos)) != string::npos){ 
    substr_length = match_pos - start_pos; 

    if (substr_length > 0){ 
     result.push_back(str.substr(start_pos, substr_length)); 
    } 
    start_pos = match_pos + delim.length(); 
} 

substr_length = str.length() - start_pos; 

if (substr_length > 0){ 
    result.push_back(str.substr(start_pos, substr_length)); 
}  
} 

int TabDelimitedSource::getdir(string dir, vector<string> &files){ 
    DIR *dp; 
    struct dirent *dirp; 
    if((dp = opendir(dir.c_str())) == NULL) { 
     cout << "Error(" << errno << ") opening " << dir << endl; 
     return errno; 
    } 

    while ((dirp = readdir(dp)) != NULL) { 
     files.push_back((const char*)(dirp->d_name)); 
    } 
    closedir(dp); 
    return 0; 
} 

TabDelimitedSource::~TabDelimitedSource(){} 

は、コールスタックです：

msvcp90d.dll!std::basic_filebuf<char,std::char_traits<char> >::close() Line 232 + 0x3 bytes C++ 
msvcp90d.dll!std::basic_fstream<char,std::char_traits<char> >::close() Line 971 + 0xb bytes C++ 
Testing.exe!TabDelimitedSource::close() Line 98 + 0xe bytes C++ 
Testing.exe!TabDelimitedSource::setup_next_buff_reader() Line 26 C++ 
Testing.exe!TabDelimitedSource::open() Line 94 C++ 
Testing.exe!TabDelimitedSource::TabDelimitedSource(const char * dir_path=0x09800fa8) Line 76 C++ 
Testing.exe!Query::load_data_source(const char * data_path=0x09800fa8, std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_database="c:/Users/dfink.LISSARD2/Documents/Visual Studio 2008/Projects/Testing/jieddo.mdb", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_dbtable="jieddo_v2", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_id="report_id", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_text="summary", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_date="occured_when", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_filter="event_type='Explosive Hazard' ", int tab_delim_column=1) Line 144 + 0x38 bytes C++ 
Testing.exe!Query::model(const char * path=0x09800fa8, std::basic_string<char,std::char_traits<char>,std::allocator<char> > database="c:/Users/dfink.LISSARD2/Documents/Visual Studio 2008/Projects/Testing/jieddo.mdb", std::basic_string<char,std::char_traits<char>,std::allocator<char> > dbtable="jieddo_v2", std::basic_string<char,std::char_traits<char>,std::allocator<char> > field_id="report_id", std::basic_string<char,std::char_traits<char>,std::allocator<char> > field_text="summary", std::basic_string<char,std::char_traits<char>,std::allocator<char> > field_date="occured_when", std::basic_string<char,std::char_traits<char>,std::allocator<char> > filter="event_type='Explosive Hazard' ", int tab_delim_column=1) Line 72 C++ 
Testing.exe!Query::Query(bool run_batch_job=true, std::basic_string<char,std::char_traits<char>,std::allocator<char> > datasource="tab-delimited-source", char * data_path=0x09800fa8, std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_database="c:/Users/dfink.LISSARD2/Documents/Visual Studio 2008/Projects/Testing/jieddo.mdb", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_dbtable="jieddo_v2", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_id="report_id", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_text="summary", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_field_date="occured_when", std::basic_string<char,std::char_traits<char>,std::allocator<char> > jdo_filter="event_type='Explosive Hazard' ", int tab_delim_column=1) Line 55 C++ 
Testing.exe!main() Line 209 + 0x1c3 bytes C++ 
Testing.exe!__tmainCRTStartup() Line 582 + 0x19 bytes C 
Testing.exe!mainCRTStartup() Line 399 C 
kernel32.dll!762e3677()  
[Frames below may be incorrect and/or missing, no symbols loaded for kernel32.dll] 
ntdll.dll!77399f02()  
ntdll.dll!77399ed5()  

私はTabDelimitedSource呼び出しています場所：

bool Query::load_data_source(const char* data_path, string jdo_database, 
        string jdo_dbtable, string jdo_field_id, 
        string jdo_field_text, string jdo_field_date, 
        string jdo_filter, int tab_delim_column){ 
    // Attempts to load the data source (to this.ds) based on the datasource name 
    // NOTE: This will write over the old data source if it exists! 
    // data_path:  Where the source files are located 
    // jdo_*:   Argument specific to Jieddo data source 
    // tab_delim_colum: Which column to extract from a tab delimited source file 
    bool load_successful = true; 
    try{ 
      if (this->datasource.compare("tab-delimited-source") == 0) { 
        this->ds = new TabDelimitedSource(data_path); 
        this->ds->setColumnHoldingDoc(tab_delim_column); 
        string pref_text_analyzer; 
        this->ds->setColumnHoldingDoc(tab_delim_column); 
      } 
      else {      
        load_successful = false; 
      } 
    } 
    catch(ifstream::failure e){ 
      cout<<"FAIL."<<"n"; 
      load_successful = false; 
    } 
    return load_successful; 
} 

編集：申し訳ありませんが、私は2行のコードで追加されていたことを忘れてしまいました（私はそれらを取り戻した）。コードは実際には上記の同じ行でブレークしますが、ロック解除関数でmlock.hに入ります。現在のインデックスが::ベクトルオブジェクトSTDのバイト数よりも小さい場合、しないことが数未満である場合、このテストは、data_source_filesはストリングのベクトルであることを

if(this->current_source_file < sizeof(this->data_source_files)){   

チェックを仮定

Answer 1

ベクトルに含まれる文字列の

data_source_files.size() 

これは、範囲外のアクセスを引き起こす可能性があります。