Question about std::list and tidying up

Question about std::list and tidying up

DanielH

Member #934

January 2001

I was using my own list class and decided to switch it to std::list.

Two classes use it.

UndoList:
std::list<UndoData*> stack;
ThemeList:
std::list<ThemeInfo*> stack;

For some reason I am getting a break at the tidying up of ThemeList.

Quote:

Unhandled exception at 0x0041e062 in sudoku.exe: 0xC0000005: Access violation reading location 0x00000001.

sudoku.exe!std::list<ThemeInfo *,std::allocator<ThemeInfo *> >::clear() Line 612 + 0xf C++
sudoku.exe!std::list<ThemeInfo *,std::allocator<ThemeInfo *> >::_Tidy() Line 931 C++
sudoku.exe!std::list<ThemeInfo *,std::allocator<ThemeInfo *> >::~list<ThemeInfo *,std::allocator<ThemeInfo *> >() Line 366 C++
sudoku.exe!ThemeList::~ThemeList() Line 30 + 0xf C++

// in game.cpp
ThemeList       themeList;

// in themelist.cpp
ThemeList::ThemeList()
{
    this->screenShot = NULL;
    this->count = 0;
    this->place = 0;
    this->current = 0;
    this->over = -1;
}

ThemeList::~ThemeList()
{
} // line 30

This happens when even when I don't use themeList in the game. themeList only gets used when I am changing themes.

[EDIT]
I changed them to this and still get the same break.
std::list<UndoData> stack;
std::list<ThemeInfo> stack;

What could this be? Im using MSVC7.

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CGamesPlay

Member #2,559

July 2002

You are deleteing a pointer that points to 0x00000001, which is invalid...

--
Tomasu: Every time you read this: hugging!

Ryan Patterson - <http://cgamesplay.com/>

ImLeftFooted

Member #3,935

October 2003

Set breakpoints at all your ctors and dtors. Namely ThemeList. See how many times the dtor is called and from where. Does the dtor get called more often then the ctor?

Other then that advice, theres not much I can figure out about what you're doing. Other then making some type of sudoku game. Try pasting your ThemeList and making the simpliest test case possible that shows the problem you're having (and obviously paste that too).

How is my posting?

ReyBrujo

Moderator

January 2001

You need to use std::list<ThemeInfo*> stack;. Can you post the code of the constructor and destructor, as well as members of ThemeInfo?

--
RB
光子「あたしただ…奪う側に回ろうと思っただけよ」
Mitsuko's last words, Battle Royale

CGamesPlay

Member #2,559

July 2002

Okay, the first sentence in Rey's post isn't true. You can use lists of objects just fine.
[append]
To clarify, std::list<ThemeInfo> stack; is perfectly valid.

--
Tomasu: Every time you read this: hugging!

Ryan Patterson - <http://cgamesplay.com/>

DanielH

Member #934

January 2001

I placed breakpoints in ctor, dtor, and each member. ctor was getting called in the beginning of the program as ThemeList is a global. dtor was getting called at the end of the program. No members were getting called and I was still getting the same break.

I removed the breakpoints ant removed stack as a member of ThemeList and added it at the top of ThemeList's source. I am having a hard time trying to duplicate the same response. I am getting no break's.

Here is the header and source, the commented out parts are what it was.

1#ifndef _THEMELIST_H
2#define _THEMELIST_H
3 
4class ThemeList
5{
6public:
7    ThemeList();
8    ~ThemeList();
9 
10    static int addToList( const char *filename, int attrib, void *param );
11    void init();
12    void uninit();
13    void draw( BITMAP *bitmap );
14    void logic();
15    void moveUp();
16    void moveDown();
17    void apply();
18    void changeScreenShot();
19    char *getCurrentFilename();
20 
21private:
22    //std::list<ThemeInfo> themeStack;  
23    RectInfo rectInfo[ 10 ];
24    BITMAP *screenShot;
25    int current;
26    int over;
27    int count;
28    int place;
29};
30 
31extern ThemeList themeList;
32 
33#endif

1#pragma warning( disable: 4312 )
2 
3#include <allegro.h>
4#include <time.h>
5#include <stdio.h>
6#include <string>
7#include <list>
8#include "defines.h"
9#include "globals.h"
10#include "module.h"
11#include "themefunctions.h"
12#include "theme.h"
13#include "themelist.h"
14 
15std::list<ThemeInfo> themeStack;
16 
17ThemeList::ThemeList()
18{
19    this->screenShot = NULL;
20    this->count = 0;
21    this->place = 0;
22    this->current = 0;
23    this->over = -1;
24}
25 
26ThemeList::~ThemeList()
27{
28}
29 
30 
31int ThemeList::addToList( const char *filename, int attrib, void *param )
32{
33    Theme temp;
34    char *extension = NULL;
35 
36    //std::list<ThemeInfo> *themeStack = (std::list<ThemeInfo>*)param;
37 
38    filename = get_filename( filename );
39    extension = get_extension( filename );
40 
41    *( extension - 1 ) = '\0';
42 
43    if ( temp.load( filename ) == 0 )
44    {
45        ThemeInfo theme;
46 
47        strcpy( theme.filename, filename );
48        strcpy( theme.themeName, temp.getName() );
49 
50        //themeStack->push_back( theme );
51        themeStack.push_back( theme );
52 
53        temp.unload();
54    }
55 
56    return 0;
57}
58 
59void ThemeList::init()
60{
61    char fileExt[ 128 ] = emptyString;
62 
63    sprintf( fileExt, themeText, "*", dllExtension );
64 
65    this->uninit();
66 
67    for_each_file_ex( fileExt, 
68                      FA_ARCH, 
69                      0, 
70                      ThemeList::addToList, 
71                      NULL );
72                      //(void*)(&this->stack) );
73 
74    this->count = (int)themeStack.size();
75 
76    if ( this->count > 0 )
77    {
78        this->over = 0;
79        this->changeScreenShot();    
80        this->over = -1;
81 
82        for ( int i = 0; i < 10; i++ )
83        {
84            theme.getThemeRectInfo( this->rectInfo[ i ], i );
85        }
86    }
87}
88 
89void ThemeList::uninit()
90{
91    if ( this->screenShot )
92    {
93        destroy_bitmap( this->screenShot );
94        this->screenShot = NULL;
95    }
96 
97    if ( themeStack.size() > 0 )
98    {
99        themeStack.clear();
100    }
101 
102    this->count = 0;
103    this->place = 0;
104    this->current = 0;
105    this->over = -1;
106}
107 
108void ThemeList::draw( BITMAP *bitmap )
109{
110    theme.drawThemeChoose( bitmap, this->screenShot );
111 
112    if ( themeStack.size() == 0 )
113    {
114        return;
115    }
116 
117    std::list<ThemeInfo>::iterator it = themeStack.begin();
118    for ( int i = 0; i < this->place; i++ )
119    {
120        it++;
121    }
122 
123    for ( int i = 0; i < 10; it++, i++ )
124    {
125        if ( it == themeStack.end() )
126        {
127            break;
128        }
129 
130        int index = i;
131 
132        if ( this->over == ( i + this->place ) )
133        {
134            index |= TF_OVER;   
135        }
136 
137        if ( this->current == ( i + this->place ) )
138        {
139            index |= TF_CURRENT;
140        }
141 
142        if ( ( index & TF_OVER ) && ( index & TF_CURRENT ) )
143        {
144            index |= TF_BOTH;
145        }
146 
147        theme.drawThemeInfo( bitmap, 
148                             (*it), 
149                             index );     
150    }
151}
152 
153void ThemeList::logic()
154{
155    if ( themeStack.size() == 0 )
156    {
157        return;
158    }
159 
160    std::list<ThemeInfo>::iterator it = themeStack.begin();
161    for ( int i = 0; i < this->place; i++ )
162    {
163        it++;
164    }
165 
166    this->over = -1;
167 
168    for ( int i = 0; i < 10; it++, i++ )
169    {
170        if ( it == themeStack.end() )
171        {
172            break;
173        }
174 
175        if ( mouseX >= rectInfo[ i ].x &&
176             mouseY >= rectInfo[ i ].y &&
177             mouseX <  ( rectInfo[ i ].x + rectInfo[ i ].width ) &&
178             mouseY <  ( rectInfo[ i ].y + rectInfo[ i ].height ) )
179        {
180            mousePtr = MP_HAND;
181 
182            this->over = ( i + this->place );
183 
184            if ( mouse1Clicked )
185            {
186                mouse1Clicked = false;
187                mousePtr = MP_ARROW;
188 
189                if ( this->current != this->over )
190                {
191                    changeScreenShot();
192                }
193            }
194        }
195    }
196}
197 
198void ThemeList::changeScreenShot()
199{
200    Theme tempTheme;
201 
202    if ( this->screenShot )
203    {
204        destroy_bitmap( this->screenShot );
205        this->screenShot = NULL;
206    }
207 
208    this->current = this->over;
209 
210    if ( this->getCurrentFilename() )
211    {
212        if ( tempTheme.load( this->getCurrentFilename() ) == 0 )
213        {
214            this->screenShot = tempTheme.getScreenshot();
215            tempTheme.unload();
216        }
217    }
218}
219 
220void ThemeList::moveUp()
221{
222    if ( this->place > 0 )
223    {
224        this->place--;
225    }
226}
227 
228void ThemeList::moveDown()
229{
230    if ( this->place < ( this->count - 10 ) )
231    {
232        this->place++;
233    }
234}
235 
236char *ThemeList::getCurrentFilename()
237{
238    if ( themeStack.size() == 0 )
239    {
240        return NULL;
241    }
242 
243    std::list<ThemeInfo>::iterator it = themeStack.begin();
244    for ( int i = 0; i < this->current; i++ )
245    {
246        it++;
247    }
248 
249    return (*it).filename;
250}
251 
252void ThemeList::apply()
253{
254    strcpy( themeName, currentThemeName );
255}

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ImLeftFooted

Member #3,935

October 2003

With this code

    for ( int i = 0; i < 10; it++, i++ )
    {
        if ( it == themeStack.end() )
        {
            break;
        }

You did good checking if it is invalid, but with two other loops you forgot to :x.

    std::list<ThemeInfo>::iterator it = themeStack.begin();
    for ( int i = 0; i < this->place; i++ )
    {
        it++;
    }

Never assume an iterator can be incremented and still valid

How is my posting?

DanielH

Member #934

January 2001

this->place is always <= to themeStack.size();

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