Getting Assert errors when my Linked List cleanup method is run

[Karl Blessing]

for a while this method seemed to do fine, fixed it up a bit<br>debuged it, the pointer addresses seemed valid(not NULL or those 0xdddddd) but yet I get an assertion error in the DebugHeap header file which didnt seem to happen the first couple of times, heres the routine.<br><br>void FileStorage::cleanup()<br>{<br> if(FHead != NULL)<br> {<br> FilePtr* DelMe = NULL;<br> FCurrent = FHead;<br> while(FCurrent != NULL)<br> {<br> DelMe = FCurrent;<br> FCurrent = FCurrent-&gt;next;<br> delete DelMe;<br> }<br> FHead = FCurrent = FEnd = DelMe = NULL;<br> }<br>}<br><br>at the delete DelMe; line is where it crashes, the address before I allowed it to continue past the breakpoint seemed like a valid address each time, and did match the Head pointer. Tho uncertain why this would cause a crash. <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)

 

[Karl Blessing]

a bit more detailed info<br>the linked list which i wrote down the address of each node as they were added and double checked before the cleanup function was ran, is read as so:<br><br>0x014b2800 -&gt; 0x014b26d0 -&gt; 0x014b25a0 -&gt; 0x014b2470 .... -&gt; NULL<br><br>now when the command reaches delete DelMe<br>FCurrent = 0x014b26d0<br>DelMe = 0x01462800<br>and FCurrent-&gt;next = 0x014b25a0<br><br>the error i get is<br><br>&quot;<br>DEBUG ERROR!<br>Program: ...OGRAM FILES\MICROSOFT VISUAL STUDIO\COMMON\TOOLS\TSTCON32.EXE<br>DAMAGE: after normal block (#199) at 0x014B2800<br>&quot;<br><br>I notice the error has something do do about the location of the first node, but i dont know what exactly and how to fix it.<br> <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)

 

[Karl Blessing]

also i removed the = NULL from where it declares DelMe since its going to be assigned to anyways. <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)

 

[Karl Blessing]

I think I notice the problem, gona test it out a bit. it seems I did not put -&gt;next = NULL whenever I add a new node, which would have been obvious to see if i traverse the list, but instead i kept a tail pointer, so the tail was always hanging to some unknown memory address instead of NULL. <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)

 

[Karl Blessing]

With giving a null -&gt;next to every new node i create, fixes the prob, only if i comment out the character array in the node, (in otherwords an empty node, with a pointer to the next one) So something with my charater array is causing the problem. <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)

 

[Karl Blessing]

if this helps you help me, heres the function that adds a new node<br><br>void FileStorage::add(char &chunker, int count)<br>{<br> FilePtr* TmpPtr = new FilePtr;<br> strcpy(TmpPtr-&gt;AByte,&chunker);<br> TmpPtr-&gt;next = NULL;<br><br> if(FHead == NULL)<br> {<br> FHead=TmpPtr;<br> FEnd = FHead;<br> }<br> else<br> {<br> FEnd-&gt;next = TmpPtr;<br> FEnd = FEnd-&gt;next;<br> }<br> chunks++;<br> bytes+=count;<br>}<br><br>AByte is of type Char[256] <p>Karl<br><a href=mailto:kb244@kb244.8m.com>kb244@kb244.8m.com</a><br><a href=

http://kb244.8m.com>

</a><br>Experienced in , or have messed with : VC++, Borland C++ Builder, VJ++6(starting),VB-Dos, VB1 thru VB6, Delphi 3 pro, Borland C++ 3(DOS), Borland C++ 4.5, HTML, ASP(somewhat), QBasic(least i didnt start with COBOL)