Hi Rasheed,
Segmentation fault is usually due to memory access violation. A common example is as follows. int x[10]; x[20] = 0; where you create an array x with 10 slots, but try to access 20th slot of x. Hope this will help. Best Regards, Teerawat Issariyakul http://www.ns2ultimate.com/ http://www.facebook.com/pages/Teerawat-Issariyakul/358240861417 http://twitter.com/T_Bear http://www.t-issariyakul.blogspot.com http://www.ece.ubc.ca/~teerawat On 4/12/2010, "Èļ¼ÀÎ ¶ó½¬µå[RASHEED HUSSAIN] rasheed1...@gmail.com" <=?EUC-KR?B?yMS8vMDOICC2872steVbUkFTSEVFRCBIVVNTQUlOXQ==?= rasheed1...@gmail.com> wrote: > >Dear NS2 Users >I am facing a very serious problem regarding modification to AODV protocol. >I have customized AODV Protocol to work as VANET Beaconing Protocol >according to DSRC Standard. >I also having implemented the duplicity mechansim where each node on >receiving a beacon, stores it for certain time to check for duplicity, >because i want the beacons to travel for multihops. >i have divided the road into regions and there is a linked list for every >region which stores the hashes of certain values taken from every beacon. >i have implemented all this, and when i run my tcl script, it gives >segmentation fault. > >basically i get the segmentation fault after adding the following code (This >whole code is included in aodv.cc and aodv is no more a routing protocol. it >is just a VANET Beaconing protocol now which i optimized for my >simulations). > >aodv/aodv.cc >recev_beacon() >{ >... >... >..... >receive the beacon and calculate the hash from some values >////////// Now Save the Beacons > > if (xx<=x && x<(xx+200)) > { > bool flag=obj.search(hash2); > if (flag==TRUE) > { > cout<<"Already exists in the linked list"<<endl; > } > else > { > obj.add(hash2, 1); > //ofstream list1;//for saving hash values > //list1.open("linkedlist1.dat", ios::app); > //list1<<hash2<<endl; > } > } // end of if > else if (x>=xx && (xx<=x && x<(xx+400))) > { > obj.add(hash2, 2); >ofstream list2;//for saving hash values > list2.open("linkedlist2.dat", ios::app); > list2<<hash2<<endl; > } > else if (x>=xx && (xx<=x && x<(xx+600))) > { > obj.add(hash2, 3); > } > else if (x>=xx && (xx<=x && x<(xx+1000))) > { > obj.add(hash2, 4); > } > >the linked list implemented is given below >//++++++++++++++++++++++++++++++++++++ >// Defining Linked Lists >//++++++++++++++++++++++++++++++++++++ >struct list1{ >unsigned int bid;list1 *link; >}; > >struct list2{ >unsigned int bid;list2 *link; >}; > > >struct list3{ >unsigned int bid;list3 *link; >}; > >struct list4{ >unsigned int bid;list4 *link; >}; > >class list{ >private: >int i; > list1 *cur1,*temp1,*start1; > list2 *cur2,*temp2,*start2; > list3 *cur3,*temp3,*start3; > list4 *cur4,*temp4,*start4; > >public: > >list() >{ >start1=NULL; >start2=NULL; >start3=NULL; >start4=NULL; >} > >void add(unsigned int hashval, int listno) >{ >//cout<<"Enter the list number to add element to";cin>>i; >// check for list no. > if (listno==1) > { > > if(start1==NULL) > { > start1=new list1; > cur1=start1; > cur1->bid=hashval; > cur1->link=NULL; > } > else > { > cur1->link=new list1; > cur1=cur1->link; > cur1->bid=hashval; > cur1->link=NULL; > } > > } > else if (listno==2) > { > if(start2==NULL) > { > start2=new list2; > cur2=start2; > cur2->bid=hashval; > cur2->link=NULL; > } > else > { > cur2->link=new list2; > cur2=cur2->link; > cur2->bid=hashval; > cur2->link=NULL; > } > } >else if (listno==3) > { > if(start3==NULL) > { > start3=new list3; > cur3=start3; > cur3->bid=hashval; > cur3->link=NULL; > } > else > { > cur3->link=new list3; > cur3=cur3->link; > cur3->bid=hashval; > cur3->link=NULL; > } > } >else if (listno==4) > { > if(start4==NULL) > { > start4=new list4; > cur4=start4; > cur4->bid=hashval; > cur4->link=NULL; > } > else > { > cur4->link=new list4; > cur4=cur4->link; > cur4->bid=hashval; > cur4->link=NULL; > } > } >} > ////////////////// searching method > bool search(unsigned int hashval) > { > bool b; > cur1=start1; > while (cur1->link!=NULL) > { > if(cur1->bid==hashval) > b=TRUE; > else > b=FALSE; > cur1=cur1->link; > } > return b; > } > >I will be looking for some help as soon as possible. >THanks to all concerned in advance!! > > >Rasheed >
