==39800== Invalid free() / delete / delete[] / realloc()
==39800== at 0x4D9D: free (vg_replace_malloc.c:477)
==39800== by 0x10000C471: Tokenizer::~Tokenizer() (in ./a.out)
==39800== by 0x10000C424: Tokenizer::~Tokenizer() (in ./a.out)
==39800== by 0x100001B8B: main (in ./a.out)
==39800== Address 0x10002a778 is 8 bytes inside a block of size 7,208 alloc'd
[Code] ....
does memory reserved by malloc() get freed when the function it is called in finishes?
View 6 Replies View RelatedHow can I view the number of bytes that have been allocated by using the malloc function?I tried:
mem = (float*)malloc(num*sizeof(float));
printf("The amount of memory allocated using malloc is %d.", mem);
Note: The variable "num" in my program is equal to 7.But every time I run the program, this value changes.
I am confused whether 'malloc'ing an array of pointers and pointer to a group of arrays are the same.
Suppose I need an integer pointer to a group of arrays of 2 elements each.
int (*LR)[2];
So to dynamically allocate this pointer for M number of arrays suppose, then what is the correct syntax?
int M;
scanf("%d",&M);
int (*LR)[2];
LR = (int*)malloc(2*sizeof(int));
Whether this is correct??
There is a part in the lesson that explains how malloc is used to allocate free memory to a pointer and gives us 2 examples:
Code:
float *ptr = malloc( sizeof(*ptr) ); and Code: float *ptr;
ptr = malloc( sizeof(*ptr) );
From my logic in the first case we allocate the memory to *ptr and in the second to ptr.
It's a bit confusing, am I missing something?
I'm trying to write a function that returns a pointer to a dynamically allocated array. Here's my code:
#include <iostream>
using namespace std;
void IndexArray(int, int);
int main(){
int *arr, n;
[Code] ....
When I try running the program, I get the error
"Unable to start program 'D:C++FilesdynamicArraySolReleasedynamicArray.exe'. The system cannot find the file specified."
I'm honestly not sure if the issue is my program, or something with C++. At the moment, I cannot debug any of my programs or else I get the same exact error. I basically need to release everything without debugging it. I last used C++ about a year ago and I'm finally back in school, and so trying to get back into it. I use Microsoft Visual C++ 2010.
I am writing a very basic database in C++ and I am accessing the data from a web browser. I am using the opensource Mongoose web server code....
I have an issue...
The way the DB works is this: on starting, the DB loads a json file of all of the data into it. I have a class called DatabaseLoader that does this - it is the class that gets rewritten depending on the data structure of the json.
This is passed to vectors (vector<Node*> and vector<Edge*>) as references from Graph object.
Once the DatabaseLoader has finished it can be destroyed and any memory allocated objects it created (except the ones in those two vectors).
From then on, the Graph object is in charge of all of the elements in the database that are stored in the two vectors. When the user browses to htpp://127.0.0.1:8000 they see the json representing each object in the vectors.
All good so far....
However, when I repeatedly hit refresh in my browser (and call me insane...) at quite a fast speed I get this error:
Code:
main(29855,0x7fff76763310) malloc: *** error for object 0x7f98b2829408: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
[1] 29855 abort ./main testing.json
It seems to me this would be if I tried to "delete" and object twice, or if one of my objects was overwriting memory somewhere. However I am not recreating anything, I am just looping over the vectors and printing out the content. When I refresh slowly, I dont see this happen - i did it quite a lot of times, but when I do it fast I think it is happening.
So is there any possibility of me hitting the c++ web server to quickly and it is trying to process the data twice, causing some sort of memory error - i.e do I need to implement threading or something??
I can paste code, but there is quite a lot now....
Goal: To allocate some memory as a char*, read in some binary data, re-interpret it as a float* and then free the memory.
My code looks like:
void someFunction(float* &result) {
char * tmp = new char[1000];
//...Fill the char buffer here...
result = (float*)tmp; //Reinterpret binary data as floats
[Code] ....
Is the cast back to char* necessary on the red line (or could I have validly left it as float*)? Would it be different if I had written char * tmp = (char*)malloc(sizeof(char)*1000); on the blue line (and correspondingly used free (char*)floatData on the red line?
I'm trying to keep track of the size of blocks of memory that a pointer points to. No matter what I do, this code below always outputs the integer 8.
If I change 1000 to 5, I still get 8. If I change it to 0, I get 8... If I change it to -1, I get 8. If I change int *a to double *a, I get 8. If I take away the & symbol, I get 8. If I use *& instead, I get 8.
Why? I want it to output 1000. If I change that to 500, I want it to output 500.
int *a;
a = malloc(1000 * sizeof(int));
int j = sizeof(&a);
printf("%d", j);
I want to build my skills where I can allocate, inspect and change memory sizes.
I'm trying to convert dicom .dcm file to .jpeg using Imebra in C++ app using QT Creator as dev environment.
I've downloaded Imebra and was able to run QT project example for Dicom2Jpeg conversion successfully. But when I tried to copy same code to my C++ app it failed to run with following error msg:
malloc: * error for object xxxxxx: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug
I have followed steps on adding Imebra files to my project as it was shown on Imebra site. Also used their qt project as example. My main.cpp open dicom file, then loads it to dataset, then calls my dialog window. It crashes on loading dataset.
#include "QApplication.h"
#include "QHBoxLayout.h"
#include "mydialog.h"
#include "iostream.h"
include "library/imebra/include/imebra.h"
int main( int argc, char ** argv ){
[Code] ....
Deeper debugging showed that source of error is in JpegCodec.cpp file readStream() function when checking JpegSignature to see if it's in wrong format with resulting internal PUNTOEXE error "detected a wrong format".
Interesting thing is that while running same test dcm file using given dicom2jpeg example (which has exact same code of opening file and loading it) gives no errors and converts to jpeg successfully. So I know it's not the file issue, but the way imebra code is integrated into my C++ app.
My dev environment: macbook pro with Lion OS, QT Creator, QT project, C++ code, ITK library added, Imebra files are completely integrated as part of the Qt project.
So, my question is how do I work/link/reference/call Imebra functionality in QT project? Am I forgetting to link something, or some object is not instantiated/deleted on time?
When using wxWidgets, i am tempted to deallocate memory using delete in the destructor, but my program crashes on closing. I try to do something like this:
class mainwnd:public wxFrame{
public:
mainwnd():wxFrame(NULL,wxID_ANY,wxT("test")){
menubar=new wxMenuBar;
[Code] .....
tell me why? and is it done automatically?
I use new to allocate a buffer, as follows:
BYTE *p;
p = new BYTE[20];
...
delete p;
After p is deleted, if I do NOT assign NULL to p, is there a way to determine whether it has already been freed?
what is the uses of the
-mudflap
and
-valgrind
tags when compiling a program in gcc?
I have a large hash table, where each index has a container that has a doubly linked list. Things work up until releasing the memory. Each record is created with malloc, and each record->data is also created with malloc and the associated string is copied in using strcpy(). The table itself is released in another part of the program and doesn't produce and error.
/**
* valgrind --track-origins=yes
*/
==16898== Conditional jump or move depends on uninitialised value(s)
==16898== at 0x8049685: shFree (SpellHash.c:110)
==16898== by 0x8049352: unload (dictionary.c:115)
==16898== by 0x8048E64: main (speller.c:158)
==16898== Uninitialised value was created by a heap allocation
[Code] .....
How to interpret valgrind. Error resolved on a small problem. Now running into issues on large (>10000 words to check) problems. It appears the virtual machine just can't keep up for some reason. Running the code on my local computer produces no errors, memory usage is minuscule, and profile tools don't report any issues.
I have airport class which should navigate planes, in its list to runways, with method move, theres a method prepare which changes the direction of flight to all planes, always before move is called, move just increments decrement x and y of plane in its list. But after calling two times in row airport->move(), I get screwed and I really dont know wheres the problem. Have I badly initiazed something? Iterator gets invalidated.
Valgrind Stacktrace
Conditional jump or move depends on uninitialised value(s)
==26207== at 0x409601: plane::move() (in /home/xnovak11/Downloads/airport/main)
==26207== by 0x401FBD: airport::move() (in /home/xnovak11/Downloads/airport/main)
==26207== by 0x405FE1: io::start(std::istream&, std:stream&, std:stream&) (in /home/xnovak11/Downloads/airport/main)
This is how I add planes into list in airport
Code:
list<plane*> planes;
list<plane*>::const_iterator planeIterator;
list<plane*>::iterator planeIteratorMoj;
bool airport::addPlane(const plane& p) {
[Code] .....
This is the method where it fails. When I call it once, no problem, after second call I get instead of normal number in cout<<after move<< s1 i get like 8795456 ....
Code:
void airport::move() {
for(planeIteratorMoj = planes.begin(); planeIteratorMoj!= planes.end(); planeIteratorMoj++) {
plane * p1 = (*planeIteratorMoj);
int s,w;
p1->getPosition(s,w);
[Code] .....
I discovered valgrind and started using it for my c code. But I get following error message at almost every malloc position, :
==19505== 40 errors in context 10 of 12: ==19505== Use of uninitialised value of size 8 ==19505== at 0x10000416E: my_method (main.c:662) ==19505== by 0x10000159E: main (main.c:182) ==19505== Uninitialised value was created by a heap allocation ==19505== at 0x47F1: malloc (vg_replace_malloc.c:302) ==19505== by 0x100001C21: my_method (main.c:333) ==19505== by 0x10000159E: main (main.c:182)
and I really don't understand what it means. I already googled it but I didn't find out what is my mistake.SO here i just put one example:
Code:
int main(int argc, char** argv) {
//i declare my variables at this position
Uint *used, *forbidden_jumps, *forbidden_jumpsV,
*forbidden_jump;
/*now i want to allocate one of them, this is my line 333 from the error message*/
//a_num is set during the execution of the program,
ALLOC(used, Uint, a_num);
}
[code].....
Is there any support page for the output of valgrind? I found it on the homepage.
The program should ask the user how many students were surveyed and dynamically allocate an array of that size. The program should then allow the user to enter the number of movies each student has seen.
#include <iostream>
#include <string>
using namespace std;
[Code].....
The problem I'm having is that where I declare movies = [numStudents]; the semicolon after the numStudents array is giving me this error - "error: expected a '{' introducing a lambda body".
I have attached the source code I am writing. I have been getting the two following errors. I know it's something to do with the pointer casting.
udp-server.c:174:3: error: subscripted value is neither array nor pointer nor vector
udp-server.c:165:3: error: cannot convert to a pointer type
The file is attached here.
udp-server-edit.txt (7.64K)
Number of downloads: 19
I'm working on a short program to calculate the mode of a vector of ints. I am new, so not extremely familiar with pointers, and passing items to functions. This is something I've struggled with (obviously, or I wouldn't be here). I am currently getting the following error when I try to compile this program using g++:
warning: pointer to a function used in arithmetic
I receive this error for the following lines: 66, 73, 75, 81.
I am not using pointers here so I do not understand why this error crops up, much less how to fix it. Here is the code I am struggling with:
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <limits>
using namespace std;
vector<int> getModes(vector<int> userValues);
[Code] ....
The errors are on lines 54, 61, 63, and 69
I've been writing the math functions for a 3d game and tried compiling it at about 30 functions in. I get this error related to my pointers to my structures. it affects almost everything in all my functions (as youll see by looking at how i do the math in the function below). The compiler gives me the error
"error: dereferencing pointer to incomplete type"
on all my struct Type4D pointers but referencing the values in my struct TypeMatrix4X4 using pointers seems to work fine i think (it doesn't seem to complian explicitly about it. so here is the important code...
one example function
Code:
struct Type4D *MatVecMult4X4RtoL(struct TypeMatrix4X4 *mat, struct Type4D *vec) {
struct Type4D *dest = (struct Type4D *) malloc(sizeof(struct Type4D));
[Code]....
I have a class Calendar which has an attribute of priority queue, that accepts records of structure defined as:
typedef void (Calendar::*eventPointer)();
struct activationRecord {
double Time;
int Priority;
eventPointer activationEvent;
};
And here is the problem. Whole day I've been trying to fill the Calendar with some test entries by calling the method
void Calendar::calendarPush(double Time, int Priority, eventPointer event)
This is how I call it
calendar.calendarPush(Time, Priority, &Calendar::calendarEmpty);
But Visual Studio keeps to warn me with this error
argument of type "bool (Calendar::*)()" is incompatible with parameter of type "eventPointer *"
#include <iostream>
#include "Calendar.h"
using namespace std;
int main() {
cout << "Initializing ..." << endl;
double Time = 0.0;
int Priority = 0;
[Code] ....
I am having trouble with this program I get the error dereferencing pointer to incomplete type in the populate function I am using BloodShed's Dev C++ compiler v4.9.9.2 I copied this program out of a book because I was having a problem with a linked list in a similar program. I think there is a problem with the compiler not supporting these types of pointer's in a function.
#include <stdio.h>
struct tel_typ {
char name[25];
char phone_no[15];
struct tel_typ *nextaddr;
[code].....
I am getting this error:
drivers/media/video/mxc/capture/gt2005.c:2256:62: error: dereferencing pointer to incomplete type
I am at a loss trying to figure this out. Here it is:
case Sensor_Flash:
{
struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
struct sensor *sensor = to_sensor(client);
if (sensor->sensor_io_request && sensor->sensor_io_request->sensor_ioctrl) {
sensor->sensor_io_request->sensor_ioctrl(icd->pdev,Cam_Flash, on);
if(on){
Lines 6 and 7 are giving me the same error. What am I doing wrong?
Below is my code snippet.I'm getting "Error:initialization from incompatible pointer type" error on line 'int *q = status;'.
Obviously, I'm missing something but has no clue...:(
void findwalls(int *p,int y,int x){
int status[y_count][x_count][4];
int *q = status;
for(int i = 0;i < (y_count * x_count * 4);i++)
*(q + i) = *(p + i);
I am trying to use 'this' pointer but i am confused why 'this' pointer is not available for static member functions.
Code:
#include <iostream>
#include <fstream>
#include <stdlib.h>
using namespace std;
const int MAX = 20;
const int MAXPTR = 100;
class name {
private :
char fname[MAX], mname[MAX], lname[MAX];
[code].....
I am using GNU GCC Compiler via Code::Block
Error : 'this' is unavailable for static member functions
Here is my code,
Code:
class A {
public:
void display() {
cout<<"A"<<endl;
[Code] .....
The compiler error is "error C2039: 'display' : is not a member of 'SP<T>'". What am I missing here?