用C ++进行内存管理？

Question

I'm developing a simple vehicle routing problem algorithm and I have a little problem with memory management. So I have following classes

In this one I store data of an Order

Order::Order(int id, int idLoc, double xCoord, double yCoord, double demand,  int startTime, int endTime, int serviceTime) {
    this->id = id;
    this->idLoc = idLoc;
    this->xCoord = xCoord;
    this->yCoord = yCoord;
    this->demand = demand;
    this->startTime = startTime;
    this->endTime = endTime;
    this->serviceTime = serviceTime;
}

Order::~Order() {
    // TODO Auto-generated destructor stub
}

In this one I store a list of Orders which represent a sequence of customers to serve during the distribution.

Route::Route(int idRoute,Vehicle *vehicleRoute) {
    id = idRoute;
    vehicle = vehicleRoute;
    demandRoute = -1;
    serviceTimeRoute =-1;
    earliestTimeRoute =-1;
    latestTimeRoute = -1;
    serviceDistanceRoute = -1;

    orders = new std::deque<Order>;
}

Route::Route(int idRoute, std::deque<Vehicle>::iterator vehicleIterator) {
    id = idRoute;
    vehicle = &(*vehicleIterator);
    demandRoute = -1;
    serviceTimeRoute =-1;
    earliestTimeRoute =-1;
    latestTimeRoute = -1;
    serviceDistanceRoute = -1;

    orders = new std::deque<Order>;
}

Route::~Route() {
    std::cout << "Destroying Route " << id  << std::endl;
    delete orders;
    std::cout << "Route Destroyed" << std::endl;
}

Finally, here I store a set of routes.

Solution::Solution() {
    solution = new std::deque<Route>;
}

Solution::~Solution() {
    std::cout << "Destroying Solution" << std::endl;
    delete solution;
    std::cout << "Solution Destroyed" << std::endl;
}

The problem is here:

readCustomers(&orderList, &depotList);
readVehicles(&vehicleList);

std::deque<Vehicle>::iterator it = vehicleList.getVehicleList()->begin();

int routeID = 0;
Route route (routeID, it);

solution.getSolution()->push_back(route); //Problem

So I read Orders and Vehicles then I create Route route which has no Orders associated yet and finally I add this route to a solution.

When I compile this code I got following output:

Route address: 0x7fff7351e110
Solution's route address: 0x1ab8270
Destroying Route 0
Route Destroyed
Destroying Solution
Destroying Route 0
Route Destroyed
Solution Destroyed

*** Error in `/home/.../': corrupted double-linked list: 0x0000000001ab5800 ***

Used valgrind to gather more information about this error, got folowing messages:

IVR [1]: Invalid read of size 8
IVF [1]: Invalid free()/delete/delete[]/realloc()

I guess I am releasing same chunk of memory twice. But I don't see where. Can any one help me with this one.

Answer 1

Route objects get copied when used in a std::deque.

I see no Copy operator and you allocate the orders with new. When a Route is now copied, the pointer is copied too. So you have two objects pointing to the same object and freeing the same memory.

Why are you using new and delete here. Embed the std::deque directly as a member and avoid new/delete.

If you need new/delete:

1. Try to use smart pointers
2. Implement a copy constructor and copy operator.

If you decide to add it as a member you need to declare it in the class:

class Route ...
{
   ...
   std::deque<Order> orders;

There is no need for new delete at all.