SFML:在Demo.exe中的0x7767FF05(ntdll.dll)处引发异常:0xC0000005:写入位置0x

Question

我在github上得到了一个代码。在我调试它之后，它给了我一个错误，如下所示。我在github上得到了一个代码。调试后，它给了我一个错误，如图所示：Demo.exe中0x7767FF05(ntdll.dll(处引发异常：0xC0000005：写入位置0x00000004的访问冲突。

[img]https://i.imgur.com/y8QG7vk.png[/img]

这是我的代码：

#include <iostream>
#include <math.h>
#include <algorithm>
#include <SFML/Graphics.hpp>
#define SFML_NO_DEPRECATED_WARNINGS
#pragma warning(suppress : 4996)
#define _CRT_SECURE_NO_WARNINGS
using namespace std;
using namespace sf;
const int window_w = 1920;
const int window_h = 1080;
float wid = 1920;
int hei = 1080;
float wid_n = 1920;
float hei_n = 1080;
const int l_size = 80;
const int r_size = 30;
const int h_size = 100;
float speed = 50;
float del = 0;
const int scale = 1;
RenderWindow window(VideoMode(window_w, window_h), "AVL Tree");
Font font;
View view;
struct Node {
int c;
Node* l, * r;
int h;
Node(int cc) :c(cc), h(1), l(NULL), r(NULL) {}
};
typedef Node* Tree;
int get_h(Tree t) {
if (!t)return 0;
return t->h;
}
int balancefact(Tree t) {
if (!t)return 0;
return get_h(t->r) - get_h(t->l);
}
void update(Tree t) {
if (!t)return;
t->h = max(get_h(t->l), get_h(t->r)) + 1;
}
Tree rot_right(Tree t) {
Tree q = t->l;
t->l = q->r;
q->r = t;
update(t);
update(q);
return q;
}
Tree rot_left(Tree t) {
Tree q = t->r;
t->r = q->l;
q->l = t;
update(t);
update(q);
return q;
}
Tree balance(Tree t) {
if (!t)return t;
update(t);
if (balancefact(t) == 2) {
if (balancefact(t->r) < 0)
t->r = rot_right(t->r);
return rot_left(t);
}
if (balancefact(t) == -2) {
if (balancefact(t->l) > 0)
t->l = rot_left(t->l);
return rot_right(t);
}
return t;
}
Tree add(int c, Tree t) {
if (!t) {
t = new Node(c);
return t;
}
if (t->c == c)return t;
if (t->c > c) {
t->r = add(c, t->r);
}
else {
t->l = add(c, t->l);
}
return balance(t);
}
Tree get_min(Tree t) {
if (!t->l)return t;
return get_min(t->l);
}
Tree erase(int c, Tree t) {
if (!t)return t;
if (t->c > c) {
t->r = erase(c, t->r);
}
else if (t->c < c) {
t->l = erase(c, t->l);
}
else if (t->l && t->r) {
t->c = get_min(t->r)->c;
t->r = erase(t->c, t->r);
}
else if (t->l)
t = t->l;
else
t = t->r;
return balance(t);
}
void draw(int x, int y, int c) {
CircleShape cir;
Text text;
text.setFont(font);
cir.setOrigin(Vector2f(r_size, r_size));
cir.setRadius(r_size);
cir.setOutlineColor(Color::Blue);
cir.setOutlineThickness(3);
text.setCharacterSize(144);
text.setString(to_string(c));
text.setOrigin(text.getLocalBounds().left + text.getLocalBounds().width / 2,
text.getLocalBounds().top + text.getLocalBounds().height / 2);
float min_size = min((r_size * 1.5f) / text.getLocalBounds().width, (r_size * 1.5f / 2) / text.getLocalBounds().height);
text.setScale(Vector2f(min_size, min_size));
cir.setPosition(x, y);
text.setPosition(Vector2f(x, y));
text.setFillColor(Color::Black);
window.draw(cir);
window.draw(text);
}
void draw_edg(int x1, int y1, int x2, int y2) {
if (x1 == 0 && y1 == 0)return;
RectangleShape line(Vector2f(sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)), 6));
line.setFillColor(Color::Cyan);
line.setPosition(Vector2f(x1, y1));
line.rotate(atan2(y2 - y1, x2 - x1) * 180.0 / atan2(0, -1));
window.draw(line);
}
int get(Tree t, int l, int h) {
if (!t)return 0;
int r = l;
if (t->l)
r = get(t->l, l, h - 1);
else
r += l_size * scale;
if (t->r)
r = get(t->r, r, h - 1);
else
r += l_size * scale;
if (!t->l && !t->r)
r += l_size;
int x_cor = l + (r - l) / 2;
int y_cor = h * h_size;
draw(x_cor, y_cor, t->c);
return r;
}
pair<int, pair<int, int>> get_edg(Tree t, int l, int h) {
if (!t)return make_pair(0, make_pair(0, 0));
int r = l;
pair<int, int> left = make_pair(0, 0);
pair<int, int> right = make_pair(0, 0);
if (t->l) {
pair<int, pair<int, int>> res = get_edg(t->l, l, h - 1);
r = res.first;
left = res.second;
}
else
r += l_size * scale;
if (t->r) {
pair<int, pair<int, int>> res = get_edg(t->r, r, h - 1);
r = res.first;
right = res.second;
}
else
r += l_size * scale;
if (!t->l && !t->r)
r += l_size;
int x_cor = l + (r - l) / 2;
int y_cor = h * h_size;
draw_edg(left.first, left.second, x_cor, y_cor);
draw_edg(right.first, right.second, x_cor, y_cor);
return make_pair(r, make_pair(x_cor, y_cor));
}
int main() {
view.reset(FloatRect(0, 0, window_w, window_h));
srand(time(NULL));
Tree t = 0;
Clock clock;
font.loadFromFile("CyrilicOld.TTF");
bool change = true;
int tim = 0;
int kadr = 0;
while (window.isOpen()) {
sf::Event event;
while (window.pollEvent(event) || change) {
float del_tim = clock.getElapsedTime().asMicroseconds();
del = del_tim / 4e4;
clock.restart();
tim += del_tim;
kadr++;
if (tim > 1e6) {
tim -= 1e6;
//      cout << kadr << endl;
kadr = 0;
}
if (event.type == Event::Closed || Keyboard::isKeyPressed(Keyboard::Escape)) {
window.close();
}
if (Keyboard::isKeyPressed(Keyboard::Dash)) {
view.zoom(1.03f);
speed = speed * 1.03f;
wid = wid * 1.03f;
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::Equal)) {
view.zoom(0.97f);
speed = speed * 0.97f;
wid = wid * 0.97f;
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::Left)) {
view.move(Vector2f(-speed * del, 0));
wid += speed * del;
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::Down)) {
view.move(Vector2f(0, speed * del));
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::Up)) {
view.move(Vector2f(0, -speed * del));
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::Right)) {
view.move(Vector2f(speed * del, 0));
wid += speed * del;
change = true;
}
if (Mouse::isButtonPressed(Mouse::Left)) {
for (int i = 0; i < 10; i++) {
int key = rand() - rand();
t = add(key, t);
}
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::A)) {
int key;
cin >> key;
t = add(key, t);
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::E)) {
int key;
cin >> key;
t = erase(key, t);
change = true;
}
if (Keyboard::isKeyPressed(Keyboard::N)) {
view.zoom(wid_n / wid);
speed *= wid_n / wid;
wid = wid_n;
}
if (change) {
window.setView(view);
window.clear(Color(128, 106, 89));
get_edg(t, 0, get_h(t));
wid_n = get(t, 0, get_h(t));
hei_n = get_h(t) * h_size;
//change = false;
window.display();
}
}
}
return 0;
}

Answer 1

将RenderWindow对象初始化为全局变量。这发生在程序启动之前，但不同的全局变量之间没有固定的顺序。您可能会遇到错误，因为在创建RenderWindow对象之前，需要初始化其他变量。

在这种情况下，程序尝试写入地址0x00000004。RenderWindow需要的全局指针可能仍然指向零，而不是有效的内存位置。因此程序崩溃。

此问题通常被称为静态初始化顺序Fiasco。

这种情况下的解决方案是仅在main()启动之后初始化window。一种可能的方法是使用std::optional:

std::optional<RenderWindow> window = std::nullopt;
//...
int main() {
window = RenderWindow(VideoMode(window_w, window_h), "AVL Tree");
//...
}

如果您想更隐式地初始化window，也可以使用singleton。就我个人而言，我喜欢在这些情况下使用Meyers单例：

auto get_window() {
static RenderWindow window(VideoMode(window_w, window_h), "AVL Tree");
return window;
}