std :: bind導致析構函數上的分段錯誤

Question

因此，發生了一些奇怪的事情。 我綁定了一個回調函數（我在代碼的其他部分中做了幾次），但是由於某種原因，這一次導致了析構函數的調用，並對其進行了段錯誤處理……

這是我的代碼的概要，其中刪除了所有多余的內容

GUILogicComponent.h

class GUILogicComponent : public LogicComponent {
private:
    std::function<void()> callback;
    EventListenerComponent* eventListener;
    SpriteComponent& sprite;
public:
    GUILogicComponent(EventListenerComponent* el, SpriteComponent& s, std::function<void()> cb);
    ~GUILogicComponent();
    void clicked(int x, int y);
};

GUILogicComponent.cpp

GUILogicComponent::GUILogicComponent(EventListenerComponent* el, SpriteComponent& s, std::function<void()> cb) : eventListener(el), sprite(s), callback(cb) {
    eventListener->addMouseFunction(std::bind(&GUILogicComponent::clicked, *this, std::placeholders::_1, std::placeholders::_2), SDL_BUTTON_LEFT);
    // TODO: Binding causes seg fault
}

GUILogicComponent::~GUILogicComponent() {
    delete eventListener;
}

void GUILogicComponent::clicked(int x, int y) {
    if (sprite.pointInSprite(x, y))
        callback();
}

GDB錯誤

Thread 3 received signal SIGSEGV, Segmentation fault.
0x0000000100004e73 in Thor_Lucas_Development::GUILogicComponent::~GUILogicComponent (
    this=<error reading variable: Cannot access memory at address 0x7fff5f3ffff8>)
    at Components/GUILogicComponent.cpp:11
11  GUILogicComponent::~GUILogicComponent() {

不知道發生了什么。 奇怪的是，刪除其他構造函數參數（刪除sprite和callback並注釋掉所有相關代碼）使我錯失了這個錯誤。

Thread 3 received signal SIGSEGV, Segmentation fault.
0x00000001000027b8 in std::__1::__tree<std::__1::__value_type<Thor_Lucas_Development::Mousecode, std::__1::function<void (int, int)> >, std::__1::__map_value_compare<Thor_Lucas_Development::Mousecode, std::__1::__value_type<Thor_Lucas_Development::Mousecode, std::__1::function<void (int, int)> >, std::__1::less<Thor_Lucas_Development::Mousecode>, true>, std::__1::allocator<std::__1::__value_type<Thor_Lucas_Development::Mousecode, std::__1::function<void (int, int)> > > >::destroy(std::__1::__tree_node<std::__1::__value_type<Thor_Lucas_Development::Mousecode, std::__1::function<void (int, int)> >, void*>*) (this=0x10070c768, __nd=0x1007365d0)
    at /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__tree:1377
1377        if (__nd != nullptr)

這是我的Util.h中的Mousecode定義

/**
 * Used to store a mouse state for mapping to functions.
 */
struct Mousecode {
    Uint8 button; /**< The mouse button pressed (i.e\. SDL_BUTTON_LEFT). */
    Uint8 state; /**< The state of the mouse button (i.e\. SDL_RELEASED). */
};

inline bool const operator==(const Mousecode& l, const Mousecode& r) {
    return (l.button == r.button) && (l.state == r.state);
}

inline bool const operator<(const Mousecode& l, const Mousecode& r) {
    return (l.button < r.button) || ((l.button == r.button) && (l.state < r.state));
}

這是EventListenerComponent在做什么

void EventListenerComponent::addMouseFunction(std::function<void(int, int)> func, Uint8 button, Uint8 state) {
    Mousecode code = {button, state};
    mouseFunctionMap[code] = func;
}

和mouseFunctionMap

std::map<Mousecode, std::function<void(int, int)>> mouseFunctionMap;

任何幫助將不勝感激...謝謝！

Answer 1

您正在通過*this創建一個臨時副本：

eventListener->addMouseFunction(std::bind(&GUILogicComponent::clicked, *this, std::placeholders::_1, std::placeholders::_2), SDL_BUTTON_LEFT);

在此行之后立即被銷毀。

您沒有顯示其他復制/移動構造函數和運算符，並且我懷疑您沒有對它們進行編碼。 請參閱什么是三規則？
這導致相同指針的雙重刪除。

您應該使用std ::: unique_ptr，因為您的組件似乎擁有其所有權。