将 shared_ptr 传递给 this 到拥有引用的对象

Question

SharedEditor 类拥有对NetworkServer 类对象的引用，而NetworkServer 对象拥有std::vector<std::shared_ptr<SharedEditor>> 的editors。在SharedEditor 构造函数中，调用server.connect() 方法来保存其引用，而在server.connect() 中，指向该编辑器的共享指针被保存到server 中。 程序编译并执行，但严重终止。

NetworkServer.h

#include <queue>
#include <memory>
#include "SharedEditor.h"
#include "Message.h"

class NetworkServer {
private:
    std::vector<std::shared_ptr<SharedEditor>> editors;
    std::deque<Message> messages;

public:
    int connect(std::shared_ptr<SharedEditor> sharedEditor);
};

NetworkServer.cpp

#include <algorithm>
#include "NetworkServer.h"

static int id = 0;

int NetworkServer::connect(std::shared_ptr<SharedEditor> sharedEditor) {
    editors.push_back(sharedEditor);
    return id++;
}

SharedEditor.h

#include <vector>
#include <map>
#include "Symbol.h"

class NetworkServer;

class SharedEditor {
private:
    NetworkServer& _server;

public:

    SharedEditor(NetworkServer &server);

};

SharedEditor.cpp

#include <exception>
#include <algorithm>
#include <random>
#include <iostream>
#include "SharedEditor.h"
#include "NetworkServer.h"

SharedEditor::SharedEditor(NetworkServer &server)
        : _server(server), _counter(0), base(32), boundary(10) {
    _siteId = server.connect(std::shared_ptr<SharedEditor>(this));
}

main.cpp

#include <iostream>
#include "NetworkServer.h"

int main() {
    NetworkServer network;
    SharedEditor ed1(network);
    SharedEditor ed2(network);


    return 0;
}

返回-1073740940 (0xC0000374)

Answer 1

您误解了智能指针的工作原理。

server.connect(std::shared_ptr<SharedEditor>(this))

您将指针this 传递给在堆栈上分配的对象。您必须只传递指向内存堆上动态分配对象的指针。

您应该执行以下操作，但您的类设计不佳，因为从语义上看不清楚network 将拥有新分配的对象。

SharedEditor* ed1 = new SharedEditor(network);