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我有一个看起来类似于这样的数据包结构：

struct packet {
    sockaddr_in m_Recv;
    int m_iPacketSize;
    unsigned char* m_ucpPacket;
}

这是我使用此结构的代码的选择：

packet tOutPacket;
tOutPacket.m_Recv = tInPacket.m_Recv;
tOutPacket.m_iPacketSize = 256;
tOutPacket.m_ucpPacket = new unsigned char[256];

// Creating a uuid (not important how it's done, the pointer has 16 bytes)
unsigned char* uuid = NetworkHandlerN::ConnectionData::createUUID(hardware_hash);
NetworkHandlerN::PacketHandler::addUUIDToPacket(tOutPacket.m_ucpPacket, uuid);
delete[] uuid;

UDPsend(tOutPacket.m_Recv, tOutPacket.m_ucpPacket, tOutPacket.m_iPacketSize);

/* Delete pointer */
delete[] tOutPacket.m_ucpPacket; // This is causing an error

这是我的 UDPsend 方法：

bool NBsocket::UDPsend(sockaddr_in& AddrSento, const unsigned char* cucpBuffer, int iSize)
{
    if(sendto(m_iSocket, reinterpret_cast<const char*>(cucpBuffer), iSize, 0, (sockaddr*) &AddrSento, sizeof(AddrSento)) == -1) {
        m_iErrorCode = 6;
        return false;
    }

    return true;
}

这是 addUUIDToPacket 方法：

static void addUUIDToPacket(unsigned char* ucpPacket, unsigned char* ucpChar) 
{
    for(int i = 0; i < ciUUIDSize; i++) {
        ucpPacket[ciHeaderSize+i] = ucpChar[i];
    }
}

首先，我以为我在tOutPacket.m_ucpPacket某处删除了指针，但我检查了它。如果我像这样（在 之前delete[]）对存储在里面的数据进行测试：

if(tOutPacket.m_ucpPacket[tOutPacket.m_iPacketSize-1] == 0x08) 
    std::cout << "0x08";

它工作得很好（是的，值应该是 0x08）

这是我的调用堆栈输出：

    ntdll.dll!77dcfadc()    Unknown
    [Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll] 
    ntdll.dll!77db4f92()    Unknown
    ntdll.dll!77d926fc()    Unknown
    ntdll.dll!77dd0b37()    Unknown
    ntdll.dll!77d8a967()    Unknown
>   msvcp110.dll!std::_Fputc<char>(char _Byte, _iobuf * _File) Line 83  C++
    msvcp110.dll!std::basic_filebuf<char,std::char_traits<char> >::overflow(int _Meta) Line 383 C++
    msvcp110.dll!std::basic_streambuf<char,std::char_traits<char> >::xsputn(const char * _Ptr, __int64 _Count) Line 406 C++

我已经测试了很多，但无法弄清楚出了什么问题。

希望可以有人帮帮我。如果需要，我可以添加该/* add data to packet */部分，但这将是更多代码。

编辑

发现错误。我向这个方法传递了一个字节：

static void addToPacket(unsigned char* ucpPacket, int iInt, int iPos) 
{
    ucpPacket[iPos+0] = iInt & 0xFF;
    ucpPacket[iPos+1] = iInt >> 8 & 0xFF;
    ucpPacket[iPos+2] = iInt >> 8 & 0xFF;
    ucpPacket[iPos+3] = iInt >> 8 & 0xFF;
}

这导致了所有的麻烦......太多的方法重载:)。一定是失去了概述。

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1 回答 1

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Before trying to actually find the bug and its cause, consider whether you have to use new[] and delete[].

  1. Is the size fixed at 256? can you just put a regular array in your struct? It's not exactly that big.

  2. Assuming not, can you use std::vector<unsigned char> ?

  3. Failing that can you use boost::shared_array<unsigned char> ? You'll have to also put in the size as a separate element (e.g. iPacketSize). For this you will still call new[] but the delete[] will be taken care of. You will have to hold on to this shared_array object as long as you require the memory it uses.

What does createUUID do? It returns unsigned char * but who owns this memory?

At what point does the data you send get copied? At the call sendto ?

于 2012-10-23T15:22:32.977 回答