我一直在处理一些 char* 指针的项目中工作,并且使用 char* 而不是 std::string 是该类的必要条件,所以...
我有这个结构定义和这个队列:
typedef struct packetQueue
{
char* buf;
int length;
packetQueue()
{
buf = new char[];
length = 0;
}
} PACKET;
并发性::concurrent_queue IP_in_queue;
我有这个缓冲区:
char sendBuf[MSG_SIZE + sizeof (IP_PACKET_HEADER_T) + 1]; // String to be send
和我的新缓冲区的结构:
PACKET ipQueue;
然后我用这个填充我的缓冲区:
// Concatenates the header with sended message
memcpy(sendBuf, (void*)&sendHeader, sizeof(sendHeader));
memcpy(&sendBuf[sizeof(sendHeader)], readMessage, sendHeader.length);
ipQueue.buf = sendBuf;
ipQueue.length = packetSize;
然后我将我的数据包推送到我的队列 IP_in_queue.push(ipQueue);//将缓冲区推送到 IP_in_queue
这是我的循环以防万一:
while ( 1 )
{
// Get the user input
cout << "> ";
cin.getline (buf, BUFLEN);
IP_PACKET_HEADER_T sendHeader; // Store the header to be send
PACKET ipQueue;
char* fakeIPAddressDst, *readMessage;
delay = atoi(strtok (buf," ")); // Takes the first delay value
fakeIPAddressDst = strtok (NULL, " "); // Stores the IP Address
readMessage = strtok (NULL, " "); // Stores the sended message
Sleep(delay); // Sleep the miliseconds defined
// Fills the header with the data neccesary data
sendHeader.DIP = inet_addr(fakeIPAddressDst);
sendHeader.SIP = inet_addr(initAddress.fakeIpAddress);
sendHeader.length = getStringLength(readMessage) + 1;
packetSize = sizeof( sendHeader ) + sendHeader.length; // Defines the size of the packet to be send
// Concatenates the header with sended message
memcpy(sendBuf, (void*)&sendHeader, sizeof(sendHeader));
memcpy(&sendBuf[sizeof(sendHeader)], readMessage, sendHeader.length);
ipQueue.buf = sendBuf;
ipQueue.length = packetSize;
numbytes = packetSize; // The number of bytes of sended buffer
char sendedString[BUFLEN + 1]; // Variable for stores the data
IP_PACKET_HEADER_T readHeader; // To store the header for showing the information
// Print out the content of the packet
// Copy from buf to the header
memcpy( (void*)&readHeader, ipQueue.buf, sizeof( IP_PACKET_HEADER_T));
// Copy message part
memcpy( sendedString, &ipQueue.buf[sizeof(IP_PACKET_HEADER_T)], numbytes - sizeof(IP_PACKET_HEADER_T));
// Append \0 to the end
sendedString[numbytes - sizeof(IP_PACKET_HEADER_T)] = '\0';
// Save the IP information of the packet in a struct for print on the screen
struct in_addr fakeAddrHost;
fakeAddrHost.s_addr = readHeader.SIP;
// Print the neccesary data
cout << "[IN] DST: " << fakeIPAddressDst << endl; // Fake IP address of the destination
cout << "[IN] SRC: " << inet_ntoa(fakeAddrHost) << endl; // Fake IP address of the host
cout << "[IN] MSG: " << sendedString << endl ; // Message to send
IP_in_queue.push(ipQueue); // Push the buffer in the IP_in_queue
}
我知道此过程中存在内存泄漏,但我不确定。 当我推送数据包时,buf 指针一直指向我的 sendBuf,对吗?因为分配是这样做的,但是如果我在推送程序崩溃后删除了 ipQueue 中的指针。我不得不说,在我将该结构插入队列后,另一个线程尝试弹出那个结构,显然如果我删除我的 ipQueue 指针,我将丢失我的缓冲区,那么我如何才能避免这种内存泄漏?
谢谢
编辑:
使用buf = nullptr定义的内存泄漏
---------- Block 1 at 0x0068BB30: 264 bytes ----------
Call Stack:
d:\program files (x86)\microsoft visual studio 11.0\vc\include\concurrent_queue.h (402): Host.exe!Concurrency::concurrent_queue<packetQueue,std::allocator<packetQueue> >::_Allocate_page + 0xF bytes
f:\dd\vctools\crt_bld\self_x86\crt\src\concurrent_queue.cpp (113): MSVCP110D.dll!Concurrency::details::_Micro_queue::_Push + 0xD bytes
f:\dd\vctools\crt_bld\self_x86\crt\src\concurrent_queue.cpp (232): MSVCP110D.dll!Concurrency::details::_Concurrent_queue_base_v4::_Internal_push
d:\program files (x86)\microsoft visual studio 11.0\vc\include\concurrent_queue.h (566): Host.exe!Concurrency::concurrent_queue<packetQueue,std::allocator<packetQueue> >::push + 0xF bytes
d:\users\silex rpr\documents\visual studio 2012\projects\project2\project2\host.cpp (802): Host.exe!main
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c (536): Host.exe!__tmainCRTStartup + 0x19 bytes
f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c (377): Host.exe!mainCRTStartup
0x7662339A (File and line number not available): kernel32.dll!BaseThreadInitThunk + 0x12 bytes
0x77179EF2 (File and line number not available): ntdll.dll!RtlInitializeExceptionChain + 0x63 bytes
0x77179EC5 (File and line number not available): ntdll.dll!RtlInitializeExceptionChain + 0x36 bytes
最佳答案
首先;这不是 C,您使用的是 C++ 编译器。 C 中的结构不能有方法和构造函数,并且 new
和 delete
不存在。
其次,您在构造函数中为 buf
分配了内存,但是...
ipQueue.buf = sendBuf;
这是一个漏洞。每次调用 new
时都需要调用 delete
。您使用 new
分配了 buf
,但从未对其调用 delete
,因此内存泄漏。
我认为没有理由在这里分配 buf
。只需将其设置为 null。
typedef struct packetQueue
{
char* buf;
int length;
packetQueue()
: buf(nullptr), length(0) { }
} PACKET;
附带说明一下,这是 C 和 C++ 的非常糟糕的混合。这是你们老师教你们的吗?
关于c++ - 使用 Char* 查找内存泄漏的原因,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12556793/