我正在尝试在 C++ 中使用 WinHTTP 执行 HTTP GET，但是在解析名称后（在状态回调函数中获取 WINHTTP_CALLBACK_STATUS_NAME_RESOLVED 之后）它在某个时候崩溃。我在 winhttp.dll 中遇到访问冲突。调用堆栈是：
winhttp.dll!HTTP_USER_REQUEST::_IndicateSocketAddress() + 0x221ed 字节
winhttp.dll!HTTP_USER_REQUEST::OnDnsNameResolved() + 0x24 字节
winhttp.dll!WEBIO_REQUEST::_OnInformation() + 0x1c0c 字节 webio.dll!_WaIndicateHttpRequestInformation@16() + 0x15a字节 webio.dll!_WaHttpInformationConnection@16() + 0x7a 字节
webio.dll!_WapTcpDnsQueryCompletionRoutine@12() + 0x2f 字节
webio.dll!_WapCallDnsQueryCompletion@12() + 0x6d 字节 webio.dll!_WaDnsResolutionWorker@8() + 0x157 字节 ntdll .dll!_TppSimplepExecuteCallback@8() + 0x7b 字节
ntdll.dll！TppWorkerThread@4() + 0x5a4 字节
kernel32.dll！@BaseThreadInitThunk@12() + 0x12 字节
ntdll.dll！__RtlUserThreadStart@8() + 0x27 字节
ntdll.dll!__RtlUserThreadStart@8() + 0x1b 字节
相关代码为：
enum OnlineState
{
OnlineState_Idle,
OnlineState_Registering
};
static OnlineState g_OnlineState = OnlineState_Idle;
HINTERNET g_Request = 0;
HINTERNET g_Connection = 0;
unsigned char g_HTTPBuffer[1024];
void HTTPRequestComplete()
{
if(g_Request != 0)
{
WinHttpCloseHandle(g_Request);
g_Request = 0;
}
if(g_Connection != 0)
{
WinHttpCloseHandle(g_Connection);
g_Connection = 0;
}
g_OnlineState = OnlineState_Idle;
}
void HTTPAsyncCallback(HINTERNET hInternet, DWORD_PTR dwContext, DWORD dwInternetStatus, LPVOID lpvStatusInformation, DWORD dwStatusInformationLength)
{
switch(dwInternetStatus)
{
case WINHTTP_CALLBACK_STATUS_SENDREQUEST_COMPLETE:
{
// Get the response
if (!WinHttpReceiveResponse(g_Request, 0))
{
// Failed to get the response
HTTPRequestComplete();
return;
}
}
break;
case WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE:
{
DWORD statusCode = 0;
DWORD statusCodeSize = sizeof(DWORD);
if (!WinHttpQueryHeaders(g_Request,
WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER,
WINHTTP_HEADER_NAME_BY_INDEX,
&statusCode,
&statusCodeSize,
WINHTTP_NO_HEADER_INDEX))
{
// Failed to query headers
HTTPRequestComplete();
return;
}
if (HTTP_STATUS_OK != statusCode)
{
// Error status
HTTPRequestComplete();
return;
}
if (!WinHttpReadData(g_Request,
g_HTTPBuffer,
sizeof(g_HTTPBuffer),
0))
{
// Error reading data
HTTPRequestComplete();
return;
}
}
break;
case WINHTTP_CALLBACK_STATUS_READ_COMPLETE:
{
if (dwStatusInformationLength > 0)
{
// Store the data
// Read the next data
if (!WinHttpReadData(g_Request,
g_HTTPBuffer,
sizeof(g_HTTPBuffer),
0))
{
// Error
HTTPRequestComplete();
return;
}
}
else
{
// Request completed OK
HTTPRequestComplete();
}
}
break;
default:
break;
}
}
// Online functionality
void Online_UpdateServer()
{
switch(g_OnlineState)
{
case OnlineState_Idle:
{
// Get our local ip address by connecting a local socket to a web address and reading the socket name
// Look up the address to connect to
addrinfo hints;
addrinfo* res = 0;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
getaddrinfo("www.google.com", "80", &hints, &res);
// Create the socket
int tempSocket = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
unsigned int localAddress = 0;
if (tempSocket >= 0)
{
// Connect the socket
connect(tempSocket, res->ai_addr, res->ai_addrlen);
// Get the socket name (our local ip address)
sockaddr_in localName;
memset(&localName, 0, sizeof(localName));
int bufferSize = sizeof(localName);
if(getsockname(tempSocket, (sockaddr*)&localName, &bufferSize) == 0)
{
// Get the IP address
localAddress = localName.sin_addr.S_un.S_addr;
}
closesocket(tempSocket);
}
// Connect
g_Connection = WinHttpConnect(g_Internet, L"www.google.com", INTERNET_DEFAULT_PORT, 0);
// Open the request
std::wstringstream urlString;
urlString << L"/";
std::wstring tempString = urlString.str();
const wchar_t* wurlString = tempString.c_str();
g_Request = WinHttpOpenRequest(g_Connection, 0, wurlString, 0, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0);
// Install the status callback function.
if(WINHTTP_INVALID_STATUS_CALLBACK == WinHttpSetStatusCallback(g_Request, (WINHTTP_STATUS_CALLBACK)HTTPAsyncCallback, WINHTTP_CALLBACK_FLAG_ALL_NOTIFICATIONS, NULL))
{
OutputDebugString(L"Error");
}
// Send the request
if(!WinHttpSendRequest(g_Request, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0))
{
OutputDebugString(L"Error");
}
// Log that we're registering
g_OnlineState = OnlineState_Registering;
}
break;
case OnlineState_Registering:
{
// Don't do anything, as we're currently registering
}
break;
default:
break;
}
}
g_Internet 的初始化如下：
// Initialise HTTP
g_Internet = WinHttpOpen(L"Boomba", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, WINHTTP_FLAG_ASYNC);
据我所知，我正在初始化并正确使用 WinHTTP，一切似乎都恢复正常，没有错误。回调被调用两次，第一次使用 WINHTTP_CALLBACK_STATUS_RESOLVING_NAME，然后使用 WINHTTP_CALLBACK_STATUS_NAME_RESOLVED，然后我遇到访问冲突：
0xC0000005：访问冲突读取位置 0x00000014
位置发生了变化，发生了各种各样的事情，所以我认为它看起来可能是一个线程问题，但我不确定可能是什么问题。有任何想法吗？（我在 Windows 7 64 位上运行）。