Error 12029 WinHTTP

Diprom

Hello. I am applying a demo project in which I use winhttp asynchronously via callback.
After cyclic sending of n-requests, error 12029 is often generated. If you insert Sleep in the code, then
all words go away without errors. I would like to understand how you can without sleep. Made specifically so that later
tie the call to the queue.

#include "stdafx.h"
#include
#include
#include
#pragma comment(lib,"winhttp")

// Context value structure.
typedef struct {
HINTERNET hSession; // HTTP Session
HINTERNET hConnect; // Connection handle
HINTERNET hRequest; // Resource request handle
DWORD dwSize; // Size of the latest data block
DWORD dwTotalSize; // Size of the total data
LPSTR lpBuffer; // Buffer for storing read data
char* SendBuffer; // Send buffer
wchar_t* URL; // URL
int Resend; // flag to resend
DWORD SendTimeout; // send timeout
DWORD ReceiveTimeout; // receive timeout
DWORD ConnectTimeout; // connect timeout
DWORD ResolveTimeout; // resolve timeout
bool IsBadRequest; // bad request complete
WINHTTP_STATUS_CALLBACK pCallback; //callback

} REQUEST_CONTEXT;

int CounterGood = 0;
int CounterBad = 0;

// This macro returns the constant name in a string.
#define CASE_OF(constant) case constant: return (L# constant)

LPCWSTR GetApiErrorString(DWORD dwResult)
{
// Return the error result as a string so that the
// name of the function causing the error can be displayed.
switch(dwResult)
{
CASE_OF( API_RECEIVE_RESPONSE );
CASE_OF( API_QUERY_DATA_AVAILABLE );
CASE_OF( API_READ_DATA );
CASE_OF( API_WRITE_DATA );
CASE_OF( API_SEND_REQUEST );
}
return L"Unknown function";
}

void Cleanup (REQUEST_CONTEXT *cpContext)
{

if (!cpContext)
{
    return;
}
if (cpContext->IsBadRequest)
    CounterBad++;
else
    CounterGood++;
WCHAR szBuffer\[256\];
// Set the memo to indicate a closed handle.
swprintf(szBuffer,sizeof(szBuffer), L"Cleanup");
//printf("%ws",szBuffer);
if (cpContext->hRequest)
{
    swprintf(szBuffer, sizeof(szBuffer), L">WinHttpSetStatusCallback

Lost User

You cannot expect anyone to plough through those 900 or so lines of code on your behalf. Please remove all the code not related to your problem and explain what the problem is, in proper detail.

Victor Nijegorodov

Diprom wrote:

After cyclic sending of n-requests, error 12029 is often generated.

What API call causes this error?

Diprom

SendRequest(rcContext);
Although this call always terminates normally. 12029 I catch in the callback AsyncCallback

Victor Nijegorodov

SendRequest looks like your own function. It calls a lot of WinHTTP functions. So which one of these WinHTTP functions fails with this error?

Lost User

Hi,

Diprom wrote:

After cyclic sending of n-requests, error 12029 is often generated.

The Windows operating system limits the number of half-open TCP connections. On the Windows 10 operating system you will be limited to 20 and on the older operating systems it could be as low as 10.

Diprom wrote:

for (int i = 0; i < 2000; i++)

That's alot of asynchronous connections... the Windows operating system will not allow you to make 2000 outgoing connections this fast. Best Wishes, -David Delaune

Scientiæ de conservata veritate.