Not via a documented API but you could try this...
/*
GetIocpQueueCount
Description:
Returns the number of queued IOCP work and I/O completion items.
Remarks:
Microsoft declined to implement the NtQueryIoCompletion routine
for user mode. This function gets past that omission by calling
the NTDLL.DLL function dynamically.
Returns:
Number of items in the queue at the instant this function was
called, or -1 if an error occurred. Errors can be retrieved
by calling GetLastError.
*/
long GetIocpQueueCount()
{
long lQueueDepth = -1;
typedef DWORD (WINAPI *LPFNNTQUERYIOCOMPLETION)(HANDLE, int, PVOID, ULONG, PULONG);
static LPFNNTQUERYIOCOMPLETION pfnNtQueryIoCompletion = NULL;
if (MFTASKQUEUENOTCREATED != m_dwStatus)
{
DWORD rc = NO_ERROR;
/* need to load dynamically */
if (NULL == pfnNtQueryIoCompletion)
{
/* Now dynamically obtain the undocumented NtQueryIoCompletion
* entry point from NTDLL.DLL
*/
HMODULE hmodDll = ::GetModuleHandleW(L"ntdll.dll");
// NTDLL is always loaded, just get its handle
if (NULL != hmodDll)
{
pfnNtQueryIoCompletion = (LPFNNTQUERYIOCOMPLETION)::GetProcAddress(
hmodDll,
"NtQueryIoCompletion"); // NB: ANSI
}
}
if (NULL != pfnNtQueryIoCompletion)
{
rc = (pfnNtQueryIoCompletion)(
m_hIOCP,
0,
(PVOID)&lQueueDepth,
sizeof(lQueueDepth),
NULL);
}
else
{
rc = ERROR_NOT_FOUND;
}
::SetLastError(rc);
}
return lQueueDepth;
}