What am I doing wrong? Memory leaks with Concurrency::samples::task_scheduler

Question

I must be doing something wrong.  I have a simple 32-bit Console app. I am running it on Windows 7 x64. I use Visual Studio 2010 SP1.

The sample code pasted below leaks memory (according to Private Bytes in perfmon).

All it does is shedule a 1 sec duration task in a task scheduler every time the ENTER key is hit.

If you hold down the ENTER key you will see memory climb in perfmon as tasks are queued quicker than they can execute.

When you stop holding down the ENTER key, the task pool runs dry like you would expect, but Private Bytes never drops.

If you hit X to delete the task_scheduler instance you will see memory drop in perfmon but never as low as when the app starts.

Looking at my exe's threads in ProcessExplorer I see lots of these:

<tid>  MSVCRT100.dll?_IsCanceling@_TaskCollection@details@Concurrency@@QAE_NXZ+0x70b

with stack traces that look like this:

ntoskrnl.exe!KeWaitForMultipleObjects+0xc0a
ntoskrnl.exe!KeAcquireSpinLockAtDpcLevel+0x732
ntoskrnl.exe!KeWaitForMutexObject+0x19f
ntoskrnl.exe!__misaligned_access+0xba4
ntoskrnl.exe!__misaligned_access+0x1821
ntoskrnl.exe!KeAcquireSpinLockAtDpcLevel+0x93d
ntoskrnl.exe!KeWaitForMutexObject+0x19f
ntoskrnl.exe!NtWaitForSingleObject+0xde
ntoskrnl.exe!KeSynchronizeExecution+0x3a23
wow64cpu.dll!TurboDispatchJumpAddressEnd+0x6c0
wow64cpu.dll!TurboDispatchJumpAddressEnd+0x4a8
wow64.dll!Wow64SystemServiceEx+0x1ce
wow64.dll!Wow64LdrpInitialize+0x429
ntdll.dll!RtlIsDosDeviceName_U+0x24c87
ntdll.dll!LdrInitializeThunk+0xe
ntdll.dll!ZwWaitForSingleObject+0x15
kernel32.dll!WaitForSingleObjectEx+0x43
kernel32.dll!WaitForSingleObject+0x12
MSVCR100.dll!?_IsCanceling@_TaskCollection@details@Concurrency@@QAE_NXZ+0x61d
MSVCR100.dll!?_IsCanceling@_TaskCollection@details@Concurrency@@QAE_NXZ+0x719
kernel32.dll!BaseThreadInitThunk+0x12
ntdll.dll!RtlInitializeExceptionChain+0x63
ntdll.dll!RtlInitializeExceptionChain+0x36

I am trying to use the task_scheduler as a really simple thread pool in my app. I thought I could use the schedule_task method to dispatch asynchronous events from my class.

What am I doing wrong? Thanks.

Here is the example code:

#include "stdafx.h"
#include "ConcRTExtras/concrt_extras.h"
//==============================================================================
int _tmain(int argc, _TCHAR* argv[])
{
    // use the task_scheduler from concrt_extras.h
    Concurrency::samples::task_scheduler* pTaskScheduler = nullptr;
    while (true)
    {
        wprintf_s(L"Hit ENTER to schedule task (X to exit):");
        int c = _getch_nolock();
        // quit the loop?
        if (c == 'x' || c == 'X') {break;}
        _putch_nolock('\n');        
        if (pTaskScheduler == nullptr)
        {
            pTaskScheduler = new Concurrency::samples::task_scheduler();
        }
        // schedule a long-lived task
        pTaskScheduler->schedule_task([]
        {
            // this speeds things up but makes no difference to mem usage
            Concurrency::scoped_oversubcription_token overSubscribe;
            Sleep(1000);
        });
    }
    delete pTaskScheduler;
    wprintf_s(L"Hit ENTER to exit:\n");
    _getch_nolock();
    return 0;
}

EDIT:

I get the same kind of leaks when I use the sample code show here in MSDN: http://msdn.microsoft.com/en-us/library/ee624185.aspx