RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First)
{
    /*
     * Validate.
     */
    AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
    AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);

    if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
        return VERR_TIMER_ACTIVE;
    if (   pTimer->fSpecificCpu
        && !RTMpIsCpuOnline(pTimer->idCpu))
        return VERR_CPU_OFFLINE;

    /*
     * Start the timer.
     */
    PKDPC pMasterDpc = pTimer->fOmniTimer
                     ? &pTimer->aSubTimers[RTMpCpuIdToSetIndex(pTimer->idCpu)].NtDpc
                     : &pTimer->aSubTimers[0].NtDpc;

#ifndef RTR0TIMER_NT_MANUAL_RE_ARM
    uint64_t u64Interval = pTimer->u64NanoInterval / 1000000; /* This is ms, believe it or not. */
    ULONG ulInterval = (ULONG)u64Interval;
    if (ulInterval != u64Interval)
        ulInterval = MAXLONG;
    else if (!ulInterval && pTimer->u64NanoInterval)
        ulInterval = 1;
#endif

    LARGE_INTEGER DueTime;
    DueTime.QuadPart = -(int64_t)(u64First / 100); /* Relative, NT time. */
    if (!DueTime.QuadPart)
        DueTime.QuadPart = -1;

    unsigned cSubTimers = pTimer->fOmniTimer ? pTimer->cSubTimers : 1;
    for (unsigned iCpu = 0; iCpu < cSubTimers; iCpu++)
        pTimer->aSubTimers[iCpu].iTick = 0;
    ASMAtomicWriteS32(&pTimer->cOmniSuspendCountDown, 0);
    ASMAtomicWriteBool(&pTimer->fSuspended, false);
#ifdef RTR0TIMER_NT_MANUAL_RE_ARM
    pTimer->uNtStartTime = rtTimerNtQueryInterruptTime() + u64First / 100;
    KeSetTimerEx(&pTimer->NtTimer, DueTime, 0, pMasterDpc);
#else
    KeSetTimerEx(&pTimer->NtTimer, DueTime, ulInterval, pMasterDpc);
#endif
    return VINF_SUCCESS;
}

int GuestCtrlEvent::Wait(ULONG uTimeoutMS)
{
    LogFlowFuncEnter();

    AssertReturn(hEventSem != NIL_RTSEMEVENT, VERR_CANCELLED);

    RTMSINTERVAL msInterval = uTimeoutMS;
    if (!uTimeoutMS)
        msInterval = RT_INDEFINITE_WAIT;
    int rc = RTSemEventWait(hEventSem, msInterval);
    if (RT_SUCCESS(rc))
        ASMAtomicWriteBool(&fCompleted, true);

    LogFlowFuncLeaveRC(rc);
    return rc;
}

RTDECL(uint32_t) RTPollSetGetCount(RTPOLLSET hPollSet)
{
    /*
     * Validate the input.
     */
    RTPOLLSETINTERNAL *pThis = hPollSet;
    AssertPtrReturn(pThis, UINT32_MAX);
    AssertReturn(pThis->u32Magic == RTPOLLSET_MAGIC, UINT32_MAX);

    /*
     * Set the busy flag and do the job.
     */
    AssertReturn(ASMAtomicCmpXchgBool(&pThis->fBusy, true,  false), UINT32_MAX);
    uint32_t cHandles = pThis->cHandles;
    ASMAtomicWriteBool(&pThis->fBusy, false);

    return cHandles;
}

void vboxClipboardDestroy (void)
{
    Log(("vboxClipboardDestroy\n"));

    /* Set the termination flag and ping the window thread. */
    ASMAtomicWriteBool (&g_ctx.fTerminate, true);

    if (g_ctx.hwnd)
    {
        PostMessage (g_ctx.hwnd, WM_CLOSE, 0, 0);
    }

    CloseHandle (g_ctx.hRenderEvent);

    /* Wait for the window thread to terminate. */
    RTThreadWait (g_ctx.thread, RT_INDEFINITE_WAIT, NULL);

    g_ctx.thread = NIL_RTTHREAD;
}

/**
 * Bootstrap VMR3Wait() worker.
 *
 * @returns VBox status code.
 * @param   pUVMCPU            Pointer to the user mode VMCPU structure.
 */
static DECLCALLBACK(int) vmR3BootstrapWait(PUVMCPU pUVCpu)
{
    PUVM pUVM = pUVCpu->pUVM;

    ASMAtomicWriteBool(&pUVCpu->vm.s.fWait, true);

    int rc = VINF_SUCCESS;
    for (;;)
    {
        /*
         * Check Relevant FFs.
         */
        if (pUVM->vm.s.pNormalReqs   || pUVM->vm.s.pPriorityReqs)   /* global requests pending? */
            break;
        if (pUVCpu->vm.s.pNormalReqs || pUVCpu->vm.s.pPriorityReqs) /* local requests pending? */
            break;

        if (    pUVCpu->pVM
            &&  (   VM_FF_ISPENDING(pUVCpu->pVM, VM_FF_EXTERNAL_SUSPENDED_MASK)
                 || VMCPU_FF_ISPENDING(VMMGetCpu(pUVCpu->pVM), VMCPU_FF_EXTERNAL_SUSPENDED_MASK)
                )
            )
            break;
        if (pUVM->vm.s.fTerminateEMT)
            break;

        /*
         * Wait for a while. Someone will wake us up or interrupt the call if
         * anything needs our attention.
         */
        rc = RTSemEventWait(pUVCpu->vm.s.EventSemWait, 1000);
        if (rc == VERR_TIMEOUT)
            rc = VINF_SUCCESS;
        else if (RT_FAILURE(rc))
        {
            rc = vmR3FatalWaitError(pUVCpu, "RTSemEventWait->%Rrc\n", rc);
            break;
        }
    }

    ASMAtomicUoWriteBool(&pUVCpu->vm.s.fWait, false);
    return rc;
}

/**
 * @interface_method_impl{PDMINETWORKUP,pfnNotifyLinkChanged}
 */
static DECLCALLBACK(void) drvR3DedicatedNicUp_NotifyLinkChanged(PPDMINETWORKUP pInterface, PDMNETWORKLINKSTATE enmLinkState)
{
    PDRVDEDICATEDNIC pThis = RT_FROM_MEMBER(pInterface, DRVDEDICATEDNIC, CTX_SUFF(INetworkUp));
    bool fLinkDown;
    switch (enmLinkState)
    {
        case PDMNETWORKLINKSTATE_DOWN:
        case PDMNETWORKLINKSTATE_DOWN_RESUME:
            fLinkDown = true;
            break;
        default:
            AssertMsgFailed(("enmLinkState=%d\n", enmLinkState));
        case PDMNETWORKLINKSTATE_UP:
            fLinkDown = false;
            break;
    }
    LogFlow(("drvR3DedicatedNicUp_NotifyLinkChanged: enmLinkState=%d %d->%d\n", enmLinkState, pThis->fLinkDown, fLinkDown));
    ASMAtomicWriteBool(&pThis->fLinkDown, fLinkDown);
}

/**
 * Worker function that stops an active timer.
 *
 * Shared by RTTimerStop and RTTimerDestroy.
 *
 * @param   pTimer      The active timer.
 */
static void rtTimerNtStopWorker(PRTTIMER pTimer)
{
    /*
     * Just cancel the timer, dequeue the DPCs and flush them (if this is supported).
     */
    ASMAtomicWriteBool(&pTimer->fSuspended, true);
    KeCancelTimer(&pTimer->NtTimer);

    for (RTCPUID iCpu = 0; iCpu < pTimer->cSubTimers; iCpu++)
        KeRemoveQueueDpc(&pTimer->aSubTimers[iCpu].NtDpc);

    /*
     * I'm a bit uncertain whether this should be done during RTTimerStop
     * or only in RTTimerDestroy()... Linux and Solaris will wait AFAIK,
     * which is why I'm keeping this here for now.
     */
    if (g_pfnrtNtKeFlushQueuedDpcs)
        g_pfnrtNtKeFlushQueuedDpcs();
}

static DECLCALLBACK(int) Once2CB(void *pvUser)
{
    if (ASMAtomicIncU32(&g_cOnce2CB) != 1)
    {
        RTPrintf("tstOnce: ERROR - Once2CB: g_cOnce2CB not zero!\n");
        g_cErrors++;
        return VERR_WRONG_ORDER;
    }
    if (pvUser != (void *)42)
    {
        RTPrintf("tstOnce: ERROR - Once2CB: pvUser=%p!\n", pvUser);
        g_cErrors++;
        return VERR_INVALID_PARAMETER;
    }
    RTThreadSleep(2);
    Assert(!g_fOnce2Ready);
    ASMAtomicWriteBool(&g_fOnce2Ready, true);
    return VINF_SUCCESS;
}

/**
 * Callback employed by drvscsiReset.
 *
 * @returns true if we've quiesced, false if we're still working.
 * @param   pDrvIns     The driver instance.
 */
static DECLCALLBACK(bool) drvscsiIsAsyncResetDone(PPDMDRVINS pDrvIns)
{
    PDRVSCSI pThis = PDMINS_2_DATA(pDrvIns, PDRVSCSI);

    if (pThis->pDrvBlockAsync)
    {
        if (pThis->StatIoDepth > 0)
            return false;
        else
            return true;
    }
    else
    {
        if (!drvscsiAsyncIOLoopNoPendingDummy(pThis, 0 /*ms*/))
            return false;
        ASMAtomicWriteBool(&pThis->fDummySignal, false);
        return true;
    }
}

/**
 * EMT worker for DBGFR3Attach.
 *
 * @returns VBox status code.
 * @param   pVM     Pointer to the VM.
 */
static DECLCALLBACK(int) dbgfR3Attach(PVM pVM)
{
    if (pVM->dbgf.s.fAttached)
    {
        Log(("dbgR3Attach: Debugger already attached\n"));
        return VERR_DBGF_ALREADY_ATTACHED;
    }

    /*
     * Create the Ping-Pong structure.
     */
    int rc = RTSemPingPongInit(&pVM->dbgf.s.PingPong);
    AssertRCReturn(rc, rc);

    /*
     * Set the attached flag.
     */
    ASMAtomicWriteBool(&pVM->dbgf.s.fAttached, true);
    return VINF_SUCCESS;
}

/** Terminate the host side of the shared clipboard - called by the hgcm layer. */
void vboxClipboardDestroy(void)
{
    Log(("vboxClipboardDestroy\n"));

    /*
     * Signal the termination of the polling thread and wait for it to respond.
     */
    ASMAtomicWriteBool(&g_ctx.fTerminate, true);
    int rc = RTThreadUserSignal(g_ctx.thread);
    AssertRC(rc);
    rc = RTThreadWait(g_ctx.thread, RT_INDEFINITE_WAIT, NULL);
    AssertRC(rc);

    /*
     * Destroy the pasteboard and uninitialize the global context record.
     */
    destroyPasteboard(&g_ctx.pasteboard);
    g_ctx.thread = NIL_RTTHREAD;
    g_ctx.pClient = NULL;
}

/**
 * Callback employed by drvscsiSuspend and drvscsiPowerOff.
 *
 * @returns true if we've quiesced, false if we're still working.
 * @param   pDrvIns     The driver instance.
 */
static DECLCALLBACK(bool) drvscsiIsAsyncSuspendOrPowerOffDone(PPDMDRVINS pDrvIns)
{
    PDRVSCSI pThis = PDMINS_2_DATA(pDrvIns, PDRVSCSI);

    if (pThis->pDrvMediaAsync)
    {
        if (pThis->StatIoDepth > 0)
            return false;
        else
            return true;
    }
    else
    {
        if (!drvscsiAsyncIOLoopNoPendingDummy(pThis, 0 /*ms*/))
            return false;
        ASMAtomicWriteBool(&pThis->fDummySignal, false);
        PDMR3ThreadSuspend(pThis->pAsyncIOThread);
        return true;
    }
}

/**
 * Timer callback function for the non-omni timers.
 *
 * @returns HRTIMER_NORESTART or HRTIMER_RESTART depending on whether it's a one-shot or interval timer.
 * @param   pDpc                Pointer to the DPC.
 * @param   pvUser              Pointer to our internal timer structure.
 * @param   SystemArgument1     Some system argument.
 * @param   SystemArgument2     Some system argument.
 */
static void _stdcall rtTimerNtSimpleCallback(IN PKDPC pDpc, IN PVOID pvUser, IN PVOID SystemArgument1, IN PVOID SystemArgument2)
{
    PRTTIMER pTimer = (PRTTIMER)pvUser;
    AssertPtr(pTimer);
#ifdef RT_STRICT
    if (KeGetCurrentIrql() < DISPATCH_LEVEL)
        RTAssertMsg2Weak("rtTimerNtSimpleCallback: Irql=%d expected >=%d\n", KeGetCurrentIrql(), DISPATCH_LEVEL);
#endif

    /*
     * Check that we haven't been suspended before doing the callout.
     */
    if (    !ASMAtomicUoReadBool(&pTimer->fSuspended)
        &&  pTimer->u32Magic == RTTIMER_MAGIC)
    {
        if (!pTimer->u64NanoInterval)
            ASMAtomicWriteBool(&pTimer->fSuspended, true);
        pTimer->pfnTimer(pTimer, pTimer->pvUser, ++pTimer->aSubTimers[0].iTick);
    }

    NOREF(pDpc); NOREF(SystemArgument1); NOREF(SystemArgument2);
}

VBoxDbgConsole::~VBoxDbgConsole()
{
    Assert(isGUIThread());

    /*
     * Wait for the thread.
     */
    ASMAtomicWriteBool(&m_fTerminate, true);
    RTSemEventSignal(m_EventSem);
    if (m_Thread != NIL_RTTHREAD)
    {
        int rc = RTThreadWait(m_Thread, 15000, NULL);
        AssertRC(rc);
        m_Thread = NIL_RTTHREAD;
    }

    /*
     * Free resources.
     */
    delete m_pTimer;
    m_pTimer = NULL;
    RTCritSectDelete(&m_Lock);
    RTSemEventDestroy(m_EventSem);
    m_EventSem = 0;
    m_pOutput = NULL;
    m_pInput = NULL;
    if (m_pszInputBuf)
    {
        RTMemFree(m_pszInputBuf);
        m_pszInputBuf = NULL;
    }
    m_cbInputBuf = 0;
    m_cbInputBufAlloc = 0;

    delete m_pFocusToInput;
    m_pFocusToInput = NULL;
    delete m_pFocusToOutput;
    m_pFocusToOutput = NULL;
}

DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
{
    if (ASMAtomicReadBool(&g_fSolCpuWatch) == true)
        return VERR_WRONG_ORDER;

    /*
     * Register the callback building the online cpu set as we do so.
     */
    RTCpuSetEmpty(&g_rtMpSolCpuSet);

    mutex_enter(&cpu_lock);
    register_cpu_setup_func(rtMpNotificationCpuEvent, NULL /* pvArg */);

    for (int i = 0; i < (int)RTMpGetCount(); ++i)
        if (cpu_is_online(cpu[i]))
            rtMpNotificationCpuEvent(CPU_ON, i, NULL /* pvArg */);

    ASMAtomicWriteBool(&g_fSolCpuWatch, true);
    mutex_exit(&cpu_lock);

    return VINF_SUCCESS;
}

/**
 * Obtain bandwidth in a bandwidth group.
 *
 * @returns True if bandwidth was allocated, false if not.
 * @param   pFilter         Pointer to the filter that allocates bandwidth.
 * @param   cbTransfer      Number of bytes to allocate.
 */
VMMDECL(bool) PDMNsAllocateBandwidth(PPDMNSFILTER pFilter, size_t cbTransfer)
{
    AssertPtrReturn(pFilter, true);
    if (!VALID_PTR(pFilter->CTX_SUFF(pBwGroup)))
        return true;

    PPDMNSBWGROUP pBwGroup = ASMAtomicReadPtrT(&pFilter->CTX_SUFF(pBwGroup), PPDMNSBWGROUP);
    int rc = PDMCritSectEnter(&pBwGroup->Lock, VERR_SEM_BUSY); AssertRC(rc);
    if (RT_UNLIKELY(rc == VERR_SEM_BUSY))
        return true;

    bool fAllowed = true;
    if (pBwGroup->cbPerSecMax)
    {
        /* Re-fill the bucket first */
        uint64_t tsNow        = RTTimeSystemNanoTS();
        uint32_t uTokensAdded = (tsNow - pBwGroup->tsUpdatedLast) * pBwGroup->cbPerSecMax / (1000 * 1000 * 1000);
        uint32_t uTokens      = RT_MIN(pBwGroup->cbBucket, uTokensAdded + pBwGroup->cbTokensLast);

        if (cbTransfer > uTokens)
        {
            fAllowed = false;
            ASMAtomicWriteBool(&pFilter->fChoked, true);
        }
        else
        {
            pBwGroup->tsUpdatedLast = tsNow;
            pBwGroup->cbTokensLast = uTokens - (uint32_t)cbTransfer;
        }
        Log2(("pdmNsAllocateBandwidth: BwGroup=%#p{%s} cbTransfer=%u uTokens=%u uTokensAdded=%u fAllowed=%RTbool\n",
              pBwGroup, R3STRING(pBwGroup->pszNameR3), cbTransfer, uTokens, uTokensAdded, fAllowed));
    }
    else
        Log2(("pdmNsAllocateBandwidth: BwGroup=%#p{%s} disabled fAllowed=%RTbool\n",
              pBwGroup, R3STRING(pBwGroup->pszNameR3), fAllowed));

    rc = PDMCritSectLeave(&pBwGroup->Lock); AssertRC(rc);
    return fAllowed;
}

/**
 * @copydoc SSMSTRMOPS::pfnClose
 */
static DECLCALLBACK(int) teleporterTcpOpClose(void *pvUser, bool fCanceled)
{
    TeleporterState *pState = (TeleporterState *)pvUser;

    if (pState->mfIsSource)
    {
        TELEPORTERTCPHDR EofHdr;
        EofHdr.u32Magic = TELEPORTERTCPHDR_MAGIC;
        EofHdr.cb       = fCanceled ? UINT32_MAX : 0;
        int rc = RTTcpWrite(pState->mhSocket, &EofHdr, sizeof(EofHdr));
        if (RT_FAILURE(rc))
        {
            LogRel(("Teleporter/TCP: EOF Header write error: %Rrc\n", rc));
            return rc;
        }
    }
    else
    {
        ASMAtomicWriteBool(&pState->mfStopReading, true);
    }

    return VINF_SUCCESS;
}

RTDECL(int) RTTimerStart(PRTTIMER pTimer, uint64_t u64First)
{
    /*
     * Validate.
     */
    AssertPtrReturn(pTimer, VERR_INVALID_HANDLE);
    AssertReturn(pTimer->u32Magic == RTTIMER_MAGIC, VERR_INVALID_HANDLE);

    if (!ASMAtomicUoReadBool(&pTimer->fSuspended))
        return VERR_TIMER_ACTIVE;
    if (   pTimer->fSpecificCpu
        && !RTMpIsCpuOnline(pTimer->idCpu))
        return VERR_CPU_OFFLINE;

    /*
     * Start the timer.
     */
    PKDPC pMasterDpc = pTimer->fOmniTimer
                     ? &pTimer->aSubTimers[RTMpCpuIdToSetIndex(pTimer->idCpu)].NtDpc
                     : &pTimer->aSubTimers[0].NtDpc;

    uint64_t u64Interval = pTimer->u64NanoInterval / 1000000; /* This is ms, believe it or not. */
    ULONG ulInterval = (ULONG)u64Interval;
    if (ulInterval != u64Interval)
        ulInterval = MAXLONG;
    else if (!ulInterval && pTimer->u64NanoInterval)
        ulInterval = 1;

    LARGE_INTEGER DueTime;
    DueTime.QuadPart = -(int64_t)(u64First / 100); /* Relative, NT time. */
    if (DueTime.QuadPart)
        DueTime.QuadPart = -1;

    ASMAtomicWriteBool(&pTimer->fSuspended, false);
    KeSetTimerEx(&pTimer->NtTimer, DueTime, ulInterval, pMasterDpc);
    return VINF_SUCCESS;
}

/**
 * Worker that we can wrap with error variable saving and restoring.
 */
static bool rtAssertShouldPanicWorker(void)
{
    /*
     * Check for the VBOX_ASSERT variable.
     */
    const char *psz = RTEnvGet("VBOX_ASSERT");

    /* not defined => default behaviour. */
    if (!psz)
        return true;

    /* 'breakpoint' or 'panic' means default behaviour. */
    if (!strcmp(psz, "breakpoint") || !strcmp(psz, "panic"))
        return true;

#ifdef VBOX_RTASSERT_WITH_GDB
    /* 'gdb' - means try launch a gdb session in xterm. */
    if (!strcmp(psz, "gdb"))
    {
        /* Did we already fire up gdb? If so, just hit the breakpoint. */
        static bool volatile s_fAlreadyLaunchedGdb = false;
        if (ASMAtomicUoReadBool(&s_fAlreadyLaunchedGdb))
            return true;

        /* Try find a suitable terminal program. */
        const char *pszTerm = RTEnvGet("VBOX_ASSERT_TERM");
        if (    !pszTerm
            ||  !RTPathExists(pszTerm))
        {
            pszTerm = "/usr/bin/gnome-terminal";
            if (!RTPathExists(pszTerm))
            {
                pszTerm = "/usr/X11R6/bin/xterm";
                if (!RTPathExists(pszTerm))
                {
                    pszTerm ="/usr/bin/xterm";
                    if (!RTPathExists(pszTerm))
                        return true;
                }
            }
        }

        /* And find gdb. */
        const char *pszGdb = RTEnvGet("VBOX_ASSERT_GDB");
        if (    !pszGdb
            ||  !RTPathExists(pszGdb))
        {
            pszGdb = "/usr/bin/gdb";
            if (!RTPathExists(pszGdb))
                pszGdb = "gdb";
        }

        /* Try spawn the process. */
        char    szCmd[512];
        size_t  cch = RTStrPrintf(szCmd, sizeof(szCmd), "%s -p %d ", pszGdb, RTProcSelf());
        if (cch < sizeof(szCmd))
        {
            char *pszExecName = &szCmd[cch];
            if (!RTProcGetExecutablePath(pszExecName, sizeof(szCmd) - cch))
                *pszExecName = '\0';
        }
        const char *apszArgs[] =
        {
            pszTerm,
            "-e",
            szCmd,
            NULL
        };
        RTPROCESS Process;
        int rc = RTProcCreate(apszArgs[0], &apszArgs[0], RTENV_DEFAULT, 0, &Process);
        if (RT_FAILURE(rc))
            return false;

        ASMAtomicWriteBool(&s_fAlreadyLaunchedGdb, true);

        /* Wait for gdb to attach. */
        RTThreadSleep(15000);
        return true;
    }
#endif

    /* '*' - don't hit the breakpoint. */
    return false;
}

void VMMDev::hgcmShutdown(void)
{
    ASMAtomicWriteBool(&m_fHGCMActive, false);
    HGCMHostShutdown();
}