ke_x.h

winNT技术操作系统,国外开放的原代码和LIUX一样

    /* Add it on the list */
    PushEntryList(&Prcb->DeferredReadyListHead, &Thread->SwapListEntry);
}

FORCEINLINE
VOID
KiRescheduleThread(IN BOOLEAN NewThread,
                   IN ULONG Cpu)
{
    /* Check if a new thread needs to be scheduled on a different CPU */
    if ((NewThread) && !(KeGetPcr()->Number == Cpu))
    {
        /* Send an IPI to request delivery */
        KiIpiSendRequest(AFFINITY_MASK(Cpu), IPI_DPC);
    }
}

//
// This routine sets the current thread in a swap busy state, which ensure that
// nobody else tries to swap it concurrently.
//
FORCEINLINE
VOID
KiSetThreadSwapBusy(IN PKTHREAD Thread)
{
    /* Make sure nobody already set it */
    ASSERT(Thread->SwapBusy == FALSE);

    /* Set it ourselves */
    Thread->SwapBusy = TRUE;
}

//
// This routine acquires the PRCB lock so that only one caller can touch
// volatile PRCB data.
//
// Since this is a simple optimized spin-lock, it must be be only acquired
// at dispatcher level or higher!
//
FORCEINLINE
VOID
KiAcquirePrcbLock(IN PKPRCB Prcb)
{
    /* Make sure we're at a safe level to touch the PRCB lock */
    ASSERT(KeGetCurrentIrql() >= DISPATCH_LEVEL);

    /* Start acquire loop */
    for (;;)
    {
        /* Acquire the lock and break out if we acquired it first */
        if (!InterlockedExchange(&Prcb->PrcbLock, 1)) break;

        /* Loop until the other CPU releases it */
        do
        {
            /* Let the CPU know that this is a loop */
            YieldProcessor();
        } while (Prcb->PrcbLock);
    }
}

//
// This routine releases the PRCB lock so that other callers can touch
// volatile PRCB data.
//
// Since this is a simple optimized spin-lock, it must be be only acquired
// at dispatcher level or higher!
//
FORCEINLINE
VOID
KiReleasePrcbLock(IN PKPRCB Prcb)
{
    /* Make sure it's acquired! */
    ASSERT(Prcb->PrcbLock != 0);

    /* Release it */
    InterlockedAnd(&Prcb->PrcbLock, 0);
}

//
// This routine acquires the thread lock so that only one caller can touch
// volatile thread data.
//
// Since this is a simple optimized spin-lock, it must be be only acquired
// at dispatcher level or higher!
//
FORCEINLINE
VOID
KiAcquireThreadLock(IN PKTHREAD Thread)
{
    /* Make sure we're at a safe level to touch the thread lock */
    ASSERT(KeGetCurrentIrql() >= DISPATCH_LEVEL);

    /* Start acquire loop */
    for (;;)
    {
        /* Acquire the lock and break out if we acquired it first */
        if (!InterlockedExchange(&Thread->ThreadLock, 1)) break;

        /* Loop until the other CPU releases it */
        do
        {
            /* Let the CPU know that this is a loop */
            YieldProcessor();
        } while (Thread->ThreadLock);
    }
}

//
// This routine releases the thread lock so that other callers can touch
// volatile thread data.
//
// Since this is a simple optimized spin-lock, it must be be only acquired
// at dispatcher level or higher!
//
FORCEINLINE
VOID
KiReleaseThreadLock(IN PKTHREAD Thread)
{
    /* Release it */
    InterlockedAnd(&Thread->ThreadLock, 0);
}

FORCEINLINE
BOOLEAN
KiTryThreadLock(IN PKTHREAD Thread)
{
    LONG Value;

    /* If the lock isn't acquired, return false */
    if (!Thread->ThreadLock) return FALSE;

    /* Otherwise, try to acquire it and check the result */
    Value = 1;
    Value = InterlockedExchange(&Thread->ThreadLock, &Value);

    /* Return the lock state */
    return (Value == TRUE);
}

FORCEINLINE
VOID
KiCheckDeferredReadyList(IN PKPRCB Prcb)
{
    /* Scan the deferred ready lists if required */
    if (Prcb->DeferredReadyListHead.Next) KiProcessDeferredReadyList(Prcb);
}

FORCEINLINE
VOID
KiRequestApcInterrupt(IN BOOLEAN NeedApc,
                      IN UCHAR Processor)
{
    /* Check if we need to request APC delivery */
    if (NeedApc)
    {
        /* Check if it's on another CPU */
        if (KeGetPcr()->Number != Cpu)
        {
            /* Send an IPI to request delivery */
            KiIpiSendRequest(AFFINITY_MASK(Cpu), IPI_DPC);
        }
        else
        {
            /* Request a software interrupt */
            HalRequestSoftwareInterrupt(APC_LEVEL);
        }
    }
}

#endif

FORCEINLINE
VOID
KiAcquireApcLock(IN PKTHREAD Thread,
                 IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Acquire the lock and raise to synchronization level */
    KeAcquireInStackQueuedSpinLockRaiseToSynch(&Thread->ApcQueueLock, Handle);
}

FORCEINLINE
VOID
KiAcquireApcLockAtDpcLevel(IN PKTHREAD Thread,
                           IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Acquire the lock */
    KeAcquireInStackQueuedSpinLockAtDpcLevel(&Thread->ApcQueueLock, Handle);
}

FORCEINLINE
VOID
KiAcquireApcLockAtApcLevel(IN PKTHREAD Thread,
                           IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Acquire the lock */
    KeAcquireInStackQueuedSpinLock(&Thread->ApcQueueLock, Handle);
}

FORCEINLINE
VOID
KiReleaseApcLock(IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Release the lock */
    KeReleaseInStackQueuedSpinLock(Handle);
}

FORCEINLINE
VOID
KiReleaseApcLockFromDpcLevel(IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Release the lock */
    KeReleaseInStackQueuedSpinLockFromDpcLevel(Handle);
}

FORCEINLINE
VOID
KiAcquireProcessLock(IN PKPROCESS Process,
                     IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Acquire the lock and raise to synchronization level */
    KeAcquireInStackQueuedSpinLockRaiseToSynch(&Process->ProcessLock, Handle);
}

FORCEINLINE
VOID
KiReleaseProcessLock(IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Release the lock */
    KeReleaseInStackQueuedSpinLock(Handle);
}

FORCEINLINE
VOID
KiReleaseProcessLockFromDpcLevel(IN PKLOCK_QUEUE_HANDLE Handle)
{
    /* Release the lock */
    KeReleaseInStackQueuedSpinLockFromDpcLevel(Handle);
}

FORCEINLINE
VOID
KiAcquireDeviceQueueLock(IN PKDEVICE_QUEUE DeviceQueue,
                         IN PKLOCK_QUEUE_HANDLE DeviceLock)
{
    /* Check if we were called from a threaded DPC */
    if (KeGetCurrentPrcb()->DpcThreadActive)
    {
        /* Lock the Queue, we're not at DPC level */
        KeAcquireInStackQueuedSpinLock(&DeviceQueue->Lock, DeviceLock);
    }
    else
    {
        /* We must be at DPC level, acquire the lock safely */
        ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);
        KeAcquireInStackQueuedSpinLockAtDpcLevel(&DeviceQueue->Lock,
                                                 DeviceLock);
    }
}

FORCEINLINE
VOID
KiReleaseDeviceQueueLock(IN PKLOCK_QUEUE_HANDLE DeviceLock)
{
    /* Check if we were called from a threaded DPC */
    if (KeGetCurrentPrcb()->DpcThreadActive)
    {
        /* Unlock the Queue, we're not at DPC level */
        KeReleaseInStackQueuedSpinLock(DeviceLock);
    }
    else
    {
        /* We must be at DPC level, release the lock safely */
        ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);
        KeReleaseInStackQueuedSpinLockFromDpcLevel(DeviceLock);
    }
}

//
// This routine queues a thread that is ready on the PRCB's ready lists.
// If this thread cannot currently run on this CPU, then the thread is
// added to the deferred ready list instead.
//
// This routine must be entered with the PRCB lock held and it will exit
// with the PRCB lock released!
//
FORCEINLINE
VOID
KxQueueReadyThread(IN PKTHREAD Thread,
                   IN PKPRCB Prcb)
{
    BOOLEAN Preempted;
    KPRIORITY Priority;

    /* Sanity checks */
    ASSERT(Prcb == KeGetCurrentPrcb());
    ASSERT(Thread->State == Running);
    ASSERT(Thread->NextProcessor == Prcb->Number);

    /* Check if this thread is allowed to run in this CPU */
#ifdef _CONFIG_SMP
    if ((Thread->Affinity) & (Prcb->SetMember))
#else
    if (TRUE)
#endif
    {
        /* Set thread ready for execution */
        Thread->State = Ready;

        /* Save current priority and if someone had pre-empted it */
        Priority = Thread->Priority;
        Preempted = Thread->Preempted;

        /* We're not pre-empting now, and set the wait time */
        Thread->Preempted = FALSE;
        Thread->WaitTime = KeTickCount.LowPart;

        /* Sanity check */
        ASSERT((Priority >= 0) && (Priority <= HIGH_PRIORITY));

        /* Insert this thread in the appropriate order */
        Preempted ? InsertHeadList(&Prcb->DispatcherReadyListHead[Priority],
                                   &Thread->WaitListEntry) :
                    InsertTailList(&Prcb->DispatcherReadyListHead[Priority],
                                   &Thread->WaitListEntry);

        /* Update the ready summary */
        Prcb->ReadySummary |= PRIORITY_MASK(Priority);

        /* Sanity check */
        ASSERT(Priority == Thread->Priority);

        /* Release the PRCB lock */
        KiReleasePrcbLock(Prcb);
    }
    else
    {
        /* Otherwise, prepare this thread to be deferred */
        Thread->State = DeferredReady;
        Thread->DeferredProcessor = Prcb->Number;

        /* Release the lock and defer scheduling */
        KiReleasePrcbLock(Prcb);
        KiDeferredReadyThread(Thread);
    }
}

//
// This routine scans for an appropriate ready thread to select at the
// given priority and for the given CPU.
//
FORCEINLINE
PKTHREAD
KiSelectReadyThread(IN KPRIORITY Priority,
                    IN PKPRCB Prcb)
{
    LONG PriorityMask, PrioritySet, HighPriority;
    PLIST_ENTRY ListEntry;
    PKTHREAD Thread;

    /* Save the current mask and get the priority set for the CPU */
    PriorityMask = Priority;
    PrioritySet = Prcb->ReadySummary >> (UCHAR)Priority;
    if (!PrioritySet) return NULL;

    /*  Get the highest priority possible */
    BitScanReverse((PULONG)&HighPriority, PrioritySet);
    ASSERT((PrioritySet & PRIORITY_MASK(HighPriority)) != 0);
    HighPriority += PriorityMask;

    /* Make sure the list isn't at highest priority */
    ASSERT(IsListEmpty(&Prcb->DispatcherReadyListHead[HighPriority]) == FALSE);

    /* Get the first thread on the list */
    ListEntry = &Prcb->DispatcherReadyListHead[HighPriority];
    Thread = CONTAINING_RECORD(ListEntry, KTHREAD, WaitListEntry);

    /* Make sure this thread is here for a reason */
    ASSERT(HighPriority == Thread->Priority);
    ASSERT(Thread->Affinity & AFFINITY_MASK(Prcb->Number));
    ASSERT(Thread->NextProcessor == Prcb->Number);

    /* Remove it from the list */
    RemoveEntryList(&Thread->WaitListEntry);
    if (IsListEmpty(&Thread->WaitListEntry))
    {
        /* The list is empty now, reset the ready summary */
        Prcb->ReadySummary ^= PRIORITY_MASK(HighPriority);
    }

    /* Sanity check and return the thread */
    ASSERT((Thread == NULL) ||
           (Thread->BasePriority == 0) ||
           (Thread->Priority != 0));
    return Thread;
}

//
// This routine computes the new priority for a thread. It is only valid for
// threads with priorities in the dynamic priority range.
//
SCHAR
FORCEINLINE
KiComputeNewPriority(IN PKTHREAD Thread)
{
    SCHAR Priority;

    /* Priority sanity checks */
    ASSERT((Thread->PriorityDecrement >= 0) &&
           (Thread->PriorityDecrement <= Thread->Priority));
    ASSERT((Thread->Priority < LOW_REALTIME_PRIORITY) ?
            TRUE : (Thread->PriorityDecrement == 0));

    /* Get the current priority */
    Priority = Thread->Priority;
    if (Priority < LOW_REALTIME_PRIORITY)
    {
        /* Decrease priority by the priority decrement */
        Priority -= (Thread->PriorityDecrement + 1);

        /* Don't go out of bounds */
        if (Priority < Thread->BasePriority) Priority = Thread->BasePriority;

        /* Reset the priority decrement */
        Thread->PriorityDecrement = 0;
    }

    /* Sanity check */
    ASSERT((Thread->BasePriority == 0) || (Priority != 0));

    /* Return the new priority */
    return Priority;
}

PRKTHREAD
FORCEINLINE
KeGetCurrentThread(VOID)
{
    /* Return the current thread */
    return ((PKIPCR)KeGetPcr())->PrcbData.CurrentThread;
}

UCHAR
FORCEINLINE
KeGetPreviousMode(VOID)
{
    /* Return the current mode */
    return KeGetCurrentThread()->PreviousMode;
}