iotimer.c File Reference

#include <ntoskrnl.h>
#include <debug.h>

Include dependency graph for iotimer.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
VOID NTAPI	IopTimerDispatch (IN PKDPC Dpc, IN PVOID DeferredContext, IN PVOID SystemArgument1, IN PVOID SystemArgument2)
VOID NTAPI	IopRemoveTimerFromTimerList (IN PIO_TIMER Timer)
NTSTATUS NTAPI	IoInitializeTimer (IN PDEVICE_OBJECT DeviceObject, IN PIO_TIMER_ROUTINE TimerRoutine, IN PVOID Context)
VOID NTAPI	IoStartTimer (IN PDEVICE_OBJECT DeviceObject)
VOID NTAPI	IoStopTimer (PDEVICE_OBJECT DeviceObject)

Variables
KSPIN_LOCK	IopTimerLock
LIST_ENTRY	IopTimerQueueHead
KDPC	IopTimerDpc
KTIMER	IopTimer
ULONG	IopTimerCount = 0

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 12 of file iotimer.c.

Function Documentation

IoInitializeTimer()

NTSTATUS NTAPI IoInitializeTimer	(	IN PDEVICE_OBJECT	DeviceObject,
		IN PIO_TIMER_ROUTINE	TimerRoutine,
		IN PVOID	Context
	)

Definition at line 92 of file iotimer.c.

{
    PIO_TIMER IoTimer = DeviceObject->Timer;
    PAGED_CODE();

    /* Check if we don't have a timer yet */
    if (!IoTimer)
    {
        /* Allocate Timer */
        IoTimer = ExAllocatePoolWithTag(NonPagedPool,
                                        sizeof(IO_TIMER),
                                        TAG_IO_TIMER);
        if (!IoTimer) return STATUS_INSUFFICIENT_RESOURCES;

        /* Set up the Timer Structure */
        RtlZeroMemory(IoTimer, sizeof(IO_TIMER));
        IoTimer->Type = IO_TYPE_TIMER;
        IoTimer->DeviceObject = DeviceObject;
        DeviceObject->Timer = IoTimer;
    }

    /* Setup the timer routine and context */
    IoTimer->TimerRoutine = TimerRoutine;
    IoTimer->Context = Context;

    /* Add it to the Timer List */
    ExInterlockedInsertTailList(&IopTimerQueueHead,
                                &IoTimer->IoTimerList,
                                &IopTimerLock);

    /* Return Success */
    return STATUS_SUCCESS;
}

Referenced by ClasspEnableTimer(), CreateCdRomDeviceObject(), IntVideoPortSetupTimer(), PcAddAdapterDevice(), ScsiPortInitialize(), USBSTOR_AddDevice(), and WdmaudAddDevice().

IopRemoveTimerFromTimerList()

VOID NTAPI IopRemoveTimerFromTimerList

(

IN PIO_TIMER

Timer

)

Definition at line 70 of file iotimer.c.

{
    KIRQL OldIrql;

    /* Lock Timers */
    KeAcquireSpinLock(&IopTimerLock, &OldIrql);

    /* Remove Timer from the List and Drop the Timer Count if Enabled */
    RemoveEntryList(&Timer->IoTimerList);
    if (Timer->TimerEnabled) IopTimerCount--;

    /* Unlock the Timers */
    KeReleaseSpinLock(&IopTimerLock, OldIrql);
}

Referenced by IoDeleteDevice().

IopTimerDispatch()

VOID NTAPI IopTimerDispatch	(	IN PKDPC	Dpc,
		IN PVOID	DeferredContext,
		IN PVOID	SystemArgument1,
		IN PVOID	SystemArgument2
	)

Definition at line 32 of file iotimer.c.

{
    KIRQL OldIrql;
    PLIST_ENTRY TimerEntry;
    PIO_TIMER Timer;
    ULONG i;

    /* Check if any Timers are actualyl enabled as of now */
    if (IopTimerCount)
    {
        /* Lock the Timers */
        KeAcquireSpinLock(&IopTimerLock, &OldIrql);

        /* Call the Timer Routine of each enabled Timer */
        for (TimerEntry = IopTimerQueueHead.Flink, i = IopTimerCount;
            (TimerEntry != &IopTimerQueueHead) && i;
            TimerEntry = TimerEntry->Flink)
        {
            /* Get the timer and check if it's enabled */
            Timer = CONTAINING_RECORD(TimerEntry, IO_TIMER, IoTimerList);
            if (Timer->TimerEnabled)
            {
                /* Call the timer routine */
                Timer->TimerRoutine(Timer->DeviceObject, Timer->Context);
                i--;
            }
        }

        /* Unlock the Timers */
        KeReleaseSpinLock(&IopTimerLock, OldIrql);
    }
}

Referenced by IoInitSystem().

IoStartTimer()

VOID NTAPI IoStartTimer

(

IN PDEVICE_OBJECT

DeviceObject

)

Definition at line 133 of file iotimer.c.

{
    KIRQL OldIrql;
    PIO_TIMER IoTimer = DeviceObject->Timer;

    /* Make sure the device isn't unloading */
    if (!(((PEXTENDED_DEVOBJ_EXTENSION)(DeviceObject->DeviceObjectExtension))->
            ExtensionFlags & (DOE_UNLOAD_PENDING |
                              DOE_DELETE_PENDING |
                              DOE_REMOVE_PENDING |
                              DOE_REMOVE_PROCESSED)))
    {
        /* Lock Timers */
        KeAcquireSpinLock(&IopTimerLock, &OldIrql);

        /* Check if the timer isn't already enabled */
        if (!IoTimer->TimerEnabled)
        {
            /* Enable it and increase the timer count */
            IoTimer->TimerEnabled = TRUE;
            IopTimerCount++;
        }

        /* Unlock Timers */
        KeReleaseSpinLock(&IopTimerLock, OldIrql);
    }
}

Referenced by ClasspEnableTimer(), CreateCdRomDeviceObject(), PcAddAdapterDevice(), ScsiPortInitialize(), VideoPortStartTimer(), and WdmaudAddDevice().

IoStopTimer()

VOID NTAPI IoStopTimer

(

PDEVICE_OBJECT

DeviceObject

)

Definition at line 166 of file iotimer.c.

{
    KIRQL OldIrql;
    PIO_TIMER IoTimer = DeviceObject->Timer;

    /* Lock Timers */
    KeAcquireSpinLock(&IopTimerLock, &OldIrql);

    /* Check if the timer is enabled */
    if (IoTimer->TimerEnabled)
    {
        /* Disable it and decrease the timer count */
        IoTimer->TimerEnabled = FALSE;
        IopTimerCount--;
    }

    /* Unlock Timers */
    KeReleaseSpinLock(&IopTimerLock, OldIrql);
}

Referenced by ClassDispatchPnp(), ClasspDisableTimer(), SpiCleanupAfterInit(), USBSTOR_FdoHandlePnp(), and VideoPortStopTimer().

Variable Documentation

IopTimer

KTIMER IopTimer

Definition at line 23 of file iotimer.c.

Referenced by IoInitSystem().

IopTimerCount

ULONG IopTimerCount = 0

Definition at line 26 of file iotimer.c.

Referenced by IopRemoveTimerFromTimerList(), IopTimerDispatch(), IoStartTimer(), and IoStopTimer().

IopTimerDpc

KDPC IopTimerDpc

Definition at line 22 of file iotimer.c.

Referenced by IoInitSystem().

IopTimerLock

KSPIN_LOCK IopTimerLock

Definition at line 18 of file iotimer.c.

Referenced by IoInitializeTimer(), IoInitSystem(), IopRemoveTimerFromTimerList(), IopTimerDispatch(), IoStartTimer(), and IoStopTimer().

IopTimerQueueHead

LIST_ENTRY IopTimerQueueHead

Definition at line 19 of file iotimer.c.

Referenced by IoInitializeTimer(), IoInitSystem(), and IopTimerDispatch().