reactos/ntoskrnl/io/iomgr/iotimer.c
2023-03-09 18:26:02 +01:00

187 lines
4.8 KiB
C

/*
* PROJECT: ReactOS Kernel
* LICENSE: GPL - See COPYING in the top level directory
* FILE: ntoskrnl/io/iomgr/iotimer.c
* PURPOSE: I/O Wrappers for Executive Timers
* PROGRAMMERS: Alex Ionescu (alex.ionescu@reactos.org)
*/
/* INCLUDES *****************************************************************/
#include <ntoskrnl.h>
#define NDEBUG
#include <debug.h>
/* GLOBALS *******************************************************************/
/* Timer Database */
KSPIN_LOCK IopTimerLock;
LIST_ENTRY IopTimerQueueHead;
/* Timer Firing */
KDPC IopTimerDpc;
KTIMER IopTimer;
/* Keep count of how many timers we have */
ULONG IopTimerCount = 0;
/* PRIVATE FUNCTIONS *********************************************************/
VOID
NTAPI
IopTimerDispatch(IN PKDPC Dpc,
IN PVOID DeferredContext,
IN PVOID SystemArgument1,
IN PVOID SystemArgument2)
{
KIRQL OldIrql;
PLIST_ENTRY TimerEntry;
PIO_TIMER Timer;
ULONG i;
/* Check if any Timers are actually 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);
}
}
VOID
NTAPI
IopRemoveTimerFromTimerList(IN PIO_TIMER Timer)
{
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);
}
/* PUBLIC FUNCTIONS **********************************************************/
/*
* @implemented
*/
NTSTATUS
NTAPI
IoInitializeTimer(IN PDEVICE_OBJECT DeviceObject,
IN PIO_TIMER_ROUTINE TimerRoutine,
IN PVOID Context)
{
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;
}
/*
* @implemented
*/
VOID
NTAPI
IoStartTimer(IN PDEVICE_OBJECT DeviceObject)
{
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);
}
}
/*
* @implemented
*/
VOID
NTAPI
IoStopTimer(PDEVICE_OBJECT DeviceObject)
{
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);
}
/* EOF */