VOID
NTAPI
KiTimerExpiration(IN PKDPC Dpc,
IN PVOID DeferredContext,
IN PVOID SystemArgument1,
IN PVOID SystemArgument2)
{
ULARGE_INTEGER SystemTime, InterruptTime;
LARGE_INTEGER Interval;
LONG Limit, Index, i;
ULONG Timers, ActiveTimers, DpcCalls;
PLIST_ENTRY ListHead, NextEntry;
KIRQL OldIrql;
PKTIMER Timer;
PKDPC TimerDpc;
ULONG Period;
DPC_QUEUE_ENTRY DpcEntry[MAX_TIMER_DPCS];
PKSPIN_LOCK_QUEUE LockQueue;
#ifdef CONFIG_SMP
PKPRCB Prcb = KeGetCurrentPrcb();
#endif
/* Disable interrupts */
_disable();
/* Query system and interrupt time */
KeQuerySystemTime((PLARGE_INTEGER)&SystemTime);
InterruptTime.QuadPart = KeQueryInterruptTime();
Limit = KeTickCount.LowPart;
/* Bring interrupts back */
_enable();
/* Get the index of the timer and normalize it */
Index = PtrToLong(SystemArgument1);
if ((Limit - Index) >= TIMER_TABLE_SIZE)
{
/* Normalize it */
Limit = Index + TIMER_TABLE_SIZE - 1;
}
/* Setup index and actual limit */
Index--;
Limit &= (TIMER_TABLE_SIZE - 1);
/* Setup accounting data */
DpcCalls = 0;
Timers = 24;
ActiveTimers = 4;
/* Lock the Database and Raise IRQL */
OldIrql = KiAcquireDispatcherLock();
/* Start expiration loop */
do
{
/* Get the current index */
Index = (Index + 1) & (TIMER_TABLE_SIZE - 1);
/* Get list pointers and loop the list */
ListHead = &KiTimerTableListHead[Index].Entry;
while (ListHead != ListHead->Flink)
{
/* Lock the timer and go to the next entry */
LockQueue = KiAcquireTimerLock(Index);
NextEntry = ListHead->Flink;
/* Get the current timer and check its due time */
Timers--;
Timer = CONTAINING_RECORD(NextEntry, KTIMER, TimerListEntry);
if ((NextEntry != ListHead) &&
(Timer->DueTime.QuadPart <= InterruptTime.QuadPart))
{
/* It's expired, remove it */
ActiveTimers--;
KiRemoveEntryTimer(Timer);
/* Make it non-inserted, unlock it, and signal it */
Timer->Header.Inserted = FALSE;
KiReleaseTimerLock(LockQueue);
Timer->Header.SignalState = 1;
/* Get the DPC and period */
TimerDpc = Timer->Dpc;
Period = Timer->Period;
/* Check if there's any waiters */
if (!IsListEmpty(&Timer->Header.WaitListHead))
{
/* Check the type of event */
if (Timer->Header.Type == TimerNotificationObject)
{
/* Unwait the thread */
KxUnwaitThread(&Timer->Header, IO_NO_INCREMENT);
}
else
{
/* Otherwise unwait the thread and signal the timer */
KxUnwaitThreadForEvent((PKEVENT)Timer, IO_NO_INCREMENT);
}
}
/* Check if we have a period */
if (Period)
{
/* Calculate the interval and insert the timer */
Interval.QuadPart = Int32x32To64(Period, -10000);
while (!KiInsertTreeTimer(Timer, Interval));
}
/* Check if we have a DPC */
if (TimerDpc)
{
#ifdef CONFIG_SMP
/*
* If the DPC is targeted to another processor,
* then insert it into that processor's DPC queue
* instead of delivering it now.
* If the DPC is a threaded DPC, and the current CPU
* has threaded DPCs enabled (KiExecuteDpc is actively parsing DPCs),
* then also insert it into the DPC queue for threaded delivery,
* instead of doing it here.
*/
if (((TimerDpc->Number >= MAXIMUM_PROCESSORS) &&
((TimerDpc->Number - MAXIMUM_PROCESSORS) != Prcb->Number)) ||
((TimerDpc->Type == ThreadedDpcObject) && (Prcb->ThreadDpcEnable)))
{
/* Queue it */
KeInsertQueueDpc(TimerDpc,
UlongToPtr(SystemTime.LowPart),
UlongToPtr(SystemTime.HighPart));
}
else
#endif
{
/* Setup the DPC Entry */
DpcEntry[DpcCalls].Dpc = TimerDpc;
DpcEntry[DpcCalls].Routine = TimerDpc->DeferredRoutine;
DpcEntry[DpcCalls].Context = TimerDpc->DeferredContext;
DpcCalls++;
ASSERT(DpcCalls < MAX_TIMER_DPCS);
}
}
/* Check if we're done processing */
if (!(ActiveTimers) || !(Timers))
{
/* Release the dispatcher while doing DPCs */
KiReleaseDispatcherLock(DISPATCH_LEVEL);
/* Start looping all DPC Entries */
for (i = 0; DpcCalls; DpcCalls--, i++)
{
/* Call the DPC */
DpcEntry[i].Routine(DpcEntry[i].Dpc,
DpcEntry[i].Context,
UlongToPtr(SystemTime.LowPart),
UlongToPtr(SystemTime.HighPart));
}
/* Reset accounting */
Timers = 24;
ActiveTimers = 4;
/* Lock the dispatcher database */
KiAcquireDispatcherLock();
}
}
else
{
/* Check if the timer list is empty */
if (NextEntry != ListHead)
{
/* Sanity check */
ASSERT(KiTimerTableListHead[Index].Time.QuadPart <=
Timer->DueTime.QuadPart);
/* Update the time */
_disable();
KiTimerTableListHead[Index].Time.QuadPart =
Timer->DueTime.QuadPart;
_enable();
}
/* Release the lock */
KiReleaseTimerLock(LockQueue);
/* Check if we've scanned all the timers we could */
if (!Timers)
{
/* Release the dispatcher while doing DPCs */
KiReleaseDispatcherLock(DISPATCH_LEVEL);
/* Start looping all DPC Entries */
for (i = 0; DpcCalls; DpcCalls--, i++)
{
/* Call the DPC */
DpcEntry[i].Routine(DpcEntry[i].Dpc,
DpcEntry[i].Context,
UlongToPtr(SystemTime.LowPart),
UlongToPtr(SystemTime.HighPart));
}
/* Reset accounting */
Timers = 24;
ActiveTimers = 4;
/* Lock the dispatcher database */
KiAcquireDispatcherLock();
}
/* Done looping */
break;
}
}
} while (Index != Limit);
/* Verify the timer table, on debug builds */
if (KeNumberProcessors == 1) KiCheckTimerTable(InterruptTime);
/* Check if we still have DPC entries */
if (DpcCalls)
{
/* Release the dispatcher while doing DPCs */
KiReleaseDispatcherLock(DISPATCH_LEVEL);
/* Start looping all DPC Entries */
for (i = 0; DpcCalls; DpcCalls--, i++)
{
/* Call the DPC */
DpcEntry[i].Routine(DpcEntry[i].Dpc,
DpcEntry[i].Context,
UlongToPtr(SystemTime.LowPart),
UlongToPtr(SystemTime.HighPart));
}
/* Lower IRQL if we need to */
if (OldIrql != DISPATCH_LEVEL) KeLowerIrql(OldIrql);
}
else
{
/* Unlock the dispatcher */
KiReleaseDispatcherLock(OldIrql);
}
}
VOID
KiTimerExpiration (
IN PKDPC TimerDpc,
IN PVOID DeferredContext,
IN PVOID SystemArgument1,
IN PVOID SystemArgument2
)
/*++
Routine Description:
This function is called when the clock interupt routine discovers that
a timer has expired.
Arguments:
TimerDpc - Supplies a pointer to a control object of type DPC.
DeferredContext - Not used.
SystemArgument1 - Supplies the starting timer table index value to
use for the timer table scan.
SystemArgument2 - Not used.
Return Value:
None.
--*/
{
ULARGE_INTEGER CurrentTime;
LIST_ENTRY ExpiredListHead;
LONG HandLimit;
LONG Index;
PLIST_ENTRY ListHead;
PLIST_ENTRY NextEntry;
KIRQL OldIrql;
PKTIMER Timer;
//
// Acquire the dispatcher database lock and read the current interrupt
// time to determine which timers have expired.
//
KiLockDispatcherDatabase(&OldIrql);
KiQueryInterruptTime((PLARGE_INTEGER)&CurrentTime);
//
// If the timer table has not wrapped, then start with the specified
// timer table index value, and scan for timer entries that have expired.
// Otherwise, start with the first entry in the timer table and scan the
// entire table for timer entries that have expired.
//
// N.B. This later condition exists when DPC processing is blocked for a
// period longer than one round trip throught the timer table.
//
HandLimit = (LONG)KiQueryLowTickCount();
if (((ULONG)(HandLimit - PtrToLong(SystemArgument1))) >= TIMER_TABLE_SIZE) {
Index = - 1;
HandLimit = TIMER_TABLE_SIZE - 1;
} else {
Index = (PtrToLong(SystemArgument1) - 1) & (TIMER_TABLE_SIZE - 1);
HandLimit &= (TIMER_TABLE_SIZE - 1);
}
InitializeListHead(&ExpiredListHead);
do {
Index = (Index + 1) & (TIMER_TABLE_SIZE - 1);
ListHead = &KiTimerTableListHead[Index];
NextEntry = ListHead->Flink;
while (NextEntry != ListHead) {
Timer = CONTAINING_RECORD(NextEntry, KTIMER, TimerListEntry);
if (Timer->DueTime.QuadPart <= CurrentTime.QuadPart) {
//
// The next timer in the current timer list has expired.
// Remove the entry from the timer list and insert the
// timer in the expired list.
//
RemoveEntryList(&Timer->TimerListEntry);
InsertTailList(&ExpiredListHead, &Timer->TimerListEntry);
NextEntry = ListHead->Flink;
} else {
break;
}
}
} while(Index != HandLimit);
#if DBG
if ((PtrToUlong(SystemArgument2) == 0) && (KeNumberProcessors == 1)) {
KiCheckTimerTable(CurrentTime);
}
#endif
//
// Process the expired timer list.
//
// N.B. The following function returns with the dispatcher database
// unlocked.
//
KiTimerListExpire(&ExpiredListHead, OldIrql);
return;
}