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/**************************************************************************
A/V Stream Camera Sample
Copyright (c) 2014, Microsoft Corporation.
File:
timer.h
Abstract:
Contains the definition of a KTimer and KPassiveTimer.
KTimer wraps a kernel timer object. KPassiveTimer uses a passive
callback through a KWorkItem.
History:
created 5/30/2014
**************************************************************************/
#pragma once
typedef void (*PKTimerCallback)( PVOID Context ) ;
class KTimer : public KWaitable, public Cancelable
{
public:
KTimer( TIMER_TYPE type=NotificationTimer );
virtual
~KTimer();
public:
//
// Override function that is invoked when a timer expires
//
virtual
void
Func() ;
//
// Cancels the timer
//
virtual
BOOLEAN
Cancel();
//
// Returns TRUE is if the timer is signalled
//
BOOLEAN
State()
{
return KeReadStateTimer( &m_Timer ) ;
}
//
// Resets (Cancels) the timer and DPC.
//
// Reset() returns TRUE if the KTIMER or the KDPC are dequeued.
// If Reset() returns FALSE the DPC may still be executing on another
// processor.
//
BOOLEAN
Reset()
{
// Try cancelling the timer.
if( !KeCancelTimer( &m_Timer ) )
{
// If the timer couldn't be cancelled, try removing the DPC.
return KeRemoveQueueDpc( &m_Dpc ) ;
}
return TRUE;
}
//
// Sets the timer
//
BOOLEAN
Set(
_In_ LARGE_INTEGER DueTime,
_In_opt_ PKTimerCallback Callback=NULL,
_In_opt_ PVOID Context=NULL,
_In_ LONG Period=0
)
{
m_Callback = Callback ;
m_Context = Context ;
m_Period = Period ;
return KeSetTimerEx( &m_Timer, DueTime, Period, &m_Dpc ) ;
}
//
// Sets the timer
//
BOOLEAN
Set(
_In_ LONGLONG DueTime,
_In_opt_ PKTimerCallback Callback=NULL,
_In_opt_ PVOID Context=NULL,
_In_ LONG Period=0
)
{
m_Callback = Callback ;
m_Context = Context ;
m_Period = Period ;
LARGE_INTEGER Due;
Due.QuadPart = DueTime;
return KeSetTimerEx( &m_Timer, Due, Period, &m_Dpc ) ;
}
//
// Support for waitable class
//
virtual
PVOID
GetDispatchObject();
private:
//
// Dpc Thunking function for KeSetTimerEx
//
_Function_class_(KDEFERRED_ROUTINE)
static
VOID
DpcThunk(
_In_ PKDPC Dpc,
_Inout_opt_ PVOID DeferredContext,
_Inout_opt_ PVOID Arg1,
_Inout_opt_ PVOID Arg2
) ;
TIMER_TYPE GetType() const
{
return m_type;
}
private:
KTIMER m_Timer ;
TIMER_TYPE m_type;
KDPC m_Dpc ;
LONG m_Period ;
protected:
PKTimerCallback m_Callback ;
PVOID m_Context ;
};
class KPassiveTimer : public KTimer
{
public:
KPassiveTimer(
_In_ PDEVICE_OBJECT DeviceObj,
_In_ TIMER_TYPE type=NotificationTimer
)
: KTimer( type )
, m_WorkItem( DeviceObj, WorkThunk, this )
{}
virtual
~KPassiveTimer();
//
// Override function that is invoked when a timer expires
//
virtual
void
Func() ;
//
// Cancels the timer
//
virtual
BOOLEAN
Cancel();
//
// Make sure it's in a valid state.
//
virtual
BOOLEAN
IsValid()
{
return m_WorkItem.IsValid();
}
private:
KWorkItem m_WorkItem;
//
// Dpc Thunking function for KeSetTimerEx
//
static
IO_WORKITEM_ROUTINE
WorkThunk;
};
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