// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of the License "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// e32\include\nkern\nkern.h
// 
// WARNING: This file contains some APIs which are internal and are subject
//          to change without notice. Such APIs should therefore not be used
//          outside the Kernel and Hardware Services package.
//

#ifndef __NKERN_H__
#define __NKERN_H__

#ifdef	__STANDALONE_NANOKERNEL__
#undef	__IN_KERNEL__
#define	__IN_KERNEL__
#endif

#include <e32const.h>
#include <nklib.h>
#include <dfcs.h>
#include <nk_trace.h>
#include <e32atomics.h>

extern "C" {
/** @internalComponent */
IMPORT_C void NKFault(const char* file, TInt line);
/** @internalComponent */
void NKIdle(TInt aStage);
}

/**
@publishedPartner
@released
*/
#define FAULT()		NKFault(__FILE__,__LINE__)

#ifdef _DEBUG

/**
@publishedPartner
@released
*/
#define __NK_ASSERT_DEBUG(c)	((void) ((c)||(FAULT(),0)) )

#else

#define __NK_ASSERT_DEBUG(c)

#endif

/**
@publishedPartner
@released
*/
#define __NK_ASSERT_ALWAYS(c)	((void) ((c)||(FAULT(),0)) )

/**
	@publishedPartner
	@released
*/
const TInt KNumPriorities=64;

const TInt KMaxCpus=8;

class NThread;


/** Spin lock

	Used for protecting a code fragment against both interrupts and concurrent
	execution on another processor.
	
	@internalComponent
*/
class TSpinLock
	{
public:
	enum TOrder
		{
		// Bit 7 of order clear for locks used with interrupts disabled
		EOrderGenericIrqLow0	=0x00u,	// Device driver spin locks, low range
		EOrderGenericIrqLow1	=0x01u,	// Device driver spin locks, low range
		EOrderGenericIrqLow2	=0x02u,	// Device driver spin locks, low range
		EOrderGenericIrqLow3	=0x03u,	// Device driver spin locks, low range
		EOrderGenericIrqHigh0	=0x18u,	// Device driver spin locks, high range
		EOrderGenericIrqHigh1	=0x19u,	// Device driver spin locks, high range
		EOrderGenericIrqHigh2	=0x1Au,	// Device driver spin locks, high range
		EOrderGenericIrqHigh3	=0x1Bu,	// Device driver spin locks, high range

		// Bit 7 of order set for locks used with interrupts enabled, preemption disabled
		EOrderGenericPreLow0	=0x80u,		// Device driver spin locks, low range
		EOrderGenericPreLow1	=0x81u,		// Device driver spin locks, low range
		EOrderGenericPreHigh0	=0x9Eu,		// Device driver spin locks, high range
		EOrderGenericPreHigh1	=0x9Fu,		// Device driver spin locks, high range

		EOrderNone				=0xFFu	// No order check required (e.g. for dynamic ordering)
		};
public:
	IMPORT_C TSpinLock(TUint aOrder);
private:
	volatile TUint64 iLock;
	};

/** Macro to disable interrupts and acquire the lock.

@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQ(lock)					((void)NKern::DisableAllInterrupts())

/** Macro to release the lock and enable interrupts.

@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQ(lock)					(NKern::EnableAllInterrupts())

/** Macro to see if someone else is waiting for the lock, enabling IRQs 
    then disabling IRQs again.

@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQ(lock)					(NKern::EnableAllInterrupts(),(void)NKern::DisableAllInterrupts(),((TBool)TRUE))

/** Macro to remember original interrupt state then disable interrupts 
    and acquire the lock.
    
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQSAVE(lock)				(NKern::DisableAllInterrupts())

/** Macro to release the lock then restore original interrupt state to that 
	supplied.
	
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQRESTORE(lock,irq)		(NKern::RestoreInterrupts(irq))

/** Macro to see if someone else is waiting for the lock, enabling IRQs to
	the original state supplied then disabling IRQs again.
    
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQRESTORE(lock,irq)		(NKern::RestoreInterrupts(irq),((void)NKern::DisableAllInterrupts()),((TBool)TRUE))

/** Macro to acquire the lock. This assumes the caller has already disabled 
    interrupts/preemption. 
	
	If interrupts/preemption is not disabled a run-time assert will occur
	This is to protect against unsafe code that might lead to same core 
	deadlock.
	
    In device driver code it is safer to use __SPIN_LOCK_IRQSAVE() instead, 
	although not as efficient should interrupts aleady be disabled for the 
	duration the lock is held.
    
@publishedPartner
@prototype
*/
#define __SPIN_LOCK(lock)

/** Macro to release the lock, don't change interrupt/preemption state.

@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK(lock)

/**
@internalComponent
*/
#define __SPIN_FLASH(lock)						((TBool)FALSE)

/** Macro to see if someone else is waiting for the lock, enabling preemption 
    then disabling it again.

@publishedPartner
@prototype
*/
#define __SPIN_FLASH_PREEMPT(lock)				((TBool)NKern::PreemptionPoint())


/** Read/Write Spin lock

	@internalComponent
*/
class TRWSpinLock
	{
public:
	IMPORT_C TRWSpinLock(TUint aOrder);		// Uses same order space as TSpinLock
private:
	volatile TUint64 iLock;
	};


/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQ_R(lock)					((void)NKern::DisableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQ_R(lock)				(NKern::EnableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQ_R(lock)				(NKern::EnableAllInterrupts(),(void)NKern::DisableAllInterrupts(),((TBool)TRUE))

/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQ_W(lock)					((void)NKern::DisableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQ_W(lock)				(NKern::EnableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQ_W(lock)				(NKern::EnableAllInterrupts(),(void)NKern::DisableAllInterrupts(),((TBool)TRUE))


/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_R(lock)						

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_R(lock)					

/**
@internalComponent
*/
#define __SPIN_FLASH_R(lock)					((TBool)FALSE)

/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_W(lock)						

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_W(lock)					

/**
@internalComponent
*/
#define __SPIN_FLASH_W(lock)					((TBool)FALSE)


/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQSAVE_R(lock)				(NKern::DisableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQRESTORE_R(lock,irq)	(NKern::RestoreInterrupts(irq))

/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQRESTORE_R(lock,irq)		(NKern::RestoreInterrupts(irq),((void)NKern::DisableAllInterrupts()),((TBool)TRUE))

/**
@publishedPartner
@prototype
*/
#define __SPIN_LOCK_IRQSAVE_W(lock)				(NKern::DisableAllInterrupts())

/**
@publishedPartner
@prototype
*/
#define __SPIN_UNLOCK_IRQRESTORE_W(lock,irq)	(NKern::RestoreInterrupts(irq))

/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_IRQRESTORE_W(lock,irq)		(NKern::RestoreInterrupts(irq),((void)NKern::DisableAllInterrupts()),((TBool)TRUE))


/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_PREEMPT_R(lock)			((TBool)NKern::PreemptionPoint())

/**
@publishedPartner
@prototype
*/
#define __SPIN_FLASH_PREEMPT_W(lock)			((TBool)NKern::PreemptionPoint())


/** Nanokernel fast semaphore

	A light-weight semaphore class that only supports a single waiting thread,
	suitable for the Symbian OS thread I/O semaphore.
	
	Initialising a NFastSemaphore involves two steps:
	
	- Constructing the semaphore
	- Setting the semaphore owning thread (the one allowed to wait on it)
	
	For example, creating one for the current thread to wait on:
	
	@code
	NFastSemaphore sem;
	sem.iOwningThread = NKern::CurrentThread();
	@endcode
	
	@publishedPartner
	@released
*/
class NFastSemaphore
	{
public:
	inline NFastSemaphore();
	inline NFastSemaphore(NThreadBase* aThread);
	IMPORT_C void SetOwner(NThreadBase* aThread);
	IMPORT_C void Wait();
	IMPORT_C void Signal();
	IMPORT_C void SignalN(TInt aCount);
	IMPORT_C void Reset();
	void WaitCancel();
public:
	TInt iCount;				/**< @internalComponent */

	/** The thread allowed to wait on the semaphore
		@internalComponent
	*/
	NThreadBase* iOwningThread;	
	};

/** Create a fast semaphore

	@publishedPartner
	@released
*/
inline NFastSemaphore::NFastSemaphore()
	: iCount(0), iOwningThread(NULL)
	{}

/** Nanokernel fast mutex

	A light-weight priority-inheritance mutex that can be used if the following
	conditions apply:
	
	- Threads that hold the mutex never block.
	- The mutex is never acquired in a nested fashion
	
	If either of these conditions is not met, a DMutex object is more appropriate.
	
	@publishedPartner
	@released
*/
class NFastMutex
	{
public:
	IMPORT_C NFastMutex();
	IMPORT_C void Wait();
	IMPORT_C void Signal();
	IMPORT_C TBool HeldByCurrentThread();	/**< @internalComponent */
public:
	NThreadBase* iHoldingThread;	/**< @internalComponent */

	/** MUST ALWAYS BE 0 or 1
		@internalComponent
	*/
	TInt iWaiting;
	};


/**
@publishedPartner
@released

The type of the callback function used by the nanokernel timer. 

@see NTimer
*/
typedef void (*NTimerFn)(TAny*);




/**
@publishedPartner
@released

A basic relative timer provided by the nanokernel.

It can generate either a one-shot interrupt or periodic interrupts.

A timeout handler is called when the timer expires, either:
- from the timer ISR - if the timer is queued via OneShot(TInt aTime) or OneShot(TInt aTime, TBool EFalse), or
- from the nanokernel timer dfc1 thread - if the timer is queued via OneShot(TInt aTime, TBool ETrue) call, or
- from any other dfc thread that provided DFC belongs to - if the timer is queued via OneShot(TInt aTime, TDfc& aDfc) call.
Call-back mechanism cannot be changed in the life time of a timer.

These timer objects may be manipulated from any context.
The timers are driven from a periodic system tick interrupt,
usually a 1ms period.

@see NTimerFn
*/
class NTimer : public SDblQueLink
	{
public:
	/**
	Default constructor.
	*/
	inline NTimer()
		: iState(EIdle)
		{}
	/**
	Constructor taking a callback function and a pointer to be passed
	to the callback function.
	
	@param aFunction The callback function.
	@param aPtr      A pointer to be passed to the callback function 
	                 when called.
	*/
	inline NTimer(NTimerFn aFunction, TAny* aPtr)
		: iPtr(aPtr), iFunction(aFunction), iState(EIdle)
		{}
	IMPORT_C TInt OneShot(TInt aTime);
	IMPORT_C TInt OneShot(TInt aTime, TBool aDfc);
	IMPORT_C TInt OneShot(TInt aTime, TDfc& aDfc);
	IMPORT_C TInt Again(TInt aTime);
	IMPORT_C TBool Cancel();
	IMPORT_C TBool IsPending();
public:
/**
	@internalComponent
*/
	enum TState
		{
		EIdle=0,			// not queued
		ETransferring=1,	// being transferred from holding to ordered queue
		EHolding=2,			// on holding queue
		EOrdered=3,			// on ordered queue
		ECritical=4,		// on ordered queue and in use by queue walk routine
		EFinal=5,			// on final queue
		};
public:
	/** Argument for callback function or the pointer to TDfc */
	TAny* iPtr;				/**< @internalComponent */

	/** Pointer to callback function. NULL value indicates that queuing of provided Dfc queue will be done
	instead of calling callback function on completion */
	NTimerFn iFunction;		/**< @internalComponent */

	TUint32 iTriggerTime;	/**< @internalComponent */
	TUint8 iCompleteInDfc;	/**< @internalComponent */
	TUint8 iState;			/**< @internalComponent */
	TUint8 iPad1;			/**< @internalComponent */

	/** Available for timer client to use.
		@internalTechnology */
	TUint8 iUserFlags;
	};

/**
@internalTechnology
*/
#define	i_NTimer_iUserFlags	iUserFlags

/**
@internalComponent
*/
#define	i_NTimer_iState		iState

/**
	@publishedPartner
	@released
*/
typedef void (*NThreadFunction)(TAny*);

/**
	@publishedPartner
	@released
*/
typedef TDfc* (*NThreadExitHandler)(NThread*);

/**
	@publishedPartner
	@released
*/
typedef void (*NThreadStateHandler)(NThread*,TInt,TInt);

/**
	@publishedPartner
	@released
*/
typedef void (*NThreadExceptionHandler)(TAny*,NThread*);

/**
	@publishedPartner
	@released
*/
typedef void (*NThreadTimeoutHandler)(NThread*,TInt);

/**
	@publishedPartner
	@released
*/
struct SNThreadHandlers
	{
	NThreadExitHandler iExitHandler;
	NThreadStateHandler iStateHandler;
	NThreadExceptionHandler iExceptionHandler;
	NThreadTimeoutHandler iTimeoutHandler;
	};

/** @internalComponent */
extern void NThread_Default_State_Handler(NThread*, TInt, TInt);

/** @internalComponent */
extern void NThread_Default_Exception_Handler(TAny*, NThread*);

/** @internalComponent */
#define NTHREAD_DEFAULT_EXIT_HANDLER		((NThreadExitHandler)0)

/** @internalComponent */
#define	NTHREAD_DEFAULT_STATE_HANDLER		(&NThread_Default_State_Handler)

/** @internalComponent */
#define	NTHREAD_DEFAULT_EXCEPTION_HANDLER	(&NThread_Default_Exception_Handler)

/** @internalComponent */
#define	NTHREAD_DEFAULT_TIMEOUT_HANDLER		((NThreadTimeoutHandler)0)


/**
	@publishedPartner
	@released
*/
struct SFastExecTable
	{
	TInt iFastExecCount;			// includes implicit function#0
	TLinAddr iFunction[1];			// first entry is for call number 1
	};

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagClaim=0x80000000;		// claim system lock

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagRelease=0x40000000;		// release system lock

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagPreprocess=0x20000000;	// preprocess

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgMask=0x1C000000;	// 3 bits indicating additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs2=0x04000000;	// 2 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs3=0x08000000;	// 3 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs4=0x0C000000;	// 4 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs5=0x10000000;	// 5 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs6=0x14000000;	// 6 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs7=0x18000000;	// 7 additional arguments

/**
	@publishedPartner
	@released
*/
const TUint32 KExecFlagExtraArgs8=0x1C000000;	// 8 additional arguments


/**
	@publishedPartner
	@released
*/
struct SSlowExecEntry
	{
	TUint32 iFlags;					// information about call
	TLinAddr iFunction;				// address of function to be called
	};


/**
	@publishedPartner
	@released
*/
struct SSlowExecTable
	{
	TInt iSlowExecCount;
	TLinAddr iInvalidExecHandler;	// used if call number invalid
	TLinAddr iPreprocessHandler;	// used for handle lookups
	SSlowExecEntry iEntries[1];		// first entry is for call number 0
	};

// Thread iAttributes Constants
const TUint8 KThreadAttImplicitSystemLock=1;	/**< @internalComponent */
const TUint8 KThreadAttAddressSpace=2;			/**< @internalComponent */
const TUint8 KThreadAttLoggable=4;				/**< @internalComponent */
const TUint8 KThreadAttDelayed=8;				/**< @internalComponent */


// Thread CPU
const TUint32 KCpuAffinityAny=0xffffffffu;		/**< @internalComponent */

/** Information needed for creating a nanothread.

	@publishedPartner
	@released
*/
struct SNThreadCreateInfo
	{
	NThreadFunction iFunction;
	TAny* iStackBase;
	TInt iStackSize;
	TInt iPriority;
	TInt iTimeslice;
	TUint8 iAttributes;
	TUint32 iCpuAffinity;
	const SNThreadHandlers* iHandlers;
	const SFastExecTable* iFastExecTable;
	const SSlowExecTable* iSlowExecTable;
	const TUint32* iParameterBlock;
	TInt iParameterBlockSize;		// if zero, iParameterBlock _is_ the initial data
									// otherwise it points to n bytes of initial data
	};

/**	Constant for use with NKern:: functions which release a fast mutex as well
	as performing some other operations.

	@publishedPartner
	@released
*/
#define	SYSTEM_LOCK		(NFastMutex*)0


/** Idle handler function
	Pointer to a function which is called whenever a CPU goes idle

	@param	aPtr	The iPtr stored in the SCpuIdleHandler structure
	@param	aStage	If positive, the number of processors still active
					If zero, indicates all processors are now idle
					-1 indicates that postamble processing is required after waking up

	@internalComponent
*/
typedef void (*TCpuIdleHandlerFn)(TAny* aPtr, TInt aStage);

/** Idle handler structure

	@internalComponent
*/
struct SCpuIdleHandler
	{
	TCpuIdleHandlerFn	iHandler;
	TAny*				iPtr;
	volatile TBool		iPostambleRequired;
	};


/**
@internalComponent
*/
enum TUserModeCallbackReason
	{
	EUserModeCallbackRun,
	EUserModeCallbackCancel,
	};


/**
A callback function executed when a thread returns to user mode.

@internalComponent
*/
typedef void (*TUserModeCallbackFunc)(TAny* aThisPtr, TUserModeCallbackReason aReasonCode);


/**
An object representing a queued callback to be executed when a thread returns to user mode.

@internalComponent
*/
class TUserModeCallback
	{
public:
	TUserModeCallback(TUserModeCallbackFunc);
	~TUserModeCallback();

public:
	TUserModeCallback* volatile iNext;
	TUserModeCallbackFunc iFunc;
	};

TUserModeCallback* const KUserModeCallbackUnqueued = ((TUserModeCallback*)1);


/** Nanokernel functions

	@publishedPartner
	@released
*/
class NKern
	{
public:
	/** Bitmask values used when blocking a nanothread.
		@see NKern::Block()
	 */
	enum TBlockMode 
		{
		EEnterCS=1,		/**< Enter thread critical section before blocking */
		ERelease=2,		/**< Release specified fast mutex before blocking */
		EClaim=4,		/**< Re-acquire specified fast mutex when unblocked */
		EObstruct=8,	/**< Signifies obstruction of thread rather than lack of work to do */
		};

	/** Values that specify the context of the processor.
		@see NKern::CurrentContext()
	*/
	enum TContext
		{
		EThread=0,			/**< The processor is in a thread context*/
		EIDFC=1,			/**< The processor is in an IDFC context*/
		EInterrupt=2,		/**< The processor is in an interrupt context*/
		EEscaped=KMaxTInt	/**< Not valid a process context on target hardware*/
		};

public:
	// Threads
	IMPORT_C static TInt ThreadCreate(NThread* aThread, SNThreadCreateInfo& anInfo);
	IMPORT_C static TBool ThreadSuspend(NThread* aThread, TInt aCount);
	IMPORT_C static TBool ThreadResume(NThread* aThread);
	IMPORT_C static TBool ThreadResume(NThread* aThread, NFastMutex* aMutex);
	IMPORT_C static TBool ThreadForceResume(NThread* aThread);
	IMPORT_C static TBool ThreadForceResume(NThread* aThread, NFastMutex* aMutex);
	IMPORT_C static void ThreadRelease(NThread* aThread, TInt aReturnValue);
	IMPORT_C static void ThreadRelease(NThread* aThread, TInt aReturnValue, NFastMutex* aMutex);
	IMPORT_C static void ThreadSetPriority(NThread* aThread, TInt aPriority);
	IMPORT_C static void ThreadSetPriority(NThread* aThread, TInt aPriority, NFastMutex* aMutex);
	IMPORT_C static void ThreadRequestSignal(NThread* aThread);
	IMPORT_C static void ThreadRequestSignal(NThread* aThread, NFastMutex* aMutex);
	IMPORT_C static void ThreadRequestSignal(NThread* aThread, TInt aCount);
	IMPORT_C static void ThreadKill(NThread* aThread);
	IMPORT_C static void ThreadKill(NThread* aThread, NFastMutex* aMutex);
	IMPORT_C static void ThreadEnterCS();
	IMPORT_C static void ThreadLeaveCS();
	static NThread* _ThreadEnterCS();		/**< @internalComponent */
	static void _ThreadLeaveCS();			/**< @internalComponent */
	IMPORT_C static TInt Block(TUint32 aTimeout, TUint aMode, NFastMutex* aMutex);
	IMPORT_C static TInt Block(TUint32 aTimeout, TUint aMode);
	IMPORT_C static void NanoBlock(TUint32 aTimeout, TUint aState, TAny* aWaitObj);
	IMPORT_C static void ThreadGetUserContext(NThread* aThread, TAny* aContext, TUint32& aAvailRegistersMask);
	IMPORT_C static void ThreadSetUserContext(NThread* aThread, TAny* aContext);
	IMPORT_C static void ThreadGetSystemContext(NThread* aThread, TAny* aContext, TUint32& aAvailRegistersMask);
	static void ThreadModifyUsp(NThread* aThread, TLinAddr aUsp);
	IMPORT_C static TInt FreezeCpu();													/**< @internalComponent */
	IMPORT_C static void EndFreezeCpu(TInt aCookie);									/**< @internalComponent */
	IMPORT_C static TUint32 ThreadSetCpuAffinity(NThread* aThread, TUint32 aAffinity);	/**< @internalComponent */
	IMPORT_C static void ThreadSetTimeslice(NThread* aThread, TInt aTimeslice);			/**< @internalComponent */
	IMPORT_C static TUint64 ThreadCpuTime(NThread* aThread);							/**< @internalComponent */
	IMPORT_C static TUint32 CpuTimeMeasFreq();											/**< @internalComponent */
	static TInt QueueUserModeCallback(NThreadBase* aThread, TUserModeCallback* aCallback);	/**< @internalComponent */
	static void MoveUserModeCallbacks(NThreadBase* aSrcThread, NThreadBase* aDestThread);	/**< @internalComponent */
	static void CancelUserModeCallbacks();												/**< @internalComponent */

	// Fast semaphores
	IMPORT_C static void FSSetOwner(NFastSemaphore* aSem,NThreadBase* aThread);
	IMPORT_C static void FSWait(NFastSemaphore* aSem);
	IMPORT_C static void FSSignal(NFastSemaphore* aSem);
	IMPORT_C static void FSSignal(NFastSemaphore* aSem, NFastMutex* aMutex);
	IMPORT_C static void FSSignalN(NFastSemaphore* aSem, TInt aCount);
	IMPORT_C static void FSSignalN(NFastSemaphore* aSem, TInt aCount, NFastMutex* aMutex);

	// Fast mutexes
	IMPORT_C static void FMWait(NFastMutex* aMutex);
	IMPORT_C static void FMSignal(NFastMutex* aMutex);
	IMPORT_C static TBool FMFlash(NFastMutex* aMutex);

	// Scheduler
	IMPORT_C static void Lock();
	IMPORT_C static NThread* LockC();	
	IMPORT_C static void Unlock();
	IMPORT_C static TInt PreemptionPoint();

	// Interrupts
	IMPORT_C static TInt DisableAllInterrupts();
	IMPORT_C static TInt DisableInterrupts(TInt aLevel);
	IMPORT_C static void RestoreInterrupts(TInt aRestoreData);
	IMPORT_C static void EnableAllInterrupts();

	// Read-modify-write
	inline static TInt LockedInc(TInt& aCount)
		{ return __e32_atomic_add_ord32(&aCount,1); }
	inline static TInt LockedDec(TInt& aCount)
		{ return __e32_atomic_add_ord32(&aCount,0xffffffff); }
	inline static TInt LockedAdd(TInt& aDest, TInt aSrc)
		{ return __e32_atomic_add_ord32(&aDest,aSrc); }
	inline static TInt64 LockedInc(TInt64& aCount)
		{ return __e32_atomic_add_ord64(&aCount,1); }
	inline static TInt64 LockedDec(TInt64& aCount)
		{ return __e32_atomic_add_ord64(&aCount,TUint64(TInt64(-1))); }
	inline static TInt64 LockedAdd(TInt64& aDest, TInt64 aSrc)		/**< @internalComponent */
		{ return __e32_atomic_add_ord64(&aDest,aSrc); }
	inline static TUint32 LockedSetClear(TUint32& aDest, TUint32 aClearMask, TUint32 aSetMask)
		{ return __e32_atomic_axo_ord32(&aDest,~(aClearMask|aSetMask),aSetMask); }
	inline static TUint16 LockedSetClear16(TUint16& aDest, TUint16 aClearMask, TUint16 aSetMask)	/**< @internalComponent */
		{ return __e32_atomic_axo_ord16(&aDest,TUint16(~(aClearMask|aSetMask)),aSetMask); }
	inline static TUint8 LockedSetClear8(TUint8& aDest, TUint8 aClearMask, TUint8 aSetMask)
		{ return __e32_atomic_axo_ord8(&aDest,TUint8(~(aClearMask|aSetMask)),aSetMask); }
	inline static TInt SafeInc(TInt& aCount)
		{ return __e32_atomic_tas_ord32(&aCount,1,1,0); }
	inline static TInt SafeDec(TInt& aCount)
		{ return __e32_atomic_tas_ord32(&aCount,1,-1,0); }
	inline static TInt AddIfGe(TInt& aCount, TInt aLimit, TInt aInc)	/**< @internalComponent */
		{ return __e32_atomic_tas_ord32(&aCount,aLimit,aInc,0); }
	inline static TInt AddIfLt(TInt& aCount, TInt aLimit, TInt aInc)	/**< @internalComponent */
		{ return __e32_atomic_tas_ord32(&aCount,aLimit,0,aInc); }
	inline static TAny* SafeSwap(TAny* aNewValue, TAny*& aPtr)
		{ return __e32_atomic_swp_ord_ptr(&aPtr, aNewValue); }
	inline static TUint8 SafeSwap8(TUint8 aNewValue, TUint8& aPtr)
		{ return __e32_atomic_swp_ord8(&aPtr, aNewValue); }
	inline static TUint16 SafeSwap16(TUint16 aNewValue, TUint16& aPtr)						/**< @internalComponent */
		{ return __e32_atomic_swp_ord16(&aPtr, aNewValue); }
	inline static TBool CompareAndSwap(TAny*& aPtr, TAny* aExpected, TAny* aNew)			/**< @internalComponent */
		{ return __e32_atomic_cas_ord_ptr(&aPtr, &aExpected, aNew); }
	inline static TBool CompareAndSwap8(TUint8& aPtr, TUint8 aExpected, TUint8 aNew)		/**< @internalComponent */
		{ return __e32_atomic_cas_ord8(&aPtr, (TUint8*)&aExpected, (TUint8)aNew); }
	inline static TBool CompareAndSwap16(TUint16& aPtr, TUint16 aExpected, TUint16 aNew)	/**< @internalComponent */
		{ return __e32_atomic_cas_ord16(&aPtr, (TUint16*)&aExpected, (TUint16)aNew); }
	inline static TUint32 SafeSwap(TUint32 aNewValue, TUint32& aPtr)						/**< @internalComponent */
		{ return __e32_atomic_swp_ord32(&aPtr, aNewValue); }
	inline static TUint SafeSwap(TUint aNewValue, TUint& aPtr)								/**< @internalComponent */
		{ return __e32_atomic_swp_ord32(&aPtr, aNewValue); }
	inline static TInt SafeSwap(TInt aNewValue, TInt& aPtr)									/**< @internalComponent */
		{ return __e32_atomic_swp_ord32(&aPtr, aNewValue); }
	inline static TBool CompareAndSwap(TUint32& aPtr, TUint32 aExpected, TUint32 aNew)		/**< @internalComponent */
		{ return __e32_atomic_cas_ord32(&aPtr, &aExpected, aNew); }
	inline static TBool CompareAndSwap(TUint& aPtr, TUint aExpected, TUint aNew)			/**< @internalComponent */
		{ return __e32_atomic_cas_ord32(&aPtr, (TUint32*)&aExpected, (TUint32)aNew); }
	inline static TBool CompareAndSwap(TInt& aPtr, TInt aExpected, TInt aNew)				/**< @internalComponent */
		{ return __e32_atomic_cas_ord32(&aPtr, (TUint32*)&aExpected, (TUint32)aNew); }


	// Miscellaneous
	IMPORT_C static NThread* CurrentThread();
	IMPORT_C static TInt CurrentCpu();										/**< @internalComponent */
	IMPORT_C static TInt NumberOfCpus();									/**< @internalComponent */
	IMPORT_C static void LockSystem();
	IMPORT_C static void UnlockSystem();
	IMPORT_C static TBool FlashSystem();
	IMPORT_C static void WaitForAnyRequest();
	IMPORT_C static void Sleep(TUint32 aTime);
	IMPORT_C static void Exit();
	IMPORT_C static void DeferredExit();
	IMPORT_C static void YieldTimeslice();									/**< @internalComponent */
	IMPORT_C static void RotateReadyList(TInt aPriority);					
	IMPORT_C static void RotateReadyList(TInt aPriority, TInt aCpu);		/**< @internalTechnology */
	IMPORT_C static void RecordIntLatency(TInt aLatency, TInt aIntMask);	/**< @internalTechnology */
	IMPORT_C static void RecordThreadLatency(TInt aLatency);				/**< @internalTechnology */
	IMPORT_C static TUint32 TickCount();
	IMPORT_C static TInt TickPeriod();
	IMPORT_C static TInt TimerTicks(TInt aMilliseconds);
	IMPORT_C static TInt TimesliceTicks(TUint32 aMicroseconds);				/**< @internalTechnology */
	IMPORT_C static TInt CurrentContext();
	IMPORT_C static TUint32 FastCounter();
	IMPORT_C static TInt FastCounterFrequency();
	static void Init0(TAny* aVariantData);
	static void Init(NThread* aThread, SNThreadCreateInfo& anInfo);
	IMPORT_C static TBool KernelLocked(TInt aCount=0);						/**< @internalTechnology */
	IMPORT_C static NFastMutex* HeldFastMutex();							/**< @internalTechnology */
	static void Idle();	
	IMPORT_C static SCpuIdleHandler* CpuIdleHandler();						/**< @internalTechnology */
	static void NotifyCrash(const TAny* a0, TInt a1);						/**< @internalTechnology */
	IMPORT_C static TBool Crashed();
	static TUint32 IdleGenerationCount();

	// Debugger support
	typedef void (*TRescheduleCallback)(NThread*);
	IMPORT_C static void SchedulerHooks(TLinAddr& aStart, TLinAddr& aEnd);
	IMPORT_C static void InsertSchedulerHooks();
	IMPORT_C static void RemoveSchedulerHooks();
	IMPORT_C static void SetRescheduleCallback(TRescheduleCallback aCallback);
	};


/** Create a fast semaphore

	@publishedPartner
	@released
*/
inline NFastSemaphore::NFastSemaphore(NThreadBase* aThread)
	:	iCount(0),
		iOwningThread(aThread ? aThread : (NThreadBase*)NKern::CurrentThread())
	{
	}


#endif