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RShPool Class Reference

class RShPool : public RHandleBase

A handle to a pool of buffers.

Pools can be created by either user-side or kernel-side components.

Upon receiving a pool handle the recipient must map either whole or part of the pool memory into its address space.

When finished with the pool, the recipient must Close() it: this invalidates the handle. Any further attempt to use it will panic the thread.

All pools are reference-counted and will only disappear after all users have closed them.

These handles are process-relative.

Inherits from

RShPool
- RHandleBase

Public Member Functions
	RShPool ()
IMPORT_C void	CancelFreeSpaceNotification ( TRequestStatus &)
IMPORT_C void	CancelLowSpaceNotification ( TRequestStatus &)
IMPORT_C TInt	Create (const TShPoolCreateInfo &, TUint )
IMPORT_C TUint	FreeCount ()
IMPORT_C void	GetInfo ( TShPoolInfo &)
IMPORT_C void	RequestFreeSpaceNotification ( TUint , TRequestStatus &)
IMPORT_C void	RequestLowSpaceNotification ( TUint , TRequestStatus &)
IMPORT_C TInt	SetBufferWindow ( TInt , TBool )

Inherited Functions
	RHandleBase::Attributes()const
	RHandleBase::BTraceId()const
	RHandleBase::Close()
	RHandleBase::DoExtendedClose()
	RHandleBase::Duplicate(const RThread &,TOwnerType)
	RHandleBase::FullName()const
	RHandleBase::FullName(TDes &)const
	RHandleBase::Handle()const
	RHandleBase::HandleInfo(THandleInfo *)
	RHandleBase::Name()const
	RHandleBase::NotifyDestruction(TRequestStatus &)
	RHandleBase::Open(const TFindHandleBase &,TOwnerType)
	RHandleBase::OpenByName(const TDesC &,TOwnerType,TInt)
	RHandleBase::RHandleBase()
	RHandleBase::RHandleBase(TInt)
	RHandleBase::SetHandle(TInt)
	RHandleBase::SetHandleNC(TInt)
	RHandleBase::SetReturnedHandle(TInt)
	RHandleBase::SetReturnedHandle(TInt,RHandleBase &)

Inherited Enumerations
	RHandleBase:TAttributes

Inherited Attributes
	RHandleBase::iHandle

Constructor & Destructor Documentation

RShPool()

IMPORT_C

RShPool

(

)

Member Functions Documentation

CancelFreeSpaceNotification(TRequestStatus &)

IMPORT_C void

CancelFreeSpaceNotification

(

TRequestStatus &

aStatus

)

Cancels a free space notification request.

The status request completes with KErrCancel.

Parameters

TRequestStatus & aStatus

The status request whose notification is to be cancelled.

CancelLowSpaceNotification(TRequestStatus &)

IMPORT_C void

CancelLowSpaceNotification

(

TRequestStatus &

aStatus

)

Cancels a low space notification request.

The status request completes with KErrCancel.

Parameters

TRequestStatus & aStatus

The status request whose notification is to be cancelled.

Create(const TShPoolCreateInfo &, TUint)

IMPORT_C TInt	Create	(	const TShPoolCreateInfo &	aBufInfo,
			TUint	aFlags
		)

Creates a pool of buffers with the required attributes and maps the memory to this process. The RShPool object is changed by this call (iHandle is set).

TShPoolCreateInfo TShPoolClientFlags

Parameters

const TShPoolCreateInfo & aBufInfo	A structure describing the parameters of the pool to be created. See TShPoolCreateInfo.
TUint aFlags	Flags to modify the behaviour of the handle. This should be a bit-wise OR of values from TShPoolHandleFlags.

FreeCount()

IMPORT_C TUint

FreeCount

(

)

const

GetInfo(TShPoolInfo &)

IMPORT_C void

GetInfo

(

TShPoolInfo &

aInfo

)

const

Retrieves information about the pool.

Parameters

TShPoolInfo & aInfo

returns pool info.

RequestFreeSpaceNotification(TUint, TRequestStatus &)

IMPORT_C void	RequestFreeSpaceNotification	(	TUint	aFreeBuffers,
			TRequestStatus &	aStatus
		)

Requests a notification when the number of free buffers in the pool rises to the level specified.

Parameters

TUint aFreeBuffers	Specifies the number of free buffers that will trigger completion of the notification.
TRequestStatus & aStatus	Status request to be completed when the condition is met.

RequestLowSpaceNotification(TUint, TRequestStatus &)

IMPORT_C void	RequestLowSpaceNotification	(	TUint	aFreeBuffers,
			TRequestStatus &	aStatus
		)

Requests a notification when the number of free buffers in the pool falls to the level specified.

Parameters

TUint aFreeBuffers	Specifies the number of free buffers that will trigger completion of the notification.
TRequestStatus & aStatus	Status request to be completed when the condition is met.

SetBufferWindow(TInt, TBool)

IMPORT_C TInt	SetBufferWindow	(	TInt	aCount,
			TBool	aAutoMap
		)

Specifies how many buffers of a page-aligned pool this process will require concurrent access to.

This determines how much of the process's address space will be allocated for buffers of this pool.

Pre-condition: the pool's buffers must be page-aligned

Parameters

TInt aCount	Specifies the number of buffers to map into the process's virtual address space (-1 specifies that all buffers will be mapped).
TBool aAutoMap	ETrue specifies that an allocated or received buffer will be automatically mapped into the process's address space.