»
Symbian OS v9.3 »
Symbian OS reference »
C++ component reference »
Base E32_EKA2 »
RBusLogicalChannel
Location:
e32cmn.h
Link against: euser.lib
class RBusLogicalChannel : public RHandleBase;
Description
The user-side handle to a logical channel.
The class provides functions that are used to open a channel to a device driver, and to make requests. A device driver provides
a derived class to give the user-side a tailored interface to the driver.
Derivation
RBusLogicalChannel - The user-side handle to a logical channel
Members
Defined in RBusLogicalChannel:
DoCancel(), DoControl(), DoControl(), DoControl(), DoCreate(), DoRequest(), DoRequest(), DoRequest(), DoSvControl(), DoSvControl(), DoSvControl(), Open(), Open()
Inherited from RHandleBase:
Attributes(),
Close(),
Duplicate(),
FullName(),
Handle(),
HandleInfo(),
Name(),
SetHandle(),
SetHandleNC(),
SetReturnedHandle(),
iHandle
Member functions
IMPORT_C TInt Open(RMessagePtr2 aMessage, TInt aParam, TOwnerType aType=EOwnerProcess);
Description
Opens a handle to a logical channel using a handle number sent by a client to a server.
This function is called by the server.
Parameters
RMessagePtr2 aMessage |
The message pointer.
|
TInt aParam |
An index specifying which of the four message arguments contains the handle number.
|
TOwnerType aType |
An enumeration whose enumerators define the ownership of this logical channel handle. If not explicitly specified, EOwnerProcess
is taken as default.
|
|
Return value
TInt
|
KErrNone, if successful; KErrArgument, if the value of aParam is outside the range 0-3; KErrBadHandle, if not a valid handle;
otherwise one of the other system-wide error codes.
|
|
IMPORT_C TInt Open(TInt aArgumentIndex, TOwnerType aType=EOwnerProcess);
Description
Opens a logical channel handle using a handle number passed as an environment data item to the child process during the creation
of that child process.
Note that this function can only be called successfully once.
Parameters
TInt aArgumentIndex |
An index that identifies the slot in the process environment data that contains the handle number. This is a value relative
to zero, i.e. 0 is the first item/slot. This can range from 0 to 15.
|
TOwnerType aType |
An enumeration whose enumerators define the ownership of this logical channel handle. If not explicitly specified, EOwnerProcess
is taken as default.
|
|
Return value
TInt
|
KErrNone, if successful; KErrNotFound, if the slot indicated by aArgumentIndex is empty; KErrArgument, if the slot does not
contain a logical channel handle; otherwise one of the other system-wide error codes.
|
|
protected: inline TInt DoCreate(const TDesC &aDevice, const TVersion &aVer, TInt aUnit, const TDesC *aDriver, const TDesC8
*anInfo, TOwnerType aType=EOwnerProcess, TBool aProtected=EFalse);
Description
Creates the logical channel.
Parameters
const TDesC &aDevice |
The name of the logical device for which the channel is to be constructed. This is the name by which the LDD factory object,
i.e. the instance of the DLogicalDevice derived class, is known.
|
const TVersion &aVer |
The required version of the logical device. The driver normally checks this against the version of the logical channel, returning
KErrNotSupported if the logical channel is not compatible.
|
TInt aUnit |
A unit of the device. This argument only has meaning if the flag KDeviceAllowUnit is set in the iParseMask data member of
the LDD factory object.
|
const TDesC *aDriver |
A pointer to a descriptor containing the name of a physical device. This is the name by which the PDD factory object, i.e.
the instance of the DPhysicalDevice derived class, is known. This is NULL, if no explicit name is to be supplied, or the logical device does not require an accompanying
physical device.
|
const TDesC8 *anInfo |
A pointer to an explicit 8-bit descriptor containing extra information for the physical device. This argument only has meaning
if the KDeviceAllowInfo flag is set in the iParseMask data member of the LDD factory object.
|
TOwnerType aType |
An enumeration whose enumerators define the ownership of this handle. If not explicitly specified, EOwnerProcess is taken
as default.
|
TBool aProtected |
If false, the channel is created as an object which is local/private to the current process. If true, the channel is an object
which may be shared with other processes using the IPC mechanisms for handle passing.
|
|
Return value
TInt
|
KErrNone, if successful; otherwise one of the other system wide error codes.
|
|
protected: IMPORT_C void DoCancel(TUint aReqMask);
Description
Cancels one or more outstanding asynchronous requests.
All outstanding requests complete with KErrCancel.
Parameters
TUint aReqMask |
A set of bits identifying the requests to be cancelled. Each bit can be used to identify a separate outstanding request. It
is up to the driver to define how the bits map to those outstanding requests.
|
|
protected: IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus &aStatus);
Description
Queues an asynchronous request for the device driver, taking no parameters.
The request is handled on the kernel-side by the logical channel's DLogicalChannelBase::Request().
Outstanding requests can be cancelled by calling DoCancel().
Parameters
TInt aReqNo |
A number identifying the request to the logical channel.
|
TRequestStatus &aStatus |
The request status object for this request.
|
|
protected: IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus &aStatus, TAny *a1);
Description
Queues an asynchronous request for the device driver, taking one parameter.
The request is handled on the kernel-side by the logical channel's DLogicalChannelBase::Request().
Outstanding requests can be cancelled by calling DoCancel().
Parameters
TInt aReqNo |
A number identifying the request to the logical channel.
|
TRequestStatus &aStatus |
The request status object for this request.
|
TAny *a1 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
|
protected: IMPORT_C void DoRequest(TInt aReqNo, TRequestStatus &aStatus, TAny *a1, TAny *a2);
Description
Queues an asynchronous request for the device driver, taking two parameters.
The request is handled on the kernel-side by the logical channel's DLogicalChannelBase::Request().
Outstanding requests can be cancelled by calling DoCancel().
Parameters
TInt aReqNo |
A number identifying the request to the logical channel.
|
TRequestStatus &aStatus |
The request status object for this request.
|
TAny *a1 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
TAny *a2 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
|
protected: IMPORT_C TInt DoControl(TInt aFunction);
Description
Makes a synchronous request to the device driver, taking no parameters.
This function does not return until the request has completed, successfully or otherwise.
Parameters
TInt aFunction |
A number identifying the request.
|
|
Return value
TInt
|
KErrNone, if successful; otherwise one of the other system-wide error codes. The value returned depends on the implementation
of the device driver.
|
|
protected: IMPORT_C TInt DoControl(TInt aFunction, TAny *a1);
Description
Makes a synchronous request to the device driver, taking one parameter.
This function does not return until the request has completed, successfully or otherwise.
Parameters
TInt aFunction |
A number identifying the request.
|
TAny *a1 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
|
Return value
TInt
|
KErrNone, if successful; otherwise one of the other system-wide error codes. The value returned depends on the implementation
of the device driver.
|
|
protected: IMPORT_C TInt DoControl(TInt aFunction, TAny *a1, TAny *a2);
Description
Makes a synchronous request to the device driver, taking two parameters.
This function does not return until the request has completed, successfully or otherwise.
Parameters
TInt aFunction |
A number identifying the request.
|
TAny *a1 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
TAny *a2 |
A 32-bit value passed to the kernel-side. Its meaning depends on the device driver requirements.
|
|
Return value
TInt
|
KErrNone, if successful; otherwise one of the other system-wide error codes. The value returned depends on the implementation
of the device driver.
|
|
protected: inline TInt DoSvControl(TInt aFunction);
Description
Parameters
Return value
protected: inline TInt DoSvControl(TInt aFunction, TAny *a1);
Description
Parameters
Return value
protected: inline TInt DoSvControl(TInt aFunction, TAny *a1, TAny *a2);
Description
Parameters
Return value
![[Index]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_index_wt.gif){kind=small}
![[Spacer]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_spacer.gif){kind=small}
![[Previous]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_prev_wt.gif){kind=small}
![[Next]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_next_wt.gif){kind=small}
![[Previous]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_prev.gif){kind=small}
![[Top]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_top.gif)
![[Next]](https://docs.huihoo.com/symbian/s60-3rd-edition-cpp-developers-library-v1.1/GUID-35228542-8C95-4849-A73F-2B4F082F0C44/html/SDL_93/a_stock/btn_next.gif){kind=small}