Class CSerial

class CSerial : public CObject;

Description

Factory for a single CPort object.

CSerial is the base class for implementations of serial port factories. It is intended to be overridden by the CSY so that C32 can call in and ask the CSY to create serial ports. In this way the factory is responsible for creating instances of CPort-derived classes for the protocol of the CSY. It also provides query functions, which return general information about the capabilities of the serial protocol implemented by the CSY.

Owned by the CPort object it creates.

Writing derived classes:

The pure virtual NewPortL() and Info() functions must be implemented in derived classes. Serial protocol modules which can take differing action based on the version of the comms server should also override QueryVersionSupported().

Derivation

• CBase - Base class for all classes to be instantiated on the heap

• CObject - Implements reference counting to track concurrent references to itself

• CSerial - Factory for a single CPort object

Members

Defined in CSerial:
CSerial(), CSerial_Reserved1(), Info(), NewPortL(), PortPlatSecCapability(), QueryVersionSupported(), iVersion, ~CSerial()

Inherited from CBase:
Delete(), operator new()

Inherited from CObject:
AccessCount(), Close(), Dec(), Extension_(), FullName(), Inc(), Name(), Open(), Owner(), SetName(), SetNameL(), SetOwner(), UniqueID()

IMPORT_C CSerial();

Description

Default constructor.

Derived classes can implement a NewL() function if they require two-phase construction.

IMPORT_C ~CSerial();

Description

Destructor.

virtual IMPORT_C TBool QueryVersionSupported(const TVersion &aVersion) const;

Description

Specifies the protocol for checking the supplied TVersion against the protocol's module version.

The default implementation calls User::QueryVersionSupported() to perform the check against the object's iVersion member.

Parameters

const TVersion &aVersion The version to be checked.

Return value

TBool ETrue if the version is supported.

virtual CPort *NewPortL(const TUint aUnit)=0;

Description

Create a new port for the supplied unit number.

Specifies the protocol for creating a new serial port for the protocol. The comms server calls this function in response to a RComm:Open() call.

Typically, the implementation would call NewL() on the protocol's CPort-based class. Any resources required by the new port object should be done at this stage. If the serial port object cannot be created for any reason, NewPortL() should leave with an appropriate error code.

The interpretation of unit numbers is specific to the particular serial protocol module. However, unit numbers on Symbian OS should be zero-based. For the default built-in serial ports implemented by the serial protocol module ecuart.csy, the unit numbers refer to the hardware ports, with 0 being the first port on the machine. If a second request is made to create a port with a unit number that has already been created and not destroyed, NewPortL() should leave with KErrAlreadyExists.

Parameters

const TUint aUnit The unit number to be created.

Return value

CPort *

virtual void Info(TSerialInfo &aSerialInfo)=0;

Description

Get info about this CSY, fill in the supplied structure.

Specifies the protocol for getting the information about the serial protocol.

Implementations should fill in the TSerialInfo structure to reflect the protocol's capabilities.

Parameters

TSerialInfo &aSerialInfo On return, set to indicate the capabilities of the serial protocol.

virtual IMPORT_C TSecurityPolicy PortPlatSecCapability(TUint aPort) const;

Description

Retrieve the security policy for a requested port. This base implementation sets the default policy to be an 'AlwaysFail' policy.

Parameters

TUint aPort Port number.

Return value

TSecurityPolicy TSecurityPolicy Security policy associated with opeing this port

private: virtual IMPORT_C void CSerial_Reserved1();

Description

Reserved virtual function.

protected: TVersion iVersion;

Description

holds the version of the CSY

Module version number. The class should initialise this member with its version number from its constructor.