Class CServer2

class CServer2 : public CActive;

Description

Abstract base class for servers (version 2).

This is an active object. It accepts requests from client threads and forwards them to the relevant server-side client session. It also handles the creation of server-side client sessions as a result of requests from client threads.

A server must define and implement a derived class.

(Note that this class should be used instead of CServer)

Derivation

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

• CActive - The core class of the active object abstraction.

• CServer2 - Abstract base class for servers (version 2).

Members

Defined in CServer2:

• CServer2(TInt,TServerType)Constructs the server object, specifying the server type and the active object p...
• DoCancel()Implements the cancellation of any outstanding request for messages.
• DoConnect(const RMessage2 &)Handles the connect request from the client.
• EGlobalSharableSessionsThe session is sharable with all other threads in the system.
• ESharableSessionsThe session is sharable with other threads in the same process.
• EUnsharableSessionsThe session is not sharable with other threads.
• Extension_(TUint,TAny *&,TAny *)Extension function
• Message()constGets a reference to the server's current message.
• NewSessionL(const TVersion &,const RMessage2 &)constCreates a server-side session object.
• ReStart()Restarts the server.
• RunError(TInt)Handles the situation where a call to CServer2::RunL(), leaves.
• RunL()Handles the receipt of a message.
• Server()constGets a handle to the server.
• Start(const TDesC &)Adds the server with the specified name to the active scheduler, and issues the ...
• StartL(const TDesC &)Adds the server with the specified name to the active scheduler, and issues the ...
• TServerTypeDefines the set of session types that the server can create.
• iSessionIter
• ~CServer2()Frees resources prior to destruction.

Inherited from CActive:

• CActive(TInt)Constructs the active object with the specified priority.
• Cancel()Cancels the wait for completion of an outstanding request.
• Deque()Removes the active object from the active scheduler's list of active objects.
• EPriorityHighA priority higher than EPriorityUserInput.
• EPriorityIdleA low priority, useful for active objects representing background processing.
• EPriorityLowA priority higher than EPriorityIdle but lower than EPriorityStandard.
• EPriorityStandardMost active objects will have this priority.
• EPriorityUserInputA priority higher than EPriorityStandard; useful for active objects handling use...
• IsActive()constDetermines whether the active object has a request outstanding.
• IsAdded()constDetermines whether the active object has been added to the active scheduler's li...
• Priority()constGets the priority of the active object.
• SetActive()Indicates that the active object has issued a request and that it is now outstan...
• SetPriority(TInt)Sets the priority of the active object.
• TPriorityDefines standard priorities for active objects.
• iStatusThe request status associated with an asynchronous request.

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

IMPORT_C virtual ~CServer2()=0;

Description

Frees resources prior to destruction.

Specifically, it cancels any outstanding request for messages, and deletes all server-side client session objects.

protected: IMPORT_C CServer2(TInt aPriority, TServerType aType=EUnsharableSessions);

Description

Constructs the server object, specifying the server type and the active object priority.

Derived classes must define and implement a constructor through which the priority can be specified. A typical implementation calls this server base class constructor through a constructor initialization list.

Parameters

TInt aPriority The priority of this active object. CServer2::TServerType aType Indicates the type of session that the server creates. If not explicitly stated, then the server creates a session that is not sharable with other threads.

Capability:

ProtServ

if aName starts with a '!' character

IMPORT_C TInt Start(const TDesC &aName);

Description

Adds the server with the specified name to the active scheduler, and issues the first request for messages.

If KNullDesC is specified for the name, then an anonymous server will be created. To create a session to such a server, an overload of RSessionBase::CreateSession(const TDesC &,const TVersion &) which takes RServer2 object as a parameter can be used.

Parameters

const TDesC16 &aName The name of the server. KNullDesC, to create anonymous servers.

Return value

TInt KErrNone, if successful, otherwise one of the other system wide error codes.

Capability:

ProtServ

if aName starts with a '!' character

IMPORT_C void StartL(const TDesC &aName);

Description

Adds the server with the specified name to the active scheduler, and issues the first request for messages, and leaves if the operation fails.

If KNullDesC is specified for the name, then an anonymous server will be created. To create a session to such a server, the overload of RSessionBase::CreateSession(const TDesC &,const TVersion &) which takes an RServer2 object as a parameter can be used.

Parameters

const TDesC16 &aName The name of the server. KNullDesC, to create anonymous servers.

IMPORT_C void ReStart();

Description

Restarts the server.

The function issues a request for messages.

inline RServer2 Server() const;

Description

Gets a handle to the server.

Note that the RServer2 object is classified as Symbian internal, and its member functions cannot be acessed. However, the handle can be passed to the RSessionBase::CreateSession(const TDesC &,const TVersion &) variants that take a server handle.

Return value

RServer2 The handle to the server.

protected: inline const RMessage2& Message() const;

Description

Gets a reference to the server's current message.

Return value

const RMessage2 & The current message that contains the client request details.

protected: IMPORT_C virtual void DoCancel();

Description

Implements the cancellation of any outstanding request for messages.

protected: IMPORT_C virtual void RunL();

Description

Handles the receipt of a message.

protected: IMPORT_C virtual TInt RunError(TInt aError);

Description

Handles the situation where a call to CServer2::RunL(), leaves.

This is the server active object's implementation of the active object framework's CServer2::RunError(TInt) function.

In practice, the leave can only be caused by a session's ServiceL() function, which is called from this CServer2::RunL(); this error is reflected back to that session by calling its ServiceError() function.

Parameters

TInt aError The leave code.

Return value

TInt KErrNone.

See also:

• CActive::RunL()Handles an active object's request completion event.
• CActive::RunError(TInt)Handles a leave occurring in the request completion event handler CActive::RunL(...
• CSession2::ServiceError(const RMessage2 &,TInt)Handles the situation when a call to CSession2::ServiceL(const RMessage2 &),...

protected: IMPORT_C virtual void DoConnect(const RMessage2 &aMessage);

Description

Handles the connect request from the client.

Parameters

const RMessage2 &aMessage Represents the details of the client request that is requesting the connection.

protected: IMPORT_C virtual TInt Extension_(TUint aExtensionId, TAny *&a0, TAny *a1);

Description

Extension function

Parameters

TUint aExtensionId TAny *&a0 TAny *a1

Return value

TInt

private: IMPORT_C virtual CSession2* NewSessionL(const TVersion &aVersion, const RMessage2 &aMessage) const=0;

Description

Creates a server-side session object.

The session represents a communication link between a client and a server, and its creation is initiated by the client through a call to one of the RSessionBase::CreateSession(const TDesC &,const TVersion &) variants.

A server must provide an implementation, which as a minimum should:

• check that the version of the server is compatible with the client by comparing the client supplied version number against the server's version number; it should leave if there is incompatibility.

• construct and return the server side client session object.

Parameters

const TVersion &aVersion The version information supplied by the client. const RMessage2 &aMessage Represents the details of the client request that is requesting the creation of the session.

Return value

CSession2 * A pointer to the newly created server-side session object.

See also:

• User::QueryVersionSupported(const TVersion &,const TVersion &)Compares two version objects and returns true if the test version is less than t...

TServerType

Description

Defines the set of session types that the server can create.

A specific session type is specified when the CServer2 object is created.

EUnsharableSessions The session is not sharable with other threads. ESharableSessions The session is sharable with other threads in the same process. EGlobalSharableSessions The session is sharable with all other threads in the system.

protected: TDblQueIter< CSession2 > iSessionIter;

Description