Class CMsvCompletedOperation

class CMsvCompletedOperation : public CMsvOperation;

Description

Utility to create a messaging operation object for an operation that has already completed.

This utility is useful, for example, for writers of MTMs, where the API requires that an asynchronous operation is returned, but where in reality, the operation has performed synchronously. It allows the program to construct an operation object for which the operation is already completed, with the progress information and error code set.

Derivation

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

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

• CMsvOperation - Defines an interface for use by objects which control asynchronous commands in t...

• CMsvCompletedOperation - Utility to create a messaging operation object for an operation that has already...

Members

Defined in CMsvCompletedOperation:

• DoCancel()Implements cancellation of an outstanding request.
• FinalProgress()Gets information about a completed operation.
• NewL(CMsvSession &,TUid,const TDesC8 &,TMsvId,TRequestStatus &,TInt)Allocates and constructs a new CMsvCompletedOperation object.
• ProgressL()Gets information on the progress of the operation.
• RunL()Handles an active object's request completion event.
• ~CMsvCompletedOperation()Destructor.

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.
• RunError(TInt)Handles a leave occurring in the request completion event handler CActive::RunL(...
• 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...

Inherited from CMsvOperation:

• CMsvOperation(CMsvSession &,TInt,TRequestStatus &)Constructor. This is called by MTM implementers from the derived class construct...
• Extension_(TUint,TAny *&,TAny *)The extension method provides a polymorphic behaviour to call the correct System...
• Id()constGets the operation ID.
• Mtm()constGets the UID of the MTM associated with the operation.
• Service()constGets the ID of the service that is associated with this operation.
• SystemProgress(TMsvSystemProgress &)This call leads to calling CMsvOperation::SystemProgress(TMsvSystemProgress &...
• iMsvSessionMessage Server session used by object. This is set by the constructor.
• iMtmThe UID of the MTM associated with the operation.
• iObserverRequestStatusRequest status of the operation observer.
• iServiceThe ID of the service that is associated with this operation.

IMPORT_C static CMsvCompletedOperation* NewL(CMsvSession &aMsvSession, TUid aMtm, const TDesC8 &aProgress, TMsvId aService, TRequestStatus &aObserverRequestStatus, TInt aErr=KErrNone);

Description

Allocates and constructs a new CMsvCompletedOperation object.

The new object is added to the active scheduler and its asynchronous request immediately set to complete.

Parameters

CMsvSession &aMsvSession Message Server session to use TUid aMtm The UID of the MTM associated with the operation. const TDesC8 &aProgress Operation progress information buffer. This is copied by the object. TMsvId aService The ID of the service that is associated with this operation. TRequestStatus &aObserverRequestStatus Request status of the operation observer. This observer is signalled that the operation is complete. TInt aErr Error code with which to complete the request. Use KErrNone to indicate that the operation completed successfully.

Return value

CMsvCompletedOperation * New CMsvOperationActiveSchedulerWait object

Leave codes

KErrNoMemory

IMPORT_C ~CMsvCompletedOperation();

Description

Destructor.

Any active request on the object is cancelled.

virtual const TDesC8& ProgressL();

Description

Gets information on the progress of the operation.

For a CMsvCompletedOperation, the progress information returned by CMsvCompletedOperation::ProgressL() and CMsvCompletedOperation::FinalProgress() is the same, and is the progress information set in the CMsvCompletedOperation::NewL(CMsvSession &,TUid,const TDesC8 &,TMsvId,TRequestStatus &,TInt) function.

Return value

const TDesC8 & Descriptor holding progress information.

See also:

• CMsvOperation::ProgressL()Gets information on the progress of the operation.

virtual const TDesC8& FinalProgress();

Description

Gets information about a completed operation.

Return value

const TDesC8 & Descriptor holding progress information.

See also:

• CMsvOperation::FinalProgress()Gets information about a completed operation.

private: virtual void DoCancel();

Description

Implements cancellation of an outstanding request.

This function is called as part of the active object's CActive::Cancel().

It must call the appropriate cancel function offered by the active object's asynchronous service provider. The asynchronous service provider's cancel is expected to act immediately.

CMsvCompletedOperation::DoCancel() must not wait for event completion; this is handled by CActive::Cancel().

See also:

• CActive::Cancel()Cancels the wait for completion of an outstanding request.

private: virtual void RunL();

Description

Handles an active object's request completion event.

A derived class must provide an implementation to handle the completed request. If appropriate, it may issue another request.

The function is called by the active scheduler when a request completion event occurs, i.e. after the active scheduler's WaitForAnyRequest() function completes.

Before calling this active object's CMsvCompletedOperation::RunL() function, the active scheduler has:

1. decided that this is the highest priority active object with a completed request

2. marked this active object's request as complete (i.e. the request is no longer outstanding)

CMsvCompletedOperation::RunL() runs under a trap harness in the active scheduler. If it leaves, then the active scheduler calls CActive::RunError(TInt) to handle the leave.

Note that once the active scheduler's Start() function has been called, all user code is run under one of the program's active object's CMsvCompletedOperation::RunL() or CActive::RunError(TInt) functions.

See also:

• CActiveScheduler::Start()Starts a new wait loop under the control of the current active scheduler.
• CActiveScheduler::Error(TInt)constHandles the result of a leave occurring in an active object’s RunL() function.
• CActiveScheduler::WaitForAnyRequest()Wait for an asynchronous request to complete.