View source

[[Category:Known Issue]]
[[Category:Location Based Services]]
[[Category:Symbian C++]]
[[Category:S60 3rd Edition, Feature Pack 1]]
{{KBKI}}
This known issue was originally created by '''Alammi''' and has been verified by Forum Nokia. 
__NOTOC__
__NOEDITSECTION__
{{KnowledgeBase
|id=KIS000850
|platform=S60 3rd Edition, Feature Pack 1
|devices=Nokia N95, Nokia E90 Communicator, Nokia 6110 Navigator
|category=Symbian C++
|subcategory=Location-based Services
|creationdate=March 25, 2008
|keywords=
}}

==Overview==
Trying to use <tt>RPositioner::NotifyPositionUpdate()</tt> to receive GPS position fails after a certain number of updates have been made, if update options have been omitted.

==Description==
Approximately after 4-5 minutes (255 update cycles), <tt>RPositioner::NotifyPositionUpdate()</tt> completes with error <tt>KErrInUse (-14)</tt>. This happens when the client has not set valid update options with <tt>RPositioner::SetUpdateOptions()</tt>.

This is not the defined return value for this API. After returning <tt>KErrInUse</tt> the RPositioner has "died" and always returns <tt>KErrInUse</tt>.

Note that the problem does not appear when using a Bluetooth GPS through the '''Location Acquisition API''', or on the emulator.

==How to reproduce==
'''Header file:'''

  class CMyPositioner : public CActive 
    {
    ...
    
    RPositionServer iPositionServer;
    RPositioner iPositioner;
    TPositionSatelliteInfo iSatelliteInfo;
    };


'''Implementation:'''

  _LIT(KRequestor, "MyPositioner");

  void CMyPositioner::ConstructL()
    {
    ...
    User::LeaveIfError( iPositionServer.Connect() );
    User::LeaveIfError( iPositioner.Open(iPositionServer) );
    User::LeaveIfError( iPositioner.SetRequestor( CRequestor::ERequestorService, 
                                                  CRequestor::EFormatApplication,
                                                  KRequestor) );
    CActiveScheduler::Add( this );
    }
  
  
  void CMyPositioner::StartL()
    {
    ...
    iPositioner.NotifyPositionUpdate( iSatelliteInfo, iStatus );
    SetActive();
    }
  
  
  void CMyPositioner::RunL()
    {
  	 if (iStatus == KErrNone)
  		  {
  		  // Got iSatelliteInfo successfully, handle it
  			HandleSatelliteInfo();
  			
  			// Request next update
  			iPositioner.NotifyPositionUpdate(iSatelliteInfo, iStatus);
  			SetActive();
  		  }
  		else
  		  {
  		  // Fails with KErrInUse (-14) after 255 cycles
  		  _LIT( KDebugMessage, "NotifyPositionUpdate() failed: %d" ); 
        RDebug::Print( KDebugMessage, iStatus.Int() );
  		  }
    }


==Solution==
Set valid update options with <tt>RPositioner::SetUpdateOptions()</tt> prior to calling <tt>RPositioner::NotifyPositionUpdate()</tt>:

  iPositioner.SetUpdateOptions(
      TPositionUpdateOptions( '''aInterval''',
                              TTimeIntervalMicroSeconds(0), /* timeout */
                              TTimeIntervalMicroSeconds(0), /* max age */
                              aAcceptPartialUpdates));
  
  iPositioner.NotifyPositionUpdate( iSatelliteInfo, iStatus );
  SetActive();
  ...

Note that the update interval (<tt>aInterval</tt>) value must be non-zero.