Categories: Known Issue | Location Based Services | Symbian C++ | S60 3rd Edition, Feature Pack 1

This page was last modified 07:35, 25 March 2008.

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This known issue was originally created by Alammi and has been verified by Forum Nokia.

Overview

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

Detailed description

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

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

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 RPositioner::SetUpdateOptions() prior to calling RPositioner::NotifyPositionUpdate():

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

Note that the update interval (aInterval) value must be non-zero.