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Avoid crash and/or long delay on shutdown in METAR loader.

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Catching loader thread on subsystem destruction is too late, since it
depends on other subsystems (which are destroyed earlier).
=> Need to stop & join thread during subsystem shutdown.
Also changed loader sleep logic - to avoid excessive delays (up to
30 seconds) on shutdown.
(Issues mostly happened when running offline with realwx enabled.)
This commit is contained in:
ThorstenB 2011-02-13 16:50:23 +01:00
parent c7cccd8758
commit ae320ca46c
1 changed files with 36 additions and 12 deletions
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48
src/Environment/realwx_ctrl.cxx
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@ -191,6 +191,7 @@ public:
NoaaMetarRealWxController( SGPropertyNode_ptr rootNode );
virtual ~NoaaMetarRealWxController();
virtual void update (bool first, double delta_time_sec);
virtual void shutdown ();
class MetarLoadRequest {
public:
@ -234,14 +235,17 @@ private:
class MetarLoadThread : public OpenThreads::Thread {
public:
MetarLoadThread( long maxAge );
virtual ~MetarLoadThread( ) { stop(); }
void requestMetar( const MetarLoadRequest & metarRequest, bool background = true );
bool hasMetar() { return _responseQueue.size() > 0; }
MetarLoadResponse getMetar() { return _responseQueue.pop(); }
virtual void run();
void stop();
private:
void fetch( const MetarLoadRequest & );
long _maxAge;
long _minRequestInterval;
volatile bool _stop;
SGBlockingQueue <MetarLoadRequest> _requestQueue;
SGBlockingQueue <MetarLoadResponse> _responseQueue;
};
@ -261,18 +265,20 @@ NoaaMetarRealWxController::NoaaMetarRealWxController( SGPropertyNode_ptr rootNod
#endif
}
NoaaMetarRealWxController::~NoaaMetarRealWxController()
void NoaaMetarRealWxController::shutdown()
{
#if defined(ENABLE_THREADS)
if( _metarLoadThread ) {
MetarLoadRequest request("");
_metarLoadThread->requestMetar(request);
_metarLoadThread->join();
delete _metarLoadThread;
_metarLoadThread = NULL;
}
#endif // ENABLE_THREADS
}
NoaaMetarRealWxController::~NoaaMetarRealWxController()
{
}
void NoaaMetarRealWxController::update( bool first, double dt )
{
_positionTimeToLive -= dt;
@ -319,7 +325,7 @@ void NoaaMetarRealWxController::update( bool first, double dt )
"NoaaMetarRealWxController::update(): spawning load request for station-id '" << stationId << "'" );
MetarLoadRequest request( stationId );
// load the metar for the neares airport in the foreground if the fdm is uninitialized
// load the metar for the nearest airport in the foreground if the fdm is uninitialized
// to make sure a metar is received
// before the automatic runway selection code runs. All subsequent calls
// run in the background
@ -348,7 +354,8 @@ void NoaaMetarRealWxController::update( bool first, double dt )
#if defined(ENABLE_THREADS)
NoaaMetarRealWxController::MetarLoadThread::MetarLoadThread( long maxAge ) :
_maxAge(maxAge),
_minRequestInterval(2000)
_minRequestInterval(2000),
_stop(false)
{
}
@ -368,24 +375,41 @@ void NoaaMetarRealWxController::MetarLoadThread::requestMetar( const MetarLoadRe
}
}
void NoaaMetarRealWxController::MetarLoadThread::stop()
{
// set stop flag and wake up the thread with an empty request
_stop = true;
MetarLoadRequest request("");
requestMetar(request);
join();
}
void NoaaMetarRealWxController::MetarLoadThread::run()
{
SGTimeStamp lastRun = SGTimeStamp::fromSec(0);
for( ;; ) {
SGTimeStamp dt = SGTimeStamp::now() - lastRun;
if( dt.getSeconds() * 1000 < _minRequestInterval )
microSleep( (_minRequestInterval - dt.getSeconds() * 1000 ) * 1000 );
lastRun = SGTimeStamp::now();
long delayMs = _minRequestInterval - dt.getSeconds() * 1000;
while (( delayMs > 0 ) && !_stop)
{
// sleep no more than 3 seconds at a time, otherwise shutdown response is too slow
long sleepMs = (delayMs>3000) ? 3000 : delayMs;
microSleep( sleepMs * 1000 );
delayMs -= sleepMs;
}
if (_stop)
break;
lastRun = SGTimeStamp::now();
const MetarLoadRequest request = _requestQueue.pop();
if( request._stationId.size() == 0 )
if (( request._stationId.size() == 0 ) || _stop)
break;
fetch( request );
}
}