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1 // environment_ctrl.cxx -- manager for natural environment information.
2 //
3 // Written by David Megginson, started February 2002.
4 //
5 // Copyright (C) 2002  David Megginson - david@megginson.com
6 //
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
11 //
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 // General Public License for more details.
16 //
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 //
21 // $Id$
22
23 #include <simgear/debug/logstream.hxx>
24
25 #include <stdlib.h>
26 #include <algorithm>
27
28 #include <simgear/structure/commands.hxx>
29 #include <simgear/structure/exception.hxx>
30
31 #include <Airports/simple.hxx>
32 #include <Main/fg_props.hxx>
33 #include <Main/util.hxx>
34
35 #include "environment_mgr.hxx"
36 #include "environment_ctrl.hxx"
37
38 SG_USING_STD(sort);
39
40
41 \f
42 ////////////////////////////////////////////////////////////////////////
43 // Implementation of FGEnvironmentCtrl abstract base class.
44 ////////////////////////////////////////////////////////////////////////
45
46 FGEnvironmentCtrl::FGEnvironmentCtrl ()
47   : _environment(0),
48     _lon_deg(0),
49     _lat_deg(0),
50     _elev_ft(0)
51 {
52 }
53
54 FGEnvironmentCtrl::~FGEnvironmentCtrl ()
55 {
56 }
57
58 void
59 FGEnvironmentCtrl::setEnvironment (FGEnvironment * environment)
60 {
61   _environment = environment;
62 }
63
64 void
65 FGEnvironmentCtrl::setLongitudeDeg (double lon_deg)
66 {
67   _lon_deg = lon_deg;
68 }
69
70 void
71 FGEnvironmentCtrl::setLatitudeDeg (double lat_deg)
72 {
73   _lat_deg = lat_deg;
74 }
75
76 void
77 FGEnvironmentCtrl::setElevationFt (double elev_ft)
78 {
79   _elev_ft = elev_ft;
80 }
81
82 void
83 FGEnvironmentCtrl::setPosition (double lon_deg, double lat_deg, double elev_ft)
84 {
85   _lon_deg = lon_deg;
86   _lat_deg = lat_deg;
87   _elev_ft = elev_ft;
88 }
89
90
91 \f
92 ////////////////////////////////////////////////////////////////////////
93 // Implementation of FGUserDefEnvironmentCtrl.
94 ////////////////////////////////////////////////////////////////////////
95
96 FGUserDefEnvironmentCtrl::FGUserDefEnvironmentCtrl ()
97   : _base_wind_speed_node(0),
98     _gust_wind_speed_node(0),
99     _current_wind_speed_kt(0),
100     _delta_wind_speed_kt(0)
101 {
102 }
103
104 FGUserDefEnvironmentCtrl::~FGUserDefEnvironmentCtrl ()
105 {
106 }
107
108 void
109 FGUserDefEnvironmentCtrl::init ()
110 {
111                                 // Fill in some defaults.
112   if (!fgHasNode("/environment/params/base-wind-speed-kt"))
113     fgSetDouble("/environment/params/base-wind-speed-kt",
114                 fgGetDouble("/environment/wind-speed-kt"));
115   if (!fgHasNode("/environment/params/gust-wind-speed-kt"))
116     fgSetDouble("/environment/params/gust-wind-speed-kt",
117                 fgGetDouble("/environment/params/base-wind-speed-kt"));
118
119   _base_wind_speed_node =
120     fgGetNode("/environment/params/base-wind-speed-kt", true);
121   _gust_wind_speed_node =
122     fgGetNode("/environment/params/gust-wind-speed-kt", true);
123
124   _current_wind_speed_kt = _base_wind_speed_node->getDoubleValue();
125   _delta_wind_speed_kt = 0.1;
126 }
127
128 void
129 FGUserDefEnvironmentCtrl::update (double dt)
130 {
131   double base_wind_speed = _base_wind_speed_node->getDoubleValue();
132   double gust_wind_speed = _gust_wind_speed_node->getDoubleValue();
133
134   if (gust_wind_speed < base_wind_speed) {
135       gust_wind_speed = base_wind_speed;
136       _gust_wind_speed_node->setDoubleValue(gust_wind_speed);
137   }
138
139   if (base_wind_speed == gust_wind_speed) {
140     _current_wind_speed_kt = base_wind_speed;
141   } else {
142     int rn = rand() % 128;
143     int sign = (_delta_wind_speed_kt < 0 ? -1 : 1);
144     double gust = _current_wind_speed_kt - base_wind_speed;
145     double incr = gust / 50;
146
147     if (rn == 0)
148       _delta_wind_speed_kt = - _delta_wind_speed_kt;
149     else if (rn < 4)
150       _delta_wind_speed_kt -= incr * sign;
151     else if (rn < 16)
152       _delta_wind_speed_kt += incr * sign;
153
154     _current_wind_speed_kt += _delta_wind_speed_kt;
155
156     if (_current_wind_speed_kt < base_wind_speed) {
157       _current_wind_speed_kt = base_wind_speed;
158       _delta_wind_speed_kt = 0.01;
159     } else if (_current_wind_speed_kt > gust_wind_speed) {
160       _current_wind_speed_kt = gust_wind_speed;
161       _delta_wind_speed_kt = -0.01;
162     }
163   }
164   
165   if (_environment != 0)
166     _environment->set_wind_speed_kt(_current_wind_speed_kt);
167 }
168
169
170 \f
171 ////////////////////////////////////////////////////////////////////////
172 // Implementation of FGInterpolateEnvironmentCtrl.
173 ////////////////////////////////////////////////////////////////////////
174
175 FGInterpolateEnvironmentCtrl::FGInterpolateEnvironmentCtrl ()
176 {
177 }
178
179 FGInterpolateEnvironmentCtrl::~FGInterpolateEnvironmentCtrl ()
180 {
181     unsigned int i;
182     for (i = 0; i < _boundary_table.size(); i++)
183         delete _boundary_table[i];
184     for (i = 0; i < _aloft_table.size(); i++)
185         delete _aloft_table[i];
186 }
187
188
189
190 void
191 FGInterpolateEnvironmentCtrl::init ()
192 {
193     read_table(fgGetNode("/environment/config/boundary", true),
194                _boundary_table);
195     read_table(fgGetNode("/environment/config/aloft", true),
196                _aloft_table);
197 }
198
199 void
200 FGInterpolateEnvironmentCtrl::reinit ()
201 {
202     unsigned int i;
203     for (i = 0; i < _boundary_table.size(); i++)
204         delete _boundary_table[i];
205     for (i = 0; i < _aloft_table.size(); i++)
206         delete _aloft_table[i];
207     _boundary_table.clear();
208     _aloft_table.clear();
209     init();
210 }
211
212 void
213 FGInterpolateEnvironmentCtrl::read_table (const SGPropertyNode * node,
214                                           vector<bucket *> &table)
215 {
216     for (int i = 0; i < node->nChildren(); i++) {
217         const SGPropertyNode * child = node->getChild(i);
218         if ( strcmp(child->getName(), "entry") == 0
219              && child->getStringValue("elevation-ft", "")[0] != '\0'
220              && ( child->getDoubleValue("elevation-ft") > 0.1 || i == 0 ) )
221         {
222             bucket * b = new bucket;
223             if (i > 0)
224                 b->environment.copy(table[i-1]->environment);
225             b->environment.read(child);
226             b->altitude_ft = b->environment.get_elevation_ft();
227             table.push_back(b);
228         }
229     }
230     sort(table.begin(), table.end());
231 }
232
233 void
234 FGInterpolateEnvironmentCtrl::update (double delta_time_sec)
235 {
236                                 // FIXME
237     double altitude_ft = fgGetDouble("/position/altitude-ft");
238     double altitude_agl_ft = fgGetDouble("/position/altitude-agl-ft");
239     double boundary_transition =
240         fgGetDouble("/environment/config/boundary-transition-ft", 500);
241
242     // double ground_elevation_ft = altitude_ft - altitude_agl_ft;
243
244     int length = _boundary_table.size();
245
246     if (length > 0) {
247                                 // boundary table
248         double boundary_limit = _boundary_table[length-1]->altitude_ft;
249         if (boundary_limit >= altitude_agl_ft) {
250             do_interpolate(_boundary_table, altitude_agl_ft,
251                            _environment);
252             return;
253         } else if ((boundary_limit + boundary_transition) >= altitude_agl_ft) {
254                                 // both tables
255             do_interpolate(_boundary_table, altitude_agl_ft, &env1);
256             do_interpolate(_aloft_table, altitude_ft, &env2);
257             double fraction =
258                 (altitude_agl_ft - boundary_limit) / boundary_transition;
259             interpolate(&env1, &env2, fraction, _environment);
260             return;
261         }
262     }
263
264                                 // aloft table
265     do_interpolate(_aloft_table, altitude_ft, _environment);
266 }
267
268 void
269 FGInterpolateEnvironmentCtrl::do_interpolate (vector<bucket *> &table,
270                                               double altitude_ft,
271                                               FGEnvironment * environment)
272 {
273     int length = table.size();
274     if (length == 0)
275         return;
276
277                                 // Boundary conditions
278     if ((length == 1) || (table[0]->altitude_ft >= altitude_ft)) {
279         environment->copy(table[0]->environment);
280         return;
281     } else if (table[length-1]->altitude_ft <= altitude_ft) {
282         environment->copy(table[length-1]->environment);
283         return;
284     }
285         
286                                 // Search the interpolation table
287     for (int i = 0; i < length - 1; i++) {
288         if ((i == length - 1) || (table[i]->altitude_ft <= altitude_ft)) {
289                 FGEnvironment * env1 = &(table[i]->environment);
290                 FGEnvironment * env2 = &(table[i+1]->environment);
291                 double fraction;
292                 if (table[i]->altitude_ft == table[i+1]->altitude_ft)
293                     fraction = 1.0;
294                 else
295                     fraction =
296                         ((altitude_ft - table[i]->altitude_ft) /
297                          (table[i+1]->altitude_ft - table[i]->altitude_ft));
298                 interpolate(env1, env2, fraction, environment);
299
300                 return;
301         }
302     }
303 }
304
305 bool
306 FGInterpolateEnvironmentCtrl::bucket::operator< (const bucket &b) const
307 {
308     return (altitude_ft < b.altitude_ft);
309 }
310
311
312 \f
313 ////////////////////////////////////////////////////////////////////////
314 // Implementation of FGMetarEnvironmentCtrl.
315 ////////////////////////////////////////////////////////////////////////
316
317 FGMetarEnvironmentCtrl::FGMetarEnvironmentCtrl ()
318     : env( new FGInterpolateEnvironmentCtrl ),
319       _icao( "" ),
320       search_interval_sec( 60.0 ),        // 1 minute
321       same_station_interval_sec( 900.0 ), // 15 minutes
322       search_elapsed( 9999.0 ),
323       fetch_elapsed( 9999.0 ),
324       proxy_host( fgGetNode("/sim/presets/proxy/host", true) ),
325       proxy_port( fgGetNode("/sim/presets/proxy/port", true) ),
326       proxy_auth( fgGetNode("/sim/presets/proxy/authentication", true) ),
327       metar_max_age( fgGetNode("/environment/params/metar-max-age-min", true) ),
328       _error_count( 0 ),
329       _dt( 0.0 ),
330       _error_dt( 0.0 )
331 {
332 #if defined(ENABLE_THREADS) && ENABLE_THREADS
333     thread = new MetarThread(this);
334     thread->start( 1 );
335 #endif // ENABLE_THREADS
336 }
337
338 FGMetarEnvironmentCtrl::~FGMetarEnvironmentCtrl ()
339 {
340 #if defined(ENABLE_THREADS) && ENABLE_THREADS
341    thread->cancel();
342    thread->join();
343 #endif // ENABLE_THREADS
344
345    delete env;
346    env = NULL;
347 }
348
349
350 // use a "command" to set station temp at station elevation
351 static void set_temp_at_altitude( float temp_degc, float altitude_ft ) {
352     SGPropertyNode args;
353     SGPropertyNode *node = args.getNode("temp-degc", 0, true);
354     node->setFloatValue( temp_degc );
355     node = args.getNode("altitude-ft", 0, true);
356     node->setFloatValue( altitude_ft );
357     globals->get_commands()->execute("set-outside-air-temp-degc", &args);
358 }
359
360
361 static void set_dewpoint_at_altitude( float dewpoint_degc, float altitude_ft ) {
362     SGPropertyNode args;
363     SGPropertyNode *node = args.getNode("dewpoint-degc", 0, true);
364     node->setFloatValue( dewpoint_degc );
365     node = args.getNode("altitude-ft", 0, true);
366     node->setFloatValue( altitude_ft );
367     globals->get_commands()->execute("set-dewpoint-temp-degc", &args);
368 }
369
370
371 void
372 FGMetarEnvironmentCtrl::update_env_config ()
373 {
374     fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
375                  fgGetDouble("/environment/metar/base-wind-range-to"),
376                  fgGetDouble("/environment/metar/base-wind-speed-kt"),
377                  fgGetDouble("/environment/metar/gust-wind-speed-kt") );
378
379     fgDefaultWeatherValue( "visibility-m",
380                            fgGetDouble("/environment/metar/min-visibility-m") );
381     set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
382                           station_elevation_ft );
383     set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
384                               station_elevation_ft );
385     fgDefaultWeatherValue( "pressure-sea-level-inhg",
386                            fgGetDouble("/environment/metar/pressure-inhg") );
387 }
388
389 void
390 FGMetarEnvironmentCtrl::init ()
391 {
392     const SGPropertyNode *longitude
393         = fgGetNode( "/position/longitude-deg", true );
394     const SGPropertyNode *latitude
395         = fgGetNode( "/position/latitude-deg", true );
396
397     bool found_metar = false;
398     long max_age = metar_max_age->getLongValue();
399     // Don't check max age during init so that we don't loop over a lot
400     // of airports metar if there is a problem.
401     // The update() calls will find a correct metar if things went wrong here
402     metar_max_age->setLongValue(60 * 24 * 7);
403
404     while ( !found_metar && (_error_count < 3) ) {
405         FGAirport a = globals->get_airports()
406             ->search( longitude->getDoubleValue(),
407                       latitude->getDoubleValue(),
408                       true );
409         FGMetarResult result = fetch_data( a.getId() );
410         if ( result.m != NULL ) {
411             SG_LOG( SG_GENERAL, SG_INFO, "closest station w/ metar = " << a.getId());
412             last_apt = a;
413             _icao = a.getId();
414             search_elapsed = 0.0;
415             fetch_elapsed = 0.0;
416             update_metar_properties( result.m );
417             update_env_config();
418             env->init();
419             found_metar = true;
420         } else {
421             // mark as no metar so it doesn't show up in subsequent
422             // searches.
423             SG_LOG( SG_GENERAL, SG_INFO, "no metar at metar = " << a.getId() );
424             globals->get_airports()->no_metar( a.getId() );
425         }
426     }
427     metar_max_age->setLongValue(max_age);
428 }
429
430 void
431 FGMetarEnvironmentCtrl::reinit ()
432 {
433     _error_count = 0;
434     _error_dt = 0.0;
435
436 #if 0
437     update_env_config();
438 #endif
439
440     env->reinit();
441 }
442
443 void
444 FGMetarEnvironmentCtrl::update(double delta_time_sec)
445 {
446
447     _dt += delta_time_sec;
448     if (_error_count >= 3)
449        return;
450
451     FGMetarResult result;
452
453     static const SGPropertyNode *longitude
454         = fgGetNode( "/position/longitude-deg", true );
455     static const SGPropertyNode *latitude
456         = fgGetNode( "/position/latitude-deg", true );
457     search_elapsed += delta_time_sec;
458     fetch_elapsed += delta_time_sec;
459
460     // if time for a new search request, push it onto the request
461     // queue
462     if ( search_elapsed > search_interval_sec ) {
463         FGAirport a = globals->get_airports()
464             ->search( longitude->getDoubleValue(),
465                       latitude->getDoubleValue(),
466                       true );
467         if ( last_apt.getId() != a.getId()
468              || fetch_elapsed > same_station_interval_sec )
469         {
470             SG_LOG( SG_GENERAL, SG_INFO, "closest station w/ metar = " << a.getId());
471             request_queue.push( a.getId() );
472             last_apt = a;
473             _icao = a.getId();
474             search_elapsed = 0.0;
475             fetch_elapsed = 0.0;
476         } else {
477             search_elapsed = 0.0;
478             SG_LOG( SG_GENERAL, SG_INFO, "same station, waiting = "
479                  << same_station_interval_sec - fetch_elapsed );
480         }
481     }
482
483 #if defined(ENABLE_THREADS) && ENABLE_THREADS
484     // No loader thread running so manually fetch the data
485     string id = "";
486     while ( !request_queue.empty() ) {
487         id = request_queue.front();
488         request_queue.pop();
489     }
490
491     if ( !id.empty() ) {
492         SG_LOG( SG_GENERAL, SG_INFO, "inline fetching = " << id );
493         result = fetch_data( id );
494         result_queue.push( result );
495     }
496 #endif // ENABLE_THREADS
497
498     // process any results from the loader.
499     while ( !result_queue.empty() ) {
500         result = result_queue.front();
501         result_queue.pop();
502         if ( result.m != NULL ) {
503             update_metar_properties( result.m );
504             delete result.m;
505             update_env_config();
506             env->reinit();
507         } else {
508             // mark as no metar so it doesn't show up in subsequent
509             // searches, and signal an immediate re-search.
510             SG_LOG( SG_GENERAL, SG_WARN,
511                     "no metar at station = " << result.icao );
512             globals->get_airports()->no_metar( result.icao );
513             search_elapsed = 9999.0;
514         }
515     }
516
517     env->update(delta_time_sec);
518 }
519
520
521 void
522 FGMetarEnvironmentCtrl::setEnvironment (FGEnvironment * environment)
523 {
524     env->setEnvironment(environment);
525 }
526
527 FGMetarResult
528 FGMetarEnvironmentCtrl::fetch_data( const string &icao )
529 {
530     FGMetarResult result;
531     result.icao = icao;
532
533     // if the last error was more than three seconds ago,
534     // then pretent nothing happened.
535     if (_error_dt < 3) {
536         _error_dt += _dt;
537
538     } else {
539         _error_dt = 0.0;
540         _error_count = 0;
541     }
542
543     // fetch station elevation if exists
544     FGAirport a = globals->get_airports()->search( icao );
545     station_elevation_ft = a.getElevation();
546
547     // fetch current metar data
548     try {
549         string host = proxy_host->getStringValue();
550         string auth = proxy_auth->getStringValue();
551         string port = proxy_port->getStringValue();
552         result.m = new FGMetar( icao, host, port, auth);
553
554         long max_age = metar_max_age->getLongValue();
555         if (max_age && result.m->getAge_min() > max_age) {
556             SG_LOG( SG_GENERAL, SG_WARN, "METAR data too old");
557             delete result.m;
558             result.m = NULL;
559         }
560
561     } catch (const sg_io_exception& e) {
562         SG_LOG( SG_GENERAL, SG_WARN, "Error fetching live weather data: "
563                 << e.getFormattedMessage().c_str() );
564 #if defined(ENABLE_THREADS) && ENABLE_THREADS
565         if (_error_count++ >= 3) {
566            SG_LOG( SG_GENERAL, SG_WARN, "Stop fetching data permanently.");
567            thread->cancel();
568            thread->join();
569         }
570 #endif
571
572         result.m = NULL;
573     }
574
575     _dt = 0;
576
577     return result;
578 }
579
580
581 void
582 FGMetarEnvironmentCtrl::update_metar_properties( FGMetar *m )
583 {
584     int i;
585     double d;
586     char s[128];
587
588     fgSetString("/environment/metar/real-metar", m->getData());
589         // don't update with real weather when we use a custom weather scenario
590         const char *current_scenario = fgGetString("/environment/weather-scenario", "METAR");
591         if( strcmp(current_scenario, "METAR") && strcmp(current_scenario, "none"))
592                 return;
593     fgSetString("/environment/metar/last-metar", m->getData());
594     fgSetString("/environment/metar/station-id", m->getId());
595     fgSetDouble("/environment/metar/min-visibility-m",
596                 m->getMinVisibility().getVisibility_m() );
597     fgSetDouble("/environment/metar/max-visibility-m",
598                 m->getMaxVisibility().getVisibility_m() );
599
600     SGMetarVisibility *dirvis = m->getDirVisibility();
601     for (i = 0; i < 8; i++, dirvis++) {
602         const char *min = "/environment/metar/visibility[%d]/min-m";
603         const char *max = "/environment/metar/visibility[%d]/max-m";
604
605         d = dirvis->getVisibility_m();
606
607         snprintf(s, 128, min, i);
608         fgSetDouble(s, d);
609         snprintf(s, 128, max, i);
610         fgSetDouble(s, d);
611     }
612
613     fgSetInt("/environment/metar/base-wind-range-from",
614              m->getWindRangeFrom() );
615     fgSetInt("/environment/metar/base-wind-range-to",
616              m->getWindRangeTo() );
617     fgSetDouble("/environment/metar/base-wind-speed-kt",
618                 m->getWindSpeed_kt() );
619     fgSetDouble("/environment/metar/gust-wind-speed-kt",
620                 m->getGustSpeed_kt() );
621     fgSetDouble("/environment/metar/temperature-degc",
622                 m->getTemperature_C() );
623     fgSetDouble("/environment/metar/dewpoint-degc",
624                 m->getDewpoint_C() );
625     fgSetDouble("/environment/metar/rel-humidity-norm",
626                 m->getRelHumidity() );
627     fgSetDouble("/environment/metar/pressure-inhg",
628                 m->getPressure_inHg() );
629
630     vector<SGMetarCloud> cv = m->getClouds();
631     vector<SGMetarCloud>::iterator cloud;
632
633     const char *cl = "/environment/clouds/layer[%i]";
634     for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
635         const char *coverage_string[5] = 
636             { "clear", "few", "scattered", "broken", "overcast" };
637         const double thickness[5] = { 0, 65, 600,750, 1000};
638         int q;
639
640         snprintf(s, 128, cl, i);
641         strncat(s, "/coverage", 128);
642         q = cloud->getCoverage();
643         fgSetString(s, coverage_string[q] );
644
645         snprintf(s, 128, cl, i);
646         strncat(s, "/elevation-ft", 128);
647         fgSetDouble(s, cloud->getAltitude_ft() + station_elevation_ft);
648
649         snprintf(s, 128, cl, i);
650         strncat(s, "/thickness-ft", 128);
651         fgSetDouble(s, thickness[q]);
652
653         snprintf(s, 128, cl, i);
654         strncat(s, "/span-m", 128);
655         fgSetDouble(s, 40000.0);
656     }
657
658     for (; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
659         snprintf(s, 128, cl, i);
660         strncat(s, "/coverage", 128);
661         fgSetString(s, "clear");
662
663         snprintf(s, 128, cl, i);
664         strncat(s, "/elevation-ft", 128);
665         fgSetDouble(s, -9999);
666
667         snprintf(s, 128, cl, i);
668         strncat(s, "/thickness-ft", 128);
669         fgSetDouble(s, 0);
670
671         snprintf(s, 128, cl, i);
672         strncat(s, "/span-m", 128);
673         fgSetDouble(s, 40000.0);
674     }
675
676     fgSetDouble("/environment/metar/rain-norm", m->getRain());
677     fgSetDouble("/environment/metar/hail-norm", m->getHail());
678     fgSetDouble("/environment/metar/snow-norm", m->getSnow());
679     fgSetBool("/environment/metar/snow-cover", m->getSnowCover());
680 }
681
682
683 #if defined(ENABLE_THREADS) && ENABLE_THREADS
684 /**
685  *
686  */
687 void
688 FGMetarEnvironmentCtrl::MetarThread::run()
689 {
690     pthread_cleanup_push( metar_cleanup_handler, fetcher );
691     while ( true )
692     {
693         set_cancel( SGThread::CANCEL_DISABLE );
694
695         string icao = fetcher->request_queue.pop();
696         SG_LOG( SG_GENERAL, SG_INFO, "Thread: fetch metar data = " << icao );
697         FGMetarResult result = fetcher->fetch_data( icao );
698
699         set_cancel( SGThread::CANCEL_DEFERRED );
700
701         fetcher->result_queue.push( result );
702     }
703     pthread_cleanup_pop(1);
704 }
705
706 /**
707  * Ensure mutex is unlocked.
708  */
709 void
710 metar_cleanup_handler( void* arg )
711 {
712     FGMetarEnvironmentCtrl* fetcher = (FGMetarEnvironmentCtrl*) arg;
713     fetcher->mutex.unlock();
714 }
715 #endif // ENABLE_THREADS
716
717
718 // end of environment_ctrl.cxx