src/Environment/environment_ctrl.cxx

   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( fgGetString("/sim/presets/airport-id") ),
 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 {
 328 #ifdef ENABLE_THREADS
 329     thread = new MetarThread(this);
 330     thread->start();
 331 #endif // ENABLE_THREADS
 332 }
 333
 334 FGMetarEnvironmentCtrl::~FGMetarEnvironmentCtrl ()
 335 {
 336 #ifdef ENABLE_THREADS
 337    thread->cancel();
 338    thread->join();
 339 #endif // ENABLE_THREADS
 340
 341    delete env;
 342    env = NULL;
 343 }
 344
 345
 346 // use a "command" to set station temp at station elevation
 347 static void set_temp_at_altitude( float temp_degc, float altitude_ft ) {
 348     SGPropertyNode args;
 349     SGPropertyNode *node = args.getNode("temp-degc", 0, true);
 350     node->setFloatValue( temp_degc );
 351     node = args.getNode("altitude-ft", 0, true);
 352     node->setFloatValue( altitude_ft );
 353     globals->get_commands()->execute("set-outside-air-temp-degc", &args);
 354 }
 355
 356
 357 static void set_dewpoint_at_altitude( float dewpoint_degc, float altitude_ft ) {
 358     SGPropertyNode args;
 359     SGPropertyNode *node = args.getNode("dewpoint-degc", 0, true);
 360     node->setFloatValue( dewpoint_degc );
 361     node = args.getNode("altitude-ft", 0, true);
 362     node->setFloatValue( altitude_ft );
 363     globals->get_commands()->execute("set-dewpoint-temp-degc", &args);
 364 }
 365
 366
 367 void
 368 FGMetarEnvironmentCtrl::update_env_config ()
 369 {
 370     fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
 371                  fgGetDouble("/environment/metar/base-wind-range-to"),
 372                  fgGetDouble("/environment/metar/base-wind-speed-kt"),
 373                  fgGetDouble("/environment/metar/gust-wind-speed-kt") );
 374
 375     fgDefaultWeatherValue( "visibility-m",
 376                            fgGetDouble("/environment/metar/min-visibility-m") );
 377     set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
 378                           station_elevation_ft );
 379     set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
 380                               station_elevation_ft );
 381     fgDefaultWeatherValue( "pressure-sea-level-inhg",
 382                            fgGetDouble("/environment/metar/pressure-inhg") );
 383 }
 384
 385 void
 386 FGMetarEnvironmentCtrl::init ()
 387 {
 388     const SGPropertyNode *longitude
 389         = fgGetNode( "/position/longitude-deg", true );
 390     const SGPropertyNode *latitude
 391         = fgGetNode( "/position/latitude-deg", true );
 392
 393     bool found_metar = false;
 394     while ( !found_metar ) {
 395         FGAirport a = globals->get_airports()
 396             ->search( longitude->getDoubleValue(),
 397                       latitude->getDoubleValue(),
 398                       true );
 399         if ( fetch_data( a.id ) ) {
 400             cout << "closest station w/ metar = " << a.id << endl;
 401             last_apt = a;
 402             _icao = a.id;
 403             search_elapsed = 0.0;
 404             fetch_elapsed = 0.0;
 405             update_env_config();
 406             env->init();
 407             found_metar = true;
 408         } else {
 409             // mark as no metar so it doesn't show up in subsequent
 410             // searches.
 411             cout << "no metar at metar = " << a.id << endl;
 412             globals->get_airports()->no_metar( a.id );
 413         }
 414     }
 415 }
 416
 417 void
 418 FGMetarEnvironmentCtrl::reinit ()
 419 {
 420 #if 0
 421     update_env_config();
 422 #endif
 423
 424     env->reinit();
 425 }
 426
 427 void
 428 FGMetarEnvironmentCtrl::update(double delta_time_sec)
 429 {
 430     static const SGPropertyNode *longitude
 431         = fgGetNode( "/position/longitude-deg", true );
 432     static const SGPropertyNode *latitude
 433         = fgGetNode( "/position/latitude-deg", true );
 434     search_elapsed += delta_time_sec;
 435     fetch_elapsed += delta_time_sec;
 436     if ( search_elapsed > search_interval_sec ) {
 437         FGAirport a = globals->get_airports()
 438             ->search( longitude->getDoubleValue(),
 439                       latitude->getDoubleValue(),
 440                       true );
 441         if ( last_apt.id != a.id
 442              || fetch_elapsed > same_station_interval_sec )
 443         {
 444             if ( fetch_data( a.id ) ) {
 445                 cout << "closest station w/ metar = " << a.id << endl;
 446                 last_apt = a;
 447                 _icao = a.id;
 448                 search_elapsed = 0.0;
 449                 fetch_elapsed = 0.0;
 450                 update_env_config();
 451                 env->reinit();
 452             } else {
 453                 // mark as no metar so it doesn't show up in subsequent
 454                 // searches.
 455                 cout << "no metar at metar = " << a.id << endl;
 456                 globals->get_airports()->no_metar( a.id );
 457             }
 458         } else {
 459             search_elapsed = 0.0;
 460             // cout << "same station, waiting = "
 461             //      << same_station_interval_sec - fetch_elapsed << endl;
 462         }
 463     }
 464
 465     env->update(delta_time_sec);
 466 }
 467
 468 void
 469 FGMetarEnvironmentCtrl::setEnvironment (FGEnvironment * environment)
 470 {
 471     env->setEnvironment(environment);
 472 }
 473
 474 bool
 475 FGMetarEnvironmentCtrl::fetch_data (const string &icao)
 476 {
 477     char s[128];
 478     double d, dt;
 479     int i;
 480
 481     if ((icao == "") && (_icao == "")) {
 482         _icao = fgGetString("/sim/presets/airport-id");
 483
 484     } else if (icao != "") {
 485         _icao = icao;
 486     }
 487
 488     // fetch station elevation if exists
 489     FGAirport a = globals->get_airports()->search( _icao );
 490     station_elevation_ft = a.elevation;
 491
 492     // fetch current metar data
 493     SGMetar *m = NULL;
 494 #ifdef ENABLE_THREADS
 495
 496     // We are only interested in the latest metar report
 497     // FIXME: Do we want to keep the latest valid report instead?
 498     while (!metar_queue.empty()) {
 499
 500         if (m != NULL)
 501             delete m;
 502
 503         m = metar_queue.pop();
 504     }
 505
 506     if ( m != NULL ) {
 507
 508 #else
 509     try {
 510         string host = proxy_host->getStringValue();
 511         string auth = proxy_auth->getStringValue();
 512         string port = proxy_port->getStringValue();
 513         m = new SGMetar( _icao, host, port, auth);
 514
 515 #endif // ENABLE_THREADS
 516
 517         d = m->getMinVisibility().getVisibility_m();
 518         d = (d != SGMetarNaN) ? d : 10000;
 519         fgSetDouble("/environment/metar/min-visibility-m", d);
 520
 521         dt =  m->getMaxVisibility().getVisibility_m();
 522         d = (dt != SGMetarNaN) ? dt : d;
 523         fgSetDouble("/environment/metar/max-visibility-m", d);
 524
 525         SGMetarVisibility *dirvis = m->getDirVisibility();
 526         for (i = 0; i < 8; i++, dirvis++) {
 527             const char *min = "/environment/metar/visibility[%d]/min-m";
 528             const char *max = "/environment/metar/visibility[%d]/max-m";
 529             char s[128];
 530
 531             d = dirvis->getVisibility_m();
 532             d = (d != SGMetarNaN) ? d : 10000;
 533
 534             snprintf(s, 128, min, i);
 535             fgSetDouble(s, d);
 536             snprintf(s, 128, max, i);
 537             fgSetDouble(s, d);
 538         }
 539
 540         i = m->getWindDir();
 541         if ( i == -1 ) {
 542             fgSetInt("/environment/metar/base-wind-range-from",
 543                         m->getWindRangeFrom() );
 544             fgSetInt("/environment/metar/base-wind-range-to",
 545                         m->getWindRangeTo() );
 546         } else {
 547             fgSetInt("/environment/metar/base-wind-range-from", i);
 548             fgSetInt("/environment/metar/base-wind-range-to", i);
 549         }
 550         fgSetDouble("/environment/metar/base-wind-speed-kt",
 551                     m->getWindSpeed_kt() );
 552
 553         d = m->getGustSpeed_kt();
 554         d = (d != SGMetarNaN) ? d : 0.0;
 555         fgSetDouble("/environment/metar/gust-wind-speed-kt", d);
 556
 557         d = m->getTemperature_C();
 558         if (d != SGMetarNaN) {
 559             dt = m->getDewpoint_C();
 560             dt = (dt != SGMetarNaN) ? dt : 0.0;
 561             fgSetDouble("/environment/metar/dewpoint-degc", dt);
 562             fgSetDouble("/environment/metar/rel-humidity-norm",
 563                         m->getRelHumidity() );
 564         }
 565         d = (d != SGMetarNaN) ? d : 15.0;
 566         fgSetDouble("/environment/metar/temperature-degc", d);
 567
 568         d = m->getPressure_inHg();
 569         d = (d != SGMetarNaN) ? d : 30.0;
 570         fgSetDouble("/environment/metar/pressure-inhg", d);
 571
 572         vector<SGMetarCloud> cv = m->getClouds();
 573         vector<SGMetarCloud>::iterator cloud;
 574
 575         const char *cl = "/environment/clouds/layer[%i]";
 576         for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
 577             const char *coverage_string[5] =
 578                           { "clear", "few", "scattered", "broken", "overcast" };
 579             const double thickness[5] = { 0, 65, 600,750, 1000};
 580             int q;
 581
 582             snprintf(s, 128, cl, i);
 583             strncat(s, "/coverage", 128);
 584             q = cloud->getCoverage();
 585             q = (q != -1 ) ? q : 0;
 586             fgSetString(s, coverage_string[q] );
 587
 588             snprintf(s, 128, cl, i);
 589             strncat(s, "/elevation-ft", 128);
 590             d = cloud->getAltitude_ft();
 591             d = (d != SGMetarNaN) ? d : -9999;
 592             fgSetDouble(s, d + station_elevation_ft);
 593
 594             snprintf(s, 128, cl, i);
 595             strncat(s, "/thickness-ft", 128);
 596             fgSetDouble(s, thickness[q]);
 597
 598             snprintf(s, 128, cl, i);
 599             strncat(s, "/span-m", 128);
 600             fgSetDouble(s, 40000.0);
 601         }
 602         for (; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 603             snprintf(s, 128, cl, i);
 604             strncat(s, "/coverage", 128);
 605             fgSetString(s, "clear");
 606
 607             snprintf(s, 128, cl, i);
 608             strncat(s, "/elevation-ft", 128);
 609             fgSetDouble(s, -9999);
 610
 611             snprintf(s, 128, cl, i);
 612             strncat(s, "/thickness-ft", 128);
 613             fgSetDouble(s, 0);
 614
 615             snprintf(s, 128, cl, i);
 616             strncat(s, "/span-m", 128);
 617             fgSetDouble(s, 40000.0);
 618         }
 619
 620         delete m;
 621
 622     }
 623 #ifdef ENABLE_THREADS
 624
 625     mutex.lock();
 626     metar_cond.signal();
 627     mutex.unlock();
 628
 629     if (m == NULL)
 630         return false;
 631
 632 #else
 633     catch (const sg_io_exception& e) {
 634         SG_LOG( SG_GENERAL, SG_WARN, "Error fetching live weather data: "
 635                                       << e.getFormattedMessage().c_str() );
 636         return false;
 637     }
 638 #endif // ENABLE_THREADS
 639
 640     return true;
 641 }
 642
 643 #ifdef ENABLE_THREADS
 644 /**
 645  *
 646  */
 647 void
 648 FGMetarEnvironmentCtrl::MetarThread::run()
 649 {
 650     SGMetar *m = NULL;
 651
 652     // pthread_cleanup_push( metar_cleanup_handler, fetcher );
 653     while ( true )
 654     {
 655         set_cancel( SGThread::CANCEL_DISABLE );
 656         try
 657         {
 658             cout << "Fetching ..." << endl;
 659             // if (m != NULL)  m = NULL;
 660             string host = fetcher->proxy_host->getStringValue();
 661             string auth = fetcher->proxy_auth->getStringValue();
 662             string port = fetcher->proxy_port->getStringValue();
 663             m = new SGMetar( fetcher->_icao, host, port, auth );
 664
 665         } catch (const sg_io_exception& e) {
 666             // SG_LOG( SG_GENERAL, SG_WARN, "Error fetching live weather data: "
 667             //                             << e.getFormattedMessage().c_str() );
 668             m = NULL;
 669         }
 670         set_cancel( SGThread::CANCEL_DEFERRED );
 671
 672         fetcher->metar_queue.push( m );
 673
 674         // Wait for the next frame signal before we fetch the next metar data
 675         fetcher->mutex.lock();
 676         fetcher->metar_cond.wait( fetcher->mutex );
 677         fetcher->mutex.unlock();
 678     }
 679     // pthread_cleanup_pop(1);
 680 }
 681
 682 /**
 683  * Ensure mutex is unlocked.
 684  */
 685 void
 686 metar_cleanup_handler( void* arg )
 687 {
 688     FGMetarEnvironmentCtrl* fetcher = (FGMetarEnvironmentCtrl*) arg;
 689     fetcher->mutex.unlock();
 690 }
 691 #endif // ENABLE_THREADS
 692
 693
 694 // end of environment_ctrl.cxx