src/unix/threadpsx.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        threadpsx.cpp
   3 // Purpose:     wxThread (Posix) Implementation
   4 // Author:      Original from Wolfram Gloger/Guilhem Lavaux
   5 // Modified by:
   6 // Created:     04/22/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Wolfram Gloger (1996, 1997)
   9 //                  Guilhem Lavaux (1998)
  10 //                  Vadim Zeitlin (1999)
  11 //                  Robert Roebling (1999)
  12 // Licence:     wxWindows licence
  13 /////////////////////////////////////////////////////////////////////////////
  14
  15 // ============================================================================
  16 // declaration
  17 // ============================================================================
  18
  19 // ----------------------------------------------------------------------------
  20 // headers
  21 // ----------------------------------------------------------------------------
  22
  23 #ifdef __GNUG__
  24     #pragma implementation "thread.h"
  25 #endif
  26
  27 // With simple makefiles, we must ignore the file body if not using
  28 // threads.
  29 #include "wx/setup.h"
  30
  31 #if wxUSE_THREADS
  32
  33 #include "wx/thread.h"
  34 #include "wx/module.h"
  35 #include "wx/utils.h"
  36 #include "wx/log.h"
  37 #include "wx/intl.h"
  38 #include "wx/dynarray.h"
  39
  40 #include <stdio.h>
  41 #include <unistd.h>
  42 #include <pthread.h>
  43 #include <errno.h>
  44 #include <time.h>
  45
  46 #if HAVE_SCHED_H
  47     #include <sched.h>
  48 #endif
  49
  50 // ----------------------------------------------------------------------------
  51 // constants
  52 // ----------------------------------------------------------------------------
  53
  54 // the possible states of the thread and transitions from them
  55 enum wxThreadState
  56 {
  57     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  58     STATE_RUNNING,      // running (=> PAUSED or EXITED)
  59     STATE_PAUSED,       // suspended (=> RUNNING or EXITED)
  60     STATE_EXITED        // thread doesn't exist any more
  61 };
  62
  63 // ----------------------------------------------------------------------------
  64 // types
  65 // ----------------------------------------------------------------------------
  66
  67 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
  68
  69 // -----------------------------------------------------------------------------
  70 // global data
  71 // -----------------------------------------------------------------------------
  72
  73 // we keep the list of all threads created by the application to be able to
  74 // terminate them on exit if there are some left - otherwise the process would
  75 // be left in memory
  76 static wxArrayThread gs_allThreads;
  77
  78 // the id of the main thread
  79 static pthread_t gs_tidMain;
  80
  81 // the key for the pointer to the associated wxThread object
  82 static pthread_key_t gs_keySelf;
  83
  84 // this mutex must be acquired before any call to a GUI function
  85 static wxMutex *gs_mutexGui;
  86
  87 // ============================================================================
  88 // implementation
  89 // ============================================================================
  90
  91 //--------------------------------------------------------------------
  92 // wxMutex (Posix implementation)
  93 //--------------------------------------------------------------------
  94
  95 class wxMutexInternal
  96 {
  97 public:
  98     pthread_mutex_t p_mutex;
  99 };
 100
 101 wxMutex::wxMutex()
 102 {
 103     p_internal = new wxMutexInternal;
 104     pthread_mutex_init( &(p_internal->p_mutex), (const pthread_mutexattr_t*) NULL );
 105     m_locked = 0;
 106 }
 107
 108 wxMutex::~wxMutex()
 109 {
 110     if (m_locked > 0)
 111         wxLogDebug("Freeing a locked mutex (%d locks)", m_locked);
 112
 113     pthread_mutex_destroy( &(p_internal->p_mutex) );
 114     delete p_internal;
 115 }
 116
 117 wxMutexError wxMutex::Lock()
 118 {
 119     int err = pthread_mutex_lock( &(p_internal->p_mutex) );
 120     if (err == EDEADLK)
 121     {
 122         wxLogDebug("Locking this mutex would lead to deadlock!");
 123
 124         return wxMUTEX_DEAD_LOCK;
 125     }
 126
 127     m_locked++;
 128
 129     return wxMUTEX_NO_ERROR;
 130 }
 131
 132 wxMutexError wxMutex::TryLock()
 133 {
 134     if (m_locked)
 135     {
 136         return wxMUTEX_BUSY;
 137     }
 138
 139     int err = pthread_mutex_trylock( &(p_internal->p_mutex) );
 140     switch (err)
 141     {
 142         case EBUSY: return wxMUTEX_BUSY;
 143     }
 144
 145     m_locked++;
 146
 147     return wxMUTEX_NO_ERROR;
 148 }
 149
 150 wxMutexError wxMutex::Unlock()
 151 {
 152     if (m_locked > 0)
 153     {
 154         m_locked--;
 155     }
 156     else
 157     {
 158         wxLogDebug("Unlocking not locked mutex.");
 159
 160         return wxMUTEX_UNLOCKED;
 161     }
 162
 163     pthread_mutex_unlock( &(p_internal->p_mutex) );
 164
 165     return wxMUTEX_NO_ERROR;
 166 }
 167
 168 //--------------------------------------------------------------------
 169 // wxCondition (Posix implementation)
 170 //--------------------------------------------------------------------
 171
 172 class wxConditionInternal
 173 {
 174 public:
 175   pthread_cond_t p_condition;
 176 };
 177
 178 wxCondition::wxCondition()
 179 {
 180     p_internal = new wxConditionInternal;
 181     pthread_cond_init( &(p_internal->p_condition), (const pthread_condattr_t *) NULL );
 182 }
 183
 184 wxCondition::~wxCondition()
 185 {
 186     pthread_cond_destroy( &(p_internal->p_condition) );
 187
 188     delete p_internal;
 189 }
 190
 191 void wxCondition::Wait(wxMutex& mutex)
 192 {
 193     pthread_cond_wait( &(p_internal->p_condition), &(mutex.p_internal->p_mutex) );
 194 }
 195
 196 bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec)
 197 {
 198     struct timespec tspec;
 199
 200     tspec.tv_sec = time(0L)+sec;
 201     tspec.tv_nsec = nsec;
 202     return (pthread_cond_timedwait(&(p_internal->p_condition), &(mutex.p_internal->p_mutex), &tspec) != ETIMEDOUT);
 203 }
 204
 205 void wxCondition::Signal()
 206 {
 207     pthread_cond_signal( &(p_internal->p_condition) );
 208 }
 209
 210 void wxCondition::Broadcast()
 211 {
 212     pthread_cond_broadcast( &(p_internal->p_condition) );
 213 }
 214
 215 //--------------------------------------------------------------------
 216 // wxThread (Posix implementation)
 217 //--------------------------------------------------------------------
 218
 219 class wxThreadInternal
 220 {
 221 public:
 222     wxThreadInternal();
 223     ~wxThreadInternal();
 224
 225     // thread entry function
 226     static void *PthreadStart(void *ptr);
 227
 228     // thread actions
 229         // start the thread
 230     wxThreadError Run();
 231         // ask the thread to terminate
 232     void Wait();
 233         // wake up threads waiting for our termination
 234     void SignalExit();
 235         // go to sleep until Resume() is called
 236     void Pause();
 237         // resume the thread
 238     void Resume();
 239
 240     // accessors
 241         // priority
 242     int GetPriority() const { return m_prio; }
 243     void SetPriority(int prio) { m_prio = prio; }
 244         // state
 245     wxThreadState GetState() const { return m_state; }
 246     void SetState(wxThreadState state) { m_state = state; }
 247         // id
 248     pthread_t GetId() const { return m_threadId; }
 249     pthread_t *GetIdPtr() { return &m_threadId; }
 250         // "cancelled" flag
 251     void SetCancelFlag() { m_cancelled = TRUE; }
 252     bool WasCancelled() const { return m_cancelled; }
 253
 254 private:
 255     pthread_t     m_threadId;   // id of the thread
 256     wxThreadState m_state;      // see wxThreadState enum
 257     int           m_prio;       // in wxWindows units: from 0 to 100
 258
 259     // set when the thread should terminate
 260     bool m_cancelled;
 261
 262     // this (mutex, cond) pair is used to synchronize the main thread and this
 263     // thread in several situations:
 264     //  1. The thread function blocks until condition is signaled by Run() when
 265     //     it's initially created - this allows thread creation in "suspended"
 266     //     state
 267     //  2. The Delete() function blocks until the condition is signaled when the
 268     //     thread exits.
 269     wxMutex     m_mutex;
 270     wxCondition m_cond;
 271
 272     // another (mutex, cond) pair for Pause()/Resume() usage
 273     //
 274     // VZ: it's possible that we might reuse the mutex and condition from above
 275     //     for this too, but as I'm not at all sure that it won't create subtle
 276     //     problems with race conditions between, say, Pause() and Delete() I
 277     //     prefer this may be a bit less efficient but much safer solution
 278     wxMutex     m_mutexSuspend;
 279     wxCondition m_condSuspend;
 280 };
 281
 282 void *wxThreadInternal::PthreadStart(void *ptr)
 283 {
 284     wxThread *thread = (wxThread *)ptr;
 285     wxThreadInternal *pthread = thread->p_internal;
 286
 287     int rc = pthread_setspecific(gs_keySelf, thread);
 288     if ( rc != 0 )
 289     {
 290         wxLogSysError(rc, _("Can not start thread: error writing TLS."));
 291
 292         return (void *)-1;
 293     }
 294
 295     // wait for the condition to be signaled from Run()
 296     // mutex state: currently locked by the thread which created us
 297     pthread->m_cond.Wait(pthread->m_mutex);
 298
 299     // mutex state: locked again on exit of Wait()
 300
 301     // call the main entry
 302     void* status = thread->Entry();
 303
 304     // terminate the thread
 305     thread->Exit(status);
 306
 307     wxFAIL_MSG("wxThread::Exit() can't return.");
 308
 309     return NULL;
 310 }
 311
 312 wxThreadInternal::wxThreadInternal()
 313 {
 314     m_state = STATE_NEW;
 315     m_cancelled = FALSE;
 316
 317     // this mutex is locked during almost all thread lifetime - it will only be
 318     // unlocked in the very end
 319     m_mutex.Lock();
 320
 321     // this mutex is used in Pause()/Resume() and is also locked all the time
 322     // unless the thread is paused
 323     m_mutexSuspend.Lock();
 324 }
 325
 326 wxThreadInternal::~wxThreadInternal()
 327 {
 328     m_mutexSuspend.Unlock();
 329
 330     // note that m_mutex will be unlocked by the thread which waits for our
 331     // termination
 332 }
 333
 334 wxThreadError wxThreadInternal::Run()
 335 {
 336     wxCHECK_MSG( GetState() == STATE_NEW, wxTHREAD_RUNNING,
 337                  "thread may only be started once after successful Create()" );
 338
 339     // the mutex was locked on Create(), so we will be able to lock it again
 340     // only when the thread really starts executing and enters the wait -
 341     // otherwise we might signal the condition before anybody is waiting for it
 342     wxMutexLocker lock(m_mutex);
 343     m_cond.Signal();
 344
 345     m_state = STATE_RUNNING;
 346
 347     return wxTHREAD_NO_ERROR;
 348
 349     // now the mutex is unlocked back - but just to allow Wait() function to
 350     // terminate by relocking it, so the net result is that the worker thread
 351     // starts executing and the mutex is still locked
 352 }
 353
 354 void wxThreadInternal::Wait()
 355 {
 356     wxCHECK_RET( WasCancelled(), "thread should have been cancelled first" );
 357
 358     // if the thread we're waiting for is waiting for the GUI mutex, we will
 359     // deadlock so make sure we release it temporarily
 360     if ( wxThread::IsMain() )
 361         wxMutexGuiLeave();
 362
 363     // entering Wait() releases the mutex thus allowing SignalExit() to acquire
 364     // it and to signal us its termination
 365     m_cond.Wait(m_mutex);
 366
 367     // mutex is still in the locked state - relocked on exit from Wait(), so
 368     // unlock it - we don't need it any more, the thread has already terminated
 369     m_mutex.Unlock();
 370
 371     // reacquire GUI mutex
 372     if ( wxThread::IsMain() )
 373         wxMutexGuiEnter();
 374 }
 375
 376 void wxThreadInternal::SignalExit()
 377 {
 378     // as mutex is currently locked, this will block until some other thread
 379     // (normally the same which created this one) unlocks it by entering Wait()
 380     m_mutex.Lock();
 381
 382     // wake up all the threads waiting for our termination
 383     m_cond.Broadcast();
 384
 385     // after this call mutex will be finally unlocked
 386     m_mutex.Unlock();
 387 }
 388
 389 void wxThreadInternal::Pause()
 390 {
 391     // the state is set from the thread which pauses us first, this function
 392     // is called later so the state should have been already set
 393     wxCHECK_RET( m_state == STATE_PAUSED,
 394                  "thread must first be paused with wxThread::Pause()." );
 395
 396     // don't pause the thread which is being terminated - this would lead to
 397     // deadlock if the thread is paused after Delete() had called Resume() but
 398     // before it had time to call Wait()
 399     if ( WasCancelled() )
 400         return;
 401
 402     // wait until the condition is signaled from Resume()
 403     m_condSuspend.Wait(m_mutexSuspend);
 404 }
 405
 406 void wxThreadInternal::Resume()
 407 {
 408     wxCHECK_RET( m_state == STATE_PAUSED,
 409                  "can't resume thread which is not suspended." );
 410
 411     // we will be able to lock this mutex only when Pause() starts waiting
 412     wxMutexLocker lock(m_mutexSuspend);
 413     m_condSuspend.Signal();
 414
 415     SetState(STATE_RUNNING);
 416 }
 417
 418 // -----------------------------------------------------------------------------
 419 // static functions
 420 // -----------------------------------------------------------------------------
 421
 422 wxThread *wxThread::This()
 423 {
 424     return (wxThread *)pthread_getspecific(gs_keySelf);
 425 }
 426
 427 bool wxThread::IsMain()
 428 {
 429     return (bool)pthread_equal(pthread_self(), gs_tidMain);
 430 }
 431
 432 void wxThread::Yield()
 433 {
 434     sched_yield();
 435 }
 436
 437 void wxThread::Sleep(unsigned long milliseconds)
 438 {
 439     wxUsleep(milliseconds);
 440 }
 441
 442 // -----------------------------------------------------------------------------
 443 // creating thread
 444 // -----------------------------------------------------------------------------
 445
 446 wxThread::wxThread()
 447 {
 448     // add this thread to the global list of all threads
 449     gs_allThreads.Add(this);
 450
 451     p_internal = new wxThreadInternal();
 452 }
 453
 454 wxThreadError wxThread::Create()
 455 {
 456     if (p_internal->GetState() != STATE_NEW)
 457         return wxTHREAD_RUNNING;
 458
 459     // set up the thread attribute: right now, we only set thread priority
 460     pthread_attr_t attr;
 461     pthread_attr_init(&attr);
 462
 463 #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
 464     int prio;
 465     if ( pthread_attr_getschedpolicy(&attr, &prio) != 0 )
 466     {
 467         wxLogError(_("Can not retrieve thread scheduling policy."));
 468     }
 469
 470     int min_prio = sched_get_priority_min(prio),
 471         max_prio = sched_get_priority_max(prio);
 472
 473     if ( min_prio == -1 || max_prio == -1 )
 474     {
 475         wxLogError(_("Can not get priority range for scheduling policy %d."),
 476                    prio);
 477     }
 478     else
 479     {
 480         struct sched_param sp;
 481         pthread_attr_getschedparam(&attr, &sp);
 482         sp.sched_priority = min_prio +
 483                            (p_internal->GetPriority()*(max_prio-min_prio))/100;
 484         pthread_attr_setschedparam(&attr, &sp);
 485     }
 486 #endif // HAVE_THREAD_PRIORITY_FUNCTIONS
 487
 488     // create the new OS thread object
 489     int rc = pthread_create(p_internal->GetIdPtr(), &attr,
 490                             wxThreadInternal::PthreadStart, (void *)this);
 491     pthread_attr_destroy(&attr);
 492
 493     if ( rc != 0 )
 494     {
 495         p_internal->SetState(STATE_EXITED);
 496         return wxTHREAD_NO_RESOURCE;
 497     }
 498
 499     return wxTHREAD_NO_ERROR;
 500 }
 501
 502 wxThreadError wxThread::Run()
 503 {
 504     return p_internal->Run();
 505 }
 506
 507 // -----------------------------------------------------------------------------
 508 // misc accessors
 509 // -----------------------------------------------------------------------------
 510
 511 void wxThread::SetPriority(unsigned int prio)
 512 {
 513     wxCHECK_RET( ((int)WXTHREAD_MIN_PRIORITY <= (int)prio) &&
 514                  ((int)prio <= (int)WXTHREAD_MAX_PRIORITY),
 515                  "invalid thread priority" );
 516
 517     wxCriticalSectionLocker lock(m_critsect);
 518
 519     switch ( p_internal->GetState() )
 520     {
 521         case STATE_NEW:
 522             // thread not yet started, priority will be set when it is
 523             p_internal->SetPriority(prio);
 524             break;
 525
 526         case STATE_RUNNING:
 527         case STATE_PAUSED:
 528 #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
 529             {
 530                 struct sched_param sparam;
 531                 sparam.sched_priority = prio;
 532
 533                 if ( pthread_setschedparam(p_internal->GetId(),
 534                                            SCHED_OTHER, &sparam) != 0 )
 535                 {
 536                     wxLogError(_("Failed to set thread priority %d."), prio);
 537                 }
 538             }
 539 #endif // HAVE_THREAD_PRIORITY_FUNCTIONS
 540             break;
 541
 542         case STATE_EXITED:
 543         default:
 544             wxFAIL_MSG("impossible to set thread priority in this state");
 545     }
 546 }
 547
 548 unsigned int wxThread::GetPriority() const
 549 {
 550     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 551
 552     return p_internal->GetPriority();
 553 }
 554
 555 unsigned long wxThread::GetID() const
 556 {
 557     return (unsigned long)p_internal->GetId();
 558 }
 559
 560 // -----------------------------------------------------------------------------
 561 // pause/resume
 562 // -----------------------------------------------------------------------------
 563
 564 wxThreadError wxThread::Pause()
 565 {
 566     wxCriticalSectionLocker lock(m_critsect);
 567
 568     if ( p_internal->GetState() != STATE_RUNNING )
 569     {
 570         wxLogDebug("Can't pause thread which is not running.");
 571
 572         return wxTHREAD_NOT_RUNNING;
 573     }
 574
 575     p_internal->SetState(STATE_PAUSED);
 576
 577     return wxTHREAD_NO_ERROR;
 578 }
 579
 580 wxThreadError wxThread::Resume()
 581 {
 582     wxCriticalSectionLocker lock(m_critsect);
 583
 584     if ( p_internal->GetState() == STATE_PAUSED )
 585     {
 586         p_internal->Resume();
 587
 588         return wxTHREAD_NO_ERROR;
 589     }
 590     else
 591     {
 592         wxLogDebug("Attempt to resume a thread which is not paused.");
 593
 594         return wxTHREAD_MISC_ERROR;
 595     }
 596 }
 597
 598 // -----------------------------------------------------------------------------
 599 // exiting thread
 600 // -----------------------------------------------------------------------------
 601
 602 wxThread::ExitCode wxThread::Delete()
 603 {
 604     m_critsect.Enter();
 605     wxThreadState state = p_internal->GetState();
 606     m_critsect.Leave();
 607
 608     // ask the thread to stop
 609     p_internal->SetCancelFlag();
 610
 611     switch ( state )
 612     {
 613         case STATE_NEW:
 614         case STATE_EXITED:
 615             // nothing to do
 616             break;
 617
 618         case STATE_PAUSED:
 619             // resume the thread first
 620             Resume();
 621
 622             // fall through
 623
 624         default:
 625             // wait until the thread stops
 626             p_internal->Wait();
 627     }
 628
 629     return NULL;
 630 }
 631
 632 wxThreadError wxThread::Kill()
 633 {
 634     switch ( p_internal->GetState() )
 635     {
 636         case STATE_NEW:
 637         case STATE_EXITED:
 638             return wxTHREAD_NOT_RUNNING;
 639
 640         default:
 641 #ifdef HAVE_PTHREAD_CANCEL
 642             if ( pthread_cancel(p_internal->GetId()) != 0 )
 643 #endif
 644             {
 645                 wxLogError(_("Failed to terminate a thread."));
 646
 647                 return wxTHREAD_MISC_ERROR;
 648             }
 649
 650             return wxTHREAD_NO_ERROR;
 651     }
 652 }
 653
 654 void wxThread::Exit(void *status)
 655 {
 656     // first call user-level clean up code
 657     OnExit();
 658
 659     // next wake up the threads waiting for us (OTOH, this function won't return
 660     // until someone waited for us!)
 661     p_internal->SignalExit();
 662
 663     p_internal->SetState(STATE_EXITED);
 664
 665     // delete both C++ thread object and terminate the OS thread object
 666     delete this;
 667     pthread_exit(status);
 668 }
 669
 670 // also test whether we were paused
 671 bool wxThread::TestDestroy()
 672 {
 673     wxCriticalSectionLocker lock(m_critsect);
 674
 675     if ( p_internal->GetState() == STATE_PAUSED )
 676     {
 677         // leave the crit section or the other threads will stop too if they try
 678         // to call any of (seemingly harmless) IsXXX() functions while we sleep
 679         m_critsect.Leave();
 680
 681         p_internal->Pause();
 682
 683         // enter it back before it's finally left in lock object dtor
 684         m_critsect.Enter();
 685     }
 686
 687     return p_internal->WasCancelled();
 688 }
 689
 690 wxThread::~wxThread()
 691 {
 692     // remove this thread from the global array
 693     gs_allThreads.Remove(this);
 694 }
 695
 696 // -----------------------------------------------------------------------------
 697 // state tests
 698 // -----------------------------------------------------------------------------
 699
 700 bool wxThread::IsRunning() const
 701 {
 702     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 703
 704     return p_internal->GetState() == STATE_RUNNING;
 705 }
 706
 707 bool wxThread::IsAlive() const
 708 {
 709     wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);
 710
 711     switch ( p_internal->GetState() )
 712     {
 713         case STATE_RUNNING:
 714         case STATE_PAUSED:
 715             return TRUE;
 716
 717         default:
 718             return FALSE;
 719     }
 720 }
 721
 722 //--------------------------------------------------------------------
 723 // wxThreadModule
 724 //--------------------------------------------------------------------
 725
 726 class wxThreadModule : public wxModule
 727 {
 728 public:
 729     virtual bool OnInit();
 730     virtual void OnExit();
 731
 732 private:
 733     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 734 };
 735
 736 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 737
 738 bool wxThreadModule::OnInit()
 739 {
 740     if ( pthread_key_create(&gs_keySelf, NULL /* dtor function */) != 0 )
 741     {
 742         wxLogError(_("Thread module initialization failed: "
 743                      "failed to create pthread key."));
 744
 745         return FALSE;
 746     }
 747
 748     gs_mutexGui = new wxMutex();
 749
 750     //wxThreadGuiInit();
 751
 752     gs_tidMain = pthread_self();
 753     gs_mutexGui->Lock();
 754
 755     return TRUE;
 756 }
 757
 758 void wxThreadModule::OnExit()
 759 {
 760     wxASSERT_MSG( wxThread::IsMain(), "only main thread can be here" );
 761
 762     // terminate any threads left
 763     size_t count = gs_allThreads.GetCount();
 764     if ( count != 0u )
 765         wxLogDebug("Some threads were not terminated by the application.");
 766
 767     for ( size_t n = 0u; n < count; n++ )
 768     {
 769         gs_allThreads[n]->Delete();
 770     }
 771
 772     // destroy GUI mutex
 773     gs_mutexGui->Unlock();
 774
 775     //wxThreadGuiExit();
 776
 777     delete gs_mutexGui;
 778
 779     // and free TLD slot
 780     (void)pthread_key_delete(gs_keySelf);
 781 }
 782
 783 // ----------------------------------------------------------------------------
 784 // global functions
 785 // ----------------------------------------------------------------------------
 786
 787 void wxMutexGuiEnter()
 788 {
 789   gs_mutexGui->Lock();
 790 }
 791
 792 void wxMutexGuiLeave()
 793 {
 794   gs_mutexGui->Unlock();
 795 }
 796
 797 #endif
 798   // wxUSE_THREADS