src/mac/thread.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        thread.cpp
   3 // Purpose:     wxThread Implementation
   4 // Author:      Original from Wolfram Gloger/Guilhem Lavaux/Vadim Zeitlin
   5 // Modified by: Stefan Csomor
   6 // Created:     04/22/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998),
   9 //                  Vadim Zeitlin (1999) , Stefan Csomor (2000)
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifdef __GNUG__
  14     #pragma implementation "thread.h"
  15 #endif
  16
  17 // ----------------------------------------------------------------------------
  18 // headers
  19 // ----------------------------------------------------------------------------
  20
  21 // For compilers that support precompilation, includes "wx.h".
  22 #include "wx/wxprec.h"
  23
  24 #if defined(__BORLANDC__)
  25     #pragma hdrstop
  26 #endif
  27
  28 #ifndef WX_PRECOMP
  29     #include "wx/wx.h"
  30 #endif
  31
  32 #if wxUSE_THREADS
  33
  34 #include "wx/module.h"
  35 #include "wx/thread.h"
  36
  37 #ifdef __WXMAC__
  38 #ifndef __DARWIN__
  39 #include <Threads.h>
  40 #endif
  41 #include "wx/mac/uma.h"
  42 #endif
  43
  44 // ----------------------------------------------------------------------------
  45 // constants
  46 // ----------------------------------------------------------------------------
  47
  48 // the possible states of the thread ("=>" shows all possible transitions from
  49 // this state)
  50 enum wxThreadState
  51 {
  52     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  53     STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
  54     STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
  55     STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
  56     STATE_EXITED        // thread is terminating
  57 };
  58
  59 // ----------------------------------------------------------------------------
  60 // this module globals
  61 // ----------------------------------------------------------------------------
  62
  63 static ThreadID gs_idMainThread = kNoThreadID ;
  64 static bool gs_waitingForThread = FALSE ;
  65
  66 // ============================================================================
  67 // MacOS implementation of thread classes
  68 // ============================================================================
  69
  70 class wxMacStCritical
  71 {
  72 public :
  73     wxMacStCritical()
  74     {
  75         if ( UMASystemIsInitialized() )
  76             ThreadBeginCritical() ;
  77     }
  78     ~wxMacStCritical()
  79     {
  80         if ( UMASystemIsInitialized() )
  81             ThreadEndCritical() ;
  82     }
  83 };
  84
  85 // ----------------------------------------------------------------------------
  86 // wxMutex implementation
  87 // ----------------------------------------------------------------------------
  88
  89 class wxMutexInternal
  90 {
  91 public:
  92     wxMutexInternal()
  93     {
  94         m_owner = kNoThreadID ;
  95     }
  96
  97     ~wxMutexInternal()
  98     {
  99     }
 100
 101 public:
 102     ThreadID m_owner ;
 103     wxArrayLong m_waiters ;
 104 };
 105
 106 wxMutex::wxMutex()
 107 {
 108     m_internal = new wxMutexInternal;
 109
 110     m_locked = 0;
 111 }
 112
 113 wxMutex::~wxMutex()
 114 {
 115     if ( m_locked > 0 )
 116     {
 117         wxLogDebug(_T("Warning: freeing a locked mutex (%d locks)."), m_locked);
 118     }
 119
 120     delete m_internal;
 121 }
 122
 123 wxMutexError wxMutex::Lock()
 124 {
 125     wxMacStCritical critical ;
 126     if ( UMASystemIsInitialized() )
 127     {
 128         OSErr err ;
 129         ThreadID current = kNoThreadID;
 130         err = ::MacGetCurrentThread(&current);
 131         // if we are not the owner, add this thread to the list of waiting threads, stop this thread
 132         // and invoke the scheduler to continue executing the owner's thread
 133         while ( m_internal->m_owner != kNoThreadID && m_internal->m_owner != current)
 134         {
 135             m_internal->m_waiters.Add(current);
 136             err = ::SetThreadStateEndCritical(kCurrentThreadID, kStoppedThreadState, m_internal->m_owner);
 137             err = ::ThreadBeginCritical();
 138         }
 139         m_internal->m_owner = current;
 140     }
 141     m_locked++;
 142
 143     return wxMUTEX_NO_ERROR;
 144 }
 145
 146 wxMutexError wxMutex::TryLock()
 147 {
 148     wxMacStCritical critical ;
 149     if ( UMASystemIsInitialized() )
 150     {
 151         OSErr err ;
 152         ThreadID current = kNoThreadID;
 153         ::MacGetCurrentThread(&current);
 154         // if we are not the owner, give an error back
 155         if ( m_internal->m_owner != kNoThreadID && m_internal->m_owner != current )
 156             return wxMUTEX_BUSY;
 157
 158         m_internal->m_owner = current;
 159     }
 160     m_locked++;
 161
 162    return wxMUTEX_NO_ERROR;
 163 }
 164
 165 wxMutexError wxMutex::Unlock()
 166 {
 167     if ( UMASystemIsInitialized() )
 168     {
 169         OSErr err;
 170         err = ::ThreadBeginCritical();
 171
 172         if (m_locked > 0)
 173             m_locked--;
 174
 175         // this mutex is not owned by anybody anmore
 176         m_internal->m_owner = kNoThreadID;
 177
 178         // now pass on to the first waiting thread
 179         ThreadID firstWaiting = kNoThreadID;
 180         bool found = false;
 181         while (!m_internal->m_waiters.IsEmpty() && !found)
 182         {
 183             firstWaiting = m_internal->m_waiters[0];
 184             err = ::SetThreadState(firstWaiting, kReadyThreadState, kNoThreadID);
 185             // in case this was not successful (dead thread), we just loop on and reset the id
 186             found = (err != threadNotFoundErr);
 187             if ( !found )
 188                 firstWaiting = kNoThreadID ;
 189             m_internal->m_waiters.RemoveAt(0) ;
 190         }
 191         // now we have a valid firstWaiting thread, which has been scheduled to run next, just end the
 192         // critical section and invoke the scheduler
 193         err = ::SetThreadStateEndCritical(kCurrentThreadID, kReadyThreadState, firstWaiting);
 194     }
 195     else
 196     {
 197         if (m_locked > 0)
 198             m_locked--;
 199     }
 200     return wxMUTEX_NO_ERROR;
 201 }
 202
 203 // ----------------------------------------------------------------------------
 204 // wxCondition implementation
 205 // ----------------------------------------------------------------------------
 206
 207 class wxConditionInternal
 208 {
 209 public:
 210     wxConditionInternal()
 211     {
 212         m_excessSignals = 0 ;
 213     }
 214     ~wxConditionInternal()
 215     {
 216     }
 217
 218     bool Wait(unsigned long msectimeout)
 219     {
 220         wxMacStCritical critical ;
 221         if ( m_excessSignals > 0 )
 222         {
 223             --m_excessSignals ;
 224             return TRUE ;
 225         }
 226         else if ( msectimeout == 0 )
 227         {
 228             return FALSE ;
 229         }
 230         else
 231         {
 232         }
 233         /*
 234         waiters++;
 235
 236         // FIXME this should be MsgWaitForMultipleObjects() as well probably
 237         DWORD rc = ::WaitForSingleObject(event, timeout);
 238
 239         waiters--;
 240
 241         return rc != WAIT_TIMEOUT;
 242         */
 243         return TRUE ;
 244     }
 245     void Signal()
 246     {
 247         wxMacStCritical critical ;
 248     }
 249
 250     wxArrayLong m_waiters ;
 251     wxInt32     m_excessSignals ;
 252 };
 253
 254 wxCondition::wxCondition()
 255 {
 256     m_internal = new wxConditionInternal;
 257 }
 258
 259 wxCondition::~wxCondition()
 260 {
 261     delete m_internal;
 262 }
 263
 264 void wxCondition::Wait()
 265 {
 266     (void)m_internal->Wait(0xFFFFFFFFL);
 267 }
 268
 269 bool wxCondition::Wait(unsigned long sec,
 270                        unsigned long nsec)
 271 {
 272     return m_internal->Wait(sec*1000 + nsec/1000000);
 273 }
 274
 275 void wxCondition::Signal()
 276 {
 277     // set the event to signaled: if a thread is already waiting on it, it will
 278     // be woken up, otherwise the event will remain in the signaled state until
 279     // someone waits on it. In any case, the system will return it to a non
 280     // signalled state afterwards. If multiple threads are waiting, only one
 281     // will be woken up.
 282     m_internal->Signal() ;
 283 }
 284
 285 void wxCondition::Broadcast()
 286 {
 287     // this works because all these threads are already waiting and so each
 288     // SetEvent() inside Signal() is really a PulseEvent() because the event
 289     // state is immediately returned to non-signaled
 290     for ( int i = 0; i < m_internal->m_waiters.Count(); i++ )
 291     {
 292         Signal();
 293     }
 294 }
 295
 296 // ----------------------------------------------------------------------------
 297 // wxCriticalSection implementation
 298 // ----------------------------------------------------------------------------
 299
 300 // it's implemented as a mutex on mac os, so it is defined in the headers
 301
 302 // ----------------------------------------------------------------------------
 303 // wxThread implementation
 304 // ----------------------------------------------------------------------------
 305
 306 // wxThreadInternal class
 307 // ----------------------
 308
 309 class wxThreadInternal
 310 {
 311 public:
 312     wxThreadInternal()
 313     {
 314         m_tid = kNoThreadID ;
 315         m_state = STATE_NEW;
 316         m_priority = WXTHREAD_DEFAULT_PRIORITY;
 317     }
 318
 319     ~wxThreadInternal()
 320     {
 321     }
 322
 323     void Free()
 324     {
 325     }
 326
 327     // create a new (suspended) thread (for the given thread object)
 328     bool Create(wxThread *thread, unsigned int stackSize);
 329
 330     // suspend/resume/terminate
 331     bool Suspend();
 332     bool Resume();
 333     void Cancel() { m_state = STATE_CANCELED; }
 334
 335     // thread state
 336     void SetState(wxThreadState state) { m_state = state; }
 337     wxThreadState GetState() const { return m_state; }
 338
 339     // thread priority
 340     void SetPriority(unsigned int priority);
 341     unsigned int GetPriority() const { return m_priority; }
 342
 343     void SetResult( void *res ) { m_result = res ; }
 344     void *GetResult() { return m_result ; }
 345
 346     // thread handle and id
 347     ThreadID  GetId() const { return m_tid; }
 348
 349     // thread function
 350     static pascal void*    MacThreadStart(wxThread* arg);
 351
 352 private:
 353     wxThreadState           m_state;      // state, see wxThreadState enum
 354     unsigned int            m_priority;   // thread priority in "wx" units
 355     ThreadID                m_tid;        // thread id
 356     void*                   m_result;
 357     static ThreadEntryUPP   s_threadEntry ;
 358 };
 359
 360 static wxArrayPtrVoid s_threads ;
 361
 362 ThreadEntryUPP wxThreadInternal::s_threadEntry = NULL ;
 363 pascal void* wxThreadInternal::MacThreadStart(wxThread *thread)
 364 {
 365     // first of all, check whether we hadn't been cancelled already
 366     if ( thread->m_internal->GetState() == STATE_EXITED )
 367     {
 368         return (void*)-1;
 369     }
 370
 371     void* rc = thread->Entry();
 372
 373     // enter m_critsect before changing the thread state
 374     thread->m_critsect.Enter();
 375     bool wasCancelled = thread->m_internal->GetState() == STATE_CANCELED;
 376     thread->m_internal->SetState(STATE_EXITED);
 377     thread->m_critsect.Leave();
 378
 379     thread->OnExit();
 380
 381     // if the thread was cancelled (from Delete()), then it the handle is still
 382     // needed there
 383     if ( thread->IsDetached() && !wasCancelled )
 384     {
 385         // auto delete
 386         delete thread;
 387     }
 388     //else: the joinable threads handle will be closed when Wait() is done
 389
 390     return rc;
 391 }
 392 void wxThreadInternal::SetPriority(unsigned int priority)
 393 {
 394     // Priorities don't exist on Mac
 395 }
 396
 397 bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize)
 398 {
 399     if ( s_threadEntry == NULL )
 400     {
 401         s_threadEntry = NewThreadEntryUPP( (ThreadEntryProcPtr) MacThreadStart ) ;
 402     }
 403     OSErr err = NewThread( kCooperativeThread,
 404                            s_threadEntry,
 405                            (void*) thread,
 406                            stackSize,
 407                            kNewSuspend,
 408                            &m_result,
 409                            &m_tid );
 410
 411     if ( err != noErr )
 412     {
 413         wxLogSysError(_("Can't create thread"));
 414         return FALSE;
 415     }
 416
 417     if ( m_priority != WXTHREAD_DEFAULT_PRIORITY )
 418     {
 419         SetPriority(m_priority);
 420     }
 421
 422     return TRUE;
 423 }
 424
 425 bool wxThreadInternal::Suspend()
 426 {
 427     OSErr err ;
 428
 429     ::ThreadBeginCritical();
 430
 431     if ( m_state != STATE_RUNNING )
 432     {
 433         ::ThreadEndCritical() ;
 434         wxLogSysError(_("Can not suspend thread %x"), m_tid);
 435         return FALSE;
 436     }
 437
 438     m_state = STATE_PAUSED;
 439
 440     err = ::SetThreadStateEndCritical(m_tid, kStoppedThreadState, kNoThreadID);
 441
 442     return TRUE;
 443 }
 444
 445 bool wxThreadInternal::Resume()
 446 {
 447     ThreadID current ;
 448     OSErr err ;
 449     err = MacGetCurrentThread( &current ) ;
 450
 451     wxASSERT( err == noErr ) ;
 452     wxASSERT( current != m_tid ) ;
 453
 454     ::ThreadBeginCritical();
 455     if ( m_state != STATE_PAUSED && m_state != STATE_NEW )
 456     {
 457         ::ThreadEndCritical() ;
 458         wxLogSysError(_("Can not resume thread %x"), m_tid);
 459         return FALSE;
 460
 461     }
 462     err = ::SetThreadStateEndCritical(m_tid, kReadyThreadState, kNoThreadID);
 463     wxASSERT( err == noErr ) ;
 464
 465     m_state = STATE_RUNNING;
 466     ::ThreadEndCritical() ;
 467     ::YieldToAnyThread() ;
 468     return TRUE;
 469 }
 470
 471 // static functions
 472 // ----------------
 473 wxThread *wxThread::This()
 474 {
 475     wxMacStCritical critical ;
 476
 477     ThreadID current ;
 478     OSErr err ;
 479
 480     err = MacGetCurrentThread( &current ) ;
 481
 482     for ( int i = 0 ; i < s_threads.Count() ; ++i )
 483     {
 484         if ( ( (wxThread*) s_threads[i] )->GetId() == current )
 485             return (wxThread*) s_threads[i] ;
 486     }
 487
 488     wxLogSysError(_("Couldn't get the current thread pointer"));
 489     return NULL;
 490 }
 491
 492 bool wxThread::IsMain()
 493 {
 494     ThreadID current ;
 495     OSErr err ;
 496
 497     err = MacGetCurrentThread( &current ) ;
 498     return current == gs_idMainThread;
 499 }
 500
 501 #ifdef Yield
 502 #undef Yield
 503 #endif
 504
 505 void wxThread::Yield()
 506 {
 507     ::YieldToAnyThread() ;
 508 }
 509
 510 void wxThread::Sleep(unsigned long milliseconds)
 511 {
 512         clock_t start = clock() ;
 513         do
 514         {
 515             YieldToAnyThread() ;
 516         } while( clock() - start < milliseconds / CLOCKS_PER_SEC ) ;
 517 }
 518
 519 int wxThread::GetCPUCount()
 520 {
 521     // we will use whatever MP API will be used for the new MP Macs
 522     return 1;
 523 }
 524
 525 unsigned long wxThread::GetCurrentId()
 526 {
 527     ThreadID current ;
 528     MacGetCurrentThread( &current ) ;
 529     return (unsigned long)current;
 530 }
 531
 532 bool wxThread::SetConcurrency(size_t level)
 533 {
 534     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 535
 536     // ok only for the default one
 537     if ( level == 0 )
 538         return 0;
 539
 540     // how many CPUs have we got?
 541     if ( GetCPUCount() == 1 )
 542     {
 543         // don't bother with all this complicated stuff - on a single
 544         // processor system it doesn't make much sense anyhow
 545         return level == 1;
 546     }
 547
 548     return TRUE ;
 549 }
 550
 551 // ctor and dtor
 552 // -------------
 553
 554 wxThread::wxThread(wxThreadKind kind)
 555 {
 556     m_internal = new wxThreadInternal();
 557
 558     m_isDetached = kind == wxTHREAD_DETACHED;
 559     s_threads.Add( (void*) this ) ;
 560 }
 561
 562 wxThread::~wxThread()
 563 {
 564     s_threads.Remove( (void*) this ) ;
 565     delete m_internal;
 566 }
 567
 568 // create/start thread
 569 // -------------------
 570
 571 wxThreadError wxThread::Create(unsigned int stackSize)
 572 {
 573     wxCriticalSectionLocker lock(m_critsect);
 574
 575     if ( !m_internal->Create(this, stackSize) )
 576         return wxTHREAD_NO_RESOURCE;
 577
 578     return wxTHREAD_NO_ERROR;
 579 }
 580
 581 wxThreadError wxThread::Run()
 582 {
 583     wxCriticalSectionLocker lock(m_critsect);
 584
 585     if ( m_internal->GetState() != STATE_NEW )
 586     {
 587         // actually, it may be almost any state at all, not only STATE_RUNNING
 588         return wxTHREAD_RUNNING;
 589     }
 590
 591     // the thread has just been created and is still suspended - let it run
 592     return Resume();
 593 }
 594
 595 // suspend/resume thread
 596 // ---------------------
 597
 598 wxThreadError wxThread::Pause()
 599 {
 600     wxCriticalSectionLocker lock(m_critsect);
 601
 602     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 603 }
 604
 605 wxThreadError wxThread::Resume()
 606 {
 607     wxCriticalSectionLocker lock(m_critsect);
 608
 609     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 610 }
 611
 612 // stopping thread
 613 // ---------------
 614
 615 wxThread::ExitCode wxThread::Wait()
 616 {
 617     // although under MacOS we can wait for any thread, it's an error to
 618     // wait for a detached one in wxWin API
 619     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 620                  _T("can't wait for detached thread") );
 621
 622     ExitCode rc = (ExitCode)-1;
 623
 624     (void)Delete(&rc);
 625
 626     m_internal->Free();
 627
 628     return rc;
 629 }
 630
 631 wxThreadError wxThread::Delete(ExitCode *pRc)
 632 {
 633     ExitCode rc = 0;
 634
 635     // Delete() is always safe to call, so consider all possible states
 636
 637     // has the thread started to run?
 638     bool shouldResume = FALSE;
 639
 640     {
 641         wxCriticalSectionLocker lock(m_critsect);
 642
 643         if ( m_internal->GetState() == STATE_NEW )
 644         {
 645             // WinThreadStart() will see it and terminate immediately
 646             m_internal->SetState(STATE_EXITED);
 647
 648             shouldResume = TRUE;
 649         }
 650     }
 651
 652     // is the thread paused?
 653     if ( shouldResume || IsPaused() )
 654         Resume();
 655
 656     // does is still run?
 657     if ( IsRunning() )
 658     {
 659         if ( IsMain() )
 660         {
 661             // set flag for wxIsWaitingForThread()
 662             gs_waitingForThread = TRUE;
 663
 664 #if wxUSE_GUI
 665             wxBeginBusyCursor();
 666 #endif // wxUSE_GUI
 667         }
 668
 669         // ask the thread to terminate
 670         {
 671             wxCriticalSectionLocker lock(m_critsect);
 672
 673             m_internal->Cancel();
 674         }
 675
 676 #if wxUSE_GUI
 677         // simply wait for the thread to terminate
 678         while( TestDestroy() )
 679         {
 680             ::YieldToAnyThread() ;
 681         }
 682 #else // !wxUSE_GUI
 683         // simply wait for the thread to terminate
 684         while( TestDestroy() )
 685         {
 686             ::YieldToAnyThread() ;
 687         }
 688 #endif // wxUSE_GUI/!wxUSE_GUI
 689
 690         if ( IsMain() )
 691         {
 692             gs_waitingForThread = FALSE;
 693
 694 #if wxUSE_GUI
 695             wxEndBusyCursor();
 696 #endif // wxUSE_GUI
 697         }
 698     }
 699
 700  //   if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 701     {
 702         wxLogLastError("GetExitCodeThread");
 703
 704         rc = (ExitCode)-1;
 705     }
 706
 707     if ( IsDetached() )
 708     {
 709         // if the thread exits normally, this is done in WinThreadStart, but in
 710         // this case it would have been too early because
 711         // MsgWaitForMultipleObject() would fail if the therad handle was
 712         // closed while we were waiting on it, so we must do it here
 713         delete this;
 714     }
 715
 716  //   wxASSERT_MSG( (DWORD)rc != STILL_ACTIVE,
 717  //                 wxT("thread must be already terminated.") );
 718
 719     if ( pRc )
 720         *pRc = rc;
 721
 722     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 723 }
 724
 725 wxThreadError wxThread::Kill()
 726 {
 727     if ( !IsRunning() )
 728         return wxTHREAD_NOT_RUNNING;
 729
 730 //    if ( !::TerminateThread(m_internal->GetHandle(), (DWORD)-1) )
 731     {
 732         wxLogSysError(_("Couldn't terminate thread"));
 733
 734         return wxTHREAD_MISC_ERROR;
 735     }
 736
 737     m_internal->Free();
 738
 739     if ( IsDetached() )
 740     {
 741         delete this;
 742     }
 743
 744     return wxTHREAD_NO_ERROR;
 745 }
 746
 747 void wxThread::Exit(ExitCode status)
 748 {
 749     m_internal->Free();
 750
 751     if ( IsDetached() )
 752     {
 753         delete this;
 754     }
 755
 756     m_internal->SetResult( status ) ;
 757
 758 /*
 759 #if defined(__VISUALC__) || (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500))
 760     _endthreadex((unsigned)status);
 761 #else // !VC++
 762     ::ExitThread((DWORD)status);
 763 #endif // VC++/!VC++
 764 */
 765     wxFAIL_MSG(wxT("Couldn't return from ExitThread()!"));
 766 }
 767
 768 // priority setting
 769 // ----------------
 770
 771 // since all these calls are execute cooperatively we don't have to use the critical section
 772
 773 void wxThread::SetPriority(unsigned int prio)
 774 {
 775     m_internal->SetPriority(prio);
 776 }
 777
 778 unsigned int wxThread::GetPriority() const
 779 {
 780     return m_internal->GetPriority();
 781 }
 782
 783 unsigned long wxThread::GetId() const
 784 {
 785     return (unsigned long)m_internal->GetId();
 786 }
 787
 788 bool wxThread::IsRunning() const
 789 {
 790     return m_internal->GetState() == STATE_RUNNING;
 791 }
 792
 793 bool wxThread::IsAlive() const
 794 {
 795     return (m_internal->GetState() == STATE_RUNNING) ||
 796            (m_internal->GetState() == STATE_PAUSED);
 797 }
 798
 799 bool wxThread::IsPaused() const
 800 {
 801     return m_internal->GetState() == STATE_PAUSED;
 802 }
 803
 804 bool wxThread::TestDestroy()
 805 {
 806     return m_internal->GetState() == STATE_CANCELED;
 807 }
 808
 809 // ----------------------------------------------------------------------------
 810 // Automatic initialization for thread module
 811 // ----------------------------------------------------------------------------
 812
 813 class wxThreadModule : public wxModule
 814 {
 815 public:
 816     virtual bool OnInit();
 817     virtual void OnExit();
 818
 819 private:
 820     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 821 };
 822
 823 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 824
 825 bool wxThreadModule::OnInit()
 826 {
 827     long response;
 828     bool hasThreadManager ;
 829     hasThreadManager = Gestalt( gestaltThreadMgrAttr, &response) == noErr && response & 1;
 830 #if !TARGET_CARBON
 831 #if GENERATINGCFM
 832     // verify presence of shared library
 833     hasThreadManager = hasThreadManager && ((Ptr)NewThread != (Ptr)kUnresolvedCFragSymbolAddress);
 834 #endif
 835 #endif
 836     if ( !hasThreadManager )
 837     {
 838         wxMessageBox( "Error" , "Thread Support is not available on this System" , wxOK ) ;
 839         return FALSE ;
 840     }
 841
 842     // no error return for GetCurrentThreadId()
 843     MacGetCurrentThread( &gs_idMainThread ) ;
 844
 845     return TRUE;
 846 }
 847
 848 void wxThreadModule::OnExit()
 849 {
 850 }
 851
 852 // ----------------------------------------------------------------------------
 853 // under MacOS we don't have currently preemptive threads, so any thread may access
 854 // the GUI at any time
 855 // ----------------------------------------------------------------------------
 856
 857 void WXDLLEXPORT wxMutexGuiEnter()
 858 {
 859 }
 860
 861 void WXDLLEXPORT wxMutexGuiLeave()
 862 {
 863 }
 864
 865 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
 866 {
 867 }
 868
 869 bool WXDLLEXPORT wxGuiOwnedByMainThread()
 870 {
 871     return false ;
 872 }
 873
 874 // wake up the main thread
 875 void WXDLLEXPORT wxWakeUpMainThread()
 876 {
 877     wxMacWakeUp() ;
 878 }
 879
 880 bool WXDLLEXPORT wxIsWaitingForThread()
 881 {
 882     return false ;
 883 }
 884
 885 #endif // wxUSE_THREADS
 886
 887 // vi:sts=4:sw=4:et