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