src/os2/thread.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/os2/thread.cpp
   3 // Purpose:     wxThread Implementation
   4 // Author:      Original from Wolfram Gloger/Guilhem Lavaux/David Webster
   5 // Modified by: Stefan Neis
   6 // Created:     04/22/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Stefan Neis (2003)
   9 //
  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 wxUSE_THREADS
  25
  26 #include <stdio.h>
  27
  28 #include "wx/app.h"
  29 #include "wx/module.h"
  30 #include "wx/intl.h"
  31 #include "wx/utils.h"
  32 #include "wx/log.h"
  33 #include "wx/thread.h"
  34
  35 #define INCL_DOSSEMAPHORES
  36 #define INCL_DOSPROCESS
  37 #define INCL_DOSMISC
  38 #define INCL_ERRORS
  39 #include <os2.h>
  40 #ifndef __EMX__
  41 #include <bseerr.h>
  42 #endif
  43 // the possible states of the thread ("=>" shows all possible transitions from
  44 // this state)
  45 enum wxThreadState
  46 {
  47     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  48     STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
  49     STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
  50     STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
  51     STATE_EXITED        // thread is terminating
  52 };
  53
  54 // ----------------------------------------------------------------------------
  55 // this module's globals
  56 // ----------------------------------------------------------------------------
  57
  58 // id of the main thread - the one which can call GUI functions without first
  59 // calling wxMutexGuiEnter()
  60 static ULONG                        s_ulIdMainThread = 1;
  61 wxMutex*                            p_wxMainMutex;
  62
  63 // OS2 substitute for Tls pointer the current parent thread object
  64 wxThread*                           m_pThread;    // pointer to the wxWindows thread object
  65
  66 // if it's FALSE, some secondary thread is holding the GUI lock
  67 static bool gs_bGuiOwnedByMainThread = TRUE;
  68
  69 // critical section which controls access to all GUI functions: any secondary
  70 // thread (i.e. except the main one) must enter this crit section before doing
  71 // any GUI calls
  72 static wxCriticalSection *gs_pCritsectGui = NULL;
  73
  74 // critical section which protects s_nWaitingForGui variable
  75 static wxCriticalSection *gs_pCritsectWaitingForGui = NULL;
  76
  77 // number of threads waiting for GUI in wxMutexGuiEnter()
  78 static size_t gs_nWaitingForGui = 0;
  79
  80 // are we waiting for a thread termination?
  81 static bool gs_bWaitingForThread = FALSE;
  82
  83 // ============================================================================
  84 // OS/2 implementation of thread and related classes
  85 // ============================================================================
  86
  87 // ----------------------------------------------------------------------------
  88 // wxMutex implementation
  89 // ----------------------------------------------------------------------------
  90 class wxMutexInternal
  91 {
  92 public:
  93     wxMutexInternal(wxMutexType mutexType);
  94     ~wxMutexInternal();
  95
  96     bool IsOk() const { return m_vMutex != NULL; }
  97
  98     wxMutexError Lock() { return LockTimeout(SEM_INDEFINITE_WAIT); }
  99     wxMutexError TryLock() { return LockTimeout(SEM_IMMEDIATE_RETURN); }
 100     wxMutexError Unlock();
 101
 102 private:
 103     wxMutexError LockTimeout(ULONG ulMilliseconds);
 104     HMTX                            m_vMutex;
 105 };
 106
 107 // all mutexes are "pseudo-"recursive under OS2 so we don't use mutexType
 108 // (Calls to DosRequestMutexSem and DosReleaseMutexSem can be nested, but
 109 //  the request count for a semaphore cannot exceed 65535. If an attempt is
 110 //  made to exceed this number, ERROR_TOO_MANY_SEM_REQUESTS is returned.)
 111 wxMutexInternal::wxMutexInternal(
 112   wxMutexType                       WXUNUSED(eMutexType)
 113 )
 114 {
 115     APIRET                          ulrc;
 116
 117     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 118     if (ulrc != 0)
 119     {
 120         wxLogSysError(_("Can not create mutex."));
 121         m_vMutex = NULL;
 122     }
 123 }
 124
 125 wxMutexInternal::~wxMutexInternal()
 126 {
 127     if (m_vMutex)
 128     {
 129         if (::DosCloseMutexSem(m_vMutex))
 130             wxLogLastError(_T("DosCloseMutexSem(mutex)"));
 131     }
 132 }
 133
 134 wxMutexError wxMutexInternal::LockTimeout(ULONG ulMilliseconds)
 135 {
 136     APIRET                          ulrc;
 137
 138     ulrc = ::DosRequestMutexSem(m_vMutex, ulMilliseconds);
 139
 140     switch (ulrc)
 141     {
 142         case ERROR_TIMEOUT:
 143         case ERROR_TOO_MANY_SEM_REQUESTS:
 144             return wxMUTEX_BUSY;
 145
 146         case NO_ERROR:
 147             // ok
 148             break;
 149
 150         case ERROR_INVALID_HANDLE:
 151         case ERROR_INTERRUPT:
 152         case ERROR_SEM_OWNER_DIED:
 153             wxLogSysError(_("Couldn't acquire a mutex lock"));
 154             return wxMUTEX_MISC_ERROR;
 155
 156         default:
 157             wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
 158             return wxMUTEX_MISC_ERROR;
 159      }
 160     return wxMUTEX_NO_ERROR;
 161 }
 162
 163 wxMutexError wxMutexInternal::Unlock()
 164 {
 165     APIRET                          ulrc;
 166
 167     ulrc = ::DosReleaseMutexSem(m_vMutex);
 168     if (ulrc != 0)
 169     {
 170         wxLogSysError(_("Couldn't release a mutex"));
 171         return wxMUTEX_MISC_ERROR;
 172     }
 173     return wxMUTEX_NO_ERROR;
 174 }
 175
 176 // --------------------------------------------------------------------------
 177 // wxSemaphore
 178 // --------------------------------------------------------------------------
 179
 180 // a trivial wrapper around OS2 event semaphore
 181 class wxSemaphoreInternal
 182 {
 183 public:
 184     wxSemaphoreInternal(int initialcount, int maxcount);
 185     ~wxSemaphoreInternal();
 186
 187     bool IsOk() const { return m_vEvent != NULL; }
 188
 189     wxSemaError Wait() { return WaitTimeout(SEM_INDEFINITE_WAIT); }
 190     wxSemaError TryWait() { return WaitTimeout(SEM_IMMEDIATE_RETURN); }
 191     wxSemaError WaitTimeout(unsigned long milliseconds);
 192
 193     wxSemaError Post();
 194
 195 private:
 196     HEV m_vEvent;
 197     HMTX m_vMutex;
 198     int m_count;
 199     int m_maxcount;
 200 };
 201
 202 wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
 203 {
 204     APIRET ulrc;
 205     if ( maxcount == 0 )
 206     {
 207         // make it practically infinite
 208         maxcount = INT_MAX;
 209     }
 210
 211     m_count = initialcount;
 212     m_maxcount = maxcount;
 213     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 214     if (ulrc != 0)
 215     {
 216         wxLogLastError(_T("DosCreateMutexSem()"));
 217         m_vMutex = NULL;
 218         m_vEvent = NULL;
 219         return;
 220     }
 221     ulrc = ::DosCreateEventSem(NULL, &m_vEvent, 0L, FALSE);
 222     if ( ulrc != 0)
 223     {
 224         wxLogLastError(_T("DosCreateEventSem()"));
 225         ::DosCloseMutexSem(m_vMutex);
 226         m_vMutex = NULL;
 227         m_vEvent = NULL;
 228     }
 229     if (initialcount)
 230         ::DosPostEventSem(m_vEvent);
 231 }
 232
 233 wxSemaphoreInternal::~wxSemaphoreInternal()
 234 {
 235     if ( m_vEvent )
 236     {
 237         if ( ::DosCloseEventSem(m_vEvent) )
 238         {
 239             wxLogLastError(_T("DosCloseEventSem(semaphore)"));
 240         }
 241         if ( ::DosCloseMutexSem(m_vMutex) )
 242         {
 243             wxLogLastError(_T("DosCloseMutexSem(semaphore)"));
 244         }
 245         else
 246             m_vEvent = NULL;
 247     }
 248 }
 249
 250 wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long ulMilliseconds)
 251 {
 252     APIRET ulrc;
 253     do {
 254         ulrc = ::DosWaitEventSem(m_vEvent, ulMilliseconds );
 255         switch ( ulrc )
 256         {
 257             case NO_ERROR:
 258                 break;
 259
 260             case ERROR_TIMEOUT:
 261                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 262                     return wxSEMA_BUSY;
 263                 else
 264                     return wxSEMA_TIMEOUT;
 265
 266             default:
 267                 wxLogLastError(_T("DosWaitEventSem(semaphore)"));
 268                 return wxSEMA_MISC_ERROR;
 269         }
 270         ulrc = :: DosRequestMutexSem(m_vMutex, ulMilliseconds);
 271         switch ( ulrc )
 272         {
 273             case NO_ERROR:
 274                 // ok
 275                 break;
 276
 277             case ERROR_TIMEOUT:
 278             case ERROR_TOO_MANY_SEM_REQUESTS:
 279                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 280                     return wxSEMA_BUSY;
 281                 else
 282                     return wxSEMA_TIMEOUT;
 283
 284             default:
 285                 wxFAIL_MSG(wxT("DosRequestMutexSem(mutex)"));
 286                 return wxSEMA_MISC_ERROR;
 287         }
 288         bool OK = false;
 289         if (m_count > 0)
 290         {
 291             m_count--;
 292             OK = true;
 293         }
 294         else
 295         {
 296             ULONG ulPostCount;
 297             ::DosResetEventSem(m_vEvent, &ulPostCount);
 298         }
 299         ::DosReleaseMutexSem(m_vMutex);
 300         if (OK)
 301             return wxSEMA_NO_ERROR;
 302     } while (ulMilliseconds == SEM_INDEFINITE_WAIT);
 303
 304     if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 305         return wxSEMA_BUSY;
 306     return wxSEMA_TIMEOUT;
 307 }
 308
 309 wxSemaError wxSemaphoreInternal::Post()
 310 {
 311     APIRET ulrc;
 312     ulrc = ::DosRequestMutexSem(m_vMutex, SEM_INDEFINITE_WAIT);
 313     if (ulrc != NO_ERROR)
 314         return wxSEMA_MISC_ERROR;
 315     bool OK = false;
 316     if (m_count < m_maxcount)
 317     {
 318         m_count++;
 319         ulrc = ::DosPostEventSem(m_vEvent);
 320         OK = true;
 321     }
 322     ::DosReleaseMutexSem(m_vMutex);
 323     if (!OK)
 324         return wxSEMA_OVERFLOW;
 325     if ( ulrc != NO_ERROR && ulrc != ERROR_ALREADY_POSTED )
 326     {
 327         wxLogLastError(_T("DosPostEventSem(semaphore)"));
 328
 329         return wxSEMA_MISC_ERROR;
 330     }
 331
 332     return wxSEMA_NO_ERROR;
 333 }
 334
 335 // ----------------------------------------------------------------------------
 336 // wxThread implementation
 337 // ----------------------------------------------------------------------------
 338
 339 // wxThreadInternal class
 340 // ----------------------
 341
 342 class wxThreadInternal
 343 {
 344 public:
 345     inline wxThreadInternal()
 346     {
 347         m_hThread = 0;
 348         m_eState = STATE_NEW;
 349         m_nPriority = WXTHREAD_DEFAULT_PRIORITY;
 350     }
 351
 352     ~wxThreadInternal()
 353     {
 354         m_hThread = 0;
 355     }
 356
 357     // create a new (suspended) thread (for the given thread object)
 358     bool Create( wxThread*    pThread
 359                 ,unsigned int uStackSize
 360                );
 361
 362     // suspend/resume/terminate
 363     bool Suspend();
 364     bool Resume();
 365     inline void Cancel() { m_eState = STATE_CANCELED; }
 366
 367     // thread state
 368     inline void SetState(wxThreadState eState) { m_eState = eState; }
 369     inline wxThreadState GetState() const { return m_eState; }
 370
 371     // thread priority
 372     void                SetPriority(unsigned int nPriority);
 373     inline unsigned int GetPriority() const { return m_nPriority; }
 374
 375     // thread handle and id
 376     inline TID GetHandle() const { return m_hThread; }
 377     TID  GetId() const { return m_hThread; }
 378
 379     // thread function
 380     static DWORD OS2ThreadStart(ULONG ulParam);
 381
 382 private:
 383     // Threads in OS/2 have only an ID, so m_hThread is both it's handle and ID
 384     // PM also has no real Tls mechanism to index pointers by so we'll just
 385     // keep track of the wxWindows parent object here.
 386     TID                             m_hThread;    // handle and ID of the thread
 387     wxThreadState                   m_eState;     // state, see wxThreadState enum
 388     unsigned int                    m_nPriority;  // thread priority in "wx" units
 389 };
 390
 391 ULONG wxThreadInternal::OS2ThreadStart(
 392   ULONG ulParam
 393 )
 394 {
 395     DWORD                           dwRet;
 396     bool bWasCancelled;
 397
 398     // first of all, check whether we hadn't been cancelled already and don't
 399     // start the user code at all then
 400     wxThread *pThread = (wxThread *)ulParam;
 401     if ( pThread->m_internal->GetState() == STATE_EXITED )
 402     {
 403         dwRet = (DWORD)-1;
 404         bWasCancelled = TRUE;
 405     }
 406     else // do run thread
 407     {
 408         dwRet = (DWORD)pThread->Entry();
 409
 410         // enter m_critsect before changing the thread state
 411         pThread->m_critsect.Enter();
 412
 413         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 414
 415         pThread->m_internal->SetState(STATE_EXITED);
 416         pThread->m_critsect.Leave();
 417     }
 418     pThread->OnExit();
 419
 420     // if the thread was cancelled (from Delete()), then it the handle is still
 421     // needed there
 422     if (pThread->IsDetached() && !bWasCancelled)
 423     {
 424         // auto delete
 425         delete pThread;
 426     }
 427     //else: the joinable threads handle will be closed when Wait() is done
 428     return dwRet;
 429 }
 430
 431 void wxThreadInternal::SetPriority(
 432   unsigned int                      nPriority
 433 )
 434 {
 435     // translate wxWindows priority to the PM one
 436     ULONG                           ulOS2_PriorityClass;
 437     ULONG                           ulOS2_SubPriority;
 438     ULONG                           ulrc;
 439
 440     m_nPriority = nPriority;
 441     if (m_nPriority <= 25)
 442         ulOS2_PriorityClass = PRTYC_IDLETIME;
 443     else if (m_nPriority <= 50)
 444         ulOS2_PriorityClass = PRTYC_REGULAR;
 445     else if (m_nPriority <= 75)
 446         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 447     else if (m_nPriority <= 100)
 448         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 449     else
 450     {
 451         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 452         ulOS2_PriorityClass = PRTYC_REGULAR;
 453     }
 454     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 455     ulrc = ::DosSetPriority( PRTYS_THREAD
 456                             ,ulOS2_PriorityClass
 457                             ,ulOS2_SubPriority
 458                             ,(ULONG)m_hThread
 459                            );
 460     if (ulrc != 0)
 461     {
 462         wxLogSysError(_("Can't set thread priority"));
 463     }
 464 }
 465
 466 bool wxThreadInternal::Create(
 467   wxThread*                         pThread
 468 , unsigned int                      uStackSize
 469 )
 470 {
 471     APIRET                          ulrc;
 472
 473     ulrc = ::DosCreateThread( &m_hThread
 474                              ,(PFNTHREAD)wxThreadInternal::OS2ThreadStart
 475                              ,(ULONG)pThread
 476                              ,CREATE_SUSPENDED | STACK_SPARSE
 477                              ,(ULONG)uStackSize
 478                             );
 479     if(ulrc != 0)
 480     {
 481         wxLogSysError(_("Can't create thread"));
 482
 483         return FALSE;
 484     }
 485     if (m_nPriority != WXTHREAD_DEFAULT_PRIORITY)
 486     {
 487         SetPriority(m_nPriority);
 488     }
 489
 490     return(TRUE);
 491 }
 492
 493 bool wxThreadInternal::Suspend()
 494 {
 495     ULONG                           ulrc = ::DosSuspendThread(m_hThread);
 496
 497     if (ulrc != 0)
 498     {
 499         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 500         return FALSE;
 501     }
 502     m_eState = STATE_PAUSED;
 503     return TRUE;
 504 }
 505
 506 bool wxThreadInternal::Resume()
 507 {
 508     ULONG                           ulrc = ::DosResumeThread(m_hThread);
 509
 510     if (ulrc != 0)
 511     {
 512         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 513         return FALSE;
 514     }
 515
 516     // don't change the state from STATE_EXITED because it's special and means
 517     // we are going to terminate without running any user code - if we did it,
 518     // the codei n Delete() wouldn't work
 519     if ( m_eState != STATE_EXITED )
 520     {
 521         m_eState = STATE_RUNNING;
 522     }
 523
 524     return TRUE;
 525 }
 526
 527 // static functions
 528 // ----------------
 529
 530 wxThread *wxThread::This()
 531 {
 532     wxThread*                       pThread = m_pThread;
 533     return pThread;
 534 }
 535
 536 bool wxThread::IsMain()
 537 {
 538     PTIB                            ptib;
 539     PPIB                            ppib;
 540
 541     ::DosGetInfoBlocks(&ptib, &ppib);
 542
 543     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 544         return TRUE;
 545     return FALSE;
 546 }
 547
 548 #ifdef Yield
 549     #undef Yield
 550 #endif
 551
 552 void wxThread::Yield()
 553 {
 554     ::DosSleep(0);
 555 }
 556
 557 void wxThread::Sleep(
 558   unsigned long                     ulMilliseconds
 559 )
 560 {
 561     ::DosSleep(ulMilliseconds);
 562 }
 563
 564 int wxThread::GetCPUCount()
 565 {
 566     ULONG CPUCount;
 567     APIRET ulrc;
 568     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 569     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 570
 571     if (ulrc != 0)
 572         CPUCount = 1;
 573
 574     return CPUCount;
 575 }
 576
 577 unsigned long wxThread::GetCurrentId()
 578 {
 579     PTIB                            ptib;
 580     PPIB                            ppib;
 581
 582     ::DosGetInfoBlocks(&ptib, &ppib);
 583     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 584 }
 585
 586 bool wxThread::SetConcurrency(size_t level)
 587 {
 588     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 589
 590     // ok only for the default one
 591     if ( level == 0 )
 592         return 0;
 593
 594     // Don't know how to realize this on OS/2.
 595     return level == 1;
 596 }
 597
 598 // ctor and dtor
 599 // -------------
 600
 601 wxThread::wxThread(wxThreadKind kind)
 602 {
 603     m_internal = new wxThreadInternal();
 604
 605     m_isDetached = kind == wxTHREAD_DETACHED;
 606 }
 607
 608 wxThread::~wxThread()
 609 {
 610     delete m_internal;
 611 }
 612
 613 // create/start thread
 614 // -------------------
 615
 616 wxThreadError wxThread::Create(
 617   unsigned int                      uStackSize
 618 )
 619 {
 620     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 621
 622     if ( !m_internal->Create(this, uStackSize) )
 623         return wxTHREAD_NO_RESOURCE;
 624
 625     return wxTHREAD_NO_ERROR;
 626 }
 627
 628 wxThreadError wxThread::Run()
 629 {
 630     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 631
 632     if ( m_internal->GetState() != STATE_NEW )
 633     {
 634         // actually, it may be almost any state at all, not only STATE_RUNNING
 635         return wxTHREAD_RUNNING;
 636     }
 637     return Resume();
 638 }
 639
 640 // suspend/resume thread
 641 // ---------------------
 642
 643 wxThreadError wxThread::Pause()
 644 {
 645     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 646
 647     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 648 }
 649
 650 wxThreadError wxThread::Resume()
 651 {
 652     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 653
 654     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 655 }
 656
 657 // stopping thread
 658 // ---------------
 659
 660 wxThread::ExitCode wxThread::Wait()
 661 {
 662     // although under Windows we can wait for any thread, it's an error to
 663     // wait for a detached one in wxWin API
 664     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 665                  _T("can't wait for detached thread") );
 666     ExitCode rc = (ExitCode)-1;
 667     (void)Delete(&rc);
 668     return(rc);
 669 }
 670
 671 wxThreadError wxThread::Delete(ExitCode *pRc)
 672 {
 673     ExitCode rc = 0;
 674
 675     // Delete() is always safe to call, so consider all possible states
 676
 677     // we might need to resume the thread, but we might also not need to cancel
 678     // it if it doesn't run yet
 679     bool shouldResume = FALSE,
 680          shouldCancel = TRUE,
 681          isRunning = FALSE;
 682
 683     // check if the thread already started to run
 684     {
 685         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 686
 687         if ( m_internal->GetState() == STATE_NEW )
 688         {
 689             // WinThreadStart() will see it and terminate immediately, no need
 690             // to cancel the thread - but we still need to resume it to let it
 691             // run
 692             m_internal->SetState(STATE_EXITED);
 693
 694             Resume();   // it knows about STATE_EXITED special case
 695
 696             shouldCancel = FALSE;
 697             isRunning = TRUE;
 698
 699             // shouldResume is correctly set to FALSE here
 700         }
 701         else
 702         {
 703             shouldResume = IsPaused();
 704         }
 705     }
 706
 707     // resume the thread if it is paused
 708     if ( shouldResume )
 709         Resume();
 710
 711     TID                             hThread = m_internal->GetHandle();
 712
 713     if ( isRunning || IsRunning())
 714     {
 715         if (IsMain())
 716         {
 717             // set flag for wxIsWaitingForThread()
 718             gs_bWaitingForThread = TRUE;
 719         }
 720
 721         // ask the thread to terminate
 722         if ( shouldCancel )
 723         {
 724             wxCriticalSectionLocker lock(m_critsect);
 725
 726             m_internal->Cancel();
 727         }
 728
 729 #if wxUSE_GUI
 730         // we can't just wait for the thread to terminate because it might be
 731         // calling some GUI functions and so it will never terminate before we
 732         // process the Windows messages that result from these functions
 733         DWORD result = 0;       // suppress warnings from broken compilers
 734         do
 735         {
 736             if ( IsMain() )
 737             {
 738                 // give the thread we're waiting for chance to do the GUI call
 739                 // it might be in
 740                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 741                 {
 742                     wxMutexGuiLeave();
 743                 }
 744             }
 745
 746             result = ::DosWaitThread(&hThread, DCWW_WAIT);
 747             // FIXME: We ought to have a message processing loop here!!
 748
 749             switch ( result )
 750             {
 751                 case ERROR_THREAD_NOT_TERMINATED:
 752                 case ERROR_INVALID_THREADID:
 753                     // error
 754                     wxLogSysError(_("Can not wait for thread termination"));
 755                     Kill();
 756                     return wxTHREAD_KILLED;
 757
 758                 case NO_ERROR:
 759                     // thread we're waiting for terminated
 760                     break;
 761
 762                 default:
 763                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 764             }
 765         } while ( result != NO_ERROR );
 766 #else // !wxUSE_GUI
 767         // simply wait for the thread to terminate
 768         //
 769         // OTOH, even console apps create windows (in wxExecute, for WinSock
 770         // &c), so may be use MsgWaitForMultipleObject() too here?
 771         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 772         {
 773             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 774         }
 775 #endif // wxUSE_GUI/!wxUSE_GUI
 776
 777         if ( IsMain() )
 778         {
 779             gs_bWaitingForThread = FALSE;
 780         }
 781     }
 782
 783 #if 0
 784     // although the thread might be already in the EXITED state it might not
 785     // have terminated yet and so we are not sure that it has actually
 786     // terminated if the "if" above hadn't been taken
 787     do
 788     {
 789         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 790         {
 791             wxLogLastError(wxT("GetExitCodeThread"));
 792
 793             rc = (ExitCode)-1;
 794         }
 795     } while ( (DWORD)rc == STILL_ACTIVE );
 796 #endif
 797
 798     if ( IsDetached() )
 799     {
 800         // if the thread exits normally, this is done in WinThreadStart, but in
 801         // this case it would have been too early because
 802         // MsgWaitForMultipleObject() would fail if the thread handle was
 803         // closed while we were waiting on it, so we must do it here
 804         delete this;
 805     }
 806
 807     if ( pRc )
 808         *pRc = rc;
 809
 810     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 811 }
 812
 813 wxThreadError wxThread::Kill()
 814 {
 815     if (!IsRunning())
 816         return wxTHREAD_NOT_RUNNING;
 817
 818     ::DosKillThread(m_internal->GetHandle());
 819     if (IsDetached())
 820     {
 821         delete this;
 822     }
 823     return wxTHREAD_NO_ERROR;
 824 }
 825
 826 void wxThread::Exit(
 827   ExitCode                          pStatus
 828 )
 829 {
 830     delete this;
 831     ::DosExit(EXIT_THREAD, ULONG(pStatus));
 832     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 833 }
 834
 835 void wxThread::SetPriority(
 836   unsigned int                      nPrio
 837 )
 838 {
 839     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 840
 841     m_internal->SetPriority(nPrio);
 842 }
 843
 844 unsigned int wxThread::GetPriority() const
 845 {
 846     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 847
 848     return m_internal->GetPriority();
 849 }
 850
 851 unsigned long wxThread::GetId() const
 852 {
 853     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 854
 855     return (unsigned long)m_internal->GetId();
 856 }
 857
 858 bool wxThread::IsRunning() const
 859 {
 860     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 861
 862     return(m_internal->GetState() == STATE_RUNNING);
 863 }
 864
 865 bool wxThread::IsAlive() const
 866 {
 867     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 868
 869     return (m_internal->GetState() == STATE_RUNNING) ||
 870            (m_internal->GetState() == STATE_PAUSED);
 871 }
 872
 873 bool wxThread::IsPaused() const
 874 {
 875     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 876
 877     return (m_internal->GetState() == STATE_PAUSED);
 878 }
 879
 880 bool wxThread::TestDestroy()
 881 {
 882     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 883
 884     return m_internal->GetState() == STATE_CANCELED;
 885 }
 886
 887 // ----------------------------------------------------------------------------
 888 // Automatic initialization for thread module
 889 // ----------------------------------------------------------------------------
 890
 891 class wxThreadModule : public wxModule
 892 {
 893 public:
 894     virtual bool OnInit();
 895     virtual void OnExit();
 896
 897 private:
 898     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 899 };
 900
 901 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 902
 903 bool wxThreadModule::OnInit()
 904 {
 905     gs_pCritsectWaitingForGui = new wxCriticalSection();
 906
 907     gs_pCritsectGui = new wxCriticalSection();
 908     gs_pCritsectGui->Enter();
 909
 910     PTIB                            ptib;
 911     PPIB                            ppib;
 912
 913     ::DosGetInfoBlocks(&ptib, &ppib);
 914
 915     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 916     return TRUE;
 917 }
 918
 919 void wxThreadModule::OnExit()
 920 {
 921     if (gs_pCritsectGui)
 922     {
 923         gs_pCritsectGui->Leave();
 924 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 925         delete gs_pCritsectGui;
 926 #endif
 927         gs_pCritsectGui = NULL;
 928     }
 929
 930 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 931     wxDELETE(gs_pCritsectWaitingForGui);
 932 #endif
 933 }
 934
 935 // ----------------------------------------------------------------------------
 936 // Helper functions
 937 // ----------------------------------------------------------------------------
 938
 939 // wake up the main thread if it's in ::GetMessage()
 940 void WXDLLEXPORT wxWakeUpMainThread()
 941 {
 942     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 943     {
 944         // should never happen
 945         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 946     }
 947 }
 948
 949 void WXDLLEXPORT wxMutexGuiEnter()
 950 {
 951     // this would dead lock everything...
 952     wxASSERT_MSG( !wxThread::IsMain(),
 953                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 954
 955     // the order in which we enter the critical sections here is crucial!!
 956
 957     // set the flag telling to the main thread that we want to do some GUI
 958     {
 959         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 960
 961         gs_nWaitingForGui++;
 962     }
 963
 964     wxWakeUpMainThread();
 965
 966     // now we may block here because the main thread will soon let us in
 967     // (during the next iteration of OnIdle())
 968     gs_pCritsectGui->Enter();
 969 }
 970
 971 void WXDLLEXPORT wxMutexGuiLeave()
 972 {
 973     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 974
 975     if ( wxThread::IsMain() )
 976     {
 977         gs_bGuiOwnedByMainThread = FALSE;
 978     }
 979     else
 980     {
 981         // decrement the number of waiters now
 982         wxASSERT_MSG(gs_nWaitingForGui > 0,
 983                       wxT("calling wxMutexGuiLeave() without entering it first?") );
 984
 985         gs_nWaitingForGui--;
 986
 987         wxWakeUpMainThread();
 988     }
 989
 990     gs_pCritsectGui->Leave();
 991 }
 992
 993 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
 994 {
 995     wxASSERT_MSG( wxThread::IsMain(),
 996                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
 997
 998     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 999
1000     if (gs_nWaitingForGui == 0)
1001     {
1002         // no threads are waiting for GUI - so we may acquire the lock without
1003         // any danger (but only if we don't already have it)
1004         if (!wxGuiOwnedByMainThread())
1005         {
1006             gs_pCritsectGui->Enter();
1007
1008             gs_bGuiOwnedByMainThread = TRUE;
1009         }
1010         //else: already have it, nothing to do
1011     }
1012     else
1013     {
1014         // some threads are waiting, release the GUI lock if we have it
1015         if (wxGuiOwnedByMainThread())
1016         {
1017             wxMutexGuiLeave();
1018         }
1019         //else: some other worker thread is doing GUI
1020     }
1021 }
1022
1023 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1024 {
1025     return gs_bGuiOwnedByMainThread;
1026 }
1027
1028 bool WXDLLEXPORT wxIsWaitingForThread()
1029 {
1030     return gs_bWaitingForThread;
1031 }
1032
1033 // ----------------------------------------------------------------------------
1034 // include common implementation code
1035 // ----------------------------------------------------------------------------
1036
1037 #include "wx/thrimpl.cpp"
1038
1039 #endif
1040   // wxUSE_THREADS