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 // ----------------------------------------------------------------------------
  14 // headers
  15 // ----------------------------------------------------------------------------
  16
  17 // For compilers that support precompilation, includes "wx.h".
  18 #include "wx/wxprec.h"
  19
  20 #if wxUSE_THREADS
  21
  22 #include <stdio.h>
  23
  24 #include "wx/app.h"
  25 #include "wx/apptrait.h"
  26 #include "wx/module.h"
  27 #include "wx/intl.h"
  28 #include "wx/utils.h"
  29 #include "wx/log.h"
  30 #include "wx/thread.h"
  31
  32 #define INCL_DOSSEMAPHORES
  33 #define INCL_DOSPROCESS
  34 #define INCL_DOSMISC
  35 #define INCL_ERRORS
  36 #include <os2.h>
  37 #ifndef __EMX__
  38 #include <bseerr.h>
  39 #endif
  40 // the possible states of the thread ("=>" shows all possible transitions from
  41 // this state)
  42 enum wxThreadState
  43 {
  44     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  45     STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
  46     STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
  47     STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
  48     STATE_EXITED        // thread is terminating
  49 };
  50
  51 // ----------------------------------------------------------------------------
  52 // this module's globals
  53 // ----------------------------------------------------------------------------
  54
  55 // id of the main thread - the one which can call GUI functions without first
  56 // calling wxMutexGuiEnter()
  57 static ULONG                        s_ulIdMainThread = 1;
  58 wxMutex*                            p_wxMainMutex;
  59
  60 // OS2 substitute for Tls pointer the current parent thread object
  61 wxThread*                           m_pThread;    // pointer to the wxWidgets thread object
  62
  63 // if it's false, some secondary thread is holding the GUI lock
  64 static bool gs_bGuiOwnedByMainThread = true;
  65
  66 // critical section which controls access to all GUI functions: any secondary
  67 // thread (i.e. except the main one) must enter this crit section before doing
  68 // any GUI calls
  69 static wxCriticalSection *gs_pCritsectGui = NULL;
  70
  71 // critical section which protects s_nWaitingForGui variable
  72 static wxCriticalSection *gs_pCritsectWaitingForGui = NULL;
  73
  74 // number of threads waiting for GUI in wxMutexGuiEnter()
  75 static size_t gs_nWaitingForGui = 0;
  76
  77 // are we waiting for a thread termination?
  78 static bool gs_bWaitingForThread = false;
  79
  80 // ============================================================================
  81 // OS/2 implementation of thread and related classes
  82 // ============================================================================
  83
  84 // ----------------------------------------------------------------------------
  85 // wxMutex implementation
  86 // ----------------------------------------------------------------------------
  87 class wxMutexInternal
  88 {
  89 public:
  90     wxMutexInternal(wxMutexType mutexType);
  91     ~wxMutexInternal();
  92
  93     bool IsOk() const { return m_vMutex != NULL; }
  94
  95     wxMutexError Lock() { return LockTimeout(SEM_INDEFINITE_WAIT); }
  96     wxMutexError TryLock() { return LockTimeout(SEM_IMMEDIATE_RETURN); }
  97     wxMutexError Unlock();
  98
  99 private:
 100     wxMutexError LockTimeout(ULONG ulMilliseconds);
 101     HMTX                            m_vMutex;
 102 };
 103
 104 // all mutexes are "pseudo-"recursive under OS2 so we don't use mutexType
 105 // (Calls to DosRequestMutexSem and DosReleaseMutexSem can be nested, but
 106 //  the request count for a semaphore cannot exceed 65535. If an attempt is
 107 //  made to exceed this number, ERROR_TOO_MANY_SEM_REQUESTS is returned.)
 108 wxMutexInternal::wxMutexInternal(wxMutexType WXUNUSED(eMutexType))
 109 {
 110     APIRET ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 111     if (ulrc != 0)
 112     {
 113         wxLogSysError(_("Can not create mutex."));
 114         m_vMutex = NULL;
 115     }
 116 }
 117
 118 wxMutexInternal::~wxMutexInternal()
 119 {
 120     if (m_vMutex)
 121     {
 122         if (::DosCloseMutexSem(m_vMutex))
 123             wxLogLastError(_T("DosCloseMutexSem(mutex)"));
 124     }
 125 }
 126
 127 wxMutexError wxMutexInternal::LockTimeout(ULONG ulMilliseconds)
 128 {
 129     APIRET                          ulrc;
 130
 131     ulrc = ::DosRequestMutexSem(m_vMutex, ulMilliseconds);
 132
 133     switch (ulrc)
 134     {
 135         case ERROR_TIMEOUT:
 136         case ERROR_TOO_MANY_SEM_REQUESTS:
 137             return wxMUTEX_BUSY;
 138
 139         case NO_ERROR:
 140             // ok
 141             break;
 142
 143         case ERROR_INVALID_HANDLE:
 144         case ERROR_INTERRUPT:
 145         case ERROR_SEM_OWNER_DIED:
 146             wxLogSysError(_("Couldn't acquire a mutex lock"));
 147             return wxMUTEX_MISC_ERROR;
 148
 149         default:
 150             wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
 151             return wxMUTEX_MISC_ERROR;
 152      }
 153     return wxMUTEX_NO_ERROR;
 154 }
 155
 156 wxMutexError wxMutexInternal::Unlock()
 157 {
 158     APIRET                          ulrc;
 159
 160     ulrc = ::DosReleaseMutexSem(m_vMutex);
 161     if (ulrc != 0)
 162     {
 163         wxLogSysError(_("Couldn't release a mutex"));
 164         return wxMUTEX_MISC_ERROR;
 165     }
 166     return wxMUTEX_NO_ERROR;
 167 }
 168
 169 // --------------------------------------------------------------------------
 170 // wxSemaphore
 171 // --------------------------------------------------------------------------
 172
 173 // a trivial wrapper around OS2 event semaphore
 174 class wxSemaphoreInternal
 175 {
 176 public:
 177     wxSemaphoreInternal(int initialcount, int maxcount);
 178     ~wxSemaphoreInternal();
 179
 180     bool IsOk() const { return m_vEvent != NULL; }
 181
 182     wxSemaError Wait() { return WaitTimeout(SEM_INDEFINITE_WAIT); }
 183     wxSemaError TryWait() { return WaitTimeout(SEM_IMMEDIATE_RETURN); }
 184     wxSemaError WaitTimeout(unsigned long milliseconds);
 185
 186     wxSemaError Post();
 187
 188 private:
 189     HEV m_vEvent;
 190     HMTX m_vMutex;
 191     int m_count;
 192     int m_maxcount;
 193 };
 194
 195 wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
 196 {
 197     APIRET ulrc;
 198     if ( maxcount == 0 )
 199     {
 200         // make it practically infinite
 201         maxcount = INT_MAX;
 202     }
 203
 204     m_count = initialcount;
 205     m_maxcount = maxcount;
 206     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 207     if (ulrc != 0)
 208     {
 209         wxLogLastError(_T("DosCreateMutexSem()"));
 210         m_vMutex = NULL;
 211         m_vEvent = NULL;
 212         return;
 213     }
 214     ulrc = ::DosCreateEventSem(NULL, &m_vEvent, 0L, FALSE);
 215     if ( ulrc != 0)
 216     {
 217         wxLogLastError(_T("DosCreateEventSem()"));
 218         ::DosCloseMutexSem(m_vMutex);
 219         m_vMutex = NULL;
 220         m_vEvent = NULL;
 221     }
 222     if (initialcount)
 223         ::DosPostEventSem(m_vEvent);
 224 }
 225
 226 wxSemaphoreInternal::~wxSemaphoreInternal()
 227 {
 228     if ( m_vEvent )
 229     {
 230         if ( ::DosCloseEventSem(m_vEvent) )
 231         {
 232             wxLogLastError(_T("DosCloseEventSem(semaphore)"));
 233         }
 234         if ( ::DosCloseMutexSem(m_vMutex) )
 235         {
 236             wxLogLastError(_T("DosCloseMutexSem(semaphore)"));
 237         }
 238         else
 239             m_vEvent = NULL;
 240     }
 241 }
 242
 243 wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long ulMilliseconds)
 244 {
 245     APIRET ulrc;
 246     do {
 247         ulrc = ::DosWaitEventSem(m_vEvent, ulMilliseconds );
 248         switch ( ulrc )
 249         {
 250             case NO_ERROR:
 251                 break;
 252
 253             case ERROR_TIMEOUT:
 254                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 255                     return wxSEMA_BUSY;
 256                 else
 257                     return wxSEMA_TIMEOUT;
 258
 259             default:
 260                 wxLogLastError(_T("DosWaitEventSem(semaphore)"));
 261                 return wxSEMA_MISC_ERROR;
 262         }
 263         ulrc = :: DosRequestMutexSem(m_vMutex, ulMilliseconds);
 264         switch ( ulrc )
 265         {
 266             case NO_ERROR:
 267                 // ok
 268                 break;
 269
 270             case ERROR_TIMEOUT:
 271             case ERROR_TOO_MANY_SEM_REQUESTS:
 272                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 273                     return wxSEMA_BUSY;
 274                 else
 275                     return wxSEMA_TIMEOUT;
 276
 277             default:
 278                 wxFAIL_MSG(wxT("DosRequestMutexSem(mutex)"));
 279                 return wxSEMA_MISC_ERROR;
 280         }
 281         bool OK = false;
 282         if (m_count > 0)
 283         {
 284             m_count--;
 285             OK = true;
 286         }
 287         else
 288         {
 289             ULONG ulPostCount;
 290             ::DosResetEventSem(m_vEvent, &ulPostCount);
 291         }
 292         ::DosReleaseMutexSem(m_vMutex);
 293         if (OK)
 294             return wxSEMA_NO_ERROR;
 295     } while (ulMilliseconds == SEM_INDEFINITE_WAIT);
 296
 297     if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 298         return wxSEMA_BUSY;
 299     return wxSEMA_TIMEOUT;
 300 }
 301
 302 wxSemaError wxSemaphoreInternal::Post()
 303 {
 304     APIRET ulrc;
 305     ulrc = ::DosRequestMutexSem(m_vMutex, SEM_INDEFINITE_WAIT);
 306     if (ulrc != NO_ERROR)
 307         return wxSEMA_MISC_ERROR;
 308     bool OK = false;
 309     if (m_count < m_maxcount)
 310     {
 311         m_count++;
 312         ulrc = ::DosPostEventSem(m_vEvent);
 313         OK = true;
 314     }
 315     ::DosReleaseMutexSem(m_vMutex);
 316     if (!OK)
 317         return wxSEMA_OVERFLOW;
 318     if ( ulrc != NO_ERROR && ulrc != ERROR_ALREADY_POSTED )
 319     {
 320         wxLogLastError(_T("DosPostEventSem(semaphore)"));
 321
 322         return wxSEMA_MISC_ERROR;
 323     }
 324
 325     return wxSEMA_NO_ERROR;
 326 }
 327
 328 // ----------------------------------------------------------------------------
 329 // wxThread implementation
 330 // ----------------------------------------------------------------------------
 331
 332 // wxThreadInternal class
 333 // ----------------------
 334
 335 class wxThreadInternal
 336 {
 337 public:
 338     inline wxThreadInternal()
 339     {
 340         m_hThread = 0;
 341         m_eState = STATE_NEW;
 342         m_nPriority = WXTHREAD_DEFAULT_PRIORITY;
 343     }
 344
 345     ~wxThreadInternal()
 346     {
 347         m_hThread = 0;
 348     }
 349
 350     // create a new (suspended) thread (for the given thread object)
 351     bool Create( wxThread*    pThread
 352                 ,unsigned int uStackSize
 353                );
 354
 355     // suspend/resume/terminate
 356     bool Suspend();
 357     bool Resume();
 358     inline void Cancel() { m_eState = STATE_CANCELED; }
 359
 360     // thread state
 361     inline void SetState(wxThreadState eState) { m_eState = eState; }
 362     inline wxThreadState GetState() const { return m_eState; }
 363
 364     // thread priority
 365     void                SetPriority(unsigned int nPriority);
 366     inline unsigned int GetPriority() const { return m_nPriority; }
 367
 368     // thread handle and id
 369     inline TID GetHandle() const { return m_hThread; }
 370     TID  GetId() const { return m_hThread; }
 371
 372     // thread function
 373     static void OS2ThreadStart(void* pParam);
 374
 375 private:
 376     // Threads in OS/2 have only an ID, so m_hThread is both it's handle and ID
 377     // PM also has no real Tls mechanism to index pointers by so we'll just
 378     // keep track of the wxWidgets parent object here.
 379     TID                             m_hThread;    // handle and ID of the thread
 380     wxThreadState                   m_eState;     // state, see wxThreadState enum
 381     unsigned int                    m_nPriority;  // thread priority in "wx" units
 382 };
 383
 384 void wxThreadInternal::OS2ThreadStart(
 385   void * pParam
 386 )
 387 {
 388     DWORD                           dwRet;
 389     bool bWasCancelled;
 390
 391     wxThread *pThread = (wxThread *)pParam;
 392
 393     // first of all, wait for the thread to be started.
 394     pThread->m_critsect.Enter();
 395     pThread->m_critsect.Leave();
 396     // Now check whether we hadn't been cancelled already and don't
 397     // start the user code at all in this case.
 398     if ( pThread->m_internal->GetState() == STATE_EXITED )
 399     {
 400         dwRet = (DWORD)-1;
 401         bWasCancelled = true;
 402     }
 403     else // do run thread
 404     {
 405         wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 406         unsigned long ulHab;
 407         if (traits)
 408             traits->InitializeGui(ulHab);
 409         dwRet = (DWORD)pThread->Entry();
 410         if (traits)
 411             traits->TerminateGui(ulHab);
 412
 413         // enter m_critsect before changing the thread state
 414         pThread->m_critsect.Enter();
 415
 416         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 417
 418         pThread->m_internal->SetState(STATE_EXITED);
 419         pThread->m_critsect.Leave();
 420     }
 421     pThread->OnExit();
 422
 423     // if the thread was cancelled (from Delete()), then it the handle is still
 424     // needed there
 425     if (pThread->IsDetached() && !bWasCancelled)
 426     {
 427         // auto delete
 428         delete pThread;
 429     }
 430     //else: the joinable threads handle will be closed when Wait() is done
 431     return;
 432 }
 433
 434 void wxThreadInternal::SetPriority(
 435   unsigned int                      nPriority
 436 )
 437 {
 438     // translate wxWidgets priority to the PM one
 439     ULONG                           ulOS2_PriorityClass;
 440     ULONG                           ulOS2_SubPriority;
 441     ULONG                           ulrc;
 442
 443     m_nPriority = nPriority;
 444     if (m_nPriority <= 25)
 445         ulOS2_PriorityClass = PRTYC_IDLETIME;
 446     else if (m_nPriority <= 50)
 447         ulOS2_PriorityClass = PRTYC_REGULAR;
 448     else if (m_nPriority <= 75)
 449         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 450     else if (m_nPriority <= 100)
 451         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 452     else
 453     {
 454         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 455         ulOS2_PriorityClass = PRTYC_REGULAR;
 456     }
 457     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 458     ulrc = ::DosSetPriority( PRTYS_THREAD
 459                             ,ulOS2_PriorityClass
 460                             ,ulOS2_SubPriority
 461                             ,(ULONG)m_hThread
 462                            );
 463     if (ulrc != 0)
 464     {
 465         wxLogSysError(_("Can't set thread priority"));
 466     }
 467 }
 468
 469 bool wxThreadInternal::Create( wxThread* pThread,
 470                                unsigned int uStackSize)
 471 {
 472     int tid;
 473
 474     if (!uStackSize)
 475         uStackSize = 131072;
 476
 477     pThread->m_critsect.Enter();
 478     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 479                              NULL, uStackSize, pThread);
 480     if(tid == -1)
 481     {
 482         wxLogSysError(_("Can't create thread"));
 483
 484         return false;
 485     }
 486     m_hThread = tid;
 487     if (m_nPriority != WXTHREAD_DEFAULT_PRIORITY)
 488     {
 489         SetPriority(m_nPriority);
 490     }
 491
 492     return true;
 493 }
 494
 495 bool wxThreadInternal::Suspend()
 496 {
 497     ULONG ulrc = ::DosSuspendThread(m_hThread);
 498
 499     if (ulrc != 0)
 500     {
 501         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 502         return false;
 503     }
 504     m_eState = STATE_PAUSED;
 505
 506     return true;
 507 }
 508
 509 bool wxThreadInternal::Resume()
 510 {
 511     ULONG ulrc = ::DosResumeThread(m_hThread);
 512
 513     if (ulrc != 0)
 514     {
 515         wxLogSysError(_("Can not resume thread %lu"), m_hThread);
 516         return false;
 517     }
 518
 519     // don't change the state from STATE_EXITED because it's special and means
 520     // we are going to terminate without running any user code - if we did it,
 521     // the codei n Delete() wouldn't work
 522     if ( m_eState != STATE_EXITED )
 523     {
 524         m_eState = STATE_RUNNING;
 525     }
 526
 527     return true;
 528 }
 529
 530 // static functions
 531 // ----------------
 532
 533 wxThread *wxThread::This()
 534 {
 535     wxThread*                       pThread = m_pThread;
 536     return pThread;
 537 }
 538
 539 bool wxThread::IsMain()
 540 {
 541     PTIB ptib;
 542     PPIB ppib;
 543
 544     ::DosGetInfoBlocks(&ptib, &ppib);
 545
 546     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 547         return true;
 548
 549     return false;
 550 }
 551
 552 #ifdef Yield
 553     #undef Yield
 554 #endif
 555
 556 void wxThread::Yield()
 557 {
 558     ::DosSleep(0);
 559 }
 560
 561 void wxThread::Sleep(
 562   unsigned long                     ulMilliseconds
 563 )
 564 {
 565     ::DosSleep(ulMilliseconds);
 566 }
 567
 568 int wxThread::GetCPUCount()
 569 {
 570     ULONG CPUCount;
 571     APIRET ulrc;
 572     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 573     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 574
 575     if (ulrc != 0)
 576         CPUCount = 1;
 577
 578     return CPUCount;
 579 }
 580
 581 unsigned long wxThread::GetCurrentId()
 582 {
 583     PTIB                            ptib;
 584     PPIB                            ppib;
 585
 586     ::DosGetInfoBlocks(&ptib, &ppib);
 587     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 588 }
 589
 590 bool wxThread::SetConcurrency(size_t level)
 591 {
 592     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 593
 594     // ok only for the default one
 595     if ( level == 0 )
 596         return 0;
 597
 598     // Don't know how to realize this on OS/2.
 599     return level == 1;
 600 }
 601
 602 // ctor and dtor
 603 // -------------
 604
 605 wxThread::wxThread(wxThreadKind kind)
 606 {
 607     m_internal = new wxThreadInternal();
 608
 609     m_isDetached = kind == wxTHREAD_DETACHED;
 610 }
 611
 612 wxThread::~wxThread()
 613 {
 614     delete m_internal;
 615 }
 616
 617 // create/start thread
 618 // -------------------
 619
 620 wxThreadError wxThread::Create(
 621   unsigned int                      uStackSize
 622 )
 623 {
 624     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 625
 626     if ( !m_internal->Create(this, uStackSize) )
 627         return wxTHREAD_NO_RESOURCE;
 628
 629     return wxTHREAD_NO_ERROR;
 630 }
 631
 632 wxThreadError wxThread::Run()
 633 {
 634     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 635
 636     if ( m_internal->GetState() != STATE_NEW )
 637     {
 638         // actually, it may be almost any state at all, not only STATE_RUNNING
 639         return wxTHREAD_RUNNING;
 640     }
 641     return Resume();
 642 }
 643
 644 // suspend/resume thread
 645 // ---------------------
 646
 647 wxThreadError wxThread::Pause()
 648 {
 649     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 650
 651     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 652 }
 653
 654 wxThreadError wxThread::Resume()
 655 {
 656     if (m_internal->GetState() == STATE_NEW)
 657     {
 658         m_internal->SetState(STATE_RUNNING);
 659         m_critsect.Leave();
 660         return wxTHREAD_NO_ERROR;
 661     }
 662
 663     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 664
 665     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 666 }
 667
 668 // stopping thread
 669 // ---------------
 670
 671 wxThread::ExitCode wxThread::Wait()
 672 {
 673     // although under Windows we can wait for any thread, it's an error to
 674     // wait for a detached one in wxWin API
 675     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 676                  _T("can't wait for detached thread") );
 677     ExitCode rc = (ExitCode)-1;
 678     (void)Delete(&rc);
 679     return(rc);
 680 }
 681
 682 wxThreadError wxThread::Delete(ExitCode *pRc)
 683 {
 684     ExitCode rc = 0;
 685
 686     // Delete() is always safe to call, so consider all possible states
 687
 688     // we might need to resume the thread, but we might also not need to cancel
 689     // it if it doesn't run yet
 690     bool shouldResume = false,
 691          shouldCancel = true,
 692          isRunning = false;
 693
 694     // check if the thread already started to run
 695     {
 696         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 697
 698         if ( m_internal->GetState() == STATE_NEW )
 699         {
 700             // WinThreadStart() will see it and terminate immediately, no need
 701             // to cancel the thread - but we still need to resume it to let it
 702             // run
 703             m_internal->SetState(STATE_EXITED);
 704
 705             Resume();   // it knows about STATE_EXITED special case
 706
 707             shouldCancel = false;
 708             isRunning = true;
 709
 710             // shouldResume is correctly set to false here
 711         }
 712         else
 713         {
 714             shouldResume = IsPaused();
 715         }
 716     }
 717
 718     // resume the thread if it is paused
 719     if ( shouldResume )
 720         Resume();
 721
 722     TID hThread = m_internal->GetHandle();
 723
 724     if ( isRunning || IsRunning())
 725     {
 726         if (IsMain())
 727         {
 728             // set flag for wxIsWaitingForThread()
 729             gs_bWaitingForThread = true;
 730         }
 731
 732         // ask the thread to terminate
 733         if ( shouldCancel )
 734         {
 735             wxCriticalSectionLocker lock(m_critsect);
 736
 737             m_internal->Cancel();
 738         }
 739
 740 #if 0
 741         // we can't just wait for the thread to terminate because it might be
 742         // calling some GUI functions and so it will never terminate before we
 743         // process the Windows messages that result from these functions
 744         DWORD result = 0;       // suppress warnings from broken compilers
 745         do
 746         {
 747             if ( IsMain() )
 748             {
 749                 // give the thread we're waiting for chance to do the GUI call
 750                 // it might be in
 751                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 752                 {
 753                     wxMutexGuiLeave();
 754                 }
 755             }
 756
 757             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 758             // FIXME: We ought to have a message processing loop here!!
 759
 760             switch ( result )
 761             {
 762                 case ERROR_INTERRUPT:
 763                 case ERROR_THREAD_NOT_TERMINATED:
 764                     break;
 765                 case ERROR_INVALID_THREADID:
 766                 case NO_ERROR:
 767                     // thread we're waiting for just terminated
 768                     // or even does not exist any more.
 769                     result = NO_ERROR;
 770                     break;
 771                 default:
 772                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 773             }
 774             if ( IsMain() )
 775             {
 776                 // event processing - needed if we are the main thread
 777                 // to give other threads a chance to do remaining GUI
 778                 // processing and terminate cleanly.
 779                 wxTheApp->HandleSockets();
 780                 if (wxTheApp->Pending())
 781                   if ( !wxTheApp->DoMessage() )
 782                   {
 783                       // WM_QUIT received: kill the thread
 784                       Kill();
 785
 786                       return wxTHREAD_KILLED;
 787                   }
 788                   else
 789                     wxUsleep(10);
 790             }
 791             else
 792                 wxUsleep(10);
 793         } while ( result != NO_ERROR );
 794 #else // !wxUSE_GUI
 795         // simply wait for the thread to terminate
 796         //
 797         // OTOH, even console apps create windows (in wxExecute, for WinSock
 798         // &c), so may be use MsgWaitForMultipleObject() too here?
 799         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 800         {
 801             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 802         }
 803 #endif // wxUSE_GUI/!wxUSE_GUI
 804
 805         if ( IsMain() )
 806         {
 807             gs_bWaitingForThread = false;
 808         }
 809     }
 810
 811 #if 0
 812     // although the thread might be already in the EXITED state it might not
 813     // have terminated yet and so we are not sure that it has actually
 814     // terminated if the "if" above hadn't been taken
 815     do
 816     {
 817         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 818         {
 819             wxLogLastError(wxT("GetExitCodeThread"));
 820
 821             rc = (ExitCode)-1;
 822         }
 823     } while ( (DWORD)rc == STILL_ACTIVE );
 824 #endif
 825
 826     if ( IsDetached() )
 827     {
 828         // if the thread exits normally, this is done in WinThreadStart, but in
 829         // this case it would have been too early because
 830         // MsgWaitForMultipleObject() would fail if the thread handle was
 831         // closed while we were waiting on it, so we must do it here
 832         delete this;
 833     }
 834
 835     if ( pRc )
 836         *pRc = rc;
 837
 838     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 839 }
 840
 841 wxThreadError wxThread::Kill()
 842 {
 843     if (!IsRunning())
 844         return wxTHREAD_NOT_RUNNING;
 845
 846     ::DosKillThread(m_internal->GetHandle());
 847     if (IsDetached())
 848     {
 849         delete this;
 850     }
 851     return wxTHREAD_NO_ERROR;
 852 }
 853
 854 void wxThread::Exit(ExitCode WXUNUSED(pStatus))
 855 {
 856     delete this;
 857     _endthread();
 858     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 859 }
 860
 861 void wxThread::SetPriority(
 862   unsigned int                      nPrio
 863 )
 864 {
 865     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 866
 867     m_internal->SetPriority(nPrio);
 868 }
 869
 870 unsigned int wxThread::GetPriority() const
 871 {
 872     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 873
 874     return m_internal->GetPriority();
 875 }
 876
 877 unsigned long wxThread::GetId() const
 878 {
 879     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 880
 881     return (unsigned long)m_internal->GetId();
 882 }
 883
 884 bool wxThread::IsRunning() const
 885 {
 886     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 887
 888     return(m_internal->GetState() == STATE_RUNNING);
 889 }
 890
 891 bool wxThread::IsAlive() const
 892 {
 893     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 894
 895     return (m_internal->GetState() == STATE_RUNNING) ||
 896            (m_internal->GetState() == STATE_PAUSED);
 897 }
 898
 899 bool wxThread::IsPaused() const
 900 {
 901     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 902
 903     return (m_internal->GetState() == STATE_PAUSED);
 904 }
 905
 906 bool wxThread::TestDestroy()
 907 {
 908     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 909
 910     return m_internal->GetState() == STATE_CANCELED;
 911 }
 912
 913 // ----------------------------------------------------------------------------
 914 // Automatic initialization for thread module
 915 // ----------------------------------------------------------------------------
 916
 917 class wxThreadModule : public wxModule
 918 {
 919 public:
 920     virtual bool OnInit();
 921     virtual void OnExit();
 922
 923 private:
 924     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 925 };
 926
 927 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 928
 929 bool wxThreadModule::OnInit()
 930 {
 931     gs_pCritsectWaitingForGui = new wxCriticalSection();
 932
 933     gs_pCritsectGui = new wxCriticalSection();
 934     gs_pCritsectGui->Enter();
 935
 936     PTIB ptib;
 937     PPIB ppib;
 938
 939     ::DosGetInfoBlocks(&ptib, &ppib);
 940
 941     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 942     return true;
 943 }
 944
 945 void wxThreadModule::OnExit()
 946 {
 947     if (gs_pCritsectGui)
 948     {
 949         gs_pCritsectGui->Leave();
 950 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 951         delete gs_pCritsectGui;
 952 #endif
 953         gs_pCritsectGui = NULL;
 954     }
 955
 956 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 957     wxDELETE(gs_pCritsectWaitingForGui);
 958 #endif
 959 }
 960
 961 // ----------------------------------------------------------------------------
 962 // Helper functions
 963 // ----------------------------------------------------------------------------
 964
 965 // wake up the main thread if it's in ::GetMessage()
 966 void WXDLLEXPORT wxWakeUpMainThread()
 967 {
 968 #if 0
 969     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 970     {
 971         // should never happen
 972         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 973     }
 974 #endif
 975 }
 976
 977 void WXDLLEXPORT wxMutexGuiEnter()
 978 {
 979     // this would dead lock everything...
 980     wxASSERT_MSG( !wxThread::IsMain(),
 981                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 982
 983     // the order in which we enter the critical sections here is crucial!!
 984
 985     // set the flag telling to the main thread that we want to do some GUI
 986     {
 987         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 988
 989         gs_nWaitingForGui++;
 990     }
 991
 992     wxWakeUpMainThread();
 993
 994     // now we may block here because the main thread will soon let us in
 995     // (during the next iteration of OnIdle())
 996     gs_pCritsectGui->Enter();
 997 }
 998
 999 void WXDLLEXPORT wxMutexGuiLeave()
1000 {
1001     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1002
1003     if ( wxThread::IsMain() )
1004     {
1005         gs_bGuiOwnedByMainThread = false;
1006     }
1007     else
1008     {
1009         // decrement the number of waiters now
1010         wxASSERT_MSG(gs_nWaitingForGui > 0,
1011                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1012
1013         gs_nWaitingForGui--;
1014
1015         wxWakeUpMainThread();
1016     }
1017
1018     gs_pCritsectGui->Leave();
1019 }
1020
1021 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1022 {
1023     wxASSERT_MSG( wxThread::IsMain(),
1024                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1025
1026     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1027
1028     if (gs_nWaitingForGui == 0)
1029     {
1030         // no threads are waiting for GUI - so we may acquire the lock without
1031         // any danger (but only if we don't already have it)
1032         if (!wxGuiOwnedByMainThread())
1033         {
1034             gs_pCritsectGui->Enter();
1035
1036             gs_bGuiOwnedByMainThread = true;
1037         }
1038         //else: already have it, nothing to do
1039     }
1040     else
1041     {
1042         // some threads are waiting, release the GUI lock if we have it
1043         if (wxGuiOwnedByMainThread())
1044         {
1045             wxMutexGuiLeave();
1046         }
1047         //else: some other worker thread is doing GUI
1048     }
1049 }
1050
1051 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1052 {
1053     return gs_bGuiOwnedByMainThread;
1054 }
1055
1056 bool WXDLLEXPORT wxIsWaitingForThread()
1057 {
1058     return gs_bWaitingForThread;
1059 }
1060
1061 // ----------------------------------------------------------------------------
1062 // include common implementation code
1063 // ----------------------------------------------------------------------------
1064
1065 #include "wx/thrimpl.cpp"
1066
1067 #endif
1068   // wxUSE_THREADS