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( void * pParam )
 385 {
 386     DWORD dwRet;
 387     bool bWasCancelled;
 388
 389     wxThread *pThread = (wxThread *)pParam;
 390
 391     // first of all, wait for the thread to be started.
 392     pThread->m_critsect.Enter();
 393     pThread->m_critsect.Leave();
 394     // Now check whether we hadn't been cancelled already and don't
 395     // start the user code at all in this case.
 396     if ( pThread->m_internal->GetState() == STATE_EXITED )
 397     {
 398         dwRet = (DWORD)-1;
 399         bWasCancelled = true;
 400     }
 401     else // do run thread
 402     {
 403         wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 404         unsigned long ulHab;
 405         if (traits)
 406             traits->InitializeGui(ulHab);
 407         dwRet = (DWORD)pThread->Entry();
 408         if (traits)
 409             traits->TerminateGui(ulHab);
 410
 411         // enter m_critsect before changing the thread state
 412         pThread->m_critsect.Enter();
 413
 414         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 415
 416         pThread->m_internal->SetState(STATE_EXITED);
 417         pThread->m_critsect.Leave();
 418     }
 419     pThread->OnExit();
 420
 421     // if the thread was cancelled (from Delete()), then it the handle is still
 422     // needed there
 423     if (pThread->IsDetached() && !bWasCancelled)
 424     {
 425         // auto delete
 426         delete pThread;
 427     }
 428     //else: the joinable threads handle will be closed when Wait() is done
 429     return;
 430 }
 431
 432 void wxThreadInternal::SetPriority(
 433   unsigned int                      nPriority
 434 )
 435 {
 436     // translate wxWidgets priority to the PM one
 437     ULONG                           ulOS2_PriorityClass;
 438     ULONG                           ulOS2_SubPriority;
 439     ULONG                           ulrc;
 440
 441     m_nPriority = nPriority;
 442     if (m_nPriority <= 25)
 443         ulOS2_PriorityClass = PRTYC_IDLETIME;
 444     else if (m_nPriority <= 50)
 445         ulOS2_PriorityClass = PRTYC_REGULAR;
 446     else if (m_nPriority <= 75)
 447         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 448     else if (m_nPriority <= 100)
 449         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 450     else
 451     {
 452         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 453         ulOS2_PriorityClass = PRTYC_REGULAR;
 454     }
 455     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 456     ulrc = ::DosSetPriority( PRTYS_THREAD
 457                             ,ulOS2_PriorityClass
 458                             ,ulOS2_SubPriority
 459                             ,(ULONG)m_hThread
 460                            );
 461     if (ulrc != 0)
 462     {
 463         wxLogSysError(_("Can't set thread priority"));
 464     }
 465 }
 466
 467 bool wxThreadInternal::Create( wxThread* pThread,
 468                                unsigned int uStackSize)
 469 {
 470     int tid;
 471
 472     if (!uStackSize)
 473         uStackSize = 131072;
 474
 475     pThread->m_critsect.Enter();
 476     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 477                              NULL, uStackSize, pThread);
 478     if(tid == -1)
 479     {
 480         wxLogSysError(_("Can't create thread"));
 481
 482         return false;
 483     }
 484     m_hThread = tid;
 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
 504     return true;
 505 }
 506
 507 bool wxThreadInternal::Resume()
 508 {
 509     ULONG ulrc = ::DosResumeThread(m_hThread);
 510
 511     if (ulrc != 0)
 512     {
 513         wxLogSysError(_("Can not resume thread %lu"), m_hThread);
 514         return false;
 515     }
 516
 517     // don't change the state from STATE_EXITED because it's special and means
 518     // we are going to terminate without running any user code - if we did it,
 519     // the codei n Delete() wouldn't work
 520     if ( m_eState != STATE_EXITED )
 521     {
 522         m_eState = STATE_RUNNING;
 523     }
 524
 525     return true;
 526 }
 527
 528 // static functions
 529 // ----------------
 530
 531 wxThread *wxThread::This()
 532 {
 533     wxThread*                       pThread = m_pThread;
 534     return pThread;
 535 }
 536
 537 bool wxThread::IsMain()
 538 {
 539     PTIB ptib;
 540     PPIB ppib;
 541
 542     ::DosGetInfoBlocks(&ptib, &ppib);
 543
 544     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 545         return true;
 546
 547     return false;
 548 }
 549
 550 #ifdef Yield
 551     #undef Yield
 552 #endif
 553
 554 void wxThread::Yield()
 555 {
 556     ::DosSleep(0);
 557 }
 558
 559 void wxThread::Sleep(
 560   unsigned long                     ulMilliseconds
 561 )
 562 {
 563     ::DosSleep(ulMilliseconds);
 564 }
 565
 566 int wxThread::GetCPUCount()
 567 {
 568     ULONG CPUCount;
 569     APIRET ulrc;
 570     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 571     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 572
 573     if (ulrc != 0)
 574         CPUCount = 1;
 575
 576     return CPUCount;
 577 }
 578
 579 unsigned long wxThread::GetCurrentId()
 580 {
 581     PTIB                            ptib;
 582     PPIB                            ppib;
 583
 584     ::DosGetInfoBlocks(&ptib, &ppib);
 585     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 586 }
 587
 588 bool wxThread::SetConcurrency(size_t level)
 589 {
 590     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 591
 592     // ok only for the default one
 593     if ( level == 0 )
 594         return 0;
 595
 596     // Don't know how to realize this on OS/2.
 597     return level == 1;
 598 }
 599
 600 // ctor and dtor
 601 // -------------
 602
 603 wxThread::wxThread(wxThreadKind kind)
 604 {
 605     m_internal = new wxThreadInternal();
 606
 607     m_isDetached = kind == wxTHREAD_DETACHED;
 608 }
 609
 610 wxThread::~wxThread()
 611 {
 612     delete m_internal;
 613 }
 614
 615 // create/start thread
 616 // -------------------
 617
 618 wxThreadError wxThread::Create(
 619   unsigned int                      uStackSize
 620 )
 621 {
 622     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 623
 624     if ( !m_internal->Create(this, uStackSize) )
 625         return wxTHREAD_NO_RESOURCE;
 626
 627     return wxTHREAD_NO_ERROR;
 628 }
 629
 630 wxThreadError wxThread::Run()
 631 {
 632     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 633
 634     if ( m_internal->GetState() != STATE_NEW )
 635     {
 636         // actually, it may be almost any state at all, not only STATE_RUNNING
 637         return wxTHREAD_RUNNING;
 638     }
 639     return Resume();
 640 }
 641
 642 // suspend/resume thread
 643 // ---------------------
 644
 645 wxThreadError wxThread::Pause()
 646 {
 647     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 648
 649     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 650 }
 651
 652 wxThreadError wxThread::Resume()
 653 {
 654     if (m_internal->GetState() == STATE_NEW)
 655     {
 656         m_internal->SetState(STATE_RUNNING);
 657         m_critsect.Leave();
 658         return wxTHREAD_NO_ERROR;
 659     }
 660
 661     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 662
 663     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 664 }
 665
 666 // stopping thread
 667 // ---------------
 668
 669 wxThread::ExitCode wxThread::Wait()
 670 {
 671     // although under Windows we can wait for any thread, it's an error to
 672     // wait for a detached one in wxWin API
 673     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 674                  _T("can't wait for detached thread") );
 675     ExitCode rc = (ExitCode)-1;
 676     (void)Delete(&rc);
 677     return(rc);
 678 }
 679
 680 wxThreadError wxThread::Delete(ExitCode *pRc)
 681 {
 682     ExitCode rc = 0;
 683
 684     // Delete() is always safe to call, so consider all possible states
 685
 686     // we might need to resume the thread, but we might also not need to cancel
 687     // it if it doesn't run yet
 688     bool shouldResume = false,
 689          shouldCancel = true,
 690          isRunning = false;
 691
 692     // check if the thread already started to run
 693     {
 694         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 695
 696         if ( m_internal->GetState() == STATE_NEW )
 697         {
 698             // WinThreadStart() will see it and terminate immediately, no need
 699             // to cancel the thread - but we still need to resume it to let it
 700             // run
 701             m_internal->SetState(STATE_EXITED);
 702
 703             Resume();   // it knows about STATE_EXITED special case
 704
 705             shouldCancel = false;
 706             isRunning = true;
 707
 708             // shouldResume is correctly set to false here
 709         }
 710         else
 711         {
 712             shouldResume = IsPaused();
 713         }
 714     }
 715
 716     // resume the thread if it is paused
 717     if ( shouldResume )
 718         Resume();
 719
 720     TID hThread = m_internal->GetHandle();
 721
 722     if ( isRunning || IsRunning())
 723     {
 724         if (IsMain())
 725         {
 726             // set flag for wxIsWaitingForThread()
 727             gs_bWaitingForThread = true;
 728         }
 729
 730         // ask the thread to terminate
 731         if ( shouldCancel )
 732         {
 733             wxCriticalSectionLocker lock(m_critsect);
 734
 735             m_internal->Cancel();
 736         }
 737
 738 #if 0
 739         // we can't just wait for the thread to terminate because it might be
 740         // calling some GUI functions and so it will never terminate before we
 741         // process the Windows messages that result from these functions
 742         DWORD result = 0;       // suppress warnings from broken compilers
 743         do
 744         {
 745             if ( IsMain() )
 746             {
 747                 // give the thread we're waiting for chance to do the GUI call
 748                 // it might be in
 749                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 750                 {
 751                     wxMutexGuiLeave();
 752                 }
 753             }
 754
 755             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 756             // FIXME: We ought to have a message processing loop here!!
 757
 758             switch ( result )
 759             {
 760                 case ERROR_INTERRUPT:
 761                 case ERROR_THREAD_NOT_TERMINATED:
 762                     break;
 763                 case ERROR_INVALID_THREADID:
 764                 case NO_ERROR:
 765                     // thread we're waiting for just terminated
 766                     // or even does not exist any more.
 767                     result = NO_ERROR;
 768                     break;
 769                 default:
 770                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 771             }
 772             if ( IsMain() )
 773             {
 774                 // event processing - needed if we are the main thread
 775                 // to give other threads a chance to do remaining GUI
 776                 // processing and terminate cleanly.
 777                 wxTheApp->HandleSockets();
 778                 if (wxTheApp->Pending())
 779                   if ( !wxTheApp->DoMessage() )
 780                   {
 781                       // WM_QUIT received: kill the thread
 782                       Kill();
 783
 784                       return wxTHREAD_KILLED;
 785                   }
 786                   else
 787                     wxUsleep(10);
 788             }
 789             else
 790                 wxUsleep(10);
 791         } while ( result != NO_ERROR );
 792 #else // !wxUSE_GUI
 793         // simply wait for the thread to terminate
 794         //
 795         // OTOH, even console apps create windows (in wxExecute, for WinSock
 796         // &c), so may be use MsgWaitForMultipleObject() too here?
 797         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 798         {
 799             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 800         }
 801 #endif // wxUSE_GUI/!wxUSE_GUI
 802
 803         if ( IsMain() )
 804         {
 805             gs_bWaitingForThread = false;
 806         }
 807     }
 808
 809 #if 0
 810     // although the thread might be already in the EXITED state it might not
 811     // have terminated yet and so we are not sure that it has actually
 812     // terminated if the "if" above hadn't been taken
 813     do
 814     {
 815         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 816         {
 817             wxLogLastError(wxT("GetExitCodeThread"));
 818
 819             rc = (ExitCode)-1;
 820         }
 821     } while ( (DWORD)rc == STILL_ACTIVE );
 822 #endif
 823
 824     if ( IsDetached() )
 825     {
 826         // if the thread exits normally, this is done in WinThreadStart, but in
 827         // this case it would have been too early because
 828         // MsgWaitForMultipleObject() would fail if the thread handle was
 829         // closed while we were waiting on it, so we must do it here
 830         delete this;
 831     }
 832
 833     if ( pRc )
 834         *pRc = rc;
 835
 836     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 837 }
 838
 839 wxThreadError wxThread::Kill()
 840 {
 841     if (!IsRunning())
 842         return wxTHREAD_NOT_RUNNING;
 843
 844     ::DosKillThread(m_internal->GetHandle());
 845     if (IsDetached())
 846     {
 847         delete this;
 848     }
 849     return wxTHREAD_NO_ERROR;
 850 }
 851
 852 void wxThread::Exit(ExitCode WXUNUSED(pStatus))
 853 {
 854     delete this;
 855     _endthread();
 856     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 857 }
 858
 859 void wxThread::SetPriority(
 860   unsigned int                      nPrio
 861 )
 862 {
 863     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 864
 865     m_internal->SetPriority(nPrio);
 866 }
 867
 868 unsigned int wxThread::GetPriority() const
 869 {
 870     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 871
 872     return m_internal->GetPriority();
 873 }
 874
 875 unsigned long wxThread::GetId() const
 876 {
 877     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 878
 879     return (unsigned long)m_internal->GetId();
 880 }
 881
 882 bool wxThread::IsRunning() const
 883 {
 884     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 885
 886     return(m_internal->GetState() == STATE_RUNNING);
 887 }
 888
 889 bool wxThread::IsAlive() const
 890 {
 891     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 892
 893     return (m_internal->GetState() == STATE_RUNNING) ||
 894            (m_internal->GetState() == STATE_PAUSED);
 895 }
 896
 897 bool wxThread::IsPaused() const
 898 {
 899     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 900
 901     return (m_internal->GetState() == STATE_PAUSED);
 902 }
 903
 904 bool wxThread::TestDestroy()
 905 {
 906     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 907
 908     return m_internal->GetState() == STATE_CANCELED;
 909 }
 910
 911 // ----------------------------------------------------------------------------
 912 // Automatic initialization for thread module
 913 // ----------------------------------------------------------------------------
 914
 915 class wxThreadModule : public wxModule
 916 {
 917 public:
 918     virtual bool OnInit();
 919     virtual void OnExit();
 920
 921 private:
 922     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 923 };
 924
 925 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 926
 927 bool wxThreadModule::OnInit()
 928 {
 929     gs_pCritsectWaitingForGui = new wxCriticalSection();
 930
 931     gs_pCritsectGui = new wxCriticalSection();
 932     gs_pCritsectGui->Enter();
 933
 934     PTIB ptib;
 935     PPIB ppib;
 936
 937     ::DosGetInfoBlocks(&ptib, &ppib);
 938
 939     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 940     return true;
 941 }
 942
 943 void wxThreadModule::OnExit()
 944 {
 945     if (gs_pCritsectGui)
 946     {
 947         gs_pCritsectGui->Leave();
 948 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 949         delete gs_pCritsectGui;
 950 #endif
 951         gs_pCritsectGui = NULL;
 952     }
 953
 954 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 955     wxDELETE(gs_pCritsectWaitingForGui);
 956 #endif
 957 }
 958
 959 // ----------------------------------------------------------------------------
 960 // Helper functions
 961 // ----------------------------------------------------------------------------
 962
 963 // wake up the main thread if it's in ::GetMessage()
 964 void WXDLLEXPORT wxWakeUpMainThread()
 965 {
 966 #if 0
 967     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 968     {
 969         // should never happen
 970         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 971     }
 972 #endif
 973 }
 974
 975 void WXDLLEXPORT wxMutexGuiEnter()
 976 {
 977     // this would dead lock everything...
 978     wxASSERT_MSG( !wxThread::IsMain(),
 979                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 980
 981     // the order in which we enter the critical sections here is crucial!!
 982
 983     // set the flag telling to the main thread that we want to do some GUI
 984     {
 985         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 986
 987         gs_nWaitingForGui++;
 988     }
 989
 990     wxWakeUpMainThread();
 991
 992     // now we may block here because the main thread will soon let us in
 993     // (during the next iteration of OnIdle())
 994     gs_pCritsectGui->Enter();
 995 }
 996
 997 void WXDLLEXPORT wxMutexGuiLeave()
 998 {
 999     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1000
1001     if ( wxThread::IsMain() )
1002     {
1003         gs_bGuiOwnedByMainThread = false;
1004     }
1005     else
1006     {
1007         // decrement the number of waiters now
1008         wxASSERT_MSG(gs_nWaitingForGui > 0,
1009                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1010
1011         gs_nWaitingForGui--;
1012
1013         wxWakeUpMainThread();
1014     }
1015
1016     gs_pCritsectGui->Leave();
1017 }
1018
1019 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1020 {
1021     wxASSERT_MSG( wxThread::IsMain(),
1022                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1023
1024     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1025
1026     if (gs_nWaitingForGui == 0)
1027     {
1028         // no threads are waiting for GUI - so we may acquire the lock without
1029         // any danger (but only if we don't already have it)
1030         if (!wxGuiOwnedByMainThread())
1031         {
1032             gs_pCritsectGui->Enter();
1033
1034             gs_bGuiOwnedByMainThread = true;
1035         }
1036         //else: already have it, nothing to do
1037     }
1038     else
1039     {
1040         // some threads are waiting, release the GUI lock if we have it
1041         if (wxGuiOwnedByMainThread())
1042         {
1043             wxMutexGuiLeave();
1044         }
1045         //else: some other worker thread is doing GUI
1046     }
1047 }
1048
1049 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1050 {
1051     return gs_bGuiOwnedByMainThread;
1052 }
1053
1054 bool WXDLLEXPORT wxIsWaitingForThread()
1055 {
1056     return gs_bWaitingForThread;
1057 }
1058
1059 // ----------------------------------------------------------------------------
1060 // include common implementation code
1061 // ----------------------------------------------------------------------------
1062
1063 #include "wx/thrimpl.cpp"
1064
1065 #endif
1066   // wxUSE_THREADS