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 bool WXDLLEXPORT wxGuiOwnedByMainThread();
 531
 532 wxThread *wxThread::This()
 533 {
 534     wxThread*                       pThread = m_pThread;
 535     return pThread;
 536 }
 537
 538 bool wxThread::IsMain()
 539 {
 540     PTIB                            ptib;
 541     PPIB                            ppib;
 542
 543     ::DosGetInfoBlocks(&ptib, &ppib);
 544
 545     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 546         return TRUE;
 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     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 655
 656     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 657 }
 658
 659 // stopping thread
 660 // ---------------
 661
 662 wxThread::ExitCode wxThread::Wait()
 663 {
 664     // although under Windows we can wait for any thread, it's an error to
 665     // wait for a detached one in wxWin API
 666     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 667                  _T("can't wait for detached thread") );
 668     ExitCode rc = (ExitCode)-1;
 669     (void)Delete(&rc);
 670     return(rc);
 671 }
 672
 673 wxThreadError wxThread::Delete(ExitCode *pRc)
 674 {
 675     ExitCode rc = 0;
 676
 677     // Delete() is always safe to call, so consider all possible states
 678
 679     // we might need to resume the thread, but we might also not need to cancel
 680     // it if it doesn't run yet
 681     bool shouldResume = FALSE,
 682          shouldCancel = TRUE,
 683          isRunning = FALSE;
 684
 685     // check if the thread already started to run
 686     {
 687         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 688
 689         if ( m_internal->GetState() == STATE_NEW )
 690         {
 691             // WinThreadStart() will see it and terminate immediately, no need
 692             // to cancel the thread - but we still need to resume it to let it
 693             // run
 694             m_internal->SetState(STATE_EXITED);
 695
 696             Resume();   // it knows about STATE_EXITED special case
 697
 698             shouldCancel = FALSE;
 699             isRunning = TRUE;
 700
 701             // shouldResume is correctly set to FALSE here
 702         }
 703         else
 704         {
 705             shouldResume = IsPaused();
 706         }
 707     }
 708
 709     // resume the thread if it is paused
 710     if ( shouldResume )
 711         Resume();
 712
 713     TID                             hThread = m_internal->GetHandle();
 714
 715     if ( isRunning || IsRunning())
 716     {
 717         if (IsMain())
 718         {
 719             // set flag for wxIsWaitingForThread()
 720             gs_bWaitingForThread = TRUE;
 721         }
 722
 723         // ask the thread to terminate
 724         if ( shouldCancel )
 725         {
 726             wxCriticalSectionLocker lock(m_critsect);
 727
 728             m_internal->Cancel();
 729         }
 730
 731 #if wxUSE_GUI
 732         // we can't just wait for the thread to terminate because it might be
 733         // calling some GUI functions and so it will never terminate before we
 734         // process the Windows messages that result from these functions
 735         DWORD result = 0;       // suppress warnings from broken compilers
 736         do
 737         {
 738             if ( IsMain() )
 739             {
 740                 // give the thread we're waiting for chance to do the GUI call
 741                 // it might be in
 742                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 743                 {
 744                     wxMutexGuiLeave();
 745                 }
 746             }
 747
 748             result = ::DosWaitThread(&hThread, DCWW_WAIT);
 749             // FIXME: We ought to have a message processing loop here!!
 750
 751             switch ( result )
 752             {
 753                 case ERROR_THREAD_NOT_TERMINATED:
 754                 case ERROR_INVALID_THREADID:
 755                     // error
 756                     wxLogSysError(_("Can not wait for thread termination"));
 757                     Kill();
 758                     return wxTHREAD_KILLED;
 759
 760                 case NO_ERROR:
 761                     // thread we're waiting for terminated
 762                     break;
 763
 764                 default:
 765                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 766             }
 767         } while ( result != NO_ERROR );
 768 #else // !wxUSE_GUI
 769         // simply wait for the thread to terminate
 770         //
 771         // OTOH, even console apps create windows (in wxExecute, for WinSock
 772         // &c), so may be use MsgWaitForMultipleObject() too here?
 773         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 774         {
 775             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 776         }
 777 #endif // wxUSE_GUI/!wxUSE_GUI
 778
 779         if ( IsMain() )
 780         {
 781             gs_bWaitingForThread = FALSE;
 782         }
 783     }
 784
 785 #if 0
 786     // although the thread might be already in the EXITED state it might not
 787     // have terminated yet and so we are not sure that it has actually
 788     // terminated if the "if" above hadn't been taken
 789     do
 790     {
 791         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 792         {
 793             wxLogLastError(wxT("GetExitCodeThread"));
 794
 795             rc = (ExitCode)-1;
 796         }
 797     } while ( (DWORD)rc == STILL_ACTIVE );
 798 #endif
 799
 800     if ( IsDetached() )
 801     {
 802         // if the thread exits normally, this is done in WinThreadStart, but in
 803         // this case it would have been too early because
 804         // MsgWaitForMultipleObject() would fail if the thread handle was
 805         // closed while we were waiting on it, so we must do it here
 806         delete this;
 807     }
 808
 809     if ( pRc )
 810         *pRc = rc;
 811
 812     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 813 }
 814
 815 wxThreadError wxThread::Kill()
 816 {
 817     if (!IsRunning())
 818         return wxTHREAD_NOT_RUNNING;
 819
 820     ::DosKillThread(m_internal->GetHandle());
 821     if (IsDetached())
 822     {
 823         delete this;
 824     }
 825     return wxTHREAD_NO_ERROR;
 826 }
 827
 828 void wxThread::Exit(
 829   ExitCode                          pStatus
 830 )
 831 {
 832     delete this;
 833     ::DosExit(EXIT_THREAD, ULONG(pStatus));
 834     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 835 }
 836
 837 void wxThread::SetPriority(
 838   unsigned int                      nPrio
 839 )
 840 {
 841     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 842
 843     m_internal->SetPriority(nPrio);
 844 }
 845
 846 unsigned int wxThread::GetPriority() const
 847 {
 848     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 849
 850     return m_internal->GetPriority();
 851 }
 852
 853 unsigned long wxThread::GetId() const
 854 {
 855     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 856
 857     return (unsigned long)m_internal->GetId();
 858 }
 859
 860 bool wxThread::IsRunning() const
 861 {
 862     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 863
 864     return(m_internal->GetState() == STATE_RUNNING);
 865 }
 866
 867 bool wxThread::IsAlive() const
 868 {
 869     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 870
 871     return (m_internal->GetState() == STATE_RUNNING) ||
 872            (m_internal->GetState() == STATE_PAUSED);
 873 }
 874
 875 bool wxThread::IsPaused() const
 876 {
 877     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 878
 879     return (m_internal->GetState() == STATE_PAUSED);
 880 }
 881
 882 bool wxThread::TestDestroy()
 883 {
 884     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 885
 886     return m_internal->GetState() == STATE_CANCELED;
 887 }
 888
 889 // ----------------------------------------------------------------------------
 890 // Automatic initialization for thread module
 891 // ----------------------------------------------------------------------------
 892
 893 class wxThreadModule : public wxModule
 894 {
 895 public:
 896     virtual bool OnInit();
 897     virtual void OnExit();
 898
 899 private:
 900     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 901 };
 902
 903 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 904
 905 bool wxThreadModule::OnInit()
 906 {
 907     gs_pCritsectWaitingForGui = new wxCriticalSection();
 908
 909     gs_pCritsectGui = new wxCriticalSection();
 910     gs_pCritsectGui->Enter();
 911
 912     PTIB                            ptib;
 913     PPIB                            ppib;
 914
 915     ::DosGetInfoBlocks(&ptib, &ppib);
 916
 917     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 918     return TRUE;
 919 }
 920
 921 void wxThreadModule::OnExit()
 922 {
 923     if (gs_pCritsectGui)
 924     {
 925         gs_pCritsectGui->Leave();
 926 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 927         delete gs_pCritsectGui;
 928 #endif
 929         gs_pCritsectGui = NULL;
 930     }
 931
 932 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 933     wxDELETE(gs_pCritsectWaitingForGui);
 934 #endif
 935 }
 936
 937 // ----------------------------------------------------------------------------
 938 // Helper functions
 939 // ----------------------------------------------------------------------------
 940
 941 // wake up the main thread if it's in ::GetMessage()
 942 void WXDLLEXPORT wxWakeUpMainThread()
 943 {
 944 #if 0
 945     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 946     {
 947         // should never happen
 948         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 949     }
 950 #endif
 951 }
 952
 953 void WXDLLEXPORT wxMutexGuiEnter()
 954 {
 955     // this would dead lock everything...
 956     wxASSERT_MSG( !wxThread::IsMain(),
 957                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 958
 959     // the order in which we enter the critical sections here is crucial!!
 960
 961     // set the flag telling to the main thread that we want to do some GUI
 962     {
 963         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 964
 965         gs_nWaitingForGui++;
 966     }
 967
 968     wxWakeUpMainThread();
 969
 970     // now we may block here because the main thread will soon let us in
 971     // (during the next iteration of OnIdle())
 972     gs_pCritsectGui->Enter();
 973 }
 974
 975 void WXDLLEXPORT wxMutexGuiLeave()
 976 {
 977     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 978
 979     if ( wxThread::IsMain() )
 980     {
 981         gs_bGuiOwnedByMainThread = FALSE;
 982     }
 983     else
 984     {
 985         // decrement the number of waiters now
 986         wxASSERT_MSG(gs_nWaitingForGui > 0,
 987                       wxT("calling wxMutexGuiLeave() without entering it first?") );
 988
 989         gs_nWaitingForGui--;
 990
 991         wxWakeUpMainThread();
 992     }
 993
 994     gs_pCritsectGui->Leave();
 995 }
 996
 997 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
 998 {
 999     wxASSERT_MSG( wxThread::IsMain(),
1000                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1001
1002     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1003
1004     if (gs_nWaitingForGui == 0)
1005     {
1006         // no threads are waiting for GUI - so we may acquire the lock without
1007         // any danger (but only if we don't already have it)
1008         if (!wxGuiOwnedByMainThread())
1009         {
1010             gs_pCritsectGui->Enter();
1011
1012             gs_bGuiOwnedByMainThread = TRUE;
1013         }
1014         //else: already have it, nothing to do
1015     }
1016     else
1017     {
1018         // some threads are waiting, release the GUI lock if we have it
1019         if (wxGuiOwnedByMainThread())
1020         {
1021             wxMutexGuiLeave();
1022         }
1023         //else: some other worker thread is doing GUI
1024     }
1025 }
1026
1027 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1028 {
1029     return gs_bGuiOwnedByMainThread;
1030 }
1031
1032 bool WXDLLEXPORT wxIsWaitingForThread()
1033 {
1034     return gs_bWaitingForThread;
1035 }
1036
1037 // ----------------------------------------------------------------------------
1038 // include common implementation code
1039 // ----------------------------------------------------------------------------
1040
1041 #include "wx/thrimpl.cpp"
1042
1043 #endif
1044   // wxUSE_THREADS