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 void OS2ThreadStart(void* pParam);
 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 void wxThreadInternal::OS2ThreadStart(
 392   void * pParam
 393 )
 394 {
 395     DWORD                           dwRet;
 396     bool bWasCancelled;
 397
 398     wxThread *pThread = (wxThread *)pParam;
 399
 400     // first of all, wait for the thread to be started.
 401     pThread->m_critsect.Enter();
 402     pThread->m_critsect.Leave();
 403     // Now check whether we hadn't been cancelled already and don't
 404     // start the user code at all in this case.
 405     if ( pThread->m_internal->GetState() == STATE_EXITED )
 406     {
 407         dwRet = (DWORD)-1;
 408         bWasCancelled = TRUE;
 409     }
 410     else // do run thread
 411     {
 412         HAB     vHab;
 413         vHab = ::WinInitialize(0);
 414         dwRet = (DWORD)pThread->Entry();
 415         ::WinTerminate(vHab);
 416
 417         // enter m_critsect before changing the thread state
 418         pThread->m_critsect.Enter();
 419
 420         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 421
 422         pThread->m_internal->SetState(STATE_EXITED);
 423         pThread->m_critsect.Leave();
 424     }
 425     pThread->OnExit();
 426
 427     // if the thread was cancelled (from Delete()), then it the handle is still
 428     // needed there
 429     if (pThread->IsDetached() && !bWasCancelled)
 430     {
 431         // auto delete
 432         delete pThread;
 433     }
 434     //else: the joinable threads handle will be closed when Wait() is done
 435     return;
 436 }
 437
 438 void wxThreadInternal::SetPriority(
 439   unsigned int                      nPriority
 440 )
 441 {
 442     // translate wxWindows priority to the PM one
 443     ULONG                           ulOS2_PriorityClass;
 444     ULONG                           ulOS2_SubPriority;
 445     ULONG                           ulrc;
 446
 447     m_nPriority = nPriority;
 448     if (m_nPriority <= 25)
 449         ulOS2_PriorityClass = PRTYC_IDLETIME;
 450     else if (m_nPriority <= 50)
 451         ulOS2_PriorityClass = PRTYC_REGULAR;
 452     else if (m_nPriority <= 75)
 453         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 454     else if (m_nPriority <= 100)
 455         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 456     else
 457     {
 458         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 459         ulOS2_PriorityClass = PRTYC_REGULAR;
 460     }
 461     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 462     ulrc = ::DosSetPriority( PRTYS_THREAD
 463                             ,ulOS2_PriorityClass
 464                             ,ulOS2_SubPriority
 465                             ,(ULONG)m_hThread
 466                            );
 467     if (ulrc != 0)
 468     {
 469         wxLogSysError(_("Can't set thread priority"));
 470     }
 471 }
 472
 473 bool wxThreadInternal::Create(
 474   wxThread*                         pThread
 475 , unsigned int                      uStackSize
 476 )
 477 {
 478     int                          tid;
 479
 480     if (!uStackSize)
 481       uStackSize = 131072;
 482     pThread->m_critsect.Enter();
 483     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 484                              NULL, uStackSize, pThread);
 485     if(tid == -1)
 486     {
 487         wxLogSysError(_("Can't create thread"));
 488
 489         return FALSE;
 490     }
 491     m_hThread = tid;
 492     if (m_nPriority != WXTHREAD_DEFAULT_PRIORITY)
 493     {
 494         SetPriority(m_nPriority);
 495     }
 496
 497     return(TRUE);
 498 }
 499
 500 bool wxThreadInternal::Suspend()
 501 {
 502     ULONG                           ulrc = ::DosSuspendThread(m_hThread);
 503
 504     if (ulrc != 0)
 505     {
 506         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 507         return FALSE;
 508     }
 509     m_eState = STATE_PAUSED;
 510     return TRUE;
 511 }
 512
 513 bool wxThreadInternal::Resume()
 514 {
 515     ULONG                           ulrc = ::DosResumeThread(m_hThread);
 516
 517     if (ulrc != 0)
 518     {
 519         wxLogSysError(_("Can not resume thread %lu"), m_hThread);
 520         return FALSE;
 521     }
 522
 523     // don't change the state from STATE_EXITED because it's special and means
 524     // we are going to terminate without running any user code - if we did it,
 525     // the codei n Delete() wouldn't work
 526     if ( m_eState != STATE_EXITED )
 527     {
 528         m_eState = STATE_RUNNING;
 529     }
 530
 531     return TRUE;
 532 }
 533
 534 // static functions
 535 // ----------------
 536
 537 wxThread *wxThread::This()
 538 {
 539     wxThread*                       pThread = m_pThread;
 540     return pThread;
 541 }
 542
 543 bool wxThread::IsMain()
 544 {
 545     PTIB                            ptib;
 546     PPIB                            ppib;
 547
 548     ::DosGetInfoBlocks(&ptib, &ppib);
 549
 550     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 551         return TRUE;
 552     return FALSE;
 553 }
 554
 555 #ifdef Yield
 556     #undef Yield
 557 #endif
 558
 559 void wxThread::Yield()
 560 {
 561     ::DosSleep(0);
 562 }
 563
 564 void wxThread::Sleep(
 565   unsigned long                     ulMilliseconds
 566 )
 567 {
 568     ::DosSleep(ulMilliseconds);
 569 }
 570
 571 int wxThread::GetCPUCount()
 572 {
 573     ULONG CPUCount;
 574     APIRET ulrc;
 575     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 576     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 577
 578     if (ulrc != 0)
 579         CPUCount = 1;
 580
 581     return CPUCount;
 582 }
 583
 584 unsigned long wxThread::GetCurrentId()
 585 {
 586     PTIB                            ptib;
 587     PPIB                            ppib;
 588
 589     ::DosGetInfoBlocks(&ptib, &ppib);
 590     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 591 }
 592
 593 bool wxThread::SetConcurrency(size_t level)
 594 {
 595     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 596
 597     // ok only for the default one
 598     if ( level == 0 )
 599         return 0;
 600
 601     // Don't know how to realize this on OS/2.
 602     return level == 1;
 603 }
 604
 605 // ctor and dtor
 606 // -------------
 607
 608 wxThread::wxThread(wxThreadKind kind)
 609 {
 610     m_internal = new wxThreadInternal();
 611
 612     m_isDetached = kind == wxTHREAD_DETACHED;
 613 }
 614
 615 wxThread::~wxThread()
 616 {
 617     delete m_internal;
 618 }
 619
 620 // create/start thread
 621 // -------------------
 622
 623 wxThreadError wxThread::Create(
 624   unsigned int                      uStackSize
 625 )
 626 {
 627     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 628
 629     if ( !m_internal->Create(this, uStackSize) )
 630         return wxTHREAD_NO_RESOURCE;
 631
 632     return wxTHREAD_NO_ERROR;
 633 }
 634
 635 wxThreadError wxThread::Run()
 636 {
 637     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 638
 639     if ( m_internal->GetState() != STATE_NEW )
 640     {
 641         // actually, it may be almost any state at all, not only STATE_RUNNING
 642         return wxTHREAD_RUNNING;
 643     }
 644     return Resume();
 645 }
 646
 647 // suspend/resume thread
 648 // ---------------------
 649
 650 wxThreadError wxThread::Pause()
 651 {
 652     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 653
 654     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 655 }
 656
 657 wxThreadError wxThread::Resume()
 658 {
 659     if (m_internal->GetState() == STATE_NEW)
 660     {
 661         m_internal->SetState(STATE_RUNNING);
 662         m_critsect.Leave();
 663         return wxTHREAD_NO_ERROR;
 664     }
 665
 666     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 667
 668     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 669 }
 670
 671 // stopping thread
 672 // ---------------
 673
 674 wxThread::ExitCode wxThread::Wait()
 675 {
 676     // although under Windows we can wait for any thread, it's an error to
 677     // wait for a detached one in wxWin API
 678     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 679                  _T("can't wait for detached thread") );
 680     ExitCode rc = (ExitCode)-1;
 681     (void)Delete(&rc);
 682     return(rc);
 683 }
 684
 685 wxThreadError wxThread::Delete(ExitCode *pRc)
 686 {
 687     ExitCode rc = 0;
 688
 689     // Delete() is always safe to call, so consider all possible states
 690
 691     // we might need to resume the thread, but we might also not need to cancel
 692     // it if it doesn't run yet
 693     bool shouldResume = FALSE,
 694          shouldCancel = TRUE,
 695          isRunning = FALSE;
 696
 697     // check if the thread already started to run
 698     {
 699         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 700
 701         if ( m_internal->GetState() == STATE_NEW )
 702         {
 703             // WinThreadStart() will see it and terminate immediately, no need
 704             // to cancel the thread - but we still need to resume it to let it
 705             // run
 706             m_internal->SetState(STATE_EXITED);
 707
 708             Resume();   // it knows about STATE_EXITED special case
 709
 710             shouldCancel = FALSE;
 711             isRunning = TRUE;
 712
 713             // shouldResume is correctly set to FALSE here
 714         }
 715         else
 716         {
 717             shouldResume = IsPaused();
 718         }
 719     }
 720
 721     // resume the thread if it is paused
 722     if ( shouldResume )
 723         Resume();
 724
 725     TID                             hThread = m_internal->GetHandle();
 726
 727     if ( isRunning || IsRunning())
 728     {
 729         if (IsMain())
 730         {
 731             // set flag for wxIsWaitingForThread()
 732             gs_bWaitingForThread = TRUE;
 733         }
 734
 735         // ask the thread to terminate
 736         if ( shouldCancel )
 737         {
 738             wxCriticalSectionLocker lock(m_critsect);
 739
 740             m_internal->Cancel();
 741         }
 742
 743 #if wxUSE_GUI
 744         // we can't just wait for the thread to terminate because it might be
 745         // calling some GUI functions and so it will never terminate before we
 746         // process the Windows messages that result from these functions
 747         DWORD result = 0;       // suppress warnings from broken compilers
 748         do
 749         {
 750             if ( IsMain() )
 751             {
 752                 // give the thread we're waiting for chance to do the GUI call
 753                 // it might be in
 754                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 755                 {
 756                     wxMutexGuiLeave();
 757                 }
 758             }
 759
 760             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 761             // FIXME: We ought to have a message processing loop here!!
 762
 763             switch ( result )
 764             {
 765                 case ERROR_INTERRUPT:
 766                 case ERROR_THREAD_NOT_TERMINATED:
 767                     break;
 768                 case ERROR_INVALID_THREADID:
 769                 case NO_ERROR:
 770                     // thread we're waiting for just terminated
 771                     // or even does not exist any more.
 772                     result = NO_ERROR;
 773                     break;
 774                 default:
 775                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 776             }
 777             if ( IsMain() )
 778             {
 779                 // event processing - needed if we are the main thread
 780                 // to give other threads a chance to do remaining GUI
 781                 // processing and terminate cleanly.
 782                 wxTheApp->HandleSockets();
 783                 if (wxTheApp->Pending())
 784                   if ( !wxTheApp->DoMessage() )
 785                   {
 786                       // WM_QUIT received: kill the thread
 787                       Kill();
 788
 789                       return wxTHREAD_KILLED;
 790                   }
 791                   else
 792                     wxUsleep(10);
 793             }
 794             else
 795                 wxUsleep(10);
 796         } while ( result != NO_ERROR );
 797 #else // !wxUSE_GUI
 798         // simply wait for the thread to terminate
 799         //
 800         // OTOH, even console apps create windows (in wxExecute, for WinSock
 801         // &c), so may be use MsgWaitForMultipleObject() too here?
 802         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 803         {
 804             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 805         }
 806 #endif // wxUSE_GUI/!wxUSE_GUI
 807
 808         if ( IsMain() )
 809         {
 810             gs_bWaitingForThread = FALSE;
 811         }
 812     }
 813
 814 #if 0
 815     // although the thread might be already in the EXITED state it might not
 816     // have terminated yet and so we are not sure that it has actually
 817     // terminated if the "if" above hadn't been taken
 818     do
 819     {
 820         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 821         {
 822             wxLogLastError(wxT("GetExitCodeThread"));
 823
 824             rc = (ExitCode)-1;
 825         }
 826     } while ( (DWORD)rc == STILL_ACTIVE );
 827 #endif
 828
 829     if ( IsDetached() )
 830     {
 831         // if the thread exits normally, this is done in WinThreadStart, but in
 832         // this case it would have been too early because
 833         // MsgWaitForMultipleObject() would fail if the thread handle was
 834         // closed while we were waiting on it, so we must do it here
 835         delete this;
 836     }
 837
 838     if ( pRc )
 839         *pRc = rc;
 840
 841     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 842 }
 843
 844 wxThreadError wxThread::Kill()
 845 {
 846     if (!IsRunning())
 847         return wxTHREAD_NOT_RUNNING;
 848
 849     ::DosKillThread(m_internal->GetHandle());
 850     if (IsDetached())
 851     {
 852         delete this;
 853     }
 854     return wxTHREAD_NO_ERROR;
 855 }
 856
 857 void wxThread::Exit(
 858   ExitCode                          pStatus
 859 )
 860 {
 861     delete this;
 862     _endthread();
 863     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 864 }
 865
 866 void wxThread::SetPriority(
 867   unsigned int                      nPrio
 868 )
 869 {
 870     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 871
 872     m_internal->SetPriority(nPrio);
 873 }
 874
 875 unsigned int wxThread::GetPriority() const
 876 {
 877     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 878
 879     return m_internal->GetPriority();
 880 }
 881
 882 unsigned long wxThread::GetId() const
 883 {
 884     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 885
 886     return (unsigned long)m_internal->GetId();
 887 }
 888
 889 bool wxThread::IsRunning() const
 890 {
 891     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 892
 893     return(m_internal->GetState() == STATE_RUNNING);
 894 }
 895
 896 bool wxThread::IsAlive() const
 897 {
 898     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 899
 900     return (m_internal->GetState() == STATE_RUNNING) ||
 901            (m_internal->GetState() == STATE_PAUSED);
 902 }
 903
 904 bool wxThread::IsPaused() const
 905 {
 906     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 907
 908     return (m_internal->GetState() == STATE_PAUSED);
 909 }
 910
 911 bool wxThread::TestDestroy()
 912 {
 913     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 914
 915     return m_internal->GetState() == STATE_CANCELED;
 916 }
 917
 918 // ----------------------------------------------------------------------------
 919 // Automatic initialization for thread module
 920 // ----------------------------------------------------------------------------
 921
 922 class wxThreadModule : public wxModule
 923 {
 924 public:
 925     virtual bool OnInit();
 926     virtual void OnExit();
 927
 928 private:
 929     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 930 };
 931
 932 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 933
 934 bool wxThreadModule::OnInit()
 935 {
 936     gs_pCritsectWaitingForGui = new wxCriticalSection();
 937
 938     gs_pCritsectGui = new wxCriticalSection();
 939     gs_pCritsectGui->Enter();
 940
 941     PTIB                            ptib;
 942     PPIB                            ppib;
 943
 944     ::DosGetInfoBlocks(&ptib, &ppib);
 945
 946     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 947     return TRUE;
 948 }
 949
 950 void wxThreadModule::OnExit()
 951 {
 952     if (gs_pCritsectGui)
 953     {
 954         gs_pCritsectGui->Leave();
 955 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 956         delete gs_pCritsectGui;
 957 #endif
 958         gs_pCritsectGui = NULL;
 959     }
 960
 961 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 962     wxDELETE(gs_pCritsectWaitingForGui);
 963 #endif
 964 }
 965
 966 // ----------------------------------------------------------------------------
 967 // Helper functions
 968 // ----------------------------------------------------------------------------
 969
 970 // wake up the main thread if it's in ::GetMessage()
 971 void WXDLLEXPORT wxWakeUpMainThread()
 972 {
 973 #if 0
 974     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 975     {
 976         // should never happen
 977         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 978     }
 979 #endif
 980 }
 981
 982 void WXDLLEXPORT wxMutexGuiEnter()
 983 {
 984     // this would dead lock everything...
 985     wxASSERT_MSG( !wxThread::IsMain(),
 986                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 987
 988     // the order in which we enter the critical sections here is crucial!!
 989
 990     // set the flag telling to the main thread that we want to do some GUI
 991     {
 992         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 993
 994         gs_nWaitingForGui++;
 995     }
 996
 997     wxWakeUpMainThread();
 998
 999     // now we may block here because the main thread will soon let us in
1000     // (during the next iteration of OnIdle())
1001     gs_pCritsectGui->Enter();
1002 }
1003
1004 void WXDLLEXPORT wxMutexGuiLeave()
1005 {
1006     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1007
1008     if ( wxThread::IsMain() )
1009     {
1010         gs_bGuiOwnedByMainThread = FALSE;
1011     }
1012     else
1013     {
1014         // decrement the number of waiters now
1015         wxASSERT_MSG(gs_nWaitingForGui > 0,
1016                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1017
1018         gs_nWaitingForGui--;
1019
1020         wxWakeUpMainThread();
1021     }
1022
1023     gs_pCritsectGui->Leave();
1024 }
1025
1026 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1027 {
1028     wxASSERT_MSG( wxThread::IsMain(),
1029                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1030
1031     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1032
1033     if (gs_nWaitingForGui == 0)
1034     {
1035         // no threads are waiting for GUI - so we may acquire the lock without
1036         // any danger (but only if we don't already have it)
1037         if (!wxGuiOwnedByMainThread())
1038         {
1039             gs_pCritsectGui->Enter();
1040
1041             gs_bGuiOwnedByMainThread = TRUE;
1042         }
1043         //else: already have it, nothing to do
1044     }
1045     else
1046     {
1047         // some threads are waiting, release the GUI lock if we have it
1048         if (wxGuiOwnedByMainThread())
1049         {
1050             wxMutexGuiLeave();
1051         }
1052         //else: some other worker thread is doing GUI
1053     }
1054 }
1055
1056 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1057 {
1058     return gs_bGuiOwnedByMainThread;
1059 }
1060
1061 bool WXDLLEXPORT wxIsWaitingForThread()
1062 {
1063     return gs_bWaitingForThread;
1064 }
1065
1066 // ----------------------------------------------------------------------------
1067 // include common implementation code
1068 // ----------------------------------------------------------------------------
1069
1070 #include "wx/thrimpl.cpp"
1071
1072 #endif
1073   // wxUSE_THREADS