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/apptrait.h"
  30 #include "wx/module.h"
  31 #include "wx/intl.h"
  32 #include "wx/utils.h"
  33 #include "wx/log.h"
  34 #include "wx/thread.h"
  35
  36 #define INCL_DOSSEMAPHORES
  37 #define INCL_DOSPROCESS
  38 #define INCL_DOSMISC
  39 #define INCL_ERRORS
  40 #include <os2.h>
  41 #ifndef __EMX__
  42 #include <bseerr.h>
  43 #endif
  44 // the possible states of the thread ("=>" shows all possible transitions from
  45 // this state)
  46 enum wxThreadState
  47 {
  48     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  49     STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
  50     STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
  51     STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
  52     STATE_EXITED        // thread is terminating
  53 };
  54
  55 // ----------------------------------------------------------------------------
  56 // this module's globals
  57 // ----------------------------------------------------------------------------
  58
  59 // id of the main thread - the one which can call GUI functions without first
  60 // calling wxMutexGuiEnter()
  61 static ULONG                        s_ulIdMainThread = 1;
  62 wxMutex*                            p_wxMainMutex;
  63
  64 // OS2 substitute for Tls pointer the current parent thread object
  65 wxThread*                           m_pThread;    // pointer to the wxWidgets thread object
  66
  67 // if it's false, some secondary thread is holding the GUI lock
  68 static bool gs_bGuiOwnedByMainThread = true;
  69
  70 // critical section which controls access to all GUI functions: any secondary
  71 // thread (i.e. except the main one) must enter this crit section before doing
  72 // any GUI calls
  73 static wxCriticalSection *gs_pCritsectGui = NULL;
  74
  75 // critical section which protects s_nWaitingForGui variable
  76 static wxCriticalSection *gs_pCritsectWaitingForGui = NULL;
  77
  78 // number of threads waiting for GUI in wxMutexGuiEnter()
  79 static size_t gs_nWaitingForGui = 0;
  80
  81 // are we waiting for a thread termination?
  82 static bool gs_bWaitingForThread = false;
  83
  84 // ============================================================================
  85 // OS/2 implementation of thread and related classes
  86 // ============================================================================
  87
  88 // ----------------------------------------------------------------------------
  89 // wxMutex implementation
  90 // ----------------------------------------------------------------------------
  91 class wxMutexInternal
  92 {
  93 public:
  94     wxMutexInternal(wxMutexType mutexType);
  95     ~wxMutexInternal();
  96
  97     bool IsOk() const { return m_vMutex != NULL; }
  98
  99     wxMutexError Lock() { return LockTimeout(SEM_INDEFINITE_WAIT); }
 100     wxMutexError TryLock() { return LockTimeout(SEM_IMMEDIATE_RETURN); }
 101     wxMutexError Unlock();
 102
 103 private:
 104     wxMutexError LockTimeout(ULONG ulMilliseconds);
 105     HMTX                            m_vMutex;
 106 };
 107
 108 // all mutexes are "pseudo-"recursive under OS2 so we don't use mutexType
 109 // (Calls to DosRequestMutexSem and DosReleaseMutexSem can be nested, but
 110 //  the request count for a semaphore cannot exceed 65535. If an attempt is
 111 //  made to exceed this number, ERROR_TOO_MANY_SEM_REQUESTS is returned.)
 112 wxMutexInternal::wxMutexInternal(wxMutexType WXUNUSED(eMutexType))
 113 {
 114     APIRET ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 115     if (ulrc != 0)
 116     {
 117         wxLogSysError(_("Can not create mutex."));
 118         m_vMutex = NULL;
 119     }
 120 }
 121
 122 wxMutexInternal::~wxMutexInternal()
 123 {
 124     if (m_vMutex)
 125     {
 126         if (::DosCloseMutexSem(m_vMutex))
 127             wxLogLastError(_T("DosCloseMutexSem(mutex)"));
 128     }
 129 }
 130
 131 wxMutexError wxMutexInternal::LockTimeout(ULONG ulMilliseconds)
 132 {
 133     APIRET                          ulrc;
 134
 135     ulrc = ::DosRequestMutexSem(m_vMutex, ulMilliseconds);
 136
 137     switch (ulrc)
 138     {
 139         case ERROR_TIMEOUT:
 140         case ERROR_TOO_MANY_SEM_REQUESTS:
 141             return wxMUTEX_BUSY;
 142
 143         case NO_ERROR:
 144             // ok
 145             break;
 146
 147         case ERROR_INVALID_HANDLE:
 148         case ERROR_INTERRUPT:
 149         case ERROR_SEM_OWNER_DIED:
 150             wxLogSysError(_("Couldn't acquire a mutex lock"));
 151             return wxMUTEX_MISC_ERROR;
 152
 153         default:
 154             wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
 155             return wxMUTEX_MISC_ERROR;
 156      }
 157     return wxMUTEX_NO_ERROR;
 158 }
 159
 160 wxMutexError wxMutexInternal::Unlock()
 161 {
 162     APIRET                          ulrc;
 163
 164     ulrc = ::DosReleaseMutexSem(m_vMutex);
 165     if (ulrc != 0)
 166     {
 167         wxLogSysError(_("Couldn't release a mutex"));
 168         return wxMUTEX_MISC_ERROR;
 169     }
 170     return wxMUTEX_NO_ERROR;
 171 }
 172
 173 // --------------------------------------------------------------------------
 174 // wxSemaphore
 175 // --------------------------------------------------------------------------
 176
 177 // a trivial wrapper around OS2 event semaphore
 178 class wxSemaphoreInternal
 179 {
 180 public:
 181     wxSemaphoreInternal(int initialcount, int maxcount);
 182     ~wxSemaphoreInternal();
 183
 184     bool IsOk() const { return m_vEvent != NULL; }
 185
 186     wxSemaError Wait() { return WaitTimeout(SEM_INDEFINITE_WAIT); }
 187     wxSemaError TryWait() { return WaitTimeout(SEM_IMMEDIATE_RETURN); }
 188     wxSemaError WaitTimeout(unsigned long milliseconds);
 189
 190     wxSemaError Post();
 191
 192 private:
 193     HEV m_vEvent;
 194     HMTX m_vMutex;
 195     int m_count;
 196     int m_maxcount;
 197 };
 198
 199 wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
 200 {
 201     APIRET ulrc;
 202     if ( maxcount == 0 )
 203     {
 204         // make it practically infinite
 205         maxcount = INT_MAX;
 206     }
 207
 208     m_count = initialcount;
 209     m_maxcount = maxcount;
 210     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 211     if (ulrc != 0)
 212     {
 213         wxLogLastError(_T("DosCreateMutexSem()"));
 214         m_vMutex = NULL;
 215         m_vEvent = NULL;
 216         return;
 217     }
 218     ulrc = ::DosCreateEventSem(NULL, &m_vEvent, 0L, FALSE);
 219     if ( ulrc != 0)
 220     {
 221         wxLogLastError(_T("DosCreateEventSem()"));
 222         ::DosCloseMutexSem(m_vMutex);
 223         m_vMutex = NULL;
 224         m_vEvent = NULL;
 225     }
 226     if (initialcount)
 227         ::DosPostEventSem(m_vEvent);
 228 }
 229
 230 wxSemaphoreInternal::~wxSemaphoreInternal()
 231 {
 232     if ( m_vEvent )
 233     {
 234         if ( ::DosCloseEventSem(m_vEvent) )
 235         {
 236             wxLogLastError(_T("DosCloseEventSem(semaphore)"));
 237         }
 238         if ( ::DosCloseMutexSem(m_vMutex) )
 239         {
 240             wxLogLastError(_T("DosCloseMutexSem(semaphore)"));
 241         }
 242         else
 243             m_vEvent = NULL;
 244     }
 245 }
 246
 247 wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long ulMilliseconds)
 248 {
 249     APIRET ulrc;
 250     do {
 251         ulrc = ::DosWaitEventSem(m_vEvent, ulMilliseconds );
 252         switch ( ulrc )
 253         {
 254             case NO_ERROR:
 255                 break;
 256
 257             case ERROR_TIMEOUT:
 258                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 259                     return wxSEMA_BUSY;
 260                 else
 261                     return wxSEMA_TIMEOUT;
 262
 263             default:
 264                 wxLogLastError(_T("DosWaitEventSem(semaphore)"));
 265                 return wxSEMA_MISC_ERROR;
 266         }
 267         ulrc = :: DosRequestMutexSem(m_vMutex, ulMilliseconds);
 268         switch ( ulrc )
 269         {
 270             case NO_ERROR:
 271                 // ok
 272                 break;
 273
 274             case ERROR_TIMEOUT:
 275             case ERROR_TOO_MANY_SEM_REQUESTS:
 276                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 277                     return wxSEMA_BUSY;
 278                 else
 279                     return wxSEMA_TIMEOUT;
 280
 281             default:
 282                 wxFAIL_MSG(wxT("DosRequestMutexSem(mutex)"));
 283                 return wxSEMA_MISC_ERROR;
 284         }
 285         bool OK = false;
 286         if (m_count > 0)
 287         {
 288             m_count--;
 289             OK = true;
 290         }
 291         else
 292         {
 293             ULONG ulPostCount;
 294             ::DosResetEventSem(m_vEvent, &ulPostCount);
 295         }
 296         ::DosReleaseMutexSem(m_vMutex);
 297         if (OK)
 298             return wxSEMA_NO_ERROR;
 299     } while (ulMilliseconds == SEM_INDEFINITE_WAIT);
 300
 301     if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 302         return wxSEMA_BUSY;
 303     return wxSEMA_TIMEOUT;
 304 }
 305
 306 wxSemaError wxSemaphoreInternal::Post()
 307 {
 308     APIRET ulrc;
 309     ulrc = ::DosRequestMutexSem(m_vMutex, SEM_INDEFINITE_WAIT);
 310     if (ulrc != NO_ERROR)
 311         return wxSEMA_MISC_ERROR;
 312     bool OK = false;
 313     if (m_count < m_maxcount)
 314     {
 315         m_count++;
 316         ulrc = ::DosPostEventSem(m_vEvent);
 317         OK = true;
 318     }
 319     ::DosReleaseMutexSem(m_vMutex);
 320     if (!OK)
 321         return wxSEMA_OVERFLOW;
 322     if ( ulrc != NO_ERROR && ulrc != ERROR_ALREADY_POSTED )
 323     {
 324         wxLogLastError(_T("DosPostEventSem(semaphore)"));
 325
 326         return wxSEMA_MISC_ERROR;
 327     }
 328
 329     return wxSEMA_NO_ERROR;
 330 }
 331
 332 // ----------------------------------------------------------------------------
 333 // wxThread implementation
 334 // ----------------------------------------------------------------------------
 335
 336 // wxThreadInternal class
 337 // ----------------------
 338
 339 class wxThreadInternal
 340 {
 341 public:
 342     inline wxThreadInternal()
 343     {
 344         m_hThread = 0;
 345         m_eState = STATE_NEW;
 346         m_nPriority = WXTHREAD_DEFAULT_PRIORITY;
 347     }
 348
 349     ~wxThreadInternal()
 350     {
 351         m_hThread = 0;
 352     }
 353
 354     // create a new (suspended) thread (for the given thread object)
 355     bool Create( wxThread*    pThread
 356                 ,unsigned int uStackSize
 357                );
 358
 359     // suspend/resume/terminate
 360     bool Suspend();
 361     bool Resume();
 362     inline void Cancel() { m_eState = STATE_CANCELED; }
 363
 364     // thread state
 365     inline void SetState(wxThreadState eState) { m_eState = eState; }
 366     inline wxThreadState GetState() const { return m_eState; }
 367
 368     // thread priority
 369     void                SetPriority(unsigned int nPriority);
 370     inline unsigned int GetPriority() const { return m_nPriority; }
 371
 372     // thread handle and id
 373     inline TID GetHandle() const { return m_hThread; }
 374     TID  GetId() const { return m_hThread; }
 375
 376     // thread function
 377     static void OS2ThreadStart(void* pParam);
 378
 379 private:
 380     // Threads in OS/2 have only an ID, so m_hThread is both it's handle and ID
 381     // PM also has no real Tls mechanism to index pointers by so we'll just
 382     // keep track of the wxWidgets parent object here.
 383     TID                             m_hThread;    // handle and ID of the thread
 384     wxThreadState                   m_eState;     // state, see wxThreadState enum
 385     unsigned int                    m_nPriority;  // thread priority in "wx" units
 386 };
 387
 388 void wxThreadInternal::OS2ThreadStart(
 389   void * pParam
 390 )
 391 {
 392     DWORD                           dwRet;
 393     bool bWasCancelled;
 394
 395     wxThread *pThread = (wxThread *)pParam;
 396
 397     // first of all, wait for the thread to be started.
 398     pThread->m_critsect.Enter();
 399     pThread->m_critsect.Leave();
 400     // Now check whether we hadn't been cancelled already and don't
 401     // start the user code at all in this case.
 402     if ( pThread->m_internal->GetState() == STATE_EXITED )
 403     {
 404         dwRet = (DWORD)-1;
 405         bWasCancelled = true;
 406     }
 407     else // do run thread
 408     {
 409         wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 410         unsigned long ulHab;
 411         if (traits)
 412             traits->InitializeGui(ulHab);
 413         dwRet = (DWORD)pThread->Entry();
 414         if (traits)
 415             traits->TerminateGui(ulHab);
 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 wxWidgets 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( wxThread* pThread,
 474                                unsigned int uStackSize)
 475 {
 476     int tid;
 477
 478     if (!uStackSize)
 479         uStackSize = 131072;
 480
 481     pThread->m_critsect.Enter();
 482     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 483                              NULL, uStackSize, pThread);
 484     if(tid == -1)
 485     {
 486         wxLogSysError(_("Can't create thread"));
 487
 488         return false;
 489     }
 490     m_hThread = tid;
 491     if (m_nPriority != WXTHREAD_DEFAULT_PRIORITY)
 492     {
 493         SetPriority(m_nPriority);
 494     }
 495
 496     return true;
 497 }
 498
 499 bool wxThreadInternal::Suspend()
 500 {
 501     ULONG ulrc = ::DosSuspendThread(m_hThread);
 502
 503     if (ulrc != 0)
 504     {
 505         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 506         return false;
 507     }
 508     m_eState = STATE_PAUSED;
 509
 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
 553     return false;
 554 }
 555
 556 #ifdef Yield
 557     #undef Yield
 558 #endif
 559
 560 void wxThread::Yield()
 561 {
 562     ::DosSleep(0);
 563 }
 564
 565 void wxThread::Sleep(
 566   unsigned long                     ulMilliseconds
 567 )
 568 {
 569     ::DosSleep(ulMilliseconds);
 570 }
 571
 572 int wxThread::GetCPUCount()
 573 {
 574     ULONG CPUCount;
 575     APIRET ulrc;
 576     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 577     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 578
 579     if (ulrc != 0)
 580         CPUCount = 1;
 581
 582     return CPUCount;
 583 }
 584
 585 unsigned long wxThread::GetCurrentId()
 586 {
 587     PTIB                            ptib;
 588     PPIB                            ppib;
 589
 590     ::DosGetInfoBlocks(&ptib, &ppib);
 591     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 592 }
 593
 594 bool wxThread::SetConcurrency(size_t level)
 595 {
 596     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 597
 598     // ok only for the default one
 599     if ( level == 0 )
 600         return 0;
 601
 602     // Don't know how to realize this on OS/2.
 603     return level == 1;
 604 }
 605
 606 // ctor and dtor
 607 // -------------
 608
 609 wxThread::wxThread(wxThreadKind kind)
 610 {
 611     m_internal = new wxThreadInternal();
 612
 613     m_isDetached = kind == wxTHREAD_DETACHED;
 614 }
 615
 616 wxThread::~wxThread()
 617 {
 618     delete m_internal;
 619 }
 620
 621 // create/start thread
 622 // -------------------
 623
 624 wxThreadError wxThread::Create(
 625   unsigned int                      uStackSize
 626 )
 627 {
 628     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 629
 630     if ( !m_internal->Create(this, uStackSize) )
 631         return wxTHREAD_NO_RESOURCE;
 632
 633     return wxTHREAD_NO_ERROR;
 634 }
 635
 636 wxThreadError wxThread::Run()
 637 {
 638     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 639
 640     if ( m_internal->GetState() != STATE_NEW )
 641     {
 642         // actually, it may be almost any state at all, not only STATE_RUNNING
 643         return wxTHREAD_RUNNING;
 644     }
 645     return Resume();
 646 }
 647
 648 // suspend/resume thread
 649 // ---------------------
 650
 651 wxThreadError wxThread::Pause()
 652 {
 653     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 654
 655     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 656 }
 657
 658 wxThreadError wxThread::Resume()
 659 {
 660     if (m_internal->GetState() == STATE_NEW)
 661     {
 662         m_internal->SetState(STATE_RUNNING);
 663         m_critsect.Leave();
 664         return wxTHREAD_NO_ERROR;
 665     }
 666
 667     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 668
 669     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 670 }
 671
 672 // stopping thread
 673 // ---------------
 674
 675 wxThread::ExitCode wxThread::Wait()
 676 {
 677     // although under Windows we can wait for any thread, it's an error to
 678     // wait for a detached one in wxWin API
 679     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 680                  _T("can't wait for detached thread") );
 681     ExitCode rc = (ExitCode)-1;
 682     (void)Delete(&rc);
 683     return(rc);
 684 }
 685
 686 wxThreadError wxThread::Delete(ExitCode *pRc)
 687 {
 688     ExitCode rc = 0;
 689
 690     // Delete() is always safe to call, so consider all possible states
 691
 692     // we might need to resume the thread, but we might also not need to cancel
 693     // it if it doesn't run yet
 694     bool shouldResume = false,
 695          shouldCancel = true,
 696          isRunning = false;
 697
 698     // check if the thread already started to run
 699     {
 700         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 701
 702         if ( m_internal->GetState() == STATE_NEW )
 703         {
 704             // WinThreadStart() will see it and terminate immediately, no need
 705             // to cancel the thread - but we still need to resume it to let it
 706             // run
 707             m_internal->SetState(STATE_EXITED);
 708
 709             Resume();   // it knows about STATE_EXITED special case
 710
 711             shouldCancel = false;
 712             isRunning = true;
 713
 714             // shouldResume is correctly set to false here
 715         }
 716         else
 717         {
 718             shouldResume = IsPaused();
 719         }
 720     }
 721
 722     // resume the thread if it is paused
 723     if ( shouldResume )
 724         Resume();
 725
 726     TID hThread = m_internal->GetHandle();
 727
 728     if ( isRunning || IsRunning())
 729     {
 730         if (IsMain())
 731         {
 732             // set flag for wxIsWaitingForThread()
 733             gs_bWaitingForThread = true;
 734         }
 735
 736         // ask the thread to terminate
 737         if ( shouldCancel )
 738         {
 739             wxCriticalSectionLocker lock(m_critsect);
 740
 741             m_internal->Cancel();
 742         }
 743
 744 #if 0
 745         // we can't just wait for the thread to terminate because it might be
 746         // calling some GUI functions and so it will never terminate before we
 747         // process the Windows messages that result from these functions
 748         DWORD result = 0;       // suppress warnings from broken compilers
 749         do
 750         {
 751             if ( IsMain() )
 752             {
 753                 // give the thread we're waiting for chance to do the GUI call
 754                 // it might be in
 755                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 756                 {
 757                     wxMutexGuiLeave();
 758                 }
 759             }
 760
 761             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 762             // FIXME: We ought to have a message processing loop here!!
 763
 764             switch ( result )
 765             {
 766                 case ERROR_INTERRUPT:
 767                 case ERROR_THREAD_NOT_TERMINATED:
 768                     break;
 769                 case ERROR_INVALID_THREADID:
 770                 case NO_ERROR:
 771                     // thread we're waiting for just terminated
 772                     // or even does not exist any more.
 773                     result = NO_ERROR;
 774                     break;
 775                 default:
 776                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 777             }
 778             if ( IsMain() )
 779             {
 780                 // event processing - needed if we are the main thread
 781                 // to give other threads a chance to do remaining GUI
 782                 // processing and terminate cleanly.
 783                 wxTheApp->HandleSockets();
 784                 if (wxTheApp->Pending())
 785                   if ( !wxTheApp->DoMessage() )
 786                   {
 787                       // WM_QUIT received: kill the thread
 788                       Kill();
 789
 790                       return wxTHREAD_KILLED;
 791                   }
 792                   else
 793                     wxUsleep(10);
 794             }
 795             else
 796                 wxUsleep(10);
 797         } while ( result != NO_ERROR );
 798 #else // !wxUSE_GUI
 799         // simply wait for the thread to terminate
 800         //
 801         // OTOH, even console apps create windows (in wxExecute, for WinSock
 802         // &c), so may be use MsgWaitForMultipleObject() too here?
 803         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 804         {
 805             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 806         }
 807 #endif // wxUSE_GUI/!wxUSE_GUI
 808
 809         if ( IsMain() )
 810         {
 811             gs_bWaitingForThread = false;
 812         }
 813     }
 814
 815 #if 0
 816     // although the thread might be already in the EXITED state it might not
 817     // have terminated yet and so we are not sure that it has actually
 818     // terminated if the "if" above hadn't been taken
 819     do
 820     {
 821         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 822         {
 823             wxLogLastError(wxT("GetExitCodeThread"));
 824
 825             rc = (ExitCode)-1;
 826         }
 827     } while ( (DWORD)rc == STILL_ACTIVE );
 828 #endif
 829
 830     if ( IsDetached() )
 831     {
 832         // if the thread exits normally, this is done in WinThreadStart, but in
 833         // this case it would have been too early because
 834         // MsgWaitForMultipleObject() would fail if the thread handle was
 835         // closed while we were waiting on it, so we must do it here
 836         delete this;
 837     }
 838
 839     if ( pRc )
 840         *pRc = rc;
 841
 842     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 843 }
 844
 845 wxThreadError wxThread::Kill()
 846 {
 847     if (!IsRunning())
 848         return wxTHREAD_NOT_RUNNING;
 849
 850     ::DosKillThread(m_internal->GetHandle());
 851     if (IsDetached())
 852     {
 853         delete this;
 854     }
 855     return wxTHREAD_NO_ERROR;
 856 }
 857
 858 void wxThread::Exit(ExitCode WXUNUSED(pStatus))
 859 {
 860     delete this;
 861     _endthread();
 862     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 863 }
 864
 865 void wxThread::SetPriority(
 866   unsigned int                      nPrio
 867 )
 868 {
 869     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 870
 871     m_internal->SetPriority(nPrio);
 872 }
 873
 874 unsigned int wxThread::GetPriority() const
 875 {
 876     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 877
 878     return m_internal->GetPriority();
 879 }
 880
 881 unsigned long wxThread::GetId() const
 882 {
 883     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 884
 885     return (unsigned long)m_internal->GetId();
 886 }
 887
 888 bool wxThread::IsRunning() const
 889 {
 890     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 891
 892     return(m_internal->GetState() == STATE_RUNNING);
 893 }
 894
 895 bool wxThread::IsAlive() const
 896 {
 897     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 898
 899     return (m_internal->GetState() == STATE_RUNNING) ||
 900            (m_internal->GetState() == STATE_PAUSED);
 901 }
 902
 903 bool wxThread::IsPaused() const
 904 {
 905     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 906
 907     return (m_internal->GetState() == STATE_PAUSED);
 908 }
 909
 910 bool wxThread::TestDestroy()
 911 {
 912     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 913
 914     return m_internal->GetState() == STATE_CANCELED;
 915 }
 916
 917 // ----------------------------------------------------------------------------
 918 // Automatic initialization for thread module
 919 // ----------------------------------------------------------------------------
 920
 921 class wxThreadModule : public wxModule
 922 {
 923 public:
 924     virtual bool OnInit();
 925     virtual void OnExit();
 926
 927 private:
 928     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 929 };
 930
 931 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 932
 933 bool wxThreadModule::OnInit()
 934 {
 935     gs_pCritsectWaitingForGui = new wxCriticalSection();
 936
 937     gs_pCritsectGui = new wxCriticalSection();
 938     gs_pCritsectGui->Enter();
 939
 940     PTIB ptib;
 941     PPIB ppib;
 942
 943     ::DosGetInfoBlocks(&ptib, &ppib);
 944
 945     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 946     return true;
 947 }
 948
 949 void wxThreadModule::OnExit()
 950 {
 951     if (gs_pCritsectGui)
 952     {
 953         gs_pCritsectGui->Leave();
 954 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 955         delete gs_pCritsectGui;
 956 #endif
 957         gs_pCritsectGui = NULL;
 958     }
 959
 960 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 961     wxDELETE(gs_pCritsectWaitingForGui);
 962 #endif
 963 }
 964
 965 // ----------------------------------------------------------------------------
 966 // Helper functions
 967 // ----------------------------------------------------------------------------
 968
 969 // wake up the main thread if it's in ::GetMessage()
 970 void WXDLLEXPORT wxWakeUpMainThread()
 971 {
 972 #if 0
 973     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 974     {
 975         // should never happen
 976         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 977     }
 978 #endif
 979 }
 980
 981 void WXDLLEXPORT wxMutexGuiEnter()
 982 {
 983     // this would dead lock everything...
 984     wxASSERT_MSG( !wxThread::IsMain(),
 985                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 986
 987     // the order in which we enter the critical sections here is crucial!!
 988
 989     // set the flag telling to the main thread that we want to do some GUI
 990     {
 991         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 992
 993         gs_nWaitingForGui++;
 994     }
 995
 996     wxWakeUpMainThread();
 997
 998     // now we may block here because the main thread will soon let us in
 999     // (during the next iteration of OnIdle())
1000     gs_pCritsectGui->Enter();
1001 }
1002
1003 void WXDLLEXPORT wxMutexGuiLeave()
1004 {
1005     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1006
1007     if ( wxThread::IsMain() )
1008     {
1009         gs_bGuiOwnedByMainThread = false;
1010     }
1011     else
1012     {
1013         // decrement the number of waiters now
1014         wxASSERT_MSG(gs_nWaitingForGui > 0,
1015                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1016
1017         gs_nWaitingForGui--;
1018
1019         wxWakeUpMainThread();
1020     }
1021
1022     gs_pCritsectGui->Leave();
1023 }
1024
1025 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1026 {
1027     wxASSERT_MSG( wxThread::IsMain(),
1028                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1029
1030     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1031
1032     if (gs_nWaitingForGui == 0)
1033     {
1034         // no threads are waiting for GUI - so we may acquire the lock without
1035         // any danger (but only if we don't already have it)
1036         if (!wxGuiOwnedByMainThread())
1037         {
1038             gs_pCritsectGui->Enter();
1039
1040             gs_bGuiOwnedByMainThread = true;
1041         }
1042         //else: already have it, nothing to do
1043     }
1044     else
1045     {
1046         // some threads are waiting, release the GUI lock if we have it
1047         if (wxGuiOwnedByMainThread())
1048         {
1049             wxMutexGuiLeave();
1050         }
1051         //else: some other worker thread is doing GUI
1052     }
1053 }
1054
1055 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1056 {
1057     return gs_bGuiOwnedByMainThread;
1058 }
1059
1060 bool WXDLLEXPORT wxIsWaitingForThread()
1061 {
1062     return gs_bWaitingForThread;
1063 }
1064
1065 // ----------------------------------------------------------------------------
1066 // include common implementation code
1067 // ----------------------------------------------------------------------------
1068
1069 #include "wx/thrimpl.cpp"
1070
1071 #endif
1072   // wxUSE_THREADS