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 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ----------------------------------------------------------------------------
  13 // headers
  14 // ----------------------------------------------------------------------------
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #if wxUSE_THREADS
  20
  21 #include "wx/thread.h"
  22
  23 #ifndef WX_PRECOMP
  24     #include "wx/intl.h"
  25     #include "wx/log.h"
  26     #include "wx/app.h"
  27     #include "wx/module.h"
  28 #endif //WX_PRECOMP
  29
  30 #include "wx/apptrait.h"
  31 #include "wx/utils.h"
  32
  33 #include <stdio.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 wxWidgets 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 Lock(unsigned long ms) { return LockTimeout(ms); }
 100     wxMutexError TryLock();
 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::TryLock()
 132 {
 133     const wxMutexError rc = LockTimeout( SEM_IMMEDIATE_RETURN );
 134
 135     // we have a special return code for timeout in this case
 136     return rc == wxMUTEX_TIMEOUT ? wxMUTEX_BUSY : rc;
 137 }
 138
 139 wxMutexError wxMutexInternal::LockTimeout(ULONG ulMilliseconds)
 140 {
 141     APIRET                          ulrc;
 142
 143     ulrc = ::DosRequestMutexSem(m_vMutex, ulMilliseconds);
 144
 145     switch (ulrc)
 146     {
 147         case ERROR_TIMEOUT:
 148             return wxMUTEX_TIMEOUT;
 149         case ERROR_TOO_MANY_SEM_REQUESTS:
 150             return wxMUTEX_BUSY;
 151
 152         case NO_ERROR:
 153             // ok
 154             break;
 155
 156         case ERROR_INVALID_HANDLE:
 157         case ERROR_INTERRUPT:
 158         case ERROR_SEM_OWNER_DIED:
 159             wxLogSysError(_("Couldn't acquire a mutex lock"));
 160             return wxMUTEX_MISC_ERROR;
 161
 162         default:
 163             wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
 164             return wxMUTEX_MISC_ERROR;
 165      }
 166     return wxMUTEX_NO_ERROR;
 167 }
 168
 169 wxMutexError wxMutexInternal::Unlock()
 170 {
 171     APIRET                          ulrc;
 172
 173     ulrc = ::DosReleaseMutexSem(m_vMutex);
 174     if (ulrc != 0)
 175     {
 176         wxLogSysError(_("Couldn't release a mutex"));
 177         return wxMUTEX_MISC_ERROR;
 178     }
 179     return wxMUTEX_NO_ERROR;
 180 }
 181
 182 // --------------------------------------------------------------------------
 183 // wxSemaphore
 184 // --------------------------------------------------------------------------
 185
 186 // a trivial wrapper around OS2 event semaphore
 187 class wxSemaphoreInternal
 188 {
 189 public:
 190     wxSemaphoreInternal(int initialcount, int maxcount);
 191     ~wxSemaphoreInternal();
 192
 193     bool IsOk() const { return m_vEvent != NULL; }
 194
 195     wxSemaError Wait() { return WaitTimeout(SEM_INDEFINITE_WAIT); }
 196     wxSemaError TryWait() { return WaitTimeout(SEM_IMMEDIATE_RETURN); }
 197     wxSemaError WaitTimeout(unsigned long milliseconds);
 198
 199     wxSemaError Post();
 200
 201 private:
 202     HEV m_vEvent;
 203     HMTX m_vMutex;
 204     int m_count;
 205     int m_maxcount;
 206 };
 207
 208 wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
 209 {
 210     APIRET ulrc;
 211     if ( maxcount == 0 )
 212     {
 213         // make it practically infinite
 214         maxcount = INT_MAX;
 215     }
 216
 217     m_count = initialcount;
 218     m_maxcount = maxcount;
 219     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 220     if (ulrc != 0)
 221     {
 222         wxLogLastError(_T("DosCreateMutexSem()"));
 223         m_vMutex = NULL;
 224         m_vEvent = NULL;
 225         return;
 226     }
 227     ulrc = ::DosCreateEventSem(NULL, &m_vEvent, 0L, FALSE);
 228     if ( ulrc != 0)
 229     {
 230         wxLogLastError(_T("DosCreateEventSem()"));
 231         ::DosCloseMutexSem(m_vMutex);
 232         m_vMutex = NULL;
 233         m_vEvent = NULL;
 234     }
 235     if (initialcount)
 236         ::DosPostEventSem(m_vEvent);
 237 }
 238
 239 wxSemaphoreInternal::~wxSemaphoreInternal()
 240 {
 241     if ( m_vEvent )
 242     {
 243         if ( ::DosCloseEventSem(m_vEvent) )
 244         {
 245             wxLogLastError(_T("DosCloseEventSem(semaphore)"));
 246         }
 247         if ( ::DosCloseMutexSem(m_vMutex) )
 248         {
 249             wxLogLastError(_T("DosCloseMutexSem(semaphore)"));
 250         }
 251         else
 252             m_vEvent = NULL;
 253     }
 254 }
 255
 256 wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long ulMilliseconds)
 257 {
 258     APIRET ulrc;
 259     do {
 260         ulrc = ::DosWaitEventSem(m_vEvent, ulMilliseconds );
 261         switch ( ulrc )
 262         {
 263             case NO_ERROR:
 264                 break;
 265
 266             case ERROR_TIMEOUT:
 267                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 268                     return wxSEMA_BUSY;
 269                 else
 270                     return wxSEMA_TIMEOUT;
 271
 272             default:
 273                 wxLogLastError(_T("DosWaitEventSem(semaphore)"));
 274                 return wxSEMA_MISC_ERROR;
 275         }
 276         ulrc = :: DosRequestMutexSem(m_vMutex, ulMilliseconds);
 277         switch ( ulrc )
 278         {
 279             case NO_ERROR:
 280                 // ok
 281                 break;
 282
 283             case ERROR_TIMEOUT:
 284             case ERROR_TOO_MANY_SEM_REQUESTS:
 285                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 286                     return wxSEMA_BUSY;
 287                 else
 288                     return wxSEMA_TIMEOUT;
 289
 290             default:
 291                 wxFAIL_MSG(wxT("DosRequestMutexSem(mutex)"));
 292                 return wxSEMA_MISC_ERROR;
 293         }
 294         bool OK = false;
 295         if (m_count > 0)
 296         {
 297             m_count--;
 298             OK = true;
 299         }
 300         else
 301         {
 302             ULONG ulPostCount;
 303             ::DosResetEventSem(m_vEvent, &ulPostCount);
 304         }
 305         ::DosReleaseMutexSem(m_vMutex);
 306         if (OK)
 307             return wxSEMA_NO_ERROR;
 308     } while (ulMilliseconds == SEM_INDEFINITE_WAIT);
 309
 310     if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 311         return wxSEMA_BUSY;
 312     return wxSEMA_TIMEOUT;
 313 }
 314
 315 wxSemaError wxSemaphoreInternal::Post()
 316 {
 317     APIRET ulrc;
 318     ulrc = ::DosRequestMutexSem(m_vMutex, SEM_INDEFINITE_WAIT);
 319     if (ulrc != NO_ERROR)
 320         return wxSEMA_MISC_ERROR;
 321     bool OK = false;
 322     if (m_count < m_maxcount)
 323     {
 324         m_count++;
 325         ulrc = ::DosPostEventSem(m_vEvent);
 326         OK = true;
 327     }
 328     ::DosReleaseMutexSem(m_vMutex);
 329     if (!OK)
 330         return wxSEMA_OVERFLOW;
 331     if ( ulrc != NO_ERROR && ulrc != ERROR_ALREADY_POSTED )
 332     {
 333         wxLogLastError(_T("DosPostEventSem(semaphore)"));
 334
 335         return wxSEMA_MISC_ERROR;
 336     }
 337
 338     return wxSEMA_NO_ERROR;
 339 }
 340
 341 // ----------------------------------------------------------------------------
 342 // wxThread implementation
 343 // ----------------------------------------------------------------------------
 344
 345 // wxThreadInternal class
 346 // ----------------------
 347
 348 class wxThreadInternal
 349 {
 350 public:
 351     inline wxThreadInternal()
 352     {
 353         m_hThread = 0;
 354         m_eState = STATE_NEW;
 355         m_nPriority = WXTHREAD_DEFAULT_PRIORITY;
 356     }
 357
 358     ~wxThreadInternal()
 359     {
 360         m_hThread = 0;
 361     }
 362
 363     // create a new (suspended) thread (for the given thread object)
 364     bool Create( wxThread*    pThread
 365                 ,unsigned int uStackSize
 366                );
 367
 368     // suspend/resume/terminate
 369     bool Suspend();
 370     bool Resume();
 371     inline void Cancel() { m_eState = STATE_CANCELED; }
 372
 373     // thread state
 374     inline void SetState(wxThreadState eState) { m_eState = eState; }
 375     inline wxThreadState GetState() const { return m_eState; }
 376
 377     // thread priority
 378     void                SetPriority(unsigned int nPriority);
 379     inline unsigned int GetPriority() const { return m_nPriority; }
 380
 381     // thread handle and id
 382     inline TID GetHandle() const { return m_hThread; }
 383     TID  GetId() const { return m_hThread; }
 384
 385     // thread function
 386     static void OS2ThreadStart(void* pParam);
 387
 388 private:
 389     // Threads in OS/2 have only an ID, so m_hThread is both it's handle and ID
 390     // PM also has no real Tls mechanism to index pointers by so we'll just
 391     // keep track of the wxWidgets parent object here.
 392     TID                             m_hThread;    // handle and ID of the thread
 393     wxThreadState                   m_eState;     // state, see wxThreadState enum
 394     unsigned int                    m_nPriority;  // thread priority in "wx" units
 395 };
 396
 397 void wxThreadInternal::OS2ThreadStart( void * pParam )
 398 {
 399     DWORD dwRet;
 400     bool bWasCancelled;
 401
 402     wxThread *pThread = (wxThread *)pParam;
 403
 404     // first of all, wait for the thread to be started.
 405     pThread->m_critsect.Enter();
 406     pThread->m_critsect.Leave();
 407     // Now check whether we hadn't been cancelled already and don't
 408     // start the user code at all in this case.
 409     if ( pThread->m_internal->GetState() == STATE_EXITED )
 410     {
 411         dwRet = (DWORD)-1;
 412         bWasCancelled = true;
 413     }
 414     else // do run thread
 415     {
 416         wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 417         unsigned long ulHab;
 418         if (traits)
 419             traits->InitializeGui(ulHab);
 420         dwRet = (DWORD)pThread->Entry();
 421         if (traits)
 422             traits->TerminateGui(ulHab);
 423
 424         // enter m_critsect before changing the thread state
 425         pThread->m_critsect.Enter();
 426
 427         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 428
 429         pThread->m_internal->SetState(STATE_EXITED);
 430         pThread->m_critsect.Leave();
 431     }
 432     pThread->OnExit();
 433
 434     // if the thread was cancelled (from Delete()), then it the handle is still
 435     // needed there
 436     if (pThread->IsDetached() && !bWasCancelled)
 437     {
 438         // auto delete
 439         delete pThread;
 440     }
 441     //else: the joinable threads handle will be closed when Wait() is done
 442     return;
 443 }
 444
 445 void wxThreadInternal::SetPriority(
 446   unsigned int                      nPriority
 447 )
 448 {
 449     // translate wxWidgets priority to the PM one
 450     ULONG                           ulOS2_PriorityClass;
 451     ULONG                           ulOS2_SubPriority;
 452     ULONG                           ulrc;
 453
 454     m_nPriority = nPriority;
 455     if (m_nPriority <= 25)
 456         ulOS2_PriorityClass = PRTYC_IDLETIME;
 457     else if (m_nPriority <= 50)
 458         ulOS2_PriorityClass = PRTYC_REGULAR;
 459     else if (m_nPriority <= 75)
 460         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 461     else if (m_nPriority <= 100)
 462         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 463     else
 464     {
 465         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 466         ulOS2_PriorityClass = PRTYC_REGULAR;
 467     }
 468     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 469     ulrc = ::DosSetPriority( PRTYS_THREAD
 470                             ,ulOS2_PriorityClass
 471                             ,ulOS2_SubPriority
 472                             ,(ULONG)m_hThread
 473                            );
 474     if (ulrc != 0)
 475     {
 476         wxLogSysError(_("Can't set thread priority"));
 477     }
 478 }
 479
 480 bool wxThreadInternal::Create( wxThread* pThread,
 481                                unsigned int uStackSize)
 482 {
 483     int tid;
 484
 485     if (!uStackSize)
 486         uStackSize = 131072;
 487
 488     pThread->m_critsect.Enter();
 489     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 490                              NULL, uStackSize, pThread);
 491     if(tid == -1)
 492     {
 493         wxLogSysError(_("Can't create thread"));
 494
 495         return false;
 496     }
 497     m_hThread = tid;
 498     if (m_nPriority != WXTHREAD_DEFAULT_PRIORITY)
 499     {
 500         SetPriority(m_nPriority);
 501     }
 502
 503     return true;
 504 }
 505
 506 bool wxThreadInternal::Suspend()
 507 {
 508     ULONG ulrc = ::DosSuspendThread(m_hThread);
 509
 510     if (ulrc != 0)
 511     {
 512         wxLogSysError(_("Can not suspend thread %lu"), m_hThread);
 513         return false;
 514     }
 515     m_eState = STATE_PAUSED;
 516
 517     return true;
 518 }
 519
 520 bool wxThreadInternal::Resume()
 521 {
 522     ULONG ulrc = ::DosResumeThread(m_hThread);
 523
 524     if (ulrc != 0)
 525     {
 526         wxLogSysError(_("Can not resume thread %lu"), m_hThread);
 527         return false;
 528     }
 529
 530     // don't change the state from STATE_EXITED because it's special and means
 531     // we are going to terminate without running any user code - if we did it,
 532     // the codei n Delete() wouldn't work
 533     if ( m_eState != STATE_EXITED )
 534     {
 535         m_eState = STATE_RUNNING;
 536     }
 537
 538     return true;
 539 }
 540
 541 // static functions
 542 // ----------------
 543
 544 wxThread *wxThread::This()
 545 {
 546     wxThread*                       pThread = m_pThread;
 547     return pThread;
 548 }
 549
 550 bool wxThread::IsMain()
 551 {
 552     PTIB ptib;
 553     PPIB ppib;
 554
 555     ::DosGetInfoBlocks(&ptib, &ppib);
 556
 557     if (ptib->tib_ptib2->tib2_ultid == s_ulIdMainThread)
 558         return true;
 559
 560     return false;
 561 }
 562
 563 #ifdef Yield
 564     #undef Yield
 565 #endif
 566
 567 void wxThread::Yield()
 568 {
 569     ::DosSleep(0);
 570 }
 571
 572 void wxThread::Sleep(
 573   unsigned long                     ulMilliseconds
 574 )
 575 {
 576     ::DosSleep(ulMilliseconds);
 577 }
 578
 579 int wxThread::GetCPUCount()
 580 {
 581     ULONG CPUCount;
 582     APIRET ulrc;
 583     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 584     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 585
 586     if (ulrc != 0)
 587         CPUCount = 1;
 588
 589     return CPUCount;
 590 }
 591
 592 unsigned long wxThread::GetCurrentId()
 593 {
 594     PTIB                            ptib;
 595     PPIB                            ppib;
 596
 597     ::DosGetInfoBlocks(&ptib, &ppib);
 598     return (unsigned long) ptib->tib_ptib2->tib2_ultid;
 599 }
 600
 601 bool wxThread::SetConcurrency(size_t level)
 602 {
 603     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
 604
 605     // ok only for the default one
 606     if ( level == 0 )
 607         return 0;
 608
 609     // Don't know how to realize this on OS/2.
 610     return level == 1;
 611 }
 612
 613 // ctor and dtor
 614 // -------------
 615
 616 wxThread::wxThread(wxThreadKind kind)
 617 {
 618     m_internal = new wxThreadInternal();
 619
 620     m_isDetached = kind == wxTHREAD_DETACHED;
 621 }
 622
 623 wxThread::~wxThread()
 624 {
 625     delete m_internal;
 626 }
 627
 628 // create/start thread
 629 // -------------------
 630
 631 wxThreadError wxThread::Create(
 632   unsigned int                      uStackSize
 633 )
 634 {
 635     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 636
 637     if ( !m_internal->Create(this, uStackSize) )
 638         return wxTHREAD_NO_RESOURCE;
 639
 640     return wxTHREAD_NO_ERROR;
 641 }
 642
 643 wxThreadError wxThread::Run()
 644 {
 645     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 646
 647     if ( m_internal->GetState() != STATE_NEW )
 648     {
 649         // actually, it may be almost any state at all, not only STATE_RUNNING
 650         return wxTHREAD_RUNNING;
 651     }
 652     return Resume();
 653 }
 654
 655 // suspend/resume thread
 656 // ---------------------
 657
 658 wxThreadError wxThread::Pause()
 659 {
 660     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 661
 662     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 663 }
 664
 665 wxThreadError wxThread::Resume()
 666 {
 667     if (m_internal->GetState() == STATE_NEW)
 668     {
 669         m_internal->SetState(STATE_RUNNING);
 670         m_critsect.Leave();
 671         return wxTHREAD_NO_ERROR;
 672     }
 673
 674     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 675
 676     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 677 }
 678
 679 // stopping thread
 680 // ---------------
 681
 682 wxThread::ExitCode wxThread::Wait()
 683 {
 684     // although under Windows we can wait for any thread, it's an error to
 685     // wait for a detached one in wxWin API
 686     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 687                  _T("can't wait for detached thread") );
 688     ExitCode rc = (ExitCode)-1;
 689     (void)Delete(&rc);
 690     return(rc);
 691 }
 692
 693 wxThreadError wxThread::Delete(ExitCode *pRc)
 694 {
 695     ExitCode rc = 0;
 696
 697     // Delete() is always safe to call, so consider all possible states
 698
 699     // we might need to resume the thread, but we might also not need to cancel
 700     // it if it doesn't run yet
 701     bool shouldResume = false,
 702          shouldCancel = true,
 703          isRunning = false;
 704
 705     // check if the thread already started to run
 706     {
 707         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 708
 709         if ( m_internal->GetState() == STATE_NEW )
 710         {
 711             // WinThreadStart() will see it and terminate immediately, no need
 712             // to cancel the thread - but we still need to resume it to let it
 713             // run
 714             m_internal->SetState(STATE_EXITED);
 715
 716             Resume();   // it knows about STATE_EXITED special case
 717
 718             shouldCancel = false;
 719             isRunning = true;
 720
 721             // shouldResume is correctly set to false here
 722         }
 723         else
 724         {
 725             shouldResume = IsPaused();
 726         }
 727     }
 728
 729     // resume the thread if it is paused
 730     if ( shouldResume )
 731         Resume();
 732
 733     TID hThread = m_internal->GetHandle();
 734
 735     if ( isRunning || IsRunning())
 736     {
 737         if (IsMain())
 738         {
 739             // set flag for wxIsWaitingForThread()
 740             gs_bWaitingForThread = true;
 741         }
 742
 743         // ask the thread to terminate
 744         if ( shouldCancel )
 745         {
 746             wxCriticalSectionLocker lock(m_critsect);
 747
 748             m_internal->Cancel();
 749         }
 750
 751 #if 0
 752         // we can't just wait for the thread to terminate because it might be
 753         // calling some GUI functions and so it will never terminate before we
 754         // process the Windows messages that result from these functions
 755         DWORD result = 0;       // suppress warnings from broken compilers
 756         do
 757         {
 758             if ( IsMain() )
 759             {
 760                 // give the thread we're waiting for chance to do the GUI call
 761                 // it might be in
 762                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 763                 {
 764                     wxMutexGuiLeave();
 765                 }
 766             }
 767
 768             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 769             // FIXME: We ought to have a message processing loop here!!
 770
 771             switch ( result )
 772             {
 773                 case ERROR_INTERRUPT:
 774                 case ERROR_THREAD_NOT_TERMINATED:
 775                     break;
 776                 case ERROR_INVALID_THREADID:
 777                 case NO_ERROR:
 778                     // thread we're waiting for just terminated
 779                     // or even does not exist any more.
 780                     result = NO_ERROR;
 781                     break;
 782                 default:
 783                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 784             }
 785             if ( IsMain() )
 786             {
 787                 // event processing - needed if we are the main thread
 788                 // to give other threads a chance to do remaining GUI
 789                 // processing and terminate cleanly.
 790                 wxTheApp->HandleSockets();
 791                 if (wxTheApp->Pending())
 792                   if ( !wxTheApp->DoMessage() )
 793                   {
 794                       // WM_QUIT received: kill the thread
 795                       Kill();
 796
 797                       return wxTHREAD_KILLED;
 798                   }
 799                   else
 800                     wxUsleep(10);
 801             }
 802             else
 803                 wxUsleep(10);
 804         } while ( result != NO_ERROR );
 805 #else // !wxUSE_GUI
 806         // simply wait for the thread to terminate
 807         //
 808         // OTOH, even console apps create windows (in wxExecute, for WinSock
 809         // &c), so may be use MsgWaitForMultipleObject() too here?
 810         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 811         {
 812             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 813         }
 814 #endif // wxUSE_GUI/!wxUSE_GUI
 815
 816         if ( IsMain() )
 817         {
 818             gs_bWaitingForThread = false;
 819         }
 820     }
 821
 822 #if 0
 823     // although the thread might be already in the EXITED state it might not
 824     // have terminated yet and so we are not sure that it has actually
 825     // terminated if the "if" above hadn't been taken
 826     do
 827     {
 828         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 829         {
 830             wxLogLastError(wxT("GetExitCodeThread"));
 831
 832             rc = (ExitCode)-1;
 833         }
 834     } while ( (DWORD)rc == STILL_ACTIVE );
 835 #endif
 836
 837     if ( IsDetached() )
 838     {
 839         // if the thread exits normally, this is done in WinThreadStart, but in
 840         // this case it would have been too early because
 841         // MsgWaitForMultipleObject() would fail if the thread handle was
 842         // closed while we were waiting on it, so we must do it here
 843         delete this;
 844     }
 845
 846     if ( pRc )
 847         *pRc = rc;
 848
 849     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 850 }
 851
 852 wxThreadError wxThread::Kill()
 853 {
 854     if (!IsRunning())
 855         return wxTHREAD_NOT_RUNNING;
 856
 857     ::DosKillThread(m_internal->GetHandle());
 858     if (IsDetached())
 859     {
 860         delete this;
 861     }
 862     return wxTHREAD_NO_ERROR;
 863 }
 864
 865 void wxThread::Exit(ExitCode WXUNUSED(pStatus))
 866 {
 867     delete this;
 868     _endthread();
 869     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 870 }
 871
 872 void wxThread::SetPriority(
 873   unsigned int                      nPrio
 874 )
 875 {
 876     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 877
 878     m_internal->SetPriority(nPrio);
 879 }
 880
 881 unsigned int wxThread::GetPriority() const
 882 {
 883     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 884
 885     return m_internal->GetPriority();
 886 }
 887
 888 unsigned long wxThread::GetId() const
 889 {
 890     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 891
 892     return (unsigned long)m_internal->GetId();
 893 }
 894
 895 bool wxThread::IsRunning() const
 896 {
 897     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 898
 899     return(m_internal->GetState() == STATE_RUNNING);
 900 }
 901
 902 bool wxThread::IsAlive() const
 903 {
 904     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 905
 906     return (m_internal->GetState() == STATE_RUNNING) ||
 907            (m_internal->GetState() == STATE_PAUSED);
 908 }
 909
 910 bool wxThread::IsPaused() const
 911 {
 912     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 913
 914     return (m_internal->GetState() == STATE_PAUSED);
 915 }
 916
 917 bool wxThread::TestDestroy()
 918 {
 919     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 920
 921     return m_internal->GetState() == STATE_CANCELED;
 922 }
 923
 924 // ----------------------------------------------------------------------------
 925 // Automatic initialization for thread module
 926 // ----------------------------------------------------------------------------
 927
 928 class wxThreadModule : public wxModule
 929 {
 930 public:
 931     virtual bool OnInit();
 932     virtual void OnExit();
 933
 934 private:
 935     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 936 };
 937
 938 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 939
 940 bool wxThreadModule::OnInit()
 941 {
 942     gs_pCritsectWaitingForGui = new wxCriticalSection();
 943
 944     gs_pCritsectGui = new wxCriticalSection();
 945     gs_pCritsectGui->Enter();
 946
 947     PTIB ptib;
 948     PPIB ppib;
 949
 950     ::DosGetInfoBlocks(&ptib, &ppib);
 951
 952     s_ulIdMainThread = ptib->tib_ptib2->tib2_ultid;
 953     return true;
 954 }
 955
 956 void wxThreadModule::OnExit()
 957 {
 958     if (gs_pCritsectGui)
 959     {
 960         gs_pCritsectGui->Leave();
 961 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 962         delete gs_pCritsectGui;
 963 #endif
 964         gs_pCritsectGui = NULL;
 965     }
 966
 967 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 968     wxDELETE(gs_pCritsectWaitingForGui);
 969 #endif
 970 }
 971
 972 // ----------------------------------------------------------------------------
 973 // Helper functions
 974 // ----------------------------------------------------------------------------
 975
 976 // wake up the main thread if it's in ::GetMessage()
 977 void WXDLLEXPORT wxWakeUpMainThread()
 978 {
 979 #if 0
 980     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 981     {
 982         // should never happen
 983         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 984     }
 985 #endif
 986 }
 987
 988 void wxMutexGuiEnterImpl()
 989 {
 990     // this would dead lock everything...
 991     wxASSERT_MSG( !wxThread::IsMain(),
 992                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 993
 994     // the order in which we enter the critical sections here is crucial!!
 995
 996     // set the flag telling to the main thread that we want to do some GUI
 997     {
 998         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 999
1000         gs_nWaitingForGui++;
1001     }
1002
1003     wxWakeUpMainThread();
1004
1005     // now we may block here because the main thread will soon let us in
1006     // (during the next iteration of OnIdle())
1007     gs_pCritsectGui->Enter();
1008 }
1009
1010 void wxMutexGuiLeaveImpl()
1011 {
1012     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1013
1014     if ( wxThread::IsMain() )
1015     {
1016         gs_bGuiOwnedByMainThread = false;
1017     }
1018     else
1019     {
1020         // decrement the number of waiters now
1021         wxASSERT_MSG(gs_nWaitingForGui > 0,
1022                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1023
1024         gs_nWaitingForGui--;
1025
1026         wxWakeUpMainThread();
1027     }
1028
1029     gs_pCritsectGui->Leave();
1030 }
1031
1032 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1033 {
1034     wxASSERT_MSG( wxThread::IsMain(),
1035                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1036
1037     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1038
1039     if (gs_nWaitingForGui == 0)
1040     {
1041         // no threads are waiting for GUI - so we may acquire the lock without
1042         // any danger (but only if we don't already have it)
1043         if (!wxGuiOwnedByMainThread())
1044         {
1045             gs_pCritsectGui->Enter();
1046
1047             gs_bGuiOwnedByMainThread = true;
1048         }
1049         //else: already have it, nothing to do
1050     }
1051     else
1052     {
1053         // some threads are waiting, release the GUI lock if we have it
1054         if (wxGuiOwnedByMainThread())
1055         {
1056             wxMutexGuiLeave();
1057         }
1058         //else: some other worker thread is doing GUI
1059     }
1060 }
1061
1062 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1063 {
1064     return gs_bGuiOwnedByMainThread;
1065 }
1066
1067 bool WXDLLEXPORT wxIsWaitingForThread()
1068 {
1069     return gs_bWaitingForThread;
1070 }
1071
1072 // ----------------------------------------------------------------------------
1073 // include common implementation code
1074 // ----------------------------------------------------------------------------
1075
1076 #include "wx/thrimpl.cpp"
1077
1078 #endif
1079   // wxUSE_THREADS