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 // Copyright:   (c) Stefan Neis (2003)
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 // ----------------------------------------------------------------------------
  12 // headers
  13 // ----------------------------------------------------------------------------
  14
  15 // For compilers that support precompilation, includes "wx.h".
  16 #include "wx/wxprec.h"
  17
  18 #if wxUSE_THREADS
  19
  20 #include "wx/thread.h"
  21
  22 #ifndef WX_PRECOMP
  23     #include "wx/intl.h"
  24     #include "wx/log.h"
  25     #include "wx/app.h"
  26     #include "wx/module.h"
  27 #endif //WX_PRECOMP
  28
  29 #include "wx/apptrait.h"
  30 #include "wx/utils.h"
  31
  32 #include <stdio.h>
  33
  34 #define INCL_DOSSEMAPHORES
  35 #define INCL_DOSPROCESS
  36 #define INCL_DOSMISC
  37 #define INCL_ERRORS
  38 #include <os2.h>
  39 #ifndef __EMX__
  40 #include <bseerr.h>
  41 #endif
  42 // the possible states of the thread ("=>" shows all possible transitions from
  43 // this state)
  44 enum wxThreadState
  45 {
  46     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  47     STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
  48     STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
  49     STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
  50     STATE_EXITED        // thread is terminating
  51 };
  52
  53 // ----------------------------------------------------------------------------
  54 // this module's globals
  55 // ----------------------------------------------------------------------------
  56
  57 // id of the main thread - the one which can call GUI functions without first
  58 // calling wxMutexGuiEnter()
  59 wxThreadIdType                      wxThread::ms_idMainThread = 0;
  60 wxMutex*                            p_wxMainMutex;
  61
  62 // OS2 substitute for Tls pointer the current parent thread object
  63 wxThread*                           m_pThread;    // pointer to the wxWidgets thread object
  64
  65 // if it's false, some secondary thread is holding the GUI lock
  66 static bool gs_bGuiOwnedByMainThread = true;
  67
  68 // critical section which controls access to all GUI functions: any secondary
  69 // thread (i.e. except the main one) must enter this crit section before doing
  70 // any GUI calls
  71 static wxCriticalSection *gs_pCritsectGui = NULL;
  72
  73 // critical section which protects s_nWaitingForGui variable
  74 static wxCriticalSection *gs_pCritsectWaitingForGui = NULL;
  75
  76 // number of threads waiting for GUI in wxMutexGuiEnter()
  77 static size_t gs_nWaitingForGui = 0;
  78
  79 // are we waiting for a thread termination?
  80 static bool gs_bWaitingForThread = false;
  81
  82 // ============================================================================
  83 // OS/2 implementation of thread and related classes
  84 // ============================================================================
  85
  86 // ----------------------------------------------------------------------------
  87 // wxMutex implementation
  88 // ----------------------------------------------------------------------------
  89 class wxMutexInternal
  90 {
  91 public:
  92     wxMutexInternal(wxMutexType mutexType);
  93     ~wxMutexInternal();
  94
  95     bool IsOk() const { return m_vMutex != NULL; }
  96
  97     wxMutexError Lock() { return LockTimeout(SEM_INDEFINITE_WAIT); }
  98     wxMutexError Lock(unsigned long ms) { return LockTimeout(ms); }
  99     wxMutexError TryLock();
 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(wxMutexType WXUNUSED(eMutexType))
 112 {
 113     APIRET ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 114     if (ulrc != 0)
 115     {
 116         wxLogSysError(_("Cannot create mutex."));
 117         m_vMutex = NULL;
 118     }
 119 }
 120
 121 wxMutexInternal::~wxMutexInternal()
 122 {
 123     if (m_vMutex)
 124     {
 125         if (::DosCloseMutexSem(m_vMutex))
 126         {
 127             wxLogLastError(wxT("DosCloseMutexSem(mutex)"));
 128         }
 129     }
 130 }
 131
 132 wxMutexError wxMutexInternal::TryLock()
 133 {
 134     const wxMutexError rc = LockTimeout( SEM_IMMEDIATE_RETURN );
 135
 136     // we have a special return code for timeout in this case
 137     return rc == wxMUTEX_TIMEOUT ? wxMUTEX_BUSY : rc;
 138 }
 139
 140 wxMutexError wxMutexInternal::LockTimeout(ULONG ulMilliseconds)
 141 {
 142     APIRET                          ulrc;
 143
 144     ulrc = ::DosRequestMutexSem(m_vMutex, ulMilliseconds);
 145
 146     switch (ulrc)
 147     {
 148         case ERROR_TIMEOUT:
 149             return wxMUTEX_TIMEOUT;
 150         case ERROR_TOO_MANY_SEM_REQUESTS:
 151             return wxMUTEX_BUSY;
 152
 153         case NO_ERROR:
 154             // ok
 155             break;
 156
 157         case ERROR_INVALID_HANDLE:
 158         case ERROR_INTERRUPT:
 159         case ERROR_SEM_OWNER_DIED:
 160             wxLogSysError(_("Couldn't acquire a mutex lock"));
 161             return wxMUTEX_MISC_ERROR;
 162
 163         default:
 164             wxFAIL_MSG(wxT("impossible return value in wxMutex::Lock"));
 165             return wxMUTEX_MISC_ERROR;
 166      }
 167     return wxMUTEX_NO_ERROR;
 168 }
 169
 170 wxMutexError wxMutexInternal::Unlock()
 171 {
 172     APIRET                          ulrc;
 173
 174     ulrc = ::DosReleaseMutexSem(m_vMutex);
 175     if (ulrc != 0)
 176     {
 177         wxLogSysError(_("Couldn't release a mutex"));
 178         return wxMUTEX_MISC_ERROR;
 179     }
 180     return wxMUTEX_NO_ERROR;
 181 }
 182
 183 // --------------------------------------------------------------------------
 184 // wxSemaphore
 185 // --------------------------------------------------------------------------
 186
 187 // a trivial wrapper around OS2 event semaphore
 188 class wxSemaphoreInternal
 189 {
 190 public:
 191     wxSemaphoreInternal(int initialcount, int maxcount);
 192     ~wxSemaphoreInternal();
 193
 194     bool IsOk() const { return m_vEvent != NULL; }
 195
 196     wxSemaError Wait() { return WaitTimeout(SEM_INDEFINITE_WAIT); }
 197     wxSemaError TryWait() { return WaitTimeout(SEM_IMMEDIATE_RETURN); }
 198     wxSemaError WaitTimeout(unsigned long milliseconds);
 199
 200     wxSemaError Post();
 201
 202 private:
 203     HEV m_vEvent;
 204     HMTX m_vMutex;
 205     int m_count;
 206     int m_maxcount;
 207 };
 208
 209 wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
 210 {
 211     APIRET ulrc;
 212     if ( maxcount == 0 )
 213     {
 214         // make it practically infinite
 215         maxcount = INT_MAX;
 216     }
 217
 218     m_count = initialcount;
 219     m_maxcount = maxcount;
 220     ulrc = ::DosCreateMutexSem(NULL, &m_vMutex, 0L, FALSE);
 221     if (ulrc != 0)
 222     {
 223         wxLogLastError(wxT("DosCreateMutexSem()"));
 224         m_vMutex = NULL;
 225         m_vEvent = NULL;
 226         return;
 227     }
 228     ulrc = ::DosCreateEventSem(NULL, &m_vEvent, 0L, FALSE);
 229     if ( ulrc != 0)
 230     {
 231         wxLogLastError(wxT("DosCreateEventSem()"));
 232         ::DosCloseMutexSem(m_vMutex);
 233         m_vMutex = NULL;
 234         m_vEvent = NULL;
 235     }
 236     if (initialcount)
 237         ::DosPostEventSem(m_vEvent);
 238 }
 239
 240 wxSemaphoreInternal::~wxSemaphoreInternal()
 241 {
 242     if ( m_vEvent )
 243     {
 244         if ( ::DosCloseEventSem(m_vEvent) )
 245         {
 246             wxLogLastError(wxT("DosCloseEventSem(semaphore)"));
 247         }
 248         if ( ::DosCloseMutexSem(m_vMutex) )
 249         {
 250             wxLogLastError(wxT("DosCloseMutexSem(semaphore)"));
 251         }
 252         else
 253             m_vEvent = NULL;
 254     }
 255 }
 256
 257 wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long ulMilliseconds)
 258 {
 259     APIRET ulrc;
 260     do {
 261         ulrc = ::DosWaitEventSem(m_vEvent, ulMilliseconds );
 262         switch ( ulrc )
 263         {
 264             case NO_ERROR:
 265                 break;
 266
 267             case ERROR_TIMEOUT:
 268                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 269                     return wxSEMA_BUSY;
 270                 else
 271                     return wxSEMA_TIMEOUT;
 272
 273             default:
 274                 wxLogLastError(wxT("DosWaitEventSem(semaphore)"));
 275                 return wxSEMA_MISC_ERROR;
 276         }
 277         ulrc = :: DosRequestMutexSem(m_vMutex, ulMilliseconds);
 278         switch ( ulrc )
 279         {
 280             case NO_ERROR:
 281                 // ok
 282                 break;
 283
 284             case ERROR_TIMEOUT:
 285             case ERROR_TOO_MANY_SEM_REQUESTS:
 286                 if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 287                     return wxSEMA_BUSY;
 288                 else
 289                     return wxSEMA_TIMEOUT;
 290
 291             default:
 292                 wxFAIL_MSG(wxT("DosRequestMutexSem(mutex)"));
 293                 return wxSEMA_MISC_ERROR;
 294         }
 295         bool OK = false;
 296         if (m_count > 0)
 297         {
 298             m_count--;
 299             OK = true;
 300         }
 301         else
 302         {
 303             ULONG ulPostCount;
 304             ::DosResetEventSem(m_vEvent, &ulPostCount);
 305         }
 306         ::DosReleaseMutexSem(m_vMutex);
 307         if (OK)
 308             return wxSEMA_NO_ERROR;
 309     } while (ulMilliseconds == SEM_INDEFINITE_WAIT);
 310
 311     if (ulMilliseconds == SEM_IMMEDIATE_RETURN)
 312         return wxSEMA_BUSY;
 313     return wxSEMA_TIMEOUT;
 314 }
 315
 316 wxSemaError wxSemaphoreInternal::Post()
 317 {
 318     APIRET ulrc;
 319     ulrc = ::DosRequestMutexSem(m_vMutex, SEM_INDEFINITE_WAIT);
 320     if (ulrc != NO_ERROR)
 321         return wxSEMA_MISC_ERROR;
 322     bool OK = false;
 323     if (m_count < m_maxcount)
 324     {
 325         m_count++;
 326         ulrc = ::DosPostEventSem(m_vEvent);
 327         OK = true;
 328     }
 329     ::DosReleaseMutexSem(m_vMutex);
 330     if (!OK)
 331         return wxSEMA_OVERFLOW;
 332     if ( ulrc != NO_ERROR && ulrc != ERROR_ALREADY_POSTED )
 333     {
 334         wxLogLastError(wxT("DosPostEventSem(semaphore)"));
 335
 336         return wxSEMA_MISC_ERROR;
 337     }
 338
 339     return wxSEMA_NO_ERROR;
 340 }
 341
 342 // ----------------------------------------------------------------------------
 343 // wxThread implementation
 344 // ----------------------------------------------------------------------------
 345
 346 // wxThreadInternal class
 347 // ----------------------
 348
 349 class wxThreadInternal
 350 {
 351 public:
 352     inline wxThreadInternal()
 353     {
 354         m_hThread = 0;
 355         m_eState = STATE_NEW;
 356         m_nPriority = wxPRIORITY_DEFAULT;
 357     }
 358
 359     ~wxThreadInternal()
 360     {
 361         m_hThread = 0;
 362     }
 363
 364     // create a new (suspended) thread (for the given thread object)
 365     bool Create( wxThread*    pThread
 366                 ,unsigned int uStackSize
 367                );
 368
 369     // suspend/resume/terminate
 370     bool Suspend();
 371     bool Resume();
 372     inline void Cancel() { m_eState = STATE_CANCELED; }
 373
 374     // thread state
 375     inline void SetState(wxThreadState eState) { m_eState = eState; }
 376     inline wxThreadState GetState() const { return m_eState; }
 377
 378     // thread priority
 379     void                SetPriority(unsigned int nPriority);
 380     inline unsigned int GetPriority() const { return m_nPriority; }
 381
 382     // thread handle and id
 383     inline TID GetHandle() const { return m_hThread; }
 384     TID  GetId() const { return m_hThread; }
 385
 386     // thread function
 387     static void OS2ThreadStart(void* pParam);
 388
 389 private:
 390     // Threads in OS/2 have only an ID, so m_hThread is both it's handle and ID
 391     // PM also has no real Tls mechanism to index pointers by so we'll just
 392     // keep track of the wxWidgets parent object here.
 393     TID                             m_hThread;    // handle and ID of the thread
 394     wxThreadState                   m_eState;     // state, see wxThreadState enum
 395     unsigned int                    m_nPriority;  // thread priority in "wx" units
 396 };
 397
 398 void wxThreadInternal::OS2ThreadStart( void * pParam )
 399 {
 400     DWORD dwRet;
 401     bool bWasCancelled;
 402
 403     wxThread *pThread = (wxThread *)pParam;
 404
 405     // first of all, wait for the thread to be started.
 406     pThread->m_critsect.Enter();
 407     pThread->m_critsect.Leave();
 408     // Now check whether we hadn't been cancelled already and don't
 409     // start the user code at all in this case.
 410     if ( pThread->m_internal->GetState() == STATE_EXITED )
 411     {
 412         dwRet = (DWORD)-1;
 413         bWasCancelled = true;
 414     }
 415     else // do run thread
 416     {
 417         wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() : NULL;
 418         unsigned long ulHab;
 419         if (traits)
 420             traits->InitializeGui(ulHab);
 421         dwRet = (DWORD)pThread->CallEntry();
 422         if (traits)
 423             traits->TerminateGui(ulHab);
 424
 425         // enter m_critsect before changing the thread state
 426         pThread->m_critsect.Enter();
 427
 428         bWasCancelled = pThread->m_internal->GetState() == STATE_CANCELED;
 429
 430         pThread->m_internal->SetState(STATE_EXITED);
 431         pThread->m_critsect.Leave();
 432     }
 433     pThread->OnExit();
 434
 435     // if the thread was cancelled (from Delete()), then it the handle is still
 436     // needed there
 437     if (pThread->IsDetached() && !bWasCancelled)
 438     {
 439         // auto delete
 440         delete pThread;
 441     }
 442     //else: the joinable threads handle will be closed when Wait() is done
 443     return;
 444 }
 445
 446 void wxThreadInternal::SetPriority(
 447   unsigned int                      nPriority
 448 )
 449 {
 450     // translate wxWidgets priority to the PM one
 451     ULONG                           ulOS2_PriorityClass;
 452     ULONG                           ulOS2_SubPriority;
 453     ULONG                           ulrc;
 454
 455     m_nPriority = nPriority;
 456     if (m_nPriority <= 25)
 457         ulOS2_PriorityClass = PRTYC_IDLETIME;
 458     else if (m_nPriority <= 50)
 459         ulOS2_PriorityClass = PRTYC_REGULAR;
 460     else if (m_nPriority <= 75)
 461         ulOS2_PriorityClass = PRTYC_TIMECRITICAL;
 462     else if (m_nPriority <= 100)
 463         ulOS2_PriorityClass = PRTYC_FOREGROUNDSERVER;
 464     else
 465     {
 466         wxFAIL_MSG(wxT("invalid value of thread priority parameter"));
 467         ulOS2_PriorityClass = PRTYC_REGULAR;
 468     }
 469     ulOS2_SubPriority = (ULONG) (((m_nPriority - 1) % 25 + 1) * 31.0 / 25);
 470     ulrc = ::DosSetPriority( PRTYS_THREAD
 471                             ,ulOS2_PriorityClass
 472                             ,ulOS2_SubPriority
 473                             ,(ULONG)m_hThread
 474                            );
 475     if (ulrc != 0)
 476     {
 477         wxLogSysError(_("Can't set thread priority"));
 478     }
 479 }
 480
 481 bool wxThreadInternal::Create( wxThread* pThread,
 482                                unsigned int uStackSize)
 483 {
 484     int tid;
 485
 486     if (!uStackSize)
 487         uStackSize = 131072;
 488
 489     pThread->m_critsect.Enter();
 490     tid = _beginthread(wxThreadInternal::OS2ThreadStart,
 491                              NULL, uStackSize, pThread);
 492     if(tid == -1)
 493     {
 494         wxLogSysError(_("Can't create thread"));
 495
 496         return false;
 497     }
 498     m_hThread = tid;
 499     if (m_nPriority != wxPRIORITY_DEFAULT)
 500     {
 501         SetPriority(m_nPriority);
 502     }
 503
 504     return true;
 505 }
 506
 507 bool wxThreadInternal::Suspend()
 508 {
 509     ULONG ulrc = ::DosSuspendThread(m_hThread);
 510
 511     if (ulrc != 0)
 512     {
 513         wxLogSysError(_("Cannot suspend thread %lu"), m_hThread);
 514         return false;
 515     }
 516     m_eState = STATE_PAUSED;
 517
 518     return true;
 519 }
 520
 521 bool wxThreadInternal::Resume()
 522 {
 523     ULONG ulrc = ::DosResumeThread(m_hThread);
 524
 525     if (ulrc != 0)
 526     {
 527         wxLogSysError(_("Cannot resume thread %lu"), m_hThread);
 528         return false;
 529     }
 530
 531     // don't change the state from STATE_EXITED because it's special and means
 532     // we are going to terminate without running any user code - if we did it,
 533     // the codei n Delete() wouldn't work
 534     if ( m_eState != STATE_EXITED )
 535     {
 536         m_eState = STATE_RUNNING;
 537     }
 538
 539     return true;
 540 }
 541
 542 // static functions
 543 // ----------------
 544
 545 wxThread *wxThread::This()
 546 {
 547     wxThread*                       pThread = m_pThread;
 548     return pThread;
 549 }
 550
 551 #ifdef Yield
 552     #undef Yield
 553 #endif
 554
 555 void wxThread::Yield()
 556 {
 557     ::DosSleep(0);
 558 }
 559
 560 int wxThread::GetCPUCount()
 561 {
 562     ULONG CPUCount;
 563     APIRET ulrc;
 564     ulrc = ::DosQuerySysInfo(26, 26, (void *)&CPUCount, sizeof(ULONG));
 565     // QSV_NUMPROCESSORS(26) is typically not defined in header files
 566
 567     if (ulrc != 0)
 568         CPUCount = 1;
 569
 570     return CPUCount;
 571 }
 572
 573 wxThreadIdType wxThread::GetCurrentId()
 574 {
 575     PTIB                            ptib;
 576     PPIB                            ppib;
 577
 578     ::DosGetInfoBlocks(&ptib, &ppib);
 579     return (wxThreadIdType) ptib->tib_ptib2->tib2_ultid;
 580 }
 581
 582 bool wxThread::SetConcurrency(size_t level)
 583 {
 584     wxASSERT_MSG( IsMain(), wxT("should only be called from the main thread") );
 585
 586     // ok only for the default one
 587     if ( level == 0 )
 588         return 0;
 589
 590     // Don't know how to realize this on OS/2.
 591     return level == 1;
 592 }
 593
 594 // ctor and dtor
 595 // -------------
 596
 597 wxThread::wxThread(wxThreadKind kind)
 598 {
 599     m_internal = new wxThreadInternal();
 600
 601     m_isDetached = kind == wxTHREAD_DETACHED;
 602 }
 603
 604 wxThread::~wxThread()
 605 {
 606     delete m_internal;
 607 }
 608
 609 // create/start thread
 610 // -------------------
 611
 612 wxThreadError wxThread::Create(
 613   unsigned int                      uStackSize
 614 )
 615 {
 616     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 617
 618     if ( !m_internal->Create(this, uStackSize) )
 619         return wxTHREAD_NO_RESOURCE;
 620
 621     return wxTHREAD_NO_ERROR;
 622 }
 623
 624 wxThreadError wxThread::Run()
 625 {
 626     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 627
 628     // Create the thread if it wasn't created yet with an explicit
 629     // Create() call:
 630     if ( !m_internal->GetHandle() )
 631     {
 632         if ( !m_internal->Create(this, 0) )
 633             return wxTHREAD_NO_RESOURCE;
 634     }
 635
 636     if ( m_internal->GetState() != STATE_NEW )
 637     {
 638         // actually, it may be almost any state at all, not only STATE_RUNNING
 639         return wxTHREAD_RUNNING;
 640     }
 641     return Resume();
 642 }
 643
 644 // suspend/resume thread
 645 // ---------------------
 646
 647 wxThreadError wxThread::Pause()
 648 {
 649     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 650
 651     return m_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 652 }
 653
 654 wxThreadError wxThread::Resume()
 655 {
 656     if (m_internal->GetState() == STATE_NEW)
 657     {
 658         m_internal->SetState(STATE_RUNNING);
 659         m_critsect.Leave();
 660         return wxTHREAD_NO_ERROR;
 661     }
 662
 663     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 664
 665     return m_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 666 }
 667
 668 // stopping thread
 669 // ---------------
 670
 671 wxThread::ExitCode wxThread::Wait(wxThreadWait waitMode)
 672 {
 673     // although under Windows we can wait for any thread, it's an error to
 674     // wait for a detached one in wxWin API
 675     wxCHECK_MSG( !IsDetached(), (ExitCode)-1,
 676                  wxT("can't wait for detached thread") );
 677     ExitCode rc = (ExitCode)-1;
 678     (void)Delete(&rc, waitMode);
 679     return(rc);
 680 }
 681
 682 wxThreadError wxThread::Delete(ExitCode *pRc, wxThreadWait WXUNUSED(waitMode))
 683 {
 684     ExitCode rc = 0;
 685
 686     // Delete() is always safe to call, so consider all possible states
 687
 688     // we might need to resume the thread, but we might also not need to cancel
 689     // it if it doesn't run yet
 690     bool shouldResume = false,
 691          shouldCancel = true,
 692          isRunning = false;
 693
 694     // check if the thread already started to run
 695     {
 696         wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 697
 698         if ( m_internal->GetState() == STATE_NEW )
 699         {
 700             // WinThreadStart() will see it and terminate immediately, no need
 701             // to cancel the thread - but we still need to resume it to let it
 702             // run
 703             m_internal->SetState(STATE_EXITED);
 704
 705             Resume();   // it knows about STATE_EXITED special case
 706
 707             shouldCancel = false;
 708             isRunning = true;
 709
 710             // shouldResume is correctly set to false here
 711         }
 712         else
 713         {
 714             shouldResume = IsPaused();
 715         }
 716     }
 717
 718     // resume the thread if it is paused
 719     if ( shouldResume )
 720         Resume();
 721
 722     TID hThread = m_internal->GetHandle();
 723
 724     if ( isRunning || IsRunning())
 725     {
 726         if (IsMain())
 727         {
 728             // set flag for wxIsWaitingForThread()
 729             gs_bWaitingForThread = true;
 730         }
 731
 732         // ask the thread to terminate
 733         if ( shouldCancel )
 734         {
 735             wxCriticalSectionLocker lock(m_critsect);
 736
 737             m_internal->Cancel();
 738         }
 739
 740 #if 0
 741         // we can't just wait for the thread to terminate because it might be
 742         // calling some GUI functions and so it will never terminate before we
 743         // process the Windows messages that result from these functions
 744         DWORD result = 0;       // suppress warnings from broken compilers
 745         do
 746         {
 747             if ( IsMain() )
 748             {
 749                 // give the thread we're waiting for chance to do the GUI call
 750                 // it might be in
 751                 if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
 752                 {
 753                     wxMutexGuiLeave();
 754                 }
 755             }
 756
 757             result = ::DosWaitThread(&hThread, DCWW_NOWAIT);
 758             // FIXME: We ought to have a message processing loop here!!
 759
 760             switch ( result )
 761             {
 762                 case ERROR_INTERRUPT:
 763                 case ERROR_THREAD_NOT_TERMINATED:
 764                     break;
 765                 case ERROR_INVALID_THREADID:
 766                 case NO_ERROR:
 767                     // thread we're waiting for just terminated
 768                     // or even does not exist any more.
 769                     result = NO_ERROR;
 770                     break;
 771                 default:
 772                     wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 773             }
 774             if ( IsMain() )
 775             {
 776                 // event processing - needed if we are the main thread
 777                 // to give other threads a chance to do remaining GUI
 778                 // processing and terminate cleanly.
 779                 wxTheApp->HandleSockets();
 780                 if (wxTheApp->Pending())
 781                   if ( !wxTheApp->DoMessage() )
 782                   {
 783                       // WM_QUIT received: kill the thread
 784                       Kill();
 785
 786                       return wxTHREAD_KILLED;
 787                   }
 788                   else
 789                     wxUsleep(10);
 790             }
 791             else
 792                 wxUsleep(10);
 793         } while ( result != NO_ERROR );
 794 #else // !wxUSE_GUI
 795         // simply wait for the thread to terminate
 796         //
 797         // OTOH, even console apps create windows (in wxExecute, for WinSock
 798         // &c), so may be use MsgWaitForMultipleObject() too here?
 799         if ( ::DosWaitThread(&hThread, DCWW_WAIT) != NO_ERROR )
 800         {
 801             wxFAIL_MSG(wxT("unexpected result of DosWaitThread"));
 802         }
 803 #endif // wxUSE_GUI/!wxUSE_GUI
 804
 805         if ( IsMain() )
 806         {
 807             gs_bWaitingForThread = false;
 808         }
 809     }
 810
 811 #if 0
 812     // although the thread might be already in the EXITED state it might not
 813     // have terminated yet and so we are not sure that it has actually
 814     // terminated if the "if" above hadn't been taken
 815     do
 816     {
 817         if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
 818         {
 819             wxLogLastError(wxT("GetExitCodeThread"));
 820
 821             rc = (ExitCode)-1;
 822         }
 823     } while ( (DWORD)rc == STILL_ACTIVE );
 824 #endif
 825
 826     if ( IsDetached() )
 827     {
 828         // if the thread exits normally, this is done in WinThreadStart, but in
 829         // this case it would have been too early because
 830         // MsgWaitForMultipleObject() would fail if the thread handle was
 831         // closed while we were waiting on it, so we must do it here
 832         delete this;
 833     }
 834
 835     if ( pRc )
 836         *pRc = rc;
 837
 838     return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR;
 839 }
 840
 841 wxThreadError wxThread::Kill()
 842 {
 843     if (!IsRunning())
 844         return wxTHREAD_NOT_RUNNING;
 845
 846     ::DosKillThread(m_internal->GetHandle());
 847     if (IsDetached())
 848     {
 849         delete this;
 850     }
 851     return wxTHREAD_NO_ERROR;
 852 }
 853
 854 void wxThread::Exit(ExitCode WXUNUSED(pStatus))
 855 {
 856     delete this;
 857     _endthread();
 858     wxFAIL_MSG(wxT("Couldn't return from DosExit()!"));
 859 }
 860
 861 void wxThread::SetPriority(
 862   unsigned int                      nPrio
 863 )
 864 {
 865     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 866
 867     m_internal->SetPriority(nPrio);
 868 }
 869
 870 unsigned int wxThread::GetPriority() const
 871 {
 872     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 873
 874     return m_internal->GetPriority();
 875 }
 876
 877 unsigned long wxThread::GetId() const
 878 {
 879     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); // const_cast
 880
 881     return (unsigned long)m_internal->GetId();
 882 }
 883
 884 bool wxThread::IsRunning() const
 885 {
 886     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 887
 888     return(m_internal->GetState() == STATE_RUNNING);
 889 }
 890
 891 bool wxThread::IsAlive() const
 892 {
 893     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 894
 895     return (m_internal->GetState() == STATE_RUNNING) ||
 896            (m_internal->GetState() == STATE_PAUSED);
 897 }
 898
 899 bool wxThread::IsPaused() const
 900 {
 901     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 902
 903     return (m_internal->GetState() == STATE_PAUSED);
 904 }
 905
 906 bool wxThread::TestDestroy()
 907 {
 908     wxCriticalSectionLocker         lock((wxCriticalSection &)m_critsect);
 909
 910     return m_internal->GetState() == STATE_CANCELED;
 911 }
 912
 913 // ----------------------------------------------------------------------------
 914 // Automatic initialization for thread module
 915 // ----------------------------------------------------------------------------
 916
 917 class wxThreadModule : public wxModule
 918 {
 919 public:
 920     virtual bool OnInit();
 921     virtual void OnExit();
 922
 923 private:
 924     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 925 };
 926
 927 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 928
 929 bool wxThreadModule::OnInit()
 930 {
 931     gs_pCritsectWaitingForGui = new wxCriticalSection();
 932
 933     gs_pCritsectGui = new wxCriticalSection();
 934     gs_pCritsectGui->Enter();
 935
 936     wxThread::ms_idMainThread = wxThread::GetCurrentId();
 937
 938     return true;
 939 }
 940
 941 void wxThreadModule::OnExit()
 942 {
 943     if (gs_pCritsectGui)
 944     {
 945         gs_pCritsectGui->Leave();
 946 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 947         delete gs_pCritsectGui;
 948 #endif
 949         gs_pCritsectGui = NULL;
 950     }
 951
 952 #if (!(defined(__VISAGECPP__) && (__IBMCPP__ < 400 || __IBMC__ < 400 )))
 953     wxDELETE(gs_pCritsectWaitingForGui);
 954 #endif
 955 }
 956
 957 // ----------------------------------------------------------------------------
 958 // Helper functions
 959 // ----------------------------------------------------------------------------
 960
 961 // wake up the main thread if it's in ::GetMessage()
 962 void WXDLLEXPORT wxWakeUpMainThread()
 963 {
 964 #if 0
 965     if ( !::WinPostQueueMsg(wxTheApp->m_hMq, WM_NULL, 0, 0) )
 966     {
 967         // should never happen
 968         wxLogLastError(wxT("WinPostMessage(WM_NULL)"));
 969     }
 970 #endif
 971 }
 972
 973 void wxMutexGuiEnterImpl()
 974 {
 975     // this would dead lock everything...
 976     wxASSERT_MSG( !wxThread::IsMain(),
 977                   wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 978
 979     // the order in which we enter the critical sections here is crucial!!
 980
 981     // set the flag telling to the main thread that we want to do some GUI
 982     {
 983         wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 984
 985         gs_nWaitingForGui++;
 986     }
 987
 988     wxWakeUpMainThread();
 989
 990     // now we may block here because the main thread will soon let us in
 991     // (during the next iteration of OnIdle())
 992     gs_pCritsectGui->Enter();
 993 }
 994
 995 void wxMutexGuiLeaveImpl()
 996 {
 997     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
 998
 999     if ( wxThread::IsMain() )
1000     {
1001         gs_bGuiOwnedByMainThread = false;
1002     }
1003     else
1004     {
1005         // decrement the number of waiters now
1006         wxASSERT_MSG(gs_nWaitingForGui > 0,
1007                       wxT("calling wxMutexGuiLeave() without entering it first?") );
1008
1009         gs_nWaitingForGui--;
1010
1011         wxWakeUpMainThread();
1012     }
1013
1014     gs_pCritsectGui->Leave();
1015 }
1016
1017 void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
1018 {
1019     wxASSERT_MSG( wxThread::IsMain(),
1020                   wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
1021
1022     wxCriticalSectionLocker enter(*gs_pCritsectWaitingForGui);
1023
1024     if (gs_nWaitingForGui == 0)
1025     {
1026         // no threads are waiting for GUI - so we may acquire the lock without
1027         // any danger (but only if we don't already have it)
1028         if (!wxGuiOwnedByMainThread())
1029         {
1030             gs_pCritsectGui->Enter();
1031
1032             gs_bGuiOwnedByMainThread = true;
1033         }
1034         //else: already have it, nothing to do
1035     }
1036     else
1037     {
1038         // some threads are waiting, release the GUI lock if we have it
1039         if (wxGuiOwnedByMainThread())
1040         {
1041             wxMutexGuiLeave();
1042         }
1043         //else: some other worker thread is doing GUI
1044     }
1045 }
1046
1047 bool WXDLLEXPORT wxGuiOwnedByMainThread()
1048 {
1049     return gs_bGuiOwnedByMainThread;
1050 }
1051
1052 bool WXDLLEXPORT wxIsWaitingForThread()
1053 {
1054     return gs_bWaitingForThread;
1055 }
1056
1057 // ----------------------------------------------------------------------------
1058 // include common implementation code
1059 // ----------------------------------------------------------------------------
1060
1061 #include "wx/thrimpl.cpp"
1062
1063 #endif
1064   // wxUSE_THREADS