src/gtk/threadpsx.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        threadpsx.cpp
   3 // Purpose:     wxThread (Posix) Implementation
   4 // Author:      Original from Wolfram Gloger/Guilhem Lavaux
   5 // Modified by:
   6 // Created:     04/22/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Wolfram Gloger (1996, 1997)
   9 //                  Guilhem Lavaux (1998)
  10 //                  Robert Roebling (1999)
  11 // Licence:     wxWindows licence
  12 /////////////////////////////////////////////////////////////////////////////
  13
  14 #ifdef __GNUG__
  15     #pragma implementation "thread.h"
  16 #endif
  17
  18 #include <stdio.h>
  19 #include <unistd.h>
  20 #include <pthread.h>
  21 #include <errno.h>
  22
  23 #ifdef __linux__
  24     #include <sched.h>
  25 #endif
  26
  27 #ifdef __SUN__
  28 extern int usleep(unsigned int useconds);
  29 #endif
  30
  31
  32 #include "wx/thread.h"
  33 #include "wx/module.h"
  34 #include "wx/utils.h"
  35 #include "wx/log.h"
  36 #include "wx/intl.h"
  37 #include "wx/dynarray.h"
  38
  39 #include "gdk/gdk.h"
  40 #include "gtk/gtk.h"
  41
  42 enum thread_state
  43 {
  44     STATE_NEW,          // didn't start execution yet (=> RUNNING)
  45     STATE_RUNNING,
  46     STATE_PAUSED,
  47     STATE_CANCELED,
  48     STATE_EXITED
  49 };
  50
  51 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
  52
  53 // -----------------------------------------------------------------------------
  54 // global data
  55 // -----------------------------------------------------------------------------
  56
  57 // we keep the list of all threads created by the application to be able to
  58 // terminate them on exit if there are some left - otherwise the process would
  59 // be left in memory
  60 static wxArrayThread gs_allThreads;
  61
  62 // the id of the main thread
  63 static pthread_t gs_tidMain;
  64
  65 // the key for the pointer to the associated wxThread object
  66 static pthread_key_t gs_keySelf;
  67
  68 // this mutex must be acquired before any call to a GUI function
  69 static wxMutex *gs_mutexGui;
  70
  71 //--------------------------------------------------------------------
  72 // common GUI thread code
  73 //--------------------------------------------------------------------
  74
  75 #include "threadgui.inc"
  76
  77 //--------------------------------------------------------------------
  78 // wxMutex (Posix implementation)
  79 //--------------------------------------------------------------------
  80
  81 class wxMutexInternal
  82 {
  83 public:
  84   pthread_mutex_t p_mutex;
  85 };
  86
  87 wxMutex::wxMutex()
  88 {
  89     p_internal = new wxMutexInternal;
  90     pthread_mutex_init( &(p_internal->p_mutex), (const pthread_mutexattr_t*) NULL );
  91     m_locked = 0;
  92 }
  93
  94 wxMutex::~wxMutex()
  95 {
  96     if (m_locked > 0)
  97         wxLogDebug("Freeing a locked mutex (%d locks)", m_locked);
  98
  99     pthread_mutex_destroy( &(p_internal->p_mutex) );
 100     delete p_internal;
 101 }
 102
 103 wxMutexError wxMutex::Lock()
 104 {
 105     int err = pthread_mutex_lock( &(p_internal->p_mutex) );
 106     if (err == EDEADLK)
 107     {
 108         wxLogDebug("Locking this mutex would lead to deadlock!");
 109
 110         return wxMUTEX_DEAD_LOCK;
 111     }
 112
 113     m_locked++;
 114
 115     return wxMUTEX_NO_ERROR;
 116 }
 117
 118 wxMutexError wxMutex::TryLock()
 119 {
 120     if (m_locked)
 121     {
 122         return wxMUTEX_BUSY;
 123     }
 124
 125     int err = pthread_mutex_trylock( &(p_internal->p_mutex) );
 126     switch (err)
 127     {
 128         case EBUSY: return wxMUTEX_BUSY;
 129     }
 130
 131     m_locked++;
 132
 133     return wxMUTEX_NO_ERROR;
 134 }
 135
 136 wxMutexError wxMutex::Unlock()
 137 {
 138     if (m_locked > 0)
 139     {
 140         m_locked--;
 141     }
 142     else
 143     {
 144         wxLogDebug("Unlocking not locked mutex.");
 145
 146         return wxMUTEX_UNLOCKED;
 147     }
 148
 149     pthread_mutex_unlock( &(p_internal->p_mutex) );
 150
 151     return wxMUTEX_NO_ERROR;
 152 }
 153
 154 //--------------------------------------------------------------------
 155 // wxCondition (Posix implementation)
 156 //--------------------------------------------------------------------
 157
 158 class wxConditionInternal
 159 {
 160 public:
 161   pthread_cond_t p_condition;
 162 };
 163
 164 wxCondition::wxCondition()
 165 {
 166     p_internal = new wxConditionInternal;
 167     pthread_cond_init( &(p_internal->p_condition), (const pthread_condattr_t *) NULL );
 168 }
 169
 170 wxCondition::~wxCondition()
 171 {
 172     pthread_cond_destroy( &(p_internal->p_condition) );
 173
 174     delete p_internal;
 175 }
 176
 177 void wxCondition::Wait(wxMutex& mutex)
 178 {
 179     pthread_cond_wait( &(p_internal->p_condition), &(mutex.p_internal->p_mutex) );
 180 }
 181
 182 bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec)
 183 {
 184     struct timespec tspec;
 185
 186     tspec.tv_sec = time(0L)+sec;
 187     tspec.tv_nsec = nsec;
 188     return (pthread_cond_timedwait(&(p_internal->p_condition), &(mutex.p_internal->p_mutex), &tspec) != ETIMEDOUT);
 189 }
 190
 191 void wxCondition::Signal()
 192 {
 193     pthread_cond_signal( &(p_internal->p_condition) );
 194 }
 195
 196 void wxCondition::Broadcast()
 197 {
 198     pthread_cond_broadcast( &(p_internal->p_condition) );
 199 }
 200
 201 //--------------------------------------------------------------------
 202 // wxThread (Posix implementation)
 203 //--------------------------------------------------------------------
 204
 205 class wxThreadInternal
 206 {
 207 public:
 208     wxThreadInternal();
 209     ~wxThreadInternal();
 210
 211     // thread entry function
 212     static void *PthreadStart(void *ptr);
 213
 214     // thread actions
 215         // start the thread
 216     wxThreadError Run();
 217         // ask the thread to terminate
 218     void Cancel();
 219         // wake up threads waiting for our termination
 220     void SignalExit();
 221         // go to sleep until Resume() is called
 222     void Pause();
 223         // resume the thread
 224     void Resume();
 225
 226     // accessors
 227         // priority
 228     int GetPriority() const { return m_prio; }
 229     void SetPriority(int prio) { m_prio = prio; }
 230         // state
 231     thread_state GetState() const { return m_state; }
 232     void SetState(thread_state state) { m_state = state; }
 233         // id
 234     pthread_t GetId() const { return thread_id; }
 235         // "cancelled" flag
 236     bool WasCancelled() const { return m_cancelled; }
 237
 238 //private: -- should be!
 239     pthread_t thread_id;
 240
 241 private:
 242     thread_state m_state;    // see thread_state enum
 243     int          m_prio;     // in wxWindows units: from 0 to 100
 244
 245     // set when the thread should terminate
 246     bool m_cancelled;
 247
 248     // this (mutex, cond) pair is used to synchronize the main thread and this
 249     // thread in several situations:
 250     //  1. The thread function blocks until condition is signaled by Run() when
 251     //     it's initially created - this allows create thread in "suspended"
 252     //     state
 253     //  2. The Delete() function blocks until the condition is signaled when the
 254     //     thread exits.
 255     wxMutex     m_mutex;
 256     wxCondition m_cond;
 257
 258     // another (mutex, cond) pair for Pause()/Resume() usage
 259     //
 260     // VZ: it's possible that we might reuse the mutex and condition from above
 261     //     for this too, but as I'm not at all sure that it won't create subtle
 262     //     problems with race conditions between, say, Pause() and Delete() I
 263     //     prefer this may be a bit less efficient but much safer solution
 264     wxMutex     m_mutexSuspend;
 265     wxCondition m_condSuspend;
 266 };
 267
 268 void *wxThreadInternal::PthreadStart(void *ptr)
 269 {
 270     wxThread *thread = (wxThread *)ptr;
 271     wxThreadInternal *pthread = thread->p_internal;
 272
 273     if ( pthread_setspecific(gs_keySelf, thread) != 0 )
 274     {
 275         wxLogError(_("Can not start thread: error writing TLS."));
 276
 277         return (void *)-1;
 278     }
 279
 280     // wait for the condition to be signaled from Run()
 281     // mutex state: currently locked by the thread which created us
 282     pthread->m_cond.Wait(pthread->m_mutex);
 283
 284     // mutex state: locked again on exit of Wait()
 285
 286     // call the main entry
 287     void* status = thread->Entry();
 288
 289     // terminate the thread
 290     thread->Exit(status);
 291
 292     wxFAIL_MSG("wxThread::Exit() can't return.");
 293
 294     return NULL;
 295 }
 296
 297 wxThreadInternal::wxThreadInternal()
 298 {
 299     m_state = STATE_NEW;
 300     m_cancelled = FALSE;
 301
 302     // this mutex is locked during almost all thread lifetime - it will only be
 303     // unlocked in the very end
 304     m_mutex.Lock();
 305
 306     // this mutex is used in Pause()/Resume() and is also locked all the time
 307     // unless the thread is paused
 308     m_mutexSuspend.Lock();
 309 }
 310
 311 wxThreadInternal::~wxThreadInternal()
 312 {
 313     m_mutexSuspend.Unlock();
 314
 315     // note that m_mutex will be unlocked by the thread which waits for our
 316     // termination
 317 }
 318
 319 wxThreadError wxThreadInternal::Run()
 320 {
 321     wxCHECK_MSG( GetState() == STATE_NEW, wxTHREAD_RUNNING,
 322                  "thread may only be started once after successful Create()" );
 323
 324     // the mutex was locked on Create(), so we will be able to lock it again
 325     // only when the thread really starts executing and enters the wait -
 326     // otherwise we might signal the condition before anybody is waiting for it
 327     wxMutexLocker lock(m_mutex);
 328     m_cond.Signal();
 329
 330     m_state = STATE_RUNNING;
 331
 332     return wxTHREAD_NO_ERROR;
 333
 334     // now the mutex is unlocked back - but just to allow Wait() function to
 335     // terminate by relocking it, so the net result is that the worker thread
 336     // starts executing and the mutex is still locked
 337 }
 338
 339 void wxThreadInternal::Cancel()
 340 {
 341     // if the thread we're waiting for is waiting for the GUI mutex, we will
 342     // deadlock so make sure we release it temporarily
 343     if ( wxThread::IsMain() )
 344         wxMutexGuiLeave();
 345
 346     // nobody ever writes this variable so it's safe to not use any
 347     // synchronization here
 348     m_cancelled = TRUE;
 349
 350     // entering Wait() releases the mutex thus allowing SignalExit() to acquire
 351     // it and to signal us its termination
 352     m_cond.Wait(m_mutex);
 353
 354     // mutex is still in the locked state - relocked on exit from Wait(), so
 355     // unlock it - we don't need it any more, the thread has already terminated
 356     m_mutex.Unlock();
 357
 358     // reacquire GUI mutex
 359     if ( wxThread::IsMain() )
 360         wxMutexGuiEnter();
 361 }
 362
 363 void wxThreadInternal::SignalExit()
 364 {
 365     // as mutex is currently locked, this will block until some other thread
 366     // (normally the same which created this one) unlocks it by entering Wait()
 367     m_mutex.Lock();
 368
 369     // wake up all the threads waiting for our termination
 370     m_cond.Broadcast();
 371
 372     // after this call mutex will be finally unlocked
 373     m_mutex.Unlock();
 374 }
 375
 376 void wxThreadInternal::Pause()
 377 {
 378     wxCHECK_RET( m_state == STATE_PAUSED,
 379                  "thread must first be paused with wxThread::Pause()." );
 380
 381     // wait until the condition is signaled from Resume()
 382     m_condSuspend.Wait(m_mutexSuspend);
 383 }
 384
 385 void wxThreadInternal::Resume()
 386 {
 387     wxCHECK_RET( m_state == STATE_PAUSED,
 388                  "can't resume thread which is not suspended." );
 389
 390     // we will be able to lock this mutex only when Pause() starts waiting
 391     wxMutexLocker lock(m_mutexSuspend);
 392     m_condSuspend.Signal();
 393
 394     SetState(STATE_RUNNING);
 395 }
 396
 397 // -----------------------------------------------------------------------------
 398 // static functions
 399 // -----------------------------------------------------------------------------
 400
 401 wxThread *wxThread::This()
 402 {
 403     return (wxThread *)pthread_getspecific(gs_keySelf);
 404 }
 405
 406 bool wxThread::IsMain()
 407 {
 408     return (bool)pthread_equal(pthread_self(), gs_tidMain);
 409 }
 410
 411 void wxThread::Yield()
 412 {
 413 #ifdef HAVE_SCHED_YIELD
 414     sched_yield();
 415 #else // !HAVE_SCHED_YIELD
 416     // may be it will have the desired effect?
 417     Sleep(0);
 418 #endif // HAVE_SCHED_YIELD
 419 }
 420
 421 void wxThread::Sleep(unsigned long milliseconds)
 422 {
 423     wxUsleep(milliseconds);
 424 }
 425
 426 // -----------------------------------------------------------------------------
 427 // creating thread
 428 // -----------------------------------------------------------------------------
 429
 430 wxThread::wxThread()
 431 {
 432     // add this thread to the global list of all threads
 433     gs_allThreads.Add(this);
 434
 435     p_internal = new wxThreadInternal();
 436 }
 437
 438 wxThreadError wxThread::Create()
 439 {
 440     if (p_internal->GetState() != STATE_NEW)
 441         return wxTHREAD_RUNNING;
 442
 443     // set up the thread attribute: right now, we only set thread priority
 444     pthread_attr_t attr;
 445     pthread_attr_init(&attr);
 446
 447 #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
 448     int prio;
 449     if ( pthread_attr_getschedpolicy(&attr, &prio) != 0 )
 450     {
 451         wxLogError(_("Can not retrieve thread scheduling policy."));
 452     }
 453
 454     int min_prio = sched_get_priority_min(prio),
 455         max_prio = sched_get_priority_max(prio);
 456
 457     if ( min_prio == -1 || max_prio == -1 )
 458     {
 459         wxLogError(_("Can not get priority range for scheduling policy %d."),
 460                    prio);
 461     }
 462     else
 463     {
 464         struct sched_param sp;
 465         pthread_attr_getschedparam(&attr, &sp);
 466         sp.sched_priority = min_prio +
 467                            (p_internal->GetPriority()*(max_prio-min_prio))/100;
 468         pthread_attr_setschedparam(&attr, &sp);
 469     }
 470 #endif // HAVE_THREAD_PRIORITY_FUNCTIONS
 471
 472     // create the new OS thread object
 473     int rc = pthread_create(&p_internal->thread_id, &attr,
 474                             wxThreadInternal::PthreadStart, (void *)this);
 475     pthread_attr_destroy(&attr);
 476
 477     if ( rc != 0 )
 478     {
 479         p_internal->SetState(STATE_EXITED);
 480         return wxTHREAD_NO_RESOURCE;
 481     }
 482
 483     return wxTHREAD_NO_ERROR;
 484 }
 485
 486 wxThreadError wxThread::Run()
 487 {
 488     return p_internal->Run();
 489 }
 490
 491 // -----------------------------------------------------------------------------
 492 // misc accessors
 493 // -----------------------------------------------------------------------------
 494
 495 void wxThread::SetPriority(unsigned int prio)
 496 {
 497     wxCHECK_RET( ((int)WXTHREAD_MIN_PRIORITY <= (int)prio) &&
 498                  ((int)prio <= (int)WXTHREAD_MAX_PRIORITY),
 499                  "invalid thread priority" );
 500
 501     wxCriticalSectionLocker lock(m_critsect);
 502
 503     switch ( p_internal->GetState() )
 504     {
 505         case STATE_NEW:
 506             // thread not yet started, priority will be set when it is
 507             p_internal->SetPriority(prio);
 508             break;
 509
 510         case STATE_RUNNING:
 511         case STATE_PAUSED:
 512 #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS
 513             {
 514                 struct sched_param sparam;
 515                 sparam.sched_priority = prio;
 516
 517                 if ( pthread_setschedparam(p_internal->GetId(),
 518                                            SCHED_OTHER, &sparam) != 0 )
 519                 {
 520                     wxLogError(_("Failed to set thread priority %d."), prio);
 521                 }
 522             }
 523 #endif // HAVE_THREAD_PRIORITY_FUNCTIONS
 524             break;
 525
 526         case STATE_EXITED:
 527         default:
 528             wxFAIL_MSG("impossible to set thread priority in this state");
 529     }
 530 }
 531
 532 unsigned int wxThread::GetPriority() const
 533 {
 534     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 535
 536     return p_internal->GetPriority();
 537 }
 538
 539 unsigned long wxThread::GetID() const
 540 {
 541     return (unsigned long)p_internal->thread_id;
 542 }
 543
 544 // -----------------------------------------------------------------------------
 545 // pause/resume
 546 // -----------------------------------------------------------------------------
 547
 548 wxThreadError wxThread::Pause()
 549 {
 550     wxCriticalSectionLocker lock(m_critsect);
 551
 552     if ( p_internal->GetState() != STATE_RUNNING )
 553     {
 554         wxLogDebug("Can't pause thread which is not running.");
 555
 556         return wxTHREAD_NOT_RUNNING;
 557     }
 558
 559     p_internal->SetState(STATE_PAUSED);
 560
 561     return wxTHREAD_NO_ERROR;
 562 }
 563
 564 wxThreadError wxThread::Resume()
 565 {
 566     wxCriticalSectionLocker lock(m_critsect);
 567
 568     if ( p_internal->GetState() == STATE_PAUSED )
 569     {
 570         p_internal->Resume();
 571
 572         return wxTHREAD_NO_ERROR;
 573     }
 574     else
 575     {
 576         wxLogDebug("Attempt to resume a thread which is not paused.");
 577
 578         return wxTHREAD_MISC_ERROR;
 579     }
 580 }
 581
 582 // -----------------------------------------------------------------------------
 583 // exiting thread
 584 // -----------------------------------------------------------------------------
 585
 586 wxThread::ExitCode wxThread::Delete()
 587 {
 588     m_critsect.Enter();
 589     thread_state state = p_internal->GetState();
 590     m_critsect.Leave();
 591
 592     switch ( state )
 593     {
 594         case STATE_NEW:
 595         case STATE_EXITED:
 596             // nothing to do
 597             break;
 598
 599         case STATE_PAUSED:
 600             // resume the thread first
 601             Resume();
 602
 603             // fall through
 604
 605         default:
 606             // set the flag telling to the thread to stop and wait
 607             p_internal->Cancel();
 608     }
 609
 610     return NULL;
 611 }
 612
 613 wxThreadError wxThread::Kill()
 614 {
 615     switch ( p_internal->GetState() )
 616     {
 617         case STATE_NEW:
 618         case STATE_EXITED:
 619             return wxTHREAD_NOT_RUNNING;
 620
 621         default:
 622 #ifdef HAVE_PTHREAD_CANCEL
 623             if ( pthread_cancel(p_internal->GetId()) != 0 )
 624 #endif
 625             {
 626                 wxLogError(_("Failed to terminate a thread."));
 627
 628                 return wxTHREAD_MISC_ERROR;
 629             }
 630
 631             return wxTHREAD_NO_ERROR;
 632     }
 633 }
 634
 635 void wxThread::Exit(void *status)
 636 {
 637     // first call user-level clean up code
 638     OnExit();
 639
 640     // next wake up the threads waiting for us (OTOH, this function won't return
 641     // until someone waited for us!)
 642     p_internal->SignalExit();
 643
 644     p_internal->SetState(STATE_EXITED);
 645
 646     // delete both C++ thread object and terminate the OS thread object
 647     delete this;
 648     pthread_exit(status);
 649 }
 650
 651 // also test whether we were paused
 652 bool wxThread::TestDestroy()
 653 {
 654     wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);
 655
 656     if ( p_internal->GetState() == STATE_PAUSED )
 657     {
 658         // leave the crit section or the other threads will stop too if they try
 659         // to call any of (seemingly harmless) IsXXX() functions while we sleep
 660         m_critsect.Leave();
 661
 662         p_internal->Pause();
 663
 664         // enter it back before it's finally left in lock object dtor
 665         m_critsect.Enter();
 666     }
 667
 668     return p_internal->WasCancelled();
 669 }
 670
 671 wxThread::~wxThread()
 672 {
 673     // remove this thread from the global array
 674     gs_allThreads.Remove(this);
 675 }
 676
 677 // -----------------------------------------------------------------------------
 678 // state tests
 679 // -----------------------------------------------------------------------------
 680
 681 bool wxThread::IsRunning() const
 682 {
 683     wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 684
 685     return p_internal->GetState() == STATE_RUNNING;
 686 }
 687
 688 bool wxThread::IsAlive() const
 689 {
 690     wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);
 691
 692     switch ( p_internal->GetState() )
 693     {
 694         case STATE_RUNNING:
 695         case STATE_PAUSED:
 696             return TRUE;
 697
 698         default:
 699             return FALSE;
 700     }
 701 }
 702
 703 //--------------------------------------------------------------------
 704 // wxThreadModule
 705 //--------------------------------------------------------------------
 706
 707 class wxThreadModule : public wxModule
 708 {
 709 public:
 710     virtual bool OnInit();
 711     virtual void OnExit();
 712
 713 private:
 714     DECLARE_DYNAMIC_CLASS(wxThreadModule)
 715 };
 716
 717 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 718
 719 bool wxThreadModule::OnInit()
 720 {
 721     if ( pthread_key_create(&gs_keySelf, NULL /* dtor function */) != 0 )
 722     {
 723         wxLogError(_("Thread module initialization failed: "
 724                      "failed to create pthread key."));
 725
 726         return FALSE;
 727     }
 728
 729     gs_mutexGui = new wxMutex();
 730     wxThreadGuiInit();
 731     gs_tidMain = pthread_self();
 732     gs_mutexGui->Lock();
 733
 734     return TRUE;
 735 }
 736
 737 void wxThreadModule::OnExit()
 738 {
 739     wxASSERT_MSG( wxThread::IsMain(), "only main thread can be here" );
 740
 741     // terminate any threads left
 742     size_t count = gs_allThreads.GetCount();
 743     if ( count != 0u )
 744         wxLogDebug("Some threads were not terminated by the application.");
 745
 746     for ( size_t n = 0u; n < count; n++ )
 747     {
 748         gs_allThreads[n]->Delete();
 749     }
 750
 751     // destroy GUI mutex
 752     gs_mutexGui->Unlock();
 753     wxThreadGuiExit();
 754     delete gs_mutexGui;
 755
 756     // and free TLD slot
 757     (void)pthread_key_delete(gs_keySelf);
 758 }