samples/thread/test.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        test.cpp
   3 // Purpose:     wxWindows thread sample
   4 // Author:      Julian Smart(minimal)/Guilhem Lavaux(thread test)
   5 // Modified by:
   6 // Created:     06/16/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart, Markus Holzem, Guilhem Lavaux
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 /*
  13     TODO: use worker threads to update progress controls instead of writing
  14           messages - it will be more visual
  15  */
  16
  17 #ifdef __GNUG__
  18     #pragma implementation "test.cpp"
  19     #pragma interface "test.cpp"
  20 #endif
  21
  22 // For compilers that support precompilation, includes "wx/wx.h".
  23 #include "wx/wxprec.h"
  24
  25 #ifdef __BORLANDC__
  26     #pragma hdrstop
  27 #endif
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/wx.h"
  31 #endif
  32
  33 #if !wxUSE_THREADS
  34     #error "This sample requires thread support!"
  35 #endif // wxUSE_THREADS
  36
  37 #include "wx/thread.h"
  38 #include "wx/dynarray.h"
  39 #include "wx/time.h"
  40
  41 #include "wx/progdlg.h"
  42
  43 class MyThread;
  44 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
  45
  46 // Define a new application type
  47 class MyApp : public wxApp
  48 {
  49 public:
  50     virtual bool OnInit();
  51
  52 public:
  53     // all the threads currently alive - as soon as the thread terminates, it's
  54     // removed from the array
  55     wxArrayThread m_threads;
  56
  57     // crit section protects access to all of the arrays below
  58     wxCriticalSection m_critsect;
  59 };
  60
  61 // Create a new application object
  62 IMPLEMENT_APP(MyApp)
  63
  64 // Define a new frame type
  65 class MyFrame: public wxFrame
  66 {
  67 public:
  68     // ctor
  69     MyFrame(wxFrame *frame, const wxString& title, int x, int y, int w, int h);
  70
  71     // operations
  72     void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
  73
  74     // accessors for MyWorkerThread (called in its context!)
  75     bool Cancelled();
  76
  77     // callbacks
  78     void OnQuit(wxCommandEvent& event);
  79     void OnAbout(wxCommandEvent& event);
  80     void OnClear(wxCommandEvent& event);
  81
  82     void OnStartThread(wxCommandEvent& event);
  83     void OnStartThreads(wxCommandEvent& event);
  84     void OnStopThread(wxCommandEvent& event);
  85     void OnPauseThread(wxCommandEvent& event);
  86     void OnResumeThread(wxCommandEvent& event);
  87
  88     void OnStartWorker(wxCommandEvent& event);
  89     void OnWorkerEvent(wxCommandEvent& event);
  90     void OnUpdateWorker(wxUpdateUIEvent& event);
  91
  92     void OnIdle(wxIdleEvent &event);
  93
  94 private:
  95     // helper function - creates a new thread (but doesn't run it)
  96     MyThread *CreateThread();
  97
  98     // just some place to put our messages in
  99     wxTextCtrl *m_txtctrl;
 100
 101     // remember the number of running threads and total number of threads
 102     size_t m_nRunning, m_nCount;
 103
 104     // the progress dialog which we show while worker thread is running
 105     wxProgressDialog *m_dlgProgress;
 106
 107     // was the worker thread cancelled by user?
 108     bool m_cancelled;
 109
 110     // protects m_cancelled
 111     wxCriticalSection m_critsectWork;
 112
 113     DECLARE_EVENT_TABLE()
 114 };
 115
 116 // ID for the menu commands
 117 enum
 118 {
 119     TEST_QUIT          = 1,
 120     TEST_TEXT          = 101,
 121     TEST_ABOUT,
 122     TEST_CLEAR,
 123     TEST_START_THREAD  = 201,
 124     TEST_START_THREADS,
 125     TEST_STOP_THREAD,
 126     TEST_PAUSE_THREAD,
 127     TEST_RESUME_THREAD,
 128     TEST_START_WORKER,
 129     WORKER_EVENT    // this one gets sent from the worker thread
 130 };
 131
 132 //--------------------------------------------------
 133 // GUI thread
 134 //--------------------------------------------------
 135
 136 class MyThread : public wxThread
 137 {
 138 public:
 139     MyThread(MyFrame *frame);
 140
 141     // thread execution starts here
 142     virtual void *Entry();
 143
 144     // called when the thread exits - whether it terminates normally or is
 145     // stopped with Delete() (but not when it is Kill()ed!)
 146     virtual void OnExit();
 147
 148     // write something to the text control
 149     void WriteText(const wxString& text);
 150
 151 public:
 152     size_t   m_count;
 153     MyFrame *m_frame;
 154 };
 155
 156 MyThread::MyThread(MyFrame *frame)
 157         : wxThread()
 158 {
 159     m_count = 0;
 160     m_frame = frame;
 161 }
 162
 163 void MyThread::WriteText(const wxString& text)
 164 {
 165     wxString msg;
 166
 167     // before doing any GUI calls we must ensure that this thread is the only
 168     // one doing it!
 169
 170     wxMutexGuiEnter();
 171
 172     msg << text;
 173     m_frame->WriteText(msg);
 174
 175     wxMutexGuiLeave();
 176 }
 177
 178 void MyThread::OnExit()
 179 {
 180     wxCriticalSectionLocker locker(wxGetApp().m_critsect);
 181
 182     wxGetApp().m_threads.Remove(this);
 183 }
 184
 185 void *MyThread::Entry()
 186 {
 187     wxString text;
 188
 189     text.Printf("Thread 0x%x started (priority = %d).\n",
 190                 GetId(), GetPriority());
 191     WriteText(text);
 192     // wxLogMessage(text); -- test wxLog thread safeness
 193
 194     for ( m_count = 0; m_count < 10; m_count++ )
 195     {
 196         // check if we were asked to exit
 197         if ( TestDestroy() )
 198             break;
 199
 200         text.Printf("[%u] Thread 0x%x here.\n", m_count, GetId());
 201         WriteText(text);
 202
 203         // wxSleep() can't be called from non-GUI thread!
 204         wxThread::Sleep(1000);
 205     }
 206
 207     text.Printf("Thread 0x%x finished.\n", GetId());
 208     WriteText(text);
 209     // wxLogMessage(text); -- test wxLog thread safeness
 210
 211     return NULL;
 212 }
 213
 214 //--------------------------------------------------
 215 // worker thread
 216 //--------------------------------------------------
 217
 218 class MyWorkerThread : public wxThread
 219 {
 220 public:
 221     MyWorkerThread(MyFrame *frame);
 222
 223     // thread execution starts here
 224     virtual void *Entry();
 225
 226     // called when the thread exits - whether it terminates normally or is
 227     // stopped with Delete() (but not when it is Kill()ed!)
 228     virtual void OnExit();
 229
 230 public:
 231     MyFrame *m_frame;
 232     size_t   m_count;
 233 };
 234
 235 MyWorkerThread::MyWorkerThread(MyFrame *frame)
 236         : wxThread()
 237 {
 238     m_frame = frame;
 239     m_count = 0;
 240 }
 241
 242 void MyWorkerThread::OnExit()
 243 {
 244 }
 245
 246 void *MyWorkerThread::Entry()
 247 {
 248     for ( m_count = 0; !m_frame->Cancelled() && (m_count < 100); m_count++ )
 249     {
 250         // check if we were asked to exit
 251         if ( TestDestroy() )
 252             break;
 253
 254         wxString text;
 255         text.Printf("[%u] Thread 0x%x here!!", m_count, GetId());
 256
 257         // create any type of command event here
 258         wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
 259         event.SetInt( m_count );
 260         event.SetString( text );
 261
 262         // send in a thread-safe way
 263         wxPostEvent( m_frame, event );
 264
 265         // same as:
 266         // m_frame->AddPendingEvent( event );
 267
 268         // wxSleep() can't be called from non-main thread!
 269         wxThread::Sleep(200);
 270     }
 271
 272     wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
 273     event.SetInt(-1); // that's all
 274     wxPostEvent( m_frame, event );
 275
 276     return NULL;
 277 }
 278
 279 //--------------------------------------------------
 280 // main program
 281 //--------------------------------------------------
 282
 283 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 284     EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
 285     EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
 286     EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
 287     EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
 288     EVT_MENU(TEST_START_THREADS, MyFrame::OnStartThreads)
 289     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
 290     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
 291     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
 292
 293     EVT_UPDATE_UI(TEST_START_WORKER, MyFrame::OnUpdateWorker)
 294     EVT_MENU(TEST_START_WORKER, MyFrame::OnStartWorker)
 295     EVT_MENU(WORKER_EVENT, MyFrame::OnWorkerEvent)
 296
 297     EVT_IDLE(MyFrame::OnIdle)
 298 END_EVENT_TABLE()
 299
 300 // `Main program' equivalent, creating windows and returning main app frame
 301 bool MyApp::OnInit()
 302 {
 303     // Create the main frame window
 304     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
 305                                  50, 50, 450, 340);
 306
 307     // Make a menubar
 308     wxMenu *file_menu = new wxMenu;
 309
 310     file_menu->Append(TEST_CLEAR, "&Clear log\tCtrl-L");
 311     file_menu->AppendSeparator();
 312     file_menu->Append(TEST_ABOUT, "&About");
 313     file_menu->AppendSeparator();
 314     file_menu->Append(TEST_QUIT, "E&xit\tAlt-X");
 315     wxMenuBar *menu_bar = new wxMenuBar;
 316     menu_bar->Append(file_menu, "&File");
 317
 318     wxMenu *thread_menu = new wxMenu;
 319     thread_menu->Append(TEST_START_THREAD, "&Start a new thread\tCtrl-N");
 320     thread_menu->Append(TEST_START_THREADS, "Start &many threads at once");
 321     thread_menu->Append(TEST_STOP_THREAD, "S&top a running thread\tCtrl-S");
 322     thread_menu->AppendSeparator();
 323     thread_menu->Append(TEST_PAUSE_THREAD, "&Pause a running thread\tCtrl-P");
 324     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
 325     thread_menu->AppendSeparator();
 326     thread_menu->Append(TEST_START_WORKER, "Start &worker thread\tCtrl-W");
 327
 328     menu_bar->Append(thread_menu, "&Thread");
 329     frame->SetMenuBar(menu_bar);
 330
 331     // Show the frame
 332     frame->Show(TRUE);
 333
 334     SetTopWindow(frame);
 335
 336     return TRUE;
 337 }
 338
 339 // My frame constructor
 340 MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 341                  int x, int y, int w, int h)
 342        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
 343 {
 344     m_nRunning = m_nCount = 0;
 345
 346     m_dlgProgress = (wxProgressDialog *)NULL;
 347
 348     CreateStatusBar(2);
 349
 350     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
 351                                wxTE_MULTILINE | wxTE_READONLY);
 352
 353 }
 354
 355 MyThread *MyFrame::CreateThread()
 356 {
 357     MyThread *thread = new MyThread(this);
 358
 359     if ( thread->Create() != wxTHREAD_NO_ERROR )
 360     {
 361         wxLogError("Can't create thread!");
 362     }
 363
 364     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 365     wxGetApp().m_threads.Add(thread);
 366
 367     return thread;
 368 }
 369
 370 void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
 371 {
 372     static long s_num = 10;
 373
 374     s_num = wxGetNumberFromUser("How many threads to start: ", "",
 375                                 "wxThread sample", s_num, 1, 10000, this);
 376     if ( s_num == -1 )
 377     {
 378         s_num = 10;
 379
 380         return;
 381     }
 382
 383     size_t count = (size_t)s_num, n;
 384
 385     wxArrayThread threads;
 386
 387     // first create them all...
 388     for ( n = 0; n < count; n++ )
 389     {
 390         wxThread *thr = CreateThread();
 391
 392         // we want to show the effect of SetPriority(): the first thread will
 393         // have the lowest priority, the second - the highest, all the rest
 394         // the normal one
 395         if ( n == 0 )
 396             thr->SetPriority(WXTHREAD_MIN_PRIORITY);
 397         else if ( n == 1 )
 398             thr->SetPriority(WXTHREAD_MAX_PRIORITY);
 399         else
 400             thr->SetPriority(WXTHREAD_DEFAULT_PRIORITY);
 401
 402         threads.Add(thr);
 403     }
 404
 405     wxString msg;
 406     msg.Printf("%d new threads created.", count);
 407     SetStatusText(msg, 1);
 408
 409     // ...and then start them
 410     for ( n = 0; n < count; n++ )
 411     {
 412         threads[n]->Run();
 413     }
 414 }
 415
 416 void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 417 {
 418     MyThread *thread = CreateThread();
 419
 420     if ( thread->Run() != wxTHREAD_NO_ERROR )
 421     {
 422         wxLogError("Can't start thread!");
 423     }
 424
 425     SetStatusText("New thread started.", 1);
 426 }
 427
 428 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 429 {
 430     // stop the last thread
 431     if ( wxGetApp().m_threads.IsEmpty() )
 432     {
 433         wxLogError("No thread to stop!");
 434     }
 435     else
 436     {
 437         wxGetApp().m_critsect.Enter();
 438
 439         wxThread *thread = wxGetApp().m_threads.Last();
 440
 441         // it's important to leave critical section before calling Delete()
 442         // because delete will (implicitly) call OnExit() which also tries
 443         // to enter the same crit section - would dead lock.
 444         wxGetApp().m_critsect.Leave();
 445
 446         thread->Delete();
 447
 448         SetStatusText("Thread stopped.", 1);
 449     }
 450 }
 451
 452 void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
 453 {
 454     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 455
 456     // resume first suspended thread
 457     size_t n = 0, count = wxGetApp().m_threads.Count();
 458     while ( n < count && !wxGetApp().m_threads[n]->IsPaused() )
 459         n++;
 460
 461     if ( n == count )
 462     {
 463         wxLogError("No thread to resume!");
 464     }
 465     else
 466     {
 467         wxGetApp().m_threads[n]->Resume();
 468
 469         SetStatusText("Thread resumed.", 1);
 470     }
 471 }
 472
 473 void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
 474 {
 475     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 476
 477     // pause last running thread
 478     int n = wxGetApp().m_threads.Count() - 1;
 479     while ( n >= 0 && !wxGetApp().m_threads[n]->IsRunning() )
 480         n--;
 481
 482     if ( n < 0 )
 483     {
 484         wxLogError("No thread to pause!");
 485     }
 486     else
 487     {
 488         wxGetApp().m_threads[n]->Pause();
 489
 490         SetStatusText("Thread paused.", 1);
 491     }
 492 }
 493
 494 // set the frame title indicating the current number of threads
 495 void MyFrame::OnIdle(wxIdleEvent &event)
 496 {
 497     // update the counts of running/total threads
 498     size_t nRunning = 0,
 499            nCount = wxGetApp().m_threads.Count();
 500     for ( size_t n = 0; n < nCount; n++ )
 501     {
 502         if ( wxGetApp().m_threads[n]->IsRunning() )
 503             nRunning++;
 504     }
 505
 506     if ( nCount != m_nCount || nRunning != m_nRunning )
 507     {
 508         m_nRunning = nRunning;
 509         m_nCount = nCount;
 510
 511         wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
 512     }
 513     //else: avoid flicker - don't print anything
 514 }
 515
 516 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
 517 {
 518     size_t count = wxGetApp().m_threads.Count();
 519     for ( size_t i = 0; i < count; i++ )
 520     {
 521         wxGetApp().m_threads[0]->Delete();
 522     }
 523
 524     Close(TRUE);
 525 }
 526
 527 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 528 {
 529     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
 530                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 531                                  "(c) 1999 Vadim Zeitlin\n"
 532                                  "(c) 2000 Robert Roebling",
 533                            "About wxThread sample",
 534                            wxOK | wxICON_INFORMATION);
 535
 536     dialog.ShowModal();
 537 }
 538
 539 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 540 {
 541     m_txtctrl->Clear();
 542 }
 543
 544 void MyFrame::OnUpdateWorker(wxUpdateUIEvent& event)
 545 {
 546     event.Enable( m_dlgProgress == NULL );
 547 }
 548
 549 void MyFrame::OnStartWorker(wxCommandEvent& WXUNUSED(event))
 550 {
 551     MyWorkerThread *thread = new MyWorkerThread(this);
 552
 553     if ( thread->Create() != wxTHREAD_NO_ERROR )
 554     {
 555         wxLogError("Can't create thread!");
 556     }
 557
 558     m_dlgProgress = new wxProgressDialog
 559                         (
 560                          "Progress dialog",
 561                          "Wait until the thread terminates or press [Cancel]",
 562                          100,
 563                          this,
 564                          wxPD_CAN_ABORT |
 565                          wxPD_APP_MODAL |
 566                          wxPD_ELAPSED_TIME |
 567                          wxPD_ESTIMATED_TIME |
 568                          wxPD_REMAINING_TIME
 569                         );
 570
 571     // thread is not running yet, no need for crit sect
 572     m_cancelled = FALSE;
 573
 574     thread->Run();
 575 }
 576
 577 void MyFrame::OnWorkerEvent(wxCommandEvent& event)
 578 {
 579 #if 0
 580     WriteText( "Got message from worker thread: " );
 581     WriteText( event.GetString() );
 582     WriteText( "\n" );
 583 #else
 584     int n = event.GetInt();
 585     if ( n == -1 )
 586     {
 587         m_dlgProgress->Destroy();
 588         m_dlgProgress = (wxProgressDialog *)NULL;
 589
 590         // the dialog is aborted because the event came from another thread, so
 591         // we may need to wake up the main event loop for the dialog to be
 592         // really closed
 593         wxWakeUpIdle();
 594     }
 595     else
 596     {
 597         if ( !m_dlgProgress->Update(n) )
 598         {
 599             wxCriticalSectionLocker lock(m_critsectWork);
 600
 601             m_cancelled = TRUE;
 602         }
 603     }
 604 #endif
 605 }
 606
 607 bool MyFrame::Cancelled()
 608 {
 609     wxCriticalSectionLocker lock(m_critsectWork);
 610
 611     return m_cancelled;
 612 }