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
 193     for ( m_count = 0; m_count < 10; m_count++ )
 194     {
 195         // check if we were asked to exit
 196         if ( TestDestroy() )
 197             break;
 198
 199         text.Printf("[%u] Thread 0x%x here.\n", m_count, GetId());
 200         WriteText(text);
 201
 202         // wxSleep() can't be called from non-GUI thread!
 203         wxThread::Sleep(1000);
 204     }
 205
 206     text.Printf("Thread 0x%x finished.\n", GetId());
 207     WriteText(text);
 208
 209     return NULL;
 210 }
 211
 212 //--------------------------------------------------
 213 // worker thread
 214 //--------------------------------------------------
 215
 216 class MyWorkerThread : public wxThread
 217 {
 218 public:
 219     MyWorkerThread(MyFrame *frame);
 220
 221     // thread execution starts here
 222     virtual void *Entry();
 223
 224     // called when the thread exits - whether it terminates normally or is
 225     // stopped with Delete() (but not when it is Kill()ed!)
 226     virtual void OnExit();
 227
 228 public:
 229     MyFrame *m_frame;
 230     size_t   m_count;
 231 };
 232
 233 MyWorkerThread::MyWorkerThread(MyFrame *frame)
 234         : wxThread()
 235 {
 236     m_frame = frame;
 237     m_count = 0;
 238 }
 239
 240 void MyWorkerThread::OnExit()
 241 {
 242 }
 243
 244 void *MyWorkerThread::Entry()
 245 {
 246     for ( m_count = 0; !m_frame->Cancelled() && (m_count < 100); m_count++ )
 247     {
 248         // check if we were asked to exit
 249         if ( TestDestroy() )
 250             break;
 251
 252         wxString text;
 253         text.Printf("[%u] Thread 0x%x here!!", m_count, GetId());
 254
 255         // create any type of command event here
 256         wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
 257         event.SetInt( m_count );
 258         event.SetString( text );
 259
 260         // send in a thread-safe way
 261         wxPostEvent( m_frame, event );
 262
 263         // same as:
 264         // m_frame->AddPendingEvent( event );
 265
 266         // wxSleep() can't be called from non-main thread!
 267         wxThread::Sleep(200);
 268     }
 269
 270     wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
 271     event.SetInt(-1); // that's all
 272     wxPostEvent( m_frame, event );
 273
 274     return NULL;
 275 }
 276
 277 //--------------------------------------------------
 278 // main program
 279 //--------------------------------------------------
 280
 281 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 282     EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
 283     EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
 284     EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
 285     EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
 286     EVT_MENU(TEST_START_THREADS, MyFrame::OnStartThreads)
 287     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
 288     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
 289     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
 290
 291     EVT_UPDATE_UI(TEST_START_WORKER, MyFrame::OnUpdateWorker)
 292     EVT_MENU(TEST_START_WORKER, MyFrame::OnStartWorker)
 293     EVT_MENU(WORKER_EVENT, MyFrame::OnWorkerEvent)
 294
 295     EVT_IDLE(MyFrame::OnIdle)
 296 END_EVENT_TABLE()
 297
 298 // `Main program' equivalent, creating windows and returning main app frame
 299 bool MyApp::OnInit()
 300 {
 301     // Create the main frame window
 302     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
 303                                  50, 50, 450, 340);
 304
 305     // Make a menubar
 306     wxMenu *file_menu = new wxMenu;
 307
 308     file_menu->Append(TEST_CLEAR, "&Clear log\tCtrl-L");
 309     file_menu->AppendSeparator();
 310     file_menu->Append(TEST_ABOUT, "&About");
 311     file_menu->AppendSeparator();
 312     file_menu->Append(TEST_QUIT, "E&xit\tAlt-X");
 313     wxMenuBar *menu_bar = new wxMenuBar;
 314     menu_bar->Append(file_menu, "&File");
 315
 316     wxMenu *thread_menu = new wxMenu;
 317     thread_menu->Append(TEST_START_THREAD, "&Start a new thread\tCtrl-N");
 318     thread_menu->Append(TEST_START_THREADS, "Start &many threads at once");
 319     thread_menu->Append(TEST_STOP_THREAD, "S&top a running thread\tCtrl-S");
 320     thread_menu->AppendSeparator();
 321     thread_menu->Append(TEST_PAUSE_THREAD, "&Pause a running thread\tCtrl-P");
 322     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
 323     thread_menu->AppendSeparator();
 324     thread_menu->Append(TEST_START_WORKER, "Start &worker thread\tCtrl-W");
 325
 326     menu_bar->Append(thread_menu, "&Thread");
 327     frame->SetMenuBar(menu_bar);
 328
 329     // Show the frame
 330     frame->Show(TRUE);
 331
 332     SetTopWindow(frame);
 333
 334     return TRUE;
 335 }
 336
 337 // My frame constructor
 338 MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 339                  int x, int y, int w, int h)
 340        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
 341 {
 342     m_nRunning = m_nCount = 0;
 343
 344     m_dlgProgress = (wxProgressDialog *)NULL;
 345
 346     CreateStatusBar(2);
 347
 348     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
 349                                wxTE_MULTILINE | wxTE_READONLY);
 350
 351 }
 352
 353 MyThread *MyFrame::CreateThread()
 354 {
 355     MyThread *thread = new MyThread(this);
 356
 357     if ( thread->Create() != wxTHREAD_NO_ERROR )
 358     {
 359         wxLogError("Can't create thread!");
 360     }
 361
 362     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 363     wxGetApp().m_threads.Add(thread);
 364
 365     return thread;
 366 }
 367
 368 void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
 369 {
 370     static long s_num = 10;
 371
 372     s_num = wxGetNumberFromUser("How many threads to start: ", "",
 373                                 "wxThread sample", s_num, 1, 10000, this);
 374     if ( s_num == -1 )
 375     {
 376         s_num = 10;
 377
 378         return;
 379     }
 380
 381     size_t count = (size_t)s_num, n;
 382
 383     wxArrayThread threads;
 384
 385     // first create them all...
 386     for ( n = 0; n < count; n++ )
 387     {
 388         wxThread *thr = CreateThread();
 389
 390         // we want to show the effect of SetPriority(): the first thread will
 391         // have the lowest priority, the second - the highest, all the rest
 392         // the normal one
 393         if ( n == 0 )
 394             thr->SetPriority(WXTHREAD_MIN_PRIORITY);
 395         else if ( n == 1 )
 396             thr->SetPriority(WXTHREAD_MAX_PRIORITY);
 397         else
 398             thr->SetPriority(WXTHREAD_DEFAULT_PRIORITY);
 399
 400         threads.Add(thr);
 401     }
 402
 403     wxString msg;
 404     msg.Printf("%d new threads created.", count);
 405     SetStatusText(msg, 1);
 406
 407     // ...and then start them
 408     for ( n = 0; n < count; n++ )
 409     {
 410         threads[n]->Run();
 411     }
 412 }
 413
 414 void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 415 {
 416     MyThread *thread = CreateThread();
 417
 418     if ( thread->Run() != wxTHREAD_NO_ERROR )
 419     {
 420         wxLogError("Can't start thread!");
 421     }
 422
 423     SetStatusText("New thread started.", 1);
 424 }
 425
 426 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 427 {
 428     // stop the last thread
 429     if ( wxGetApp().m_threads.IsEmpty() )
 430     {
 431         wxLogError("No thread to stop!");
 432     }
 433     else
 434     {
 435         wxGetApp().m_critsect.Enter();
 436
 437         wxThread *thread = wxGetApp().m_threads.Last();
 438
 439         // it's important to leave critical section before calling Delete()
 440         // because delete will (implicitly) call OnExit() which also tries
 441         // to enter the same crit section - would dead lock.
 442         wxGetApp().m_critsect.Leave();
 443
 444         thread->Delete();
 445
 446         SetStatusText("Thread stopped.", 1);
 447     }
 448 }
 449
 450 void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
 451 {
 452     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 453
 454     // resume first suspended thread
 455     size_t n = 0, count = wxGetApp().m_threads.Count();
 456     while ( n < count && !wxGetApp().m_threads[n]->IsPaused() )
 457         n++;
 458
 459     if ( n == count )
 460     {
 461         wxLogError("No thread to resume!");
 462     }
 463     else
 464     {
 465         wxGetApp().m_threads[n]->Resume();
 466
 467         SetStatusText("Thread resumed.", 1);
 468     }
 469 }
 470
 471 void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
 472 {
 473     wxCriticalSectionLocker enter(wxGetApp().m_critsect);
 474
 475     // pause last running thread
 476     int n = wxGetApp().m_threads.Count() - 1;
 477     while ( n >= 0 && !wxGetApp().m_threads[n]->IsRunning() )
 478         n--;
 479
 480     if ( n < 0 )
 481     {
 482         wxLogError("No thread to pause!");
 483     }
 484     else
 485     {
 486         wxGetApp().m_threads[n]->Pause();
 487
 488         SetStatusText("Thread paused.", 1);
 489     }
 490 }
 491
 492 // set the frame title indicating the current number of threads
 493 void MyFrame::OnIdle(wxIdleEvent &event)
 494 {
 495     // update the counts of running/total threads
 496     size_t nRunning = 0,
 497            nCount = wxGetApp().m_threads.Count();
 498     for ( size_t n = 0; n < nCount; n++ )
 499     {
 500         if ( wxGetApp().m_threads[n]->IsRunning() )
 501             nRunning++;
 502     }
 503
 504     if ( nCount != m_nCount || nRunning != m_nRunning )
 505     {
 506         m_nRunning = nRunning;
 507         m_nCount = nCount;
 508
 509         wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
 510     }
 511     //else: avoid flicker - don't print anything
 512 }
 513
 514 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
 515 {
 516     size_t count = wxGetApp().m_threads.Count();
 517     for ( size_t i = 0; i < count; i++ )
 518     {
 519         wxGetApp().m_threads[0]->Delete();
 520     }
 521
 522     Close(TRUE);
 523 }
 524
 525 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 526 {
 527     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
 528                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 529                                  "(c) 1999 Vadim Zeitlin\n"
 530                                  "(c) 2000 Robert Roebling",
 531                            "About wxThread sample",
 532                            wxOK | wxICON_INFORMATION);
 533
 534     dialog.ShowModal();
 535 }
 536
 537 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 538 {
 539     m_txtctrl->Clear();
 540 }
 541
 542 void MyFrame::OnUpdateWorker(wxUpdateUIEvent& event)
 543 {
 544     event.Enable( m_dlgProgress == NULL );
 545 }
 546
 547 void MyFrame::OnStartWorker(wxCommandEvent& WXUNUSED(event))
 548 {
 549     MyWorkerThread *thread = new MyWorkerThread(this);
 550
 551     if ( thread->Create() != wxTHREAD_NO_ERROR )
 552     {
 553         wxLogError("Can't create thread!");
 554     }
 555
 556     m_dlgProgress = new wxProgressDialog
 557                         (
 558                          "Progress dialog",
 559                          "Wait until the thread terminates or press [Cancel]",
 560                          100,
 561                          this,
 562                          wxPD_CAN_ABORT |
 563                          wxPD_APP_MODAL |
 564                          wxPD_ELAPSED_TIME |
 565                          wxPD_ESTIMATED_TIME |
 566                          wxPD_REMAINING_TIME
 567                         );
 568
 569     // thread is not running yet, no need for crit sect
 570     m_cancelled = FALSE;
 571
 572     thread->Run();
 573 }
 574
 575 void MyFrame::OnWorkerEvent(wxCommandEvent& event)
 576 {
 577 #if 0
 578     WriteText( "Got message from worker thread: " );
 579     WriteText( event.GetString() );
 580     WriteText( "\n" );
 581 #else
 582     int n = event.GetInt();
 583     if ( n == -1 )
 584     {
 585         m_dlgProgress->Destroy();
 586         m_dlgProgress = (wxProgressDialog *)NULL;
 587
 588         // the dialog is aborted because the event came from another thread, so
 589         // we may need to wake up the main event loop for the dialog to be
 590         // really closed
 591         wxWakeUpIdle();
 592     }
 593     else
 594     {
 595         if ( !m_dlgProgress->Update(n) )
 596         {
 597             wxCriticalSectionLocker lock(m_critsectWork);
 598
 599             m_cancelled = TRUE;
 600         }
 601     }
 602 #endif
 603 }
 604
 605 bool MyFrame::Cancelled()
 606 {
 607     wxCriticalSectionLocker lock(m_critsectWork);
 608
 609     return m_cancelled;
 610 }