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:
  14
  15     1. show how SetPriority() works.
  16     2. use worker threads to update progress controls instead of writing
  17        messages - it will be more visual
  18  */
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "test.cpp"
  22     #pragma interface "test.cpp"
  23 #endif
  24
  25 // For compilers that support precompilation, includes "wx/wx.h".
  26 #include "wx/wxprec.h"
  27
  28 #ifdef __BORLANDC__
  29     #pragma hdrstop
  30 #endif
  31
  32 #ifndef WX_PRECOMP
  33     #include "wx/wx.h"
  34 #endif
  35
  36 #if !wxUSE_THREADS
  37     #error "This sample requires thread support!"
  38 #endif // wxUSE_THREADS
  39
  40 #include "wx/thread.h"
  41 #include "wx/dynarray.h"
  42 #include "wx/time.h"
  43
  44 // Define a new application type
  45 class MyApp : public wxApp
  46 {
  47 public:
  48     bool OnInit();
  49 };
  50
  51 class MyThread;
  52 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
  53
  54 // Define a new frame type
  55 class MyFrame: public wxFrame
  56 {
  57 public:
  58     // ctor
  59     MyFrame(wxFrame *frame, const wxString& title, int x, int y, int w, int h);
  60
  61     // operations
  62     void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
  63
  64     // callbacks
  65     void OnQuit(wxCommandEvent& event);
  66     void OnAbout(wxCommandEvent& event);
  67     void OnClear(wxCommandEvent& event);
  68
  69     void OnStartThread(wxCommandEvent& event);
  70     void OnStartThreads(wxCommandEvent& event);
  71     void OnStopThread(wxCommandEvent& event);
  72     void OnPauseThread(wxCommandEvent& event);
  73     void OnResumeThread(wxCommandEvent& event);
  74
  75     void OnIdle(wxIdleEvent &event);
  76
  77     // called by dying thread _in_that_thread_context_
  78     void OnThreadExit(wxThread *thread);
  79
  80 private:
  81     // helper function - creates a new thread (but doesn't run it)
  82     MyThread *CreateThread();
  83
  84     // crit section protects access to all of the arrays below
  85     wxCriticalSection m_critsect;
  86
  87     // all the threads currently alive - as soon as the thread terminates, it's
  88     // removed from the array
  89     wxArrayThread m_threads;
  90
  91     // just some place to put our messages in
  92     wxTextCtrl *m_txtctrl;
  93
  94     // remember the number of running threads and total number of threads
  95     size_t m_nRunning, m_nCount;
  96
  97     DECLARE_EVENT_TABLE()
  98 };
  99
 100 class MyThread : public wxThread
 101 {
 102 public:
 103     MyThread(MyFrame *frame);
 104
 105     // thread execution starts here
 106     virtual void *Entry();
 107
 108     // called when the thread exits - whether it terminates normally or is
 109     // stopped with Delete() (but not when it is Kill()ed!)
 110     virtual void OnExit();
 111
 112     // write something to the text control
 113     void WriteText(const wxString& text);
 114
 115 public:
 116     size_t   m_count;
 117     MyFrame *m_frame;
 118 };
 119
 120 MyThread::MyThread(MyFrame *frame)
 121         : wxThread()
 122 {
 123     m_count = 0;
 124     m_frame = frame;
 125 }
 126
 127 void MyThread::WriteText(const wxString& text)
 128 {
 129     wxString msg;
 130
 131     // before doing any GUI calls we must ensure that this thread is the only
 132     // one doing it!
 133
 134     wxMutexGuiEnter();
 135
 136     msg << wxTime().FormatTime() << ": " << text;
 137
 138     m_frame->WriteText(msg);
 139
 140     wxMutexGuiLeave();
 141 }
 142
 143 void MyThread::OnExit()
 144 {
 145     m_frame->OnThreadExit(this);
 146 }
 147
 148 void *MyThread::Entry()
 149 {
 150     wxString text;
 151
 152     text.Printf("Thread 0x%x started.\n", GetID());
 153     WriteText(text);
 154
 155     for ( m_count = 0; m_count < 10; m_count++ )
 156     {
 157         // check if we were asked to exit
 158         if ( TestDestroy() )
 159             break;
 160
 161         text.Printf("[%u] Thread 0x%x here.\n", m_count, GetID());
 162         WriteText(text);
 163
 164         // wxSleep() can't be called from non-GUI thread!
 165         wxThread::Sleep(1000);
 166     }
 167
 168     text.Printf("Thread 0x%x finished.\n", GetID());
 169     WriteText(text);
 170
 171     return NULL;
 172 }
 173
 174 // ID for the menu commands
 175 enum
 176 {
 177     TEST_QUIT          = 1,
 178     TEST_TEXT          = 101,
 179     TEST_ABOUT,
 180     TEST_CLEAR,
 181     TEST_START_THREAD  = 201,
 182     TEST_START_THREADS,
 183     TEST_STOP_THREAD,
 184     TEST_PAUSE_THREAD,
 185     TEST_RESUME_THREAD
 186 };
 187
 188 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 189     EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
 190     EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
 191     EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
 192     EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
 193     EVT_MENU(TEST_START_THREADS, MyFrame::OnStartThreads)
 194     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
 195     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
 196     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
 197
 198     EVT_IDLE(MyFrame::OnIdle)
 199 END_EVENT_TABLE()
 200
 201 // Create a new application object
 202 IMPLEMENT_APP  (MyApp)
 203
 204 // `Main program' equivalent, creating windows and returning main app frame
 205 bool MyApp::OnInit()
 206 {
 207     // Create the main frame window
 208     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
 209                                  50, 50, 450, 340);
 210
 211     // Make a menubar
 212     wxMenu *file_menu = new wxMenu;
 213
 214     file_menu->Append(TEST_CLEAR, "&Clear log");
 215     file_menu->AppendSeparator();
 216     file_menu->Append(TEST_ABOUT, "&About");
 217     file_menu->AppendSeparator();
 218     file_menu->Append(TEST_QUIT, "E&xit");
 219     wxMenuBar *menu_bar = new wxMenuBar;
 220     menu_bar->Append(file_menu, "&File");
 221
 222     wxMenu *thread_menu = new wxMenu;
 223     thread_menu->Append(TEST_START_THREAD, "&Start a new thread");
 224     thread_menu->Append(TEST_START_THREADS, "Start &many threads at once");
 225     thread_menu->Append(TEST_STOP_THREAD, "S&top a running thread");
 226     thread_menu->AppendSeparator();
 227     thread_menu->Append(TEST_PAUSE_THREAD, "&Pause a running thread");
 228     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread");
 229     menu_bar->Append(thread_menu, "&Thread");
 230     frame->SetMenuBar(menu_bar);
 231
 232     // Show the frame
 233     frame->Show(TRUE);
 234
 235     SetTopWindow(frame);
 236
 237     return TRUE;
 238 }
 239
 240 // My frame constructor
 241 MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 242                  int x, int y, int w, int h)
 243        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
 244 {
 245     m_nRunning = m_nCount = 0;
 246
 247     CreateStatusBar(2);
 248
 249     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
 250                                wxTE_MULTILINE | wxTE_READONLY);
 251
 252 }
 253
 254 MyThread *MyFrame::CreateThread()
 255 {
 256     MyThread *thread = new MyThread(this);
 257
 258     if ( thread->Create() != wxTHREAD_NO_ERROR )
 259     {
 260         wxLogError("Can't create thread!");
 261     }
 262
 263     wxCriticalSectionLocker enter(m_critsect);
 264     m_threads.Add(thread);
 265
 266     return thread;
 267 }
 268
 269 void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
 270 {
 271     static wxString s_str;
 272     s_str = wxGetTextFromUser("How many threads to start: ",
 273                               "wxThread sample",
 274                               s_str, this);
 275     if ( s_str.IsEmpty() )
 276         return;
 277
 278     size_t count, n;
 279     sscanf(s_str, "%u", &count);
 280     if ( count == 0 )
 281         return;
 282
 283     wxArrayThread threads;
 284
 285     // first create them all...
 286     for ( n = 0; n < count; n++ )
 287     {
 288         threads.Add(CreateThread());
 289     }
 290
 291     wxString msg;
 292     msg.Printf("%d new threads created.", count);
 293     SetStatusText(msg, 1);
 294
 295     // ...and then start them
 296     for ( n = 0; n < count; n++ )
 297     {
 298         threads[n]->Run();
 299     }
 300 }
 301
 302 void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 303 {
 304     MyThread *thread = CreateThread();
 305
 306     if ( thread->Run() != wxTHREAD_NO_ERROR )
 307     {
 308         wxLogError("Can't start thread!");
 309     }
 310
 311     SetStatusText("New thread started.", 1);
 312 }
 313
 314 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 315 {
 316     // stop the last thread
 317     if ( m_threads.IsEmpty() )
 318     {
 319         wxLogError("No thread to stop!");
 320     }
 321     else
 322     {
 323         m_critsect.Enter();
 324
 325         wxThread *thread = m_threads.Last();
 326
 327         // it's important to leave critical section before calling Delete()
 328         // because delete will (implicitly) call OnThreadExit() which also tries
 329         // to enter the same crit section - would dead lock.
 330         m_critsect.Leave();
 331
 332         thread->Delete();
 333
 334         SetStatusText("Thread stopped.", 1);
 335     }
 336 }
 337
 338 void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
 339 {
 340     wxCriticalSectionLocker enter(m_critsect);
 341
 342     // resume first suspended thread
 343     size_t n = 0, count = m_threads.Count();
 344     while ( n < count && !m_threads[n]->IsPaused() )
 345         n++;
 346
 347     if ( n == count )
 348     {
 349         wxLogError("No thread to resume!");
 350     }
 351     else
 352     {
 353         m_threads[n]->Resume();
 354
 355         SetStatusText("Thread resumed.", 1);
 356     }
 357 }
 358
 359 void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
 360 {
 361     wxCriticalSectionLocker enter(m_critsect);
 362
 363     // pause last running thread
 364     int n = m_threads.Count() - 1;
 365     while ( n >= 0 && !m_threads[n]->IsRunning() )
 366         n--;
 367
 368     if ( n < 0 )
 369     {
 370         wxLogError("No thread to pause!");
 371     }
 372     else
 373     {
 374         m_threads[n]->Pause();
 375
 376         SetStatusText("Thread paused.", 1);
 377     }
 378 }
 379
 380 // set the frame title indicating the current number of threads
 381 void MyFrame::OnIdle(wxIdleEvent &event)
 382 {
 383     // update the counts of running/total threads
 384     size_t nRunning = 0,
 385            nCount = m_threads.Count();
 386     for ( size_t n = 0; n < nCount; n++ )
 387     {
 388         if ( m_threads[n]->IsRunning() )
 389             nRunning++;
 390     }
 391
 392     if ( nCount != m_nCount || nRunning != m_nRunning )
 393     {
 394         m_nRunning = nRunning;
 395         m_nCount = nCount;
 396
 397         wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
 398     }
 399     //else: avoid flicker - don't print anything
 400 }
 401
 402 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
 403 {
 404     size_t count = m_threads.Count();
 405     for ( size_t i = 0; i < count; i++ )
 406     {
 407         m_threads[i]->Delete();
 408     }
 409
 410     Close(TRUE);
 411 }
 412
 413 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 414 {
 415     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
 416                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 417                                  "(c) 1999 Vadim Zeitlin",
 418                            "About wxThread sample",
 419                            wxOK | wxICON_INFORMATION);
 420
 421     dialog.ShowModal();
 422 }
 423
 424 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 425 {
 426     m_txtctrl->Clear();
 427 }
 428
 429 void MyFrame::OnThreadExit(wxThread *thread)
 430 {
 431     wxCriticalSectionLocker enter(m_critsect);
 432
 433     m_threads.Remove(thread);
 434 }