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     wxMutexGuiLocker guiLocker;
 134     msg << wxTime().FormatTime() << ": " << text;
 135
 136     m_frame->WriteText(msg);
 137 }
 138
 139 void MyThread::OnExit()
 140 {
 141     m_frame->OnThreadExit(this);
 142 }
 143
 144 void *MyThread::Entry()
 145 {
 146     wxString text;
 147
 148     text.Printf("Thread 0x%x started.\n", GetID());
 149     WriteText(text);
 150
 151     for ( m_count = 0; m_count < 10; m_count++ )
 152     {
 153         // check if we were asked to exit
 154         if ( TestDestroy() )
 155             break;
 156
 157         text.Printf("[%u] Thread 0x%x here.\n", m_count, GetID());
 158         WriteText(text);
 159
 160         // wxSleep() can't be called from non-GUI thread!
 161         wxThread::Sleep(1000);
 162     }
 163
 164     text.Printf("Thread 0x%x finished.\n", GetID());
 165     WriteText(text);
 166
 167     return NULL;
 168 }
 169
 170 // ID for the menu commands
 171 enum
 172 {
 173     TEST_QUIT          = 1,
 174     TEST_TEXT          = 101,
 175     TEST_ABOUT,
 176     TEST_CLEAR,
 177     TEST_START_THREAD  = 201,
 178     TEST_START_THREADS,
 179     TEST_STOP_THREAD,
 180     TEST_PAUSE_THREAD,
 181     TEST_RESUME_THREAD
 182 };
 183
 184 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 185     EVT_MENU(TEST_QUIT, MyFrame::OnQuit)
 186     EVT_MENU(TEST_ABOUT, MyFrame::OnAbout)
 187     EVT_MENU(TEST_CLEAR, MyFrame::OnClear)
 188     EVT_MENU(TEST_START_THREAD, MyFrame::OnStartThread)
 189     EVT_MENU(TEST_START_THREADS, MyFrame::OnStartThreads)
 190     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
 191     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
 192     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
 193
 194     EVT_IDLE(MyFrame::OnIdle)
 195 END_EVENT_TABLE()
 196
 197 // Create a new application object
 198 IMPLEMENT_APP  (MyApp)
 199
 200 // `Main program' equivalent, creating windows and returning main app frame
 201 bool MyApp::OnInit()
 202 {
 203     // Create the main frame window
 204     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
 205                                  50, 50, 450, 340);
 206
 207     // Make a menubar
 208     wxMenu *file_menu = new wxMenu;
 209
 210     file_menu->Append(TEST_CLEAR, "&Clear log");
 211     file_menu->AppendSeparator();
 212     file_menu->Append(TEST_ABOUT, "&About");
 213     file_menu->AppendSeparator();
 214     file_menu->Append(TEST_QUIT, "E&xit");
 215     wxMenuBar *menu_bar = new wxMenuBar;
 216     menu_bar->Append(file_menu, "&File");
 217
 218     wxMenu *thread_menu = new wxMenu;
 219     thread_menu->Append(TEST_START_THREAD, "&Start a new thread");
 220     thread_menu->Append(TEST_START_THREADS, "Start &many threads at once");
 221     thread_menu->Append(TEST_STOP_THREAD, "S&top a running thread");
 222     thread_menu->AppendSeparator();
 223     thread_menu->Append(TEST_PAUSE_THREAD, "&Pause a running thread");
 224     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread");
 225     menu_bar->Append(thread_menu, "&Thread");
 226     frame->SetMenuBar(menu_bar);
 227
 228     // Show the frame
 229     frame->Show(TRUE);
 230
 231     SetTopWindow(frame);
 232
 233     return TRUE;
 234 }
 235
 236 // My frame constructor
 237 MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 238                  int x, int y, int w, int h)
 239        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
 240 {
 241     m_nRunning = m_nCount = 0;
 242
 243     CreateStatusBar(2);
 244
 245     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
 246                                wxTE_MULTILINE | wxTE_READONLY);
 247
 248 }
 249
 250 MyThread *MyFrame::CreateThread()
 251 {
 252     MyThread *thread = new MyThread(this);
 253
 254     if ( thread->Create() != wxTHREAD_NO_ERROR )
 255     {
 256         wxLogError("Can't create thread!");
 257     }
 258
 259     wxCriticalSectionLocker enter(m_critsect);
 260     m_threads.Add(thread);
 261
 262     return thread;
 263 }
 264
 265 void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
 266 {
 267     static wxString s_str;
 268     s_str = wxGetTextFromUser("How many threads to start: ",
 269                               "wxThread sample",
 270                               s_str, this);
 271     if ( s_str.IsEmpty() )
 272         return;
 273
 274     size_t count, n;
 275     sscanf(s_str, "%u", &count);
 276     if ( count == 0 )
 277         return;
 278
 279     wxArrayThread threads;
 280
 281     // first create them all...
 282     for ( n = 0; n < count; n++ )
 283     {
 284         threads.Add(CreateThread());
 285     }
 286
 287     wxString msg;
 288     msg.Printf("%d new threads created.", count);
 289     SetStatusText(msg, 1);
 290
 291     // ...and then start them
 292     for ( n = 0; n < count; n++ )
 293     {
 294         threads[n]->Run();
 295     }
 296 }
 297
 298 void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 299 {
 300     MyThread *thread = CreateThread();
 301
 302     if ( thread->Run() != wxTHREAD_NO_ERROR )
 303     {
 304         wxLogError("Can't start thread!");
 305     }
 306
 307     SetStatusText("New thread started.", 1);
 308 }
 309
 310 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 311 {
 312     // stop the last thread
 313     if ( m_threads.IsEmpty() )
 314     {
 315         wxLogError("No thread to stop!");
 316     }
 317     else
 318     {
 319         m_critsect.Enter();
 320
 321         wxThread *thread = m_threads.Last();
 322
 323         // it's important to leave critical section before calling Delete()
 324         // because delete will (implicitly) call OnThreadExit() which also tries
 325         // to enter the same crit section - would dead lock.
 326         m_critsect.Leave();
 327
 328         thread->Delete();
 329
 330         SetStatusText("Thread stopped.", 1);
 331     }
 332 }
 333
 334 void MyFrame::OnResumeThread(wxCommandEvent& WXUNUSED(event) )
 335 {
 336     wxCriticalSectionLocker enter(m_critsect);
 337
 338     // resume first suspended thread
 339     size_t n = 0, count = m_threads.Count();
 340     while ( n < count && !m_threads[n]->IsPaused() )
 341         n++;
 342
 343     if ( n == count )
 344     {
 345         wxLogError("No thread to resume!");
 346     }
 347     else
 348     {
 349         m_threads[n]->Resume();
 350
 351         SetStatusText("Thread resumed.", 1);
 352     }
 353 }
 354
 355 void MyFrame::OnPauseThread(wxCommandEvent& WXUNUSED(event) )
 356 {
 357     wxCriticalSectionLocker enter(m_critsect);
 358
 359     // pause last running thread
 360     int n = m_threads.Count() - 1;
 361     while ( n >= 0 && !m_threads[n]->IsRunning() )
 362         n--;
 363
 364     if ( n < 0 )
 365     {
 366         wxLogError("No thread to pause!");
 367     }
 368     else
 369     {
 370         m_threads[n]->Pause();
 371
 372         SetStatusText("Thread paused.", 1);
 373     }
 374 }
 375
 376 // set the frame title indicating the current number of threads
 377 void MyFrame::OnIdle(wxIdleEvent &event)
 378 {
 379     // update the counts of running/total threads
 380     size_t nRunning = 0,
 381            nCount = m_threads.Count();
 382     for ( size_t n = 0; n < nCount; n++ )
 383     {
 384         if ( m_threads[n]->IsRunning() )
 385             nRunning++;
 386     }
 387
 388     if ( nCount != m_nCount || nRunning != m_nRunning )
 389     {
 390         m_nRunning = nRunning;
 391         m_nCount = nCount;
 392
 393         wxLogStatus(this, "%u threads total, %u running.", nCount, nRunning);
 394     }
 395     //else: avoid flicker - don't print anything
 396 }
 397
 398 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
 399 {
 400     size_t count = m_threads.Count();
 401     for ( size_t i = 0; i < count; i++ )
 402     {
 403         m_threads[i]->Delete();
 404     }
 405
 406     Close(TRUE);
 407 }
 408
 409 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 410 {
 411     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
 412                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 413                                  "(c) 1999 Vadim Zeitlin",
 414                            "About wxThread sample",
 415                            wxOK | wxICON_INFORMATION);
 416
 417     dialog.ShowModal();
 418 }
 419
 420 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 421 {
 422     m_txtctrl->Clear();
 423 }
 424
 425 void MyFrame::OnThreadExit(wxThread *thread)
 426 {
 427     wxCriticalSectionLocker enter(m_critsect);
 428
 429     m_threads.Remove(thread);
 430 }