fixed (?) race condition in the sample

[wxWidgets.git] / samples / thread / test.cpp

diff --git a/samples/thread/test.cpp b/samples/thread/test.cpp
index 7996d8f532fa917a89872c95957e2d11ae4a158f..be40d23a60855f6b37bba938e19a318fbd76ee0a 100644 (file)
--- a/samples/thread/test.cpp
+++ b/samples/thread/test.cpp
@@ -38,6 +38,11 @@
 #include "wx/dynarray.h"
 #include "wx/time.h"
 
 #include "wx/dynarray.h"
 #include "wx/time.h"
 

+#include "wx/progdlg.h"
+
+// uncomment this to get some debugging messages from the trace code
+//#define TRACE
+

 class MyThread;
 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
 
 class MyThread;
 WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
 


@@ -69,6 +74,9 @@ public:
     // operations
     void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
 
     // operations
     void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
 

+    // accessors for MyWorkerThread (called in its context!)
+    bool Cancelled();
+

     // callbacks
     void OnQuit(wxCommandEvent& event);
     void OnAbout(wxCommandEvent& event);
     // callbacks
     void OnQuit(wxCommandEvent& event);
     void OnAbout(wxCommandEvent& event);


@@ -79,9 +87,10 @@ public:
     void OnStopThread(wxCommandEvent& event);
     void OnPauseThread(wxCommandEvent& event);
     void OnResumeThread(wxCommandEvent& event);
     void OnStopThread(wxCommandEvent& event);
     void OnPauseThread(wxCommandEvent& event);
     void OnResumeThread(wxCommandEvent& event);

-    
+

     void OnStartWorker(wxCommandEvent& event);
     void OnWorkerEvent(wxCommandEvent& event);
     void OnStartWorker(wxCommandEvent& event);
     void OnWorkerEvent(wxCommandEvent& event);

+    void OnUpdateWorker(wxUpdateUIEvent& event);

 
     void OnIdle(wxIdleEvent &event);
 
 
     void OnIdle(wxIdleEvent &event);
 


@@ -95,6 +104,15 @@ private:
     // remember the number of running threads and total number of threads
     size_t m_nRunning, m_nCount;
 
     // remember the number of running threads and total number of threads
     size_t m_nRunning, m_nCount;
 

+    // the progress dialog which we show while worker thread is running
+    wxProgressDialog *m_dlgProgress;
+
+    // was the worker thread cancelled by user?
+    bool m_cancelled;
+
+    // protects m_cancelled
+    wxCriticalSection m_critsectWork;
+

     DECLARE_EVENT_TABLE()
 };
 
     DECLARE_EVENT_TABLE()
 };
 


@@ -155,9 +173,8 @@ void MyThread::WriteText(const wxString& text)
     wxMutexGuiEnter();
 
     msg << text;
     wxMutexGuiEnter();
 
     msg << text;

-

     m_frame->WriteText(msg);
     m_frame->WriteText(msg);

-    
+

     wxMutexGuiLeave();
 }
 
     wxMutexGuiLeave();
 }
 


@@ -175,6 +192,7 @@ void *MyThread::Entry()
     text.Printf("Thread 0x%x started (priority = %d).\n",
                 GetId(), GetPriority());
     WriteText(text);
     text.Printf("Thread 0x%x started (priority = %d).\n",
                 GetId(), GetPriority());
     WriteText(text);

+    // wxLogMessage(text); -- test wxLog thread safeness

 
     for ( m_count = 0; m_count < 10; m_count++ )
     {
 
     for ( m_count = 0; m_count < 10; m_count++ )
     {


@@ -191,6 +209,7 @@ void *MyThread::Entry()
 
     text.Printf("Thread 0x%x finished.\n", GetId());
     WriteText(text);
 
     text.Printf("Thread 0x%x finished.\n", GetId());
     WriteText(text);

+    // wxLogMessage(text); -- test wxLog thread safeness

 
     return NULL;
 }
 
     return NULL;
 }


@@ -229,20 +248,34 @@ void MyWorkerThread::OnExit()
 
 void *MyWorkerThread::Entry()
 {
 
 void *MyWorkerThread::Entry()
 {

-    for ( m_count = 0; m_count < 10; m_count++ )
+    for ( m_count = 0; !m_frame->Cancelled() && (m_count < 100); m_count++ )

     {
         // check if we were asked to exit
         if ( TestDestroy() )
             break;
     {
         // check if we were asked to exit
         if ( TestDestroy() )
             break;

-        
+
+        wxString text;
+        text.Printf("[%u] Thread 0x%x here!!", m_count, GetId());
+
+        // create any type of command event here

         wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
         wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );

-        event.SetInt( WORKER_EVENT );
+        event.SetInt( m_count );
+        event.SetString( text );
+
+        // send in a thread-safe way

         wxPostEvent( m_frame, event );
 
         wxPostEvent( m_frame, event );
 

-        // wxSleep() can't be called from non-GUI thread!
-        wxThread::Sleep(1000);
+        // same as:
+        // m_frame->AddPendingEvent( event );
+
+        // wxSleep() can't be called from non-main thread!
+        wxThread::Sleep(200);

     }
 
     }
 

+    wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
+    event.SetInt(-1); // that's all
+    wxPostEvent( m_frame, event );
+

     return NULL;
 }
 
     return NULL;
 }
 


@@ -259,7 +292,8 @@ BEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)
     EVT_MENU(TEST_STOP_THREAD, MyFrame::OnStopThread)
     EVT_MENU(TEST_PAUSE_THREAD, MyFrame::OnPauseThread)
     EVT_MENU(TEST_RESUME_THREAD, MyFrame::OnResumeThread)

-    
+
+    EVT_UPDATE_UI(TEST_START_WORKER, MyFrame::OnUpdateWorker)

     EVT_MENU(TEST_START_WORKER, MyFrame::OnStartWorker)
     EVT_MENU(WORKER_EVENT, MyFrame::OnWorkerEvent)
 
     EVT_MENU(TEST_START_WORKER, MyFrame::OnStartWorker)
     EVT_MENU(WORKER_EVENT, MyFrame::OnWorkerEvent)
 


@@ -269,6 +303,10 @@ END_EVENT_TABLE()
 // `Main program' equivalent, creating windows and returning main app frame
 bool MyApp::OnInit()
 {
 // `Main program' equivalent, creating windows and returning main app frame
 bool MyApp::OnInit()
 {

+#ifdef TRACE
+    wxLog::AddTraceMask("thread");
+#endif
+

     // Create the main frame window
     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
                                  50, 50, 450, 340);
     // Create the main frame window
     MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
                                  50, 50, 450, 340);


@@ -293,7 +331,7 @@ bool MyApp::OnInit()
     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
     thread_menu->AppendSeparator();
     thread_menu->Append(TEST_START_WORKER, "Start &worker thread\tCtrl-W");
     thread_menu->Append(TEST_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
     thread_menu->AppendSeparator();
     thread_menu->Append(TEST_START_WORKER, "Start &worker thread\tCtrl-W");

-    
+

     menu_bar->Append(thread_menu, "&Thread");
     frame->SetMenuBar(menu_bar);
 
     menu_bar->Append(thread_menu, "&Thread");
     frame->SetMenuBar(menu_bar);
 


@@ -312,6 +350,8 @@ MyFrame::MyFrame(wxFrame *frame, const wxString& title,
 {
     m_nRunning = m_nCount = 0;
 
 {
     m_nRunning = m_nCount = 0;
 

+    m_dlgProgress = (wxProgressDialog *)NULL;
+

     CreateStatusBar(2);
 
     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
     CreateStatusBar(2);
 
     m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),


@@ -394,15 +434,17 @@ void MyFrame::OnStartThread(wxCommandEvent& WXUNUSED(event) )
 
 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 {
 
 void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
 {

+    wxGetApp().m_critsect.Enter();
+

     // stop the last thread
     if ( wxGetApp().m_threads.IsEmpty() )
     {
         wxLogError("No thread to stop!");
     // stop the last thread
     if ( wxGetApp().m_threads.IsEmpty() )
     {
         wxLogError("No thread to stop!");

+
+        wxGetApp().m_critsect.Leave();

     }
     else
     {
     }
     else
     {

-        wxGetApp().m_critsect.Enter();
-

         wxThread *thread = wxGetApp().m_threads.Last();
 
         // it's important to leave critical section before calling Delete()
         wxThread *thread = wxGetApp().m_threads.Last();
 
         // it's important to leave critical section before calling Delete()


@@ -495,7 +537,8 @@ void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 {
     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"
 {
     wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
                                  "(c) 1998 Julian Smart, Guilhem Lavaux\n"

-                                 "(c) 1999 Vadim Zeitlin",
+                                 "(c) 1999 Vadim Zeitlin\n"
+                                 "(c) 2000 Robert Roebling",

                            "About wxThread sample",
                            wxOK | wxICON_INFORMATION);
 
                            "About wxThread sample",
                            wxOK | wxICON_INFORMATION);
 


@@ -504,9 +547,19 @@ void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
 
 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 {
 
 void MyFrame::OnClear(wxCommandEvent& WXUNUSED(event))
 {

+#ifdef TRACE
+    // log a separator
+    wxLogTrace("-------- log window cleared --------");
+#endif
+

     m_txtctrl->Clear();
 }
 
     m_txtctrl->Clear();
 }
 

+void MyFrame::OnUpdateWorker(wxUpdateUIEvent& event)
+{
+    event.Enable( m_dlgProgress == NULL );
+}
+

 void MyFrame::OnStartWorker(wxCommandEvent& WXUNUSED(event))
 {
     MyWorkerThread *thread = new MyWorkerThread(this);
 void MyFrame::OnStartWorker(wxCommandEvent& WXUNUSED(event))
 {
     MyWorkerThread *thread = new MyWorkerThread(this);


@@ -515,12 +568,59 @@ void MyFrame::OnStartWorker(wxCommandEvent& WXUNUSED(event))
     {
         wxLogError("Can't create thread!");
     }
     {
         wxLogError("Can't create thread!");
     }

-    
+
+    m_dlgProgress = new wxProgressDialog
+                        (
+                         "Progress dialog",
+                         "Wait until the thread terminates or press [Cancel]",
+                         100,
+                         this,
+                         wxPD_CAN_ABORT |
+                         wxPD_APP_MODAL |
+                         wxPD_ELAPSED_TIME |
+                         wxPD_ESTIMATED_TIME |
+                         wxPD_REMAINING_TIME
+                        );
+
+    // thread is not running yet, no need for crit sect
+    m_cancelled = FALSE;
+

     thread->Run();
 }
 
     thread->Run();
 }
 

-void MyFrame::OnWorkerEvent(wxCommandEvent& WXUNUSED(event))
+void MyFrame::OnWorkerEvent(wxCommandEvent& event)

 {
 {

-    WriteText( "Got message from worker thread\n" );
+#if 0
+    WriteText( "Got message from worker thread: " );
+    WriteText( event.GetString() );
+    WriteText( "\n" );
+#else
+    int n = event.GetInt();
+    if ( n == -1 )
+    {
+        m_dlgProgress->Destroy();
+        m_dlgProgress = (wxProgressDialog *)NULL;
+
+        // the dialog is aborted because the event came from another thread, so
+        // we may need to wake up the main event loop for the dialog to be
+        // really closed
+        wxWakeUpIdle();
+    }
+    else
+    {
+        if ( !m_dlgProgress->Update(n) )
+        {
+            wxCriticalSectionLocker lock(m_critsectWork);
+
+            m_cancelled = TRUE;
+        }
+    }
+#endif

 }
 
 }
 

+bool MyFrame::Cancelled()
+{
+    wxCriticalSectionLocker lock(m_critsectWork);
+
+    return m_cancelled;
+}