/////////////////////////////////////////////////////////////////////////////
// Name: thread.cpp
-// Purpose: wxWindows thread sample
-// Author: Julian Smart(minimal)/Guilhem Lavaux(thread test)
+// Purpose: wxWidgets thread sample
+// Author: Guilhem Lavaux, Vadim Zeitlin
// Modified by:
// Created: 06/16/98
// RCS-ID: $Id$
-// Copyright: (c) Julian Smart, Markus Holzem, Guilhem Lavaux
+// Copyright: (c) 1998-2002 wxWidgets team
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
-/*
- TODO: use worker threads to update progress controls instead of writing
- messages - it will be more visual
- */
-
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
#include "wx/thread.h"
#include "wx/dynarray.h"
-#include "wx/time.h"
+#include "wx/numdlg.h"
#include "wx/progdlg.h"
+#include "../sample.xpm"
+
+// define this to use wxExecute in the exec tests, otherwise just use system
#define USE_EXECUTE
+
#ifdef USE_EXECUTE
#define EXEC(cmd) wxExecute((cmd), wxEXEC_SYNC)
#else
#endif
class MyThread;
-WX_DEFINE_ARRAY(wxThread *, wxArrayThread);
+WX_DEFINE_ARRAY_PTR(wxThread *, wxArrayThread);
// Define a new application type
class MyApp : public wxApp
{
public:
+ MyApp();
+ virtual ~MyApp(){};
+
virtual bool OnInit();
-public:
+ // critical section protects access to all of the fields below
+ wxCriticalSection m_critsect;
+
// all the threads currently alive - as soon as the thread terminates, it's
// removed from the array
wxArrayThread m_threads;
- // crit section protects access to all of the arrays below
- wxCriticalSection m_critsect;
+ // semaphore used to wait for the threads to exit, see MyFrame::OnQuit()
+ wxSemaphore m_semAllDone;
+
+ // indicates that we're shutting down and all threads should exit
+ bool m_shuttingDown;
};
// Create a new application object
public:
// ctor
MyFrame(wxFrame *frame, const wxString& title, int x, int y, int w, int h);
+ virtual ~MyFrame();
- // operations
- void WriteText(const wxString& text) { m_txtctrl->WriteText(text); }
+ // this function is MT-safe, i.e. it can be called from worker threads
+ // safely without any additional locking
+ void LogThreadMessage(const wxString& text)
+ {
+ wxCriticalSectionLocker lock(m_csMessages);
+ m_messages.push_back(text);
+
+ // as we effectively log the messages from the idle event handler,
+ // ensure it's going to be called now that we have some messages to log
+ wxWakeUpIdle();
+ }
// accessors for MyWorkerThread (called in its context!)
bool Cancelled();
- // callbacks
+private:
+ // event handlers
void OnQuit(wxCommandEvent& event);
void OnClear(wxCommandEvent& event);
void OnIdle(wxIdleEvent &event);
-private:
// helper function - creates a new thread (but doesn't run it)
MyThread *CreateThread();
+ // update display in our status bar: called during idle handling
+ void UpdateThreadStatus();
+
+ // log the messages queued by LogThreadMessage()
+ void DoLogThreadMessages();
+
+
// just some place to put our messages in
wxTextCtrl *m_txtctrl;
+ // the array of pending messages to be displayed and the critical section
+ // protecting it
+ wxArrayString m_messages;
+ wxCriticalSection m_csMessages;
+
// remember the number of running threads and total number of threads
- size_t m_nRunning, m_nCount;
+ size_t m_nRunning,
+ m_nCount;
// the progress dialog which we show while worker thread is running
wxProgressDialog *m_dlgProgress;
// ID for the menu commands
enum
{
- THREAD_QUIT = 1,
+ THREAD_QUIT = wxID_EXIT,
+ THREAD_ABOUT = wxID_ABOUT,
THREAD_TEXT = 101,
THREAD_CLEAR,
THREAD_START_THREAD = 201,
THREAD_EXEC_THREAD,
THREAD_SHOWCPUS,
- THREAD_ABOUT,
WORKER_EVENT // this one gets sent from the worker thread
};
{
public:
MyThread(MyFrame *frame);
+ virtual ~MyThread();
// thread execution starts here
virtual void *Entry();
- // called when the thread exits - whether it terminates normally or is
- // stopped with Delete() (but not when it is Kill()ed!)
- virtual void OnExit();
-
- // write something to the text control
- void WriteText(const wxString& text);
+ // write something to the text control in the main frame
+ void WriteText(const wxString& text)
+ {
+ m_frame->LogThreadMessage(text);
+ }
public:
- size_t m_count;
+ unsigned m_count;
MyFrame *m_frame;
};
m_frame = frame;
}
-void MyThread::WriteText(const wxString& text)
+MyThread::~MyThread()
{
- wxString msg;
-
- // before doing any GUI calls we must ensure that this thread is the only
- // one doing it!
-
- wxMutexGuiEnter();
-
- msg << text;
- m_frame->WriteText(msg);
+ wxCriticalSectionLocker locker(wxGetApp().m_critsect);
- wxMutexGuiLeave();
-}
+ wxArrayThread& threads = wxGetApp().m_threads;
+ threads.Remove(this);
-void MyThread::OnExit()
-{
- wxCriticalSectionLocker locker(wxGetApp().m_critsect);
+ if ( threads.IsEmpty() )
+ {
+ // signal the main thread that there are no more threads left if it is
+ // waiting for us
+ if ( wxGetApp().m_shuttingDown )
+ {
+ wxGetApp().m_shuttingDown = false;
- wxGetApp().m_threads.Remove(this);
+ wxGetApp().m_semAllDone.Post();
+ }
+ }
}
void *MyThread::Entry()
{
wxString text;
- text.Printf(wxT("Thread 0x%x started (priority = %d).\n"),
+ text.Printf(wxT("Thread 0x%lx started (priority = %u).\n"),
GetId(), GetPriority());
WriteText(text);
// wxLogMessage(text); -- test wxLog thread safeness
for ( m_count = 0; m_count < 10; m_count++ )
{
- // check if we were asked to exit
+ // check if the application is shutting down: in this case all threads
+ // should stop a.s.a.p.
+ {
+ wxCriticalSectionLocker locker(wxGetApp().m_critsect);
+ if ( wxGetApp().m_shuttingDown )
+ return NULL;
+ }
+
+ // check if just this thread was asked to exit
if ( TestDestroy() )
break;
- text.Printf(wxT("[%u] Thread 0x%x here.\n"), m_count, GetId());
+ text.Printf(wxT("[%u] Thread 0x%lx here.\n"), m_count, GetId());
WriteText(text);
// wxSleep() can't be called from non-GUI thread!
wxThread::Sleep(1000);
}
- text.Printf(wxT("Thread 0x%x finished.\n"), GetId());
+ text.Printf(wxT("Thread 0x%lx finished.\n"), GetId());
WriteText(text);
// wxLogMessage(text); -- test wxLog thread safeness
public:
MyFrame *m_frame;
- size_t m_count;
+ unsigned m_count;
};
MyWorkerThread::MyWorkerThread(MyFrame *frame)
// send in a thread-safe way
wxPostEvent( m_frame, event );
- // wxSleep() can't be called from non-main thread!
- wxThread::Sleep(200);
+ wxMilliSleep(200);
}
wxCommandEvent event( wxEVT_COMMAND_MENU_SELECTED, WORKER_EVENT );
virtual ExitCode Entry()
{
- return (ExitCode)EXEC(m_command);
+ return wxUIntToPtr(EXEC(m_command));
}
private:
EVT_IDLE(MyFrame::OnIdle)
END_EVENT_TABLE()
+MyApp::MyApp()
+{
+ m_shuttingDown = false;
+}
+
// `Main program' equivalent, creating windows and returning main app frame
bool MyApp::OnInit()
{
+ if ( !wxApp::OnInit() )
+ return false;
+
// uncomment this to get some debugging messages from the trace code
// on the console (or just set WXTRACE env variable to include "thread")
//wxLog::AddTraceMask("thread");
// Create the main frame window
- MyFrame *frame = new MyFrame((wxFrame *)NULL, "wxWindows threads sample",
+ MyFrame *frame = new MyFrame((wxFrame *)NULL, _T("wxWidgets threads sample"),
50, 50, 450, 340);
// Make a menubar
wxMenuBar *menuBar = new wxMenuBar;
wxMenu *menuFile = new wxMenu;
- menuFile->Append(THREAD_CLEAR, "&Clear log\tCtrl-L");
+ menuFile->Append(THREAD_CLEAR, _T("&Clear log\tCtrl-L"));
menuFile->AppendSeparator();
- menuFile->Append(THREAD_QUIT, "E&xit\tAlt-X");
- menuBar->Append(menuFile, "&File");
+ menuFile->Append(THREAD_QUIT, _T("E&xit\tAlt-X"));
+ menuBar->Append(menuFile, _T("&File"));
wxMenu *menuThread = new wxMenu;
- menuThread->Append(THREAD_START_THREAD, "&Start a new thread\tCtrl-N");
- menuThread->Append(THREAD_START_THREADS, "Start &many threads at once");
- menuThread->Append(THREAD_STOP_THREAD, "S&top a running thread\tCtrl-S");
+ menuThread->Append(THREAD_START_THREAD, _T("&Start a new thread\tCtrl-N"));
+ menuThread->Append(THREAD_START_THREADS, _T("Start &many threads at once"));
+ menuThread->Append(THREAD_STOP_THREAD, _T("S&top a running thread\tCtrl-S"));
menuThread->AppendSeparator();
- menuThread->Append(THREAD_PAUSE_THREAD, "&Pause a running thread\tCtrl-P");
- menuThread->Append(THREAD_RESUME_THREAD, "&Resume suspended thread\tCtrl-R");
+ menuThread->Append(THREAD_PAUSE_THREAD, _T("&Pause a running thread\tCtrl-P"));
+ menuThread->Append(THREAD_RESUME_THREAD, _T("&Resume suspended thread\tCtrl-R"));
menuThread->AppendSeparator();
- menuThread->Append(THREAD_START_WORKER, "Start &worker thread\tCtrl-W");
- menuBar->Append(menuThread, "&Thread");
+ menuThread->Append(THREAD_START_WORKER, _T("Start &worker thread\tCtrl-W"));
+ menuBar->Append(menuThread, _T("&Thread"));
wxMenu *menuExec = new wxMenu;
- menuExec->Append(THREAD_EXEC_MAIN, "&Launch a program from main thread\tF5");
- menuExec->Append(THREAD_EXEC_THREAD, "L&aunch a program from a thread\tCtrl-F5");
- menuBar->Append(menuExec, "&Execute");
+ menuExec->Append(THREAD_EXEC_MAIN, _T("&Launch a program from main thread\tF5"));
+ menuExec->Append(THREAD_EXEC_THREAD, _T("L&aunch a program from a thread\tCtrl-F5"));
+ menuBar->Append(menuExec, _T("&Execute"));
wxMenu *menuHelp = new wxMenu;
- menuHelp->Append(THREAD_SHOWCPUS, "&Show CPU count");
+ menuHelp->Append(THREAD_SHOWCPUS, _T("&Show CPU count"));
menuHelp->AppendSeparator();
- menuHelp->Append(THREAD_ABOUT, "&About...");
- menuBar->Append(menuHelp, "&Help");
+ menuHelp->Append(THREAD_ABOUT, _T("&About..."));
+ menuBar->Append(menuHelp, _T("&Help"));
frame->SetMenuBar(menuBar);
-
+
// Show the frame
- frame->Show(TRUE);
+ frame->Show(true);
SetTopWindow(frame);
- return TRUE;
+ return true;
}
// My frame constructor
MyFrame::MyFrame(wxFrame *frame, const wxString& title,
int x, int y, int w, int h)
- : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
+ : wxFrame(frame, wxID_ANY, title, wxPoint(x, y), wxSize(w, h))
{
+ SetIcon(wxIcon(sample_xpm));
+
m_nRunning = m_nCount = 0;
m_dlgProgress = (wxProgressDialog *)NULL;
+#if wxUSE_STATUSBAR
CreateStatusBar(2);
+#endif // wxUSE_STATUSBAR
- m_txtctrl = new wxTextCtrl(this, -1, "", wxPoint(0, 0), wxSize(0, 0),
+ m_txtctrl = new wxTextCtrl(this, wxID_ANY, _T(""), wxPoint(0, 0), wxSize(0, 0),
wxTE_MULTILINE | wxTE_READONLY);
}
+MyFrame::~MyFrame()
+{
+ // NB: although the OS will terminate all the threads anyhow when the main
+ // one exits, it's good practice to do it ourselves -- even if it's not
+ // completely trivial in this example
+
+ // tell all the threads to terminate: note that they can't terminate while
+ // we're deleting them because they will block in their OnExit() -- this is
+ // important as otherwise we might access invalid array elements
+
+ {
+ wxCriticalSectionLocker locker(wxGetApp().m_critsect);
+
+ // check if we have any threads running first
+ const wxArrayThread& threads = wxGetApp().m_threads;
+ size_t count = threads.GetCount();
+
+ if ( !count )
+ return;
+
+ // set the flag indicating that all threads should exit
+ wxGetApp().m_shuttingDown = true;
+ }
+
+ // now wait for them to really terminate
+ wxGetApp().m_semAllDone.Wait();
+}
+
MyThread *MyFrame::CreateThread()
{
MyThread *thread = new MyThread(this);
void MyFrame::OnStartThreads(wxCommandEvent& WXUNUSED(event) )
{
- static long s_num = 10;
+ static long s_num;
- s_num = wxGetNumberFromUser("How many threads to start: ", "",
- "wxThread sample", s_num, 1, 10000, this);
+ s_num = wxGetNumberFromUser(_T("How many threads to start: "), _T(""),
+ _T("wxThread sample"), s_num, 1, 10000, this);
if ( s_num == -1 )
{
s_num = 10;
return;
}
- size_t count = (size_t)s_num, n;
+ unsigned count = unsigned(s_num), n;
wxArrayThread threads;
threads.Add(thr);
}
+#if wxUSE_STATUSBAR
wxString msg;
msg.Printf(wxT("%d new threads created."), count);
SetStatusText(msg, 1);
+#endif // wxUSE_STATUSBAR
// ...and then start them
for ( n = 0; n < count; n++ )
wxLogError(wxT("Can't start thread!"));
}
- SetStatusText("New thread started.", 1);
+#if wxUSE_STATUSBAR
+ SetStatusText(_T("New thread started."), 1);
+#endif // wxUSE_STATUSBAR
}
void MyFrame::OnStopThread(wxCommandEvent& WXUNUSED(event) )
{
- wxGetApp().m_critsect.Enter();
+ wxCriticalSectionLocker enter(wxGetApp().m_critsect);
// stop the last thread
if ( wxGetApp().m_threads.IsEmpty() )
{
wxLogError(wxT("No thread to stop!"));
-
- wxGetApp().m_critsect.Leave();
}
else
{
- wxThread *thread = wxGetApp().m_threads.Last();
-
- // it's important to leave critical section before calling Delete()
- // because delete will (implicitly) call OnExit() which also tries
- // to enter the same crit section - would dead lock.
- wxGetApp().m_critsect.Leave();
+ wxGetApp().m_threads.Last()->Delete();
- thread->Delete();
-
- SetStatusText("Thread stopped.", 1);
+#if wxUSE_STATUSBAR
+ SetStatusText(_T("Last thread stopped."), 1);
+#endif // wxUSE_STATUSBAR
}
}
{
wxGetApp().m_threads[n]->Resume();
- SetStatusText("Thread resumed.", 1);
+#if wxUSE_STATUSBAR
+ SetStatusText(_T("Thread resumed."), 1);
+#endif // wxUSE_STATUSBAR
}
}
{
wxGetApp().m_threads[n]->Pause();
- SetStatusText("Thread paused.", 1);
+#if wxUSE_STATUSBAR
+ SetStatusText(_T("Thread paused."), 1);
+#endif // wxUSE_STATUSBAR
}
}
-// set the frame title indicating the current number of threads
-void MyFrame::OnIdle(wxIdleEvent &event)
+void MyFrame::OnIdle(wxIdleEvent& event)
{
+ DoLogThreadMessages();
+
+ UpdateThreadStatus();
+
+ event.Skip();
+}
+
+void MyFrame::DoLogThreadMessages()
+{
+ wxCriticalSectionLocker lock(m_csMessages);
+
+ const size_t count = m_messages.size();
+ for ( size_t n = 0; n < count; n++ )
+ {
+ m_txtctrl->AppendText(m_messages[n]);
+ }
+
+ m_messages.clear();
+}
+
+void MyFrame::UpdateThreadStatus()
+{
+ wxCriticalSectionLocker enter(wxGetApp().m_critsect);
+
// update the counts of running/total threads
size_t nRunning = 0,
nCount = wxGetApp().m_threads.Count();
m_nRunning = nRunning;
m_nCount = nCount;
- wxLogStatus(this, wxT("%u threads total, %u running."), nCount, nRunning);
+ wxLogStatus(this, wxT("%u threads total, %u running."), unsigned(nCount), unsigned(nRunning));
}
//else: avoid flicker - don't print anything
}
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event) )
{
- size_t count = wxGetApp().m_threads.Count();
- for ( size_t i = 0; i < count; i++ )
- {
- wxGetApp().m_threads[0]->Delete();
- }
-
- Close(TRUE);
+ Close(true);
}
void MyFrame::OnExecMain(wxCommandEvent& WXUNUSED(event))
{
wxLogMessage(wxT("The exit code from the main program is %ld"),
- EXEC("/bin/echo \"main program\""));
+ EXEC(_T("/bin/echo \"main program\"")));
}
void MyFrame::OnExecThread(wxCommandEvent& WXUNUSED(event))
thread.Run();
wxLogMessage(wxT("The exit code from a child thread is %ld"),
- (long)thread.Wait());
+ (long)wxPtrToUInt(thread.Wait()));
}
void MyFrame::OnShowCPUs(wxCommandEvent& WXUNUSED(event))
switch ( nCPUs )
{
case -1:
- msg = "Unknown number of CPUs";
+ msg = _T("Unknown number of CPUs");
break;
case 0:
- msg = "WARNING: you're running without any CPUs!";
+ msg = _T("WARNING: you're running without any CPUs!");
break;
case 1:
- msg = "This system only has one CPU.";
+ msg = _T("This system only has one CPU.");
break;
default:
msg.Printf(wxT("This system has %d CPUs"), nCPUs);
}
-
+
wxLogMessage(msg);
}
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event) )
{
- wxMessageDialog dialog(this, "wxWindows multithreaded application sample\n"
- "(c) 1998 Julian Smart, Guilhem Lavaux\n"
- "(c) 1999 Vadim Zeitlin\n"
- "(c) 2000 Robert Roebling",
- "About wxThread sample",
+ wxMessageDialog dialog(this,
+ _T("wxWidgets multithreaded application sample\n")
+ _T("(c) 1998 Julian Smart, Guilhem Lavaux\n")
+ _T("(c) 1999 Vadim Zeitlin\n")
+ _T("(c) 2000 Robert Roebling"),
+ _T("About wxThread sample"),
wxOK | wxICON_INFORMATION);
dialog.ShowModal();
if ( thread->Create() != wxTHREAD_NO_ERROR )
{
wxLogError(wxT("Can't create thread!"));
+ return;
}
m_dlgProgress = new wxProgressDialog
(
- "Progress dialog",
- "Wait until the thread terminates or press [Cancel]",
+ _T("Progress dialog"),
+ _T("Wait until the thread terminates or press [Cancel]"),
100,
this,
wxPD_CAN_ABORT |
);
// thread is not running yet, no need for crit sect
- m_cancelled = FALSE;
+ m_cancelled = false;
thread->Run();
}
void MyFrame::OnWorkerEvent(wxCommandEvent& event)
{
-#if 0
- WriteText( "Got message from worker thread: " );
- WriteText( event.GetString() );
- WriteText( "\n" );
-#else
int n = event.GetInt();
if ( n == -1 )
{
{
wxCriticalSectionLocker lock(m_critsectWork);
- m_cancelled = TRUE;
+ m_cancelled = true;
}
}
-#endif
}
bool MyFrame::Cancelled()