threadpsx.cpp

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        return wxTHREAD_NOT_RUNNING;
    }

    // just set a flag, the thread will be really paused only during the next
    // call to TestDestroy()
    m_internal->SetState(STATE_PAUSED);

    return wxTHREAD_NO_ERROR;
}

wxThreadError wxThread::Resume()
{
    wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR,
                 _T("a thread can't resume itself") );

    wxCriticalSectionLocker lock(m_critsect);

    wxThreadState state = m_internal->GetState();

    switch ( state )
    {
        case STATE_PAUSED:
            wxLogTrace(TRACE_THREADS, _T("Thread %ld suspended, resuming."),
                       GetId());

            m_internal->Resume();

            return wxTHREAD_NO_ERROR;

        case STATE_EXITED:
            wxLogTrace(TRACE_THREADS, _T("Thread %ld exited, won't resume."),
                       GetId());
            return wxTHREAD_NO_ERROR;

        default:
            wxLogDebug(_T("Attempt to resume a thread which is not paused."));

            return wxTHREAD_MISC_ERROR;
    }
}

// -----------------------------------------------------------------------------
// exiting thread
// -----------------------------------------------------------------------------

wxThread::ExitCode wxThread::Wait()
{
    wxCHECK_MSG( This() != this, (ExitCode)-1,
                 _T("a thread can't wait for itself") );

    wxCHECK_MSG( !m_isDetached, (ExitCode)-1,
                 _T("can't wait for detached thread") );

    m_internal->Wait();

    return m_internal->GetExitCode();
}

wxThreadError wxThread::Delete(ExitCode *rc)
{
    wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR,
                 _T("a thread can't delete itself") );

    bool isDetached = m_isDetached;

    m_critsect.Enter();
    wxThreadState state = m_internal->GetState();

    // ask the thread to stop
    m_internal->SetCancelFlag();

    m_critsect.Leave();

    switch ( state )
    {
        case STATE_NEW:
            // we need to wake up the thread so that PthreadStart() will
            // terminate - right now it's blocking on run semaphore in
            // PthreadStart()
            m_internal->SignalRun();

            // fall through

        case STATE_EXITED:
            // nothing to do
            break;

        case STATE_PAUSED:
            // resume the thread first
            m_internal->Resume();

            // fall through

        default:
            if ( !isDetached )
            {
                // wait until the thread stops
                m_internal->Wait();

                if ( rc )
                {
                    // return the exit code of the thread
                    *rc = m_internal->GetExitCode();
                }
            }
            //else: can't wait for detached threads
    }

    return wxTHREAD_NO_ERROR;
}

wxThreadError wxThread::Kill()
{
    wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR,
                 _T("a thread can't kill itself") );

    switch ( m_internal->GetState() )
    {
        case STATE_NEW:
        case STATE_EXITED:
            return wxTHREAD_NOT_RUNNING;

        case STATE_PAUSED:
            // resume the thread first
            Resume();

            // fall through

        default:
#ifdef HAVE_PTHREAD_CANCEL
            if ( pthread_cancel(m_internal->GetId()) != 0 )
#endif
            {
                wxLogError(_("Failed to terminate a thread."));

                return wxTHREAD_MISC_ERROR;
            }

            if ( m_isDetached )
            {
                // if we use cleanup function, this will be done from
                // wxPthreadCleanup()
#ifndef wxHAVE_PTHREAD_CLEANUP
                ScheduleThreadForDeletion();

                // don't call OnExit() here, it can only be called in the
                // threads context and we're in the context of another thread

                DeleteThread(this);
#endif // wxHAVE_PTHREAD_CLEANUP
            }
            else
            {
                m_internal->SetExitCode(EXITCODE_CANCELLED);
            }

            return wxTHREAD_NO_ERROR;
    }
}

void wxThread::Exit(ExitCode status)
{
    wxASSERT_MSG( This() == this,
                  _T("wxThread::Exit() can only be called in the context of the same thread") );

    if ( m_isDetached )
    {
        // from the moment we call OnExit(), the main program may terminate at
        // any moment, so mark this thread as being already in process of being
        // deleted or wxThreadModule::OnExit() will try to delete it again
        ScheduleThreadForDeletion();
    }

    // don't enter m_critsect before calling OnExit() because the user code
    // might deadlock if, for example, it signals a condition in OnExit() (a
    // common case) while the main thread calls any of functions entering
    // m_critsect on us (almost all of them do)
    OnExit();

    // delete C++ thread object if this is a detached thread - user is
    // responsible for doing this for joinable ones
    if ( m_isDetached )
    {
        // FIXME I'm feeling bad about it - what if another thread function is
        //       called (in another thread context) now? It will try to access
        //       half destroyed object which will probably result in something
        //       very bad - but we can't protect this by a crit section unless
        //       we make it a global object, but this would mean that we can
        //       only call one thread function at a time :-(
        DeleteThread(this);
        pthread_setspecific(gs_keySelf, 0);
    }
    else
    {
        m_critsect.Enter();
        m_internal->SetState(STATE_EXITED);
        m_critsect.Leave();
    }

    // terminate the thread (pthread_exit() never returns)
    pthread_exit(status);

    wxFAIL_MSG(_T("pthread_exit() failed"));
}

// also test whether we were paused
bool wxThread::TestDestroy()
{
    wxASSERT_MSG( This() == this,
                  _T("wxThread::TestDestroy() can only be called in the context of the same thread") );

    m_critsect.Enter();

    if ( m_internal->GetState() == STATE_PAUSED )
    {
        m_internal->SetReallyPaused(TRUE);

        // leave the crit section or the other threads will stop too if they
        // try to call any of (seemingly harmless) IsXXX() functions while we
        // sleep
        m_critsect.Leave();

        m_internal->Pause();
    }
    else
    {
        // thread wasn't requested to pause, nothing to do
        m_critsect.Leave();
    }

    return m_internal->WasCancelled();
}

wxThread::~wxThread()
{
#ifdef __WXDEBUG__
    m_critsect.Enter();

    // check that the thread either exited or couldn't be created
    if ( m_internal->GetState() != STATE_EXITED &&
         m_internal->GetState() != STATE_NEW )
    {
        wxLogDebug(_T("The thread %ld is being destroyed although it is still running! The application may crash."), GetId());
    }

    m_critsect.Leave();
#endif // __WXDEBUG__

    delete m_internal;

    // remove this thread from the global array
    gs_allThreads.Remove(this);
}

// -----------------------------------------------------------------------------
// state tests
// -----------------------------------------------------------------------------

bool wxThread::IsRunning() const
{
    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);

    return m_internal->GetState() == STATE_RUNNING;
}

bool wxThread::IsAlive() const
{
    wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);

    switch ( m_internal->GetState() )
    {
        case STATE_RUNNING:
        case STATE_PAUSED:
            return TRUE;

        default:
            return FALSE;
    }
}

bool wxThread::IsPaused() const
{
    wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect);

    return (m_internal->GetState() == STATE_PAUSED);
}

//--------------------------------------------------------------------
// wxThreadModule
//--------------------------------------------------------------------

class wxThreadModule : public wxModule
{
public:
    virtual bool OnInit();
    virtual void OnExit();

private:
    DECLARE_DYNAMIC_CLASS(wxThreadModule)
};

IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)

bool wxThreadModule::OnInit()
{
    int rc = pthread_key_create(&gs_keySelf, NULL /* dtor function */);
    if ( rc != 0 )
    {
        wxLogSysError(rc, _("Thread module initialization failed: failed to create thread key"));

        return FALSE;
    }

    gs_tidMain = pthread_self();

    gs_mutexGui = new wxMutex();
    gs_mutexGui->Lock();

    gs_mutexDeleteThread = new wxMutex();
    gs_condAllDeleted = new wxCondition( *gs_mutexDeleteThread );

    return TRUE;
}

void wxThreadModule::OnExit()
{
    wxASSERT_MSG( wxThread::IsMain(), wxT("only main thread can be here") );

    // are there any threads left which are being deleted right now?
    size_t nThreadsBeingDeleted;

    {
        wxMutexLocker lock( *gs_mutexDeleteThread );
        nThreadsBeingDeleted = gs_nThreadsBeingDeleted;

        if ( nThreadsBeingDeleted > 0 )
        {
            wxLogTrace(TRACE_THREADS,
                       _T("Waiting for %lu threads to disappear"),
                       (unsigned long)nThreadsBeingDeleted);

            // have to wait until all of them disappear
            gs_condAllDeleted->Wait();
        }
    }

    // terminate any threads left
    size_t count = gs_allThreads.GetCount();
    if ( count != 0u )
    {
        wxLogDebug(wxT("%lu threads were not terminated by the application."),
                   (unsigned long)count);
    }

    for ( size_t n = 0u; n < count; n++ )
    {
        // Delete calls the destructor which removes the current entry. We
        // should only delete the first one each time.
        gs_allThreads[0]->Delete();
    }

    // destroy GUI mutex
    gs_mutexGui->Unlock();
    delete gs_mutexGui;

    // and free TLD slot
    (void)pthread_key_delete(gs_keySelf);

    delete gs_condAllDeleted;
    delete gs_mutexDeleteThread;
}

// ----------------------------------------------------------------------------
// global functions
// ----------------------------------------------------------------------------

static void ScheduleThreadForDeletion()
{
    wxMutexLocker lock( *gs_mutexDeleteThread );

    gs_nThreadsBeingDeleted++;

    wxLogTrace(TRACE_THREADS, _T("%lu thread%s waiting to be deleted"),
               (unsigned long)gs_nThreadsBeingDeleted,
               gs_nThreadsBeingDeleted == 1 ? "" : "s");
}

static void DeleteThread(wxThread *This)
{
    // gs_mutexDeleteThread should be unlocked before signalling the condition
    // or wxThreadModule::OnExit() would deadlock
    wxMutexLocker locker( *gs_mutexDeleteThread );

    wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId());

    delete This;

    wxCHECK_RET( gs_nThreadsBeingDeleted > 0,
                 _T("no threads scheduled for deletion, yet we delete one?") );

    wxLogTrace(TRACE_THREADS, _T("%lu scheduled for deletion threads left."),
               (unsigned long)gs_nThreadsBeingDeleted - 1);

    if ( !--gs_nThreadsBeingDeleted )
    {
        // no more threads left, signal it
        gs_condAllDeleted->Signal();
    }
}

void wxMutexGuiEnter()
{
    gs_mutexGui->Lock();
}

void wxMutexGuiLeave()
{
    gs_mutexGui->Unlock();
}

// ----------------------------------------------------------------------------
// include common implementation code
// ----------------------------------------------------------------------------

#include "wx/thrimpl.cpp"

#endif // wxUSE_THREADS