X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/b89156b5dbb3c1270452379801a79613cd69bb32..c6eba8f8b204b0d722db0007e3e0d5e2d2d20085:/src/msw/thread.cpp

diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp
index 33ca0a645a..1b26944ae7 100644
--- a/src/msw/thread.cpp
+++ b/src/msw/thread.cpp
@@ -2,321 +2,863 @@
 // Name:        thread.cpp
 // Purpose:     wxThread Implementation
 // Author:      Original from Wolfram Gloger/Guilhem Lavaux
-// Modified by:
+// Modified by: Vadim Zeitlin to make it work :-)
 // Created:     04/22/98
 // RCS-ID:      $Id$
-// Copyright:   (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998)
+// Copyright:   (c) Wolfram Gloger (1996, 1997); Guilhem Lavaux (1998),
+//                  Vadim Zeitlin (1999)
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 #ifdef __GNUG__
-#pragma implementation "thread.h"
+    #pragma implementation "thread.h"
 #endif
 
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #if defined(__BORLANDC__)
-#pragma hdrstop
+    #pragma hdrstop
 #endif
 
 #ifndef WX_PRECOMP
-#include "wx/wx.h"
+    #include "wx/wx.h"
 #endif
 
+#if wxUSE_THREADS
+
 #include <stdio.h>
 
 #include <windows.h>
+
 #include "wx/module.h"
 #include "wx/thread.h"
 
-enum thread_state {
-  STATE_IDLE = 0,
-  STATE_RUNNING,
-  STATE_CANCELED,
-  STATE_EXITED
+// the possible states of the thread ("=>" shows all possible transitions from
+// this state)
+enum wxThreadState
+{
+    STATE_NEW,          // didn't start execution yet (=> RUNNING)
+    STATE_RUNNING,      // thread is running (=> PAUSED, CANCELED)
+    STATE_PAUSED,       // thread is temporarily suspended (=> RUNNING)
+    STATE_CANCELED,     // thread should terminate a.s.a.p. (=> EXITED)
+    STATE_EXITED        // thread is terminating
 };
 
-/////////////////////////////////////////////////////////////////////////////
-// Static variables
-/////////////////////////////////////////////////////////////////////////////
+// ----------------------------------------------------------------------------
+// static variables
+// ----------------------------------------------------------------------------
 
-static HANDLE p_mainid;
-wxMutex wxMainMutex; // controls access to all GUI functions
+// TLS index of the slot where we store the pointer to the current thread
+static DWORD s_tlsThisThread = 0xFFFFFFFF;
 
-/////////////////////////////////////////////////////////////////////////////
-// Windows implementation
-/////////////////////////////////////////////////////////////////////////////
+// id of the main thread - the one which can call GUI functions without first
+// calling wxMutexGuiEnter()
+static DWORD s_idMainThread = 0;
+
+// if it's FALSE, some secondary thread is holding the GUI lock
+static bool s_bGuiOwnedByMainThread = TRUE;
+
+// critical section which controls access to all GUI functions: any secondary
+// thread (i.e. except the main one) must enter this crit section before doing
+// any GUI calls
+static wxCriticalSection *s_critsectGui = NULL;
 
-class wxMutexInternal {
+// critical section which protects s_nWaitingForGui variable
+static wxCriticalSection *s_critsectWaitingForGui = NULL;
+
+// number of threads waiting for GUI in wxMutexGuiEnter()
+static size_t s_nWaitingForGui = 0;
+
+// are we waiting for a thread termination?
+static bool s_waitingForThread = FALSE;
+
+// ============================================================================
+// Windows implementation of thread classes
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wxMutex implementation
+// ----------------------------------------------------------------------------
+class wxMutexInternal
+{
 public:
-  HANDLE p_mutex;
+    HANDLE p_mutex;
 };
 
 wxMutex::wxMutex()
 {
-  p_internal = new wxMutexInternal;
-  p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL);
-  m_locked = 0;
+    p_internal = new wxMutexInternal;
+    p_internal->p_mutex = CreateMutex(NULL, FALSE, NULL);
+    if ( !p_internal->p_mutex )
+    {
+        wxLogSysError(_("Can not create mutex."));
+    }
+
+    m_locked = 0;
 }
 
 wxMutex::~wxMutex()
 {
-  if (m_locked > 0)
-    wxDebugMsg("wxMutex warning: freeing a locked mutex (%d locks)\n", m_locked);
-  CloseHandle(p_internal->p_mutex);
+    if (m_locked > 0)
+        wxLogDebug("Warning: freeing a locked mutex (%d locks).", m_locked);
+    CloseHandle(p_internal->p_mutex);
 }
 
 wxMutexError wxMutex::Lock()
 {
-  DWORD ret;
+    DWORD ret;
 
-  ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
-  if (ret == WAIT_ABANDONED)
-    return MUTEX_BUSY;
+    ret = WaitForSingleObject(p_internal->p_mutex, INFINITE);
+    switch ( ret )
+    {
+        case WAIT_ABANDONED:
+            return wxMUTEX_BUSY;
 
-  m_locked++;
-  return MUTEX_NO_ERROR;
+        case WAIT_OBJECT_0:
+            // ok
+            break;
+
+        case WAIT_FAILED:
+            wxLogSysError(_("Couldn't acquire a mutex lock"));
+            return wxMUTEX_MISC_ERROR;
+
+        case WAIT_TIMEOUT:
+        default:
+            wxFAIL_MSG("impossible return value in wxMutex::Lock");
+    }
+
+    m_locked++;
+    return wxMUTEX_NO_ERROR;
 }
 
 wxMutexError wxMutex::TryLock()
 {
-  DWORD ret;
+    DWORD ret;
 
-  ret = WaitForSingleObject(p_internal->p_mutex, 0);
-  if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED)
-    return MUTEX_BUSY;
+    ret = WaitForSingleObject(p_internal->p_mutex, 0);
+    if (ret == WAIT_TIMEOUT || ret == WAIT_ABANDONED)
+        return wxMUTEX_BUSY;
 
-  m_locked++;
-  return MUTEX_NO_ERROR;
+    m_locked++;
+    return wxMUTEX_NO_ERROR;
 }
 
 wxMutexError wxMutex::Unlock()
 {
-  BOOL ret;
+    if (m_locked > 0)
+        m_locked--;
 
-  if (m_locked > 0)
-    m_locked--;
+    BOOL ret = ReleaseMutex(p_internal->p_mutex);
+    if ( ret == 0 )
+    {
+        wxLogSysError(_("Couldn't release a mutex"));
+        return wxMUTEX_MISC_ERROR;
+    }
 
-    // Why does this have 3 args? The redundant ones removed by JACS
-//  ret = ReleaseMutex(p_internal->p_mutex, 1, NULL);
-  ret = ReleaseMutex(p_internal->p_mutex);
-  return MUTEX_NO_ERROR;
+    return wxMUTEX_NO_ERROR;
 }
 
-class wxConditionInternal {
+// ----------------------------------------------------------------------------
+// wxCondition implementation
+// ----------------------------------------------------------------------------
+
+class wxConditionInternal
+{
 public:
-  HANDLE event;
-  int waiters;
+    HANDLE event;
+    int waiters;
 };
 
 wxCondition::wxCondition()
 {
-  p_internal = new wxConditionInternal;
-  p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL);
-  p_internal->waiters = 0;
+    p_internal = new wxConditionInternal;
+    p_internal->event = CreateEvent(NULL, FALSE, FALSE, NULL);
+    if ( !p_internal->event )
+    {
+        wxLogSysError(_("Can not create event object."));
+    }
+
+    p_internal->waiters = 0;
 }
 
 wxCondition::~wxCondition()
 {
-  CloseHandle(p_internal->event);
+    CloseHandle(p_internal->event);
 }
 
 void wxCondition::Wait(wxMutex& mutex)
 {
-  mutex.Unlock();
-  p_internal->waiters++;
-  WaitForSingleObject(p_internal->event, INFINITE);
-  p_internal->waiters--;
-  mutex.Lock();
+    mutex.Unlock();
+    p_internal->waiters++;
+    WaitForSingleObject(p_internal->event, INFINITE);
+    p_internal->waiters--;
+    mutex.Lock();
 }
 
-bool wxCondition::Wait(wxMutex& mutex, unsigned long sec,
+bool wxCondition::Wait(wxMutex& mutex,
+                       unsigned long sec,
                        unsigned long nsec)
 {
-  DWORD ret;
+    DWORD ret;
 
-  mutex.Unlock();
-  p_internal->waiters++;
-  ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000));
-  p_internal->waiters--;
-  mutex.Lock();
+    mutex.Unlock();
+    p_internal->waiters++;
+    ret = WaitForSingleObject(p_internal->event, (sec*1000)+(nsec/1000000));
+    p_internal->waiters--;
+    mutex.Lock();
 
-  return (ret != WAIT_TIMEOUT);
+    return (ret != WAIT_TIMEOUT);
 }
 
 void wxCondition::Signal()
 {
-  SetEvent(p_internal->event);
+    SetEvent(p_internal->event);
 }
 
 void wxCondition::Broadcast()
 {
-  int i;
-
-  for (i=0;i<p_internal->waiters;i++)
-    SetEvent(p_internal->event);
+    int i;
+
+    for (i=0;i<p_internal->waiters;i++)
+    {
+        if ( SetEvent(p_internal->event) == 0 )
+        {
+            wxLogSysError(_("Couldn't change the state of event object."));
+        }
+    }
 }
 
-class wxThreadInternal {
+// ----------------------------------------------------------------------------
+// wxCriticalSection implementation
+// ----------------------------------------------------------------------------
+
+class wxCriticalSectionInternal
+{
 public:
-  static DWORD WinThreadStart(LPVOID arg);
+    // init the critical section object
+    wxCriticalSectionInternal()
+        { ::InitializeCriticalSection(&m_data); }
 
-  HANDLE thread_id;
-  int state;
-  int prio, defer;
-  DWORD tid;
+    // implicit cast to the associated data
+    operator CRITICAL_SECTION *() { return &m_data; }
+
+    // free the associated ressources
+    ~wxCriticalSectionInternal()
+        { ::DeleteCriticalSection(&m_data); }
+
+private:
+    CRITICAL_SECTION m_data;
 };
 
-DWORD wxThreadInternal::WinThreadStart(LPVOID arg)
+wxCriticalSection::wxCriticalSection()
 {
-  wxThread *ptr = (wxThread *)arg;
-  DWORD ret;
+    m_critsect = new wxCriticalSectionInternal;
+}
 
-  ret = (DWORD)ptr->Entry();
-  ptr->p_internal->state = STATE_EXITED;
+wxCriticalSection::~wxCriticalSection()
+{
+    delete m_critsect;
+}
 
-  return ret;
+void wxCriticalSection::Enter()
+{
+    ::EnterCriticalSection(*m_critsect);
 }
 
-wxThreadError wxThread::Create()
+void wxCriticalSection::Leave()
+{
+    ::LeaveCriticalSection(*m_critsect);
+}
+
+// ----------------------------------------------------------------------------
+// wxThread implementation
+// ----------------------------------------------------------------------------
+
+// wxThreadInternal class
+// ----------------------
+
+class wxThreadInternal
+{
+public:
+    wxThreadInternal()
+    {
+        m_hThread = 0;
+        m_state = STATE_NEW;
+        m_priority = WXTHREAD_DEFAULT_PRIORITY;
+    }
+
+    // create a new (suspended) thread (for the given thread object)
+    bool Create(wxThread *thread);
+
+    // suspend/resume/terminate
+    bool Suspend();
+    bool Resume();
+    void Cancel() { m_state = STATE_CANCELED; }
+
+    // thread state
+    void SetState(wxThreadState state) { m_state = state; }
+    wxThreadState GetState() const { return m_state; }
+
+    // thread priority
+    void SetPriority(unsigned int priority) { m_priority = priority; }
+    unsigned int GetPriority() const { return m_priority; }
+
+    // thread handle and id
+    HANDLE GetHandle() const { return m_hThread; }
+    DWORD  GetId() const { return m_tid; }
+
+    // thread function
+    static DWORD WinThreadStart(wxThread *thread);
+
+private:
+    HANDLE        m_hThread;    // handle of the thread
+    wxThreadState m_state;      // state, see wxThreadState enum
+    unsigned int  m_priority;   // thread priority in "wx" units
+    DWORD         m_tid;        // thread id
+};
+
+DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
 {
-  int win_prio, prio = p_internal->prio;
+    // store the thread object in the TLS
+    if ( !::TlsSetValue(s_tlsThisThread, thread) )
+    {
+        wxLogSysError(_("Can not start thread: error writing TLS."));
+
+        return (DWORD)-1;
+    }
 
-  p_internal->thread_id = CreateThread(NULL, 0,
-                   (LPTHREAD_START_ROUTINE)wxThreadInternal::WinThreadStart,
-                   (void *)this, CREATE_SUSPENDED, &p_internal->tid);
-  if (p_internal->thread_id == NULL) {
-    printf("Error = %d\n", GetLastError());
-    return THREAD_NO_RESOURCE;
-  }
+    DWORD ret = (DWORD)thread->Entry();
+    thread->p_internal->SetState(STATE_EXITED);
+    thread->OnExit();
 
-  if (prio <= 20)
-    win_prio = THREAD_PRIORITY_LOWEST;
-  else if (prio <= 40)
-    win_prio = THREAD_PRIORITY_BELOW_NORMAL;
-  else if (prio <= 60)
-    win_prio = THREAD_PRIORITY_NORMAL;
-  else if (prio <= 80)
-    win_prio = THREAD_PRIORITY_ABOVE_NORMAL;
-  else if (prio <= 100)
-    win_prio = THREAD_PRIORITY_HIGHEST;
+    delete thread;
+
+    return ret;
+}
 
-  SetThreadPriority(p_internal->thread_id, win_prio);
+bool wxThreadInternal::Create(wxThread *thread)
+{
+    m_hThread = ::CreateThread
+                  (
+                    NULL,                               // default security
+                    0,                                  // default stack size
+                    (LPTHREAD_START_ROUTINE)            // thread entry point
+                    wxThreadInternal::WinThreadStart,   //
+                    (LPVOID)thread,                     // parameter
+                    CREATE_SUSPENDED,                   // flags
+                    &m_tid                              // [out] thread id
+                  );
+
+    if ( m_hThread == NULL )
+    {
+        wxLogSysError(_("Can't create thread"));
+
+        return FALSE;
+    }
+
+    // translate wxWindows priority to the Windows one
+    int win_priority;
+    if (m_priority <= 20)
+        win_priority = THREAD_PRIORITY_LOWEST;
+    else if (m_priority <= 40)
+        win_priority = THREAD_PRIORITY_BELOW_NORMAL;
+    else if (m_priority <= 60)
+        win_priority = THREAD_PRIORITY_NORMAL;
+    else if (m_priority <= 80)
+        win_priority = THREAD_PRIORITY_ABOVE_NORMAL;
+    else if (m_priority <= 100)
+        win_priority = THREAD_PRIORITY_HIGHEST;
+    else
+    {
+        wxFAIL_MSG("invalid value of thread priority parameter");
+        win_priority = THREAD_PRIORITY_NORMAL;
+    }
+
+    if ( ::SetThreadPriority(m_hThread, win_priority) == 0 )
+    {
+        wxLogSysError(_("Can't set thread priority"));
+    }
 
-  ResumeThread(p_internal->thread_id);
-  p_internal->state = STATE_RUNNING;
- 
-  return THREAD_NO_ERROR;
+    return TRUE;
 }
 
-wxThreadError wxThread::Destroy()
+bool wxThreadInternal::Suspend()
 {
-  if (p_internal->state != STATE_RUNNING)
-    return THREAD_NOT_RUNNING;
+    DWORD nSuspendCount = ::SuspendThread(m_hThread);
+    if ( nSuspendCount == (DWORD)-1 )
+    {
+        wxLogSysError(_("Can not suspend thread %x"), m_hThread);
+
+        return FALSE;
+    }
 
-  if (p_internal->defer == FALSE)
-    TerminateThread(p_internal->thread_id, 0);
-  else
-    p_internal->state = STATE_CANCELED;
+    m_state = STATE_PAUSED;
 
-  return THREAD_NO_ERROR;
+    return TRUE;
 }
 
-void wxThread::Exit(void *status)
+bool wxThreadInternal::Resume()
+{
+    DWORD nSuspendCount = ::ResumeThread(m_hThread);
+    if ( nSuspendCount == (DWORD)-1 )
+    {
+        wxLogSysError(_("Can not resume thread %x"), m_hThread);
+
+        return FALSE;
+    }
+
+    m_state = STATE_RUNNING;
+
+    return TRUE;
+}
+
+// static functions
+// ----------------
+
+wxThread *wxThread::This()
+{
+    wxThread *thread = (wxThread *)::TlsGetValue(s_tlsThisThread);
+
+    // be careful, 0 may be a valid return value as well
+    if ( !thread && (::GetLastError() != NO_ERROR) )
+    {
+        wxLogSysError(_("Couldn't get the current thread pointer"));
+
+        // return NULL...
+    }
+
+    return thread;
+}
+
+bool wxThread::IsMain()
+{
+    return ::GetCurrentThreadId() == s_idMainThread;
+}
+
+#ifdef Yield
+    #undef Yield
+#endif
+
+void wxThread::Yield()
+{
+    // 0 argument to Sleep() is special
+    ::Sleep(0);
+}
+
+void wxThread::Sleep(unsigned long milliseconds)
+{
+    ::Sleep(milliseconds);
+}
+
+// create/start thread
+// -------------------
+
+wxThreadError wxThread::Create()
+{
+    if ( !p_internal->Create(this) )
+        return wxTHREAD_NO_RESOURCE;
+
+    return wxTHREAD_NO_ERROR;
+}
+
+wxThreadError wxThread::Run()
 {
-  p_internal->state = STATE_EXITED;
-  ExitThread((DWORD)status);
+    wxCriticalSectionLocker lock(m_critsect);
+
+    if ( p_internal->GetState() != STATE_NEW )
+    {
+        // actually, it may be almost any state at all, not only STATE_RUNNING
+        return wxTHREAD_RUNNING;
+    }
+
+    return Resume();
 }
 
-void wxThread::SetPriority(int prio)
+// suspend/resume thread
+// ---------------------
+
+wxThreadError wxThread::Pause()
 {
-  p_internal->prio = prio;
+    wxCriticalSectionLocker lock(m_critsect);
+
+    return p_internal->Suspend() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 }
 
-int wxThread::GetPriority()
+wxThreadError wxThread::Resume()
 {
-  return p_internal->prio;
+    wxCriticalSectionLocker lock(m_critsect);
+
+    return p_internal->Resume() ? wxTHREAD_NO_ERROR : wxTHREAD_MISC_ERROR;
 }
 
-void wxThread::DeferDestroy(bool on)
+// stopping thread
+// ---------------
+
+wxThread::ExitCode wxThread::Delete()
 {
-  p_internal->defer = on;
+    ExitCode rc = 0;
+
+    // Delete() is always safe to call, so consider all possible states
+    if ( IsPaused() )
+        Resume();
+
+    if ( IsRunning() )
+    {
+        if ( IsMain() )
+        {
+            // set flag for wxIsWaitingForThread()
+            s_waitingForThread = TRUE;
+
+            wxBeginBusyCursor();
+        }
+
+        HANDLE hThread;
+        {
+            wxCriticalSectionLocker lock(m_critsect);
+
+            p_internal->Cancel();
+            hThread = p_internal->GetHandle();
+        }
+
+        // we can't just wait for the thread to terminate because it might be
+        // calling some GUI functions and so it will never terminate before we
+        // process the Windows messages that result from these functions
+        DWORD result;
+        do
+        {
+            result = ::MsgWaitForMultipleObjects
+                     (
+                       1,              // number of objects to wait for
+                       &hThread,       // the objects
+                       FALSE,          // don't wait for all objects
+                       INFINITE,       // no timeout
+                       QS_ALLEVENTS    // return as soon as there are any events
+                     );
+
+            switch ( result )
+            {
+                case 0xFFFFFFFF:
+                    // error
+                    wxLogSysError(_("Can not wait for thread termination"));
+                    Kill();
+                    return (ExitCode)-1;
+
+                case WAIT_OBJECT_0:
+                    // thread we're waiting for terminated
+                    break;
+
+                case WAIT_OBJECT_0 + 1:
+                    // new message arrived, process it
+                    if ( !wxTheApp->DoMessage() )
+                    {
+                        // WM_QUIT received: kill the thread
+                        Kill();
+
+                        return (ExitCode)-1;
+                    }
+
+                    if ( IsMain() )
+                    {
+                        // give the thread we're waiting for chance to exit
+                        // from the GUI call it might have been in
+                        if ( (s_nWaitingForGui > 0) && wxGuiOwnedByMainThread() )
+                        {
+                            wxMutexGuiLeave();
+                        }
+                    }
+
+                    break;
+
+                default:
+                    wxFAIL_MSG("unexpected result of MsgWaitForMultipleObject");
+            }
+        } while ( result != WAIT_OBJECT_0 );
+
+        if ( IsMain() )
+        {
+            s_waitingForThread = FALSE;
+
+            wxEndBusyCursor();
+        }
+
+        if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
+        {
+            wxLogLastError("GetExitCodeThread");
+
+            rc = (ExitCode)-1;
+        }
+
+        wxASSERT_MSG( (LPVOID)rc != (LPVOID)STILL_ACTIVE,
+                      "thread must be already terminated." );
+
+        ::CloseHandle(hThread);
+    }
+
+    return rc;
 }
 
-void wxThread::TestDestroy()
+wxThreadError wxThread::Kill()
 {
-  if (p_internal->state == STATE_CANCELED)
-    ExitThread(0);
+    if ( !IsRunning() )
+        return wxTHREAD_NOT_RUNNING;
+
+    if ( !::TerminateThread(p_internal->GetHandle(), (DWORD)-1) )
+    {
+        wxLogSysError(_("Couldn't terminate thread"));
+
+        return wxTHREAD_MISC_ERROR;
+    }
+
+    delete this;
+
+    return wxTHREAD_NO_ERROR;
 }
 
-void *wxThread::Join()
+void wxThread::Exit(void *status)
 {
-  DWORD exit_code;
+    delete this;
 
-  if (p_internal->state == STATE_IDLE)
-    return NULL;
+    ::ExitThread((DWORD)status);
+
+    wxFAIL_MSG("Couldn't return from ExitThread()!");
+}
 
-  if (wxThread::IsMain())
-    wxMainMutex.Unlock();
-  WaitForSingleObject(p_internal->thread_id, INFINITE);
-  if (wxThread::IsMain())
-    wxMainMutex.Lock();
+void wxThread::SetPriority(unsigned int prio)
+{
+    wxCriticalSectionLocker lock(m_critsect);
 
-  GetExitCodeThread(p_internal->thread_id, &exit_code);
-  CloseHandle(p_internal->thread_id);
+    p_internal->SetPriority(prio);
+}
 
-  p_internal->state = STATE_IDLE;
+unsigned int wxThread::GetPriority() const
+{
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 
-  return (void *)exit_code;
+    return p_internal->GetPriority();
 }
 
 unsigned long wxThread::GetID() const
 {
-  return (unsigned long)p_internal->tid;
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+    return (unsigned long)p_internal->GetId();
 }
 
-bool wxThread::IsMain() const
+bool wxThread::IsRunning() const
 {
-  return (GetCurrentThread() == p_mainid);
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+    return p_internal->GetState() == STATE_RUNNING;
 }
 
-wxThread::wxThread()
+bool wxThread::IsAlive() const
 {
-  p_internal = new wxThreadInternal();
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
 
-  p_internal->defer = FALSE;
-  p_internal->prio  = WXTHREAD_DEFAULT_PRIORITY;
-  p_internal->state = STATE_IDLE;
+    return (p_internal->GetState() == STATE_RUNNING) ||
+           (p_internal->GetState() == STATE_PAUSED);
 }
 
-wxThread::~wxThread()
+bool wxThread::IsPaused() const
+{
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+    return (p_internal->GetState() == STATE_PAUSED);
+}
+
+bool wxThread::TestDestroy()
 {
-  Destroy();
-  Join();
-  delete p_internal;
+    wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect);
+
+    return p_internal->GetState() == STATE_CANCELED;
 }
 
-// The default callback just joins the thread and throws away the result.
-void wxThread::OnExit()
+wxThread::wxThread()
 {
-  Join();
+    p_internal = new wxThreadInternal();
 }
 
-// Automatic initialization
-class wxThreadModule : public wxModule {
-  DECLARE_DYNAMIC_CLASS(wxThreadModule)
+wxThread::~wxThread()
+{
+    delete p_internal;
+}
+
+// ----------------------------------------------------------------------------
+// Automatic initialization for thread module
+// ----------------------------------------------------------------------------
+
+class wxThreadModule : public wxModule
+{
 public:
-  virtual bool OnInit() {
-    p_mainid = GetCurrentThread();
-    wxMainMutex.Lock();
-    return TRUE;
-  }
+    virtual bool OnInit();
+    virtual void OnExit();
 
-  // Global cleanup
-  virtual void OnExit() {
-    wxMainMutex.Unlock();
-  }
+private:
+    DECLARE_DYNAMIC_CLASS(wxThreadModule)
 };
 
 IMPLEMENT_DYNAMIC_CLASS(wxThreadModule, wxModule)
 
+bool wxThreadModule::OnInit()
+{
+    // allocate TLS index for storing the pointer to the current thread
+    s_tlsThisThread = ::TlsAlloc();
+    if ( s_tlsThisThread == 0xFFFFFFFF )
+    {
+        // in normal circumstances it will only happen if all other
+        // TLS_MINIMUM_AVAILABLE (>= 64) indices are already taken - in other
+        // words, this should never happen
+        wxLogSysError(_("Thread module initialization failed: "
+                        "impossible to allocate index in thread "
+                        "local storage"));
+
+        return FALSE;
+    }
+
+    // main thread doesn't have associated wxThread object, so store 0 in the
+    // TLS instead
+    if ( !::TlsSetValue(s_tlsThisThread, (LPVOID)0) )
+    {
+        ::TlsFree(s_tlsThisThread);
+        s_tlsThisThread = 0xFFFFFFFF;
+
+        wxLogSysError(_("Thread module initialization failed: "
+                        "can not store value in thread local storage"));
+
+        return FALSE;
+    }
+
+    s_critsectWaitingForGui = new wxCriticalSection();
+
+    s_critsectGui = new wxCriticalSection();
+    s_critsectGui->Enter();
+
+    // no error return for GetCurrentThreadId()
+    s_idMainThread = ::GetCurrentThreadId();
+
+    return TRUE;
+}
+
+void wxThreadModule::OnExit()
+{
+    if ( !::TlsFree(s_tlsThisThread) )
+    {
+        wxLogLastError("TlsFree failed.");
+    }
+
+    if ( s_critsectGui )
+    {
+        s_critsectGui->Leave();
+        delete s_critsectGui;
+        s_critsectGui = NULL;
+    }
+
+    wxDELETE(s_critsectWaitingForGui);
+}
+
+// ----------------------------------------------------------------------------
+// under Windows, these functions are implemented usign a critical section and
+// not a mutex, so the names are a bit confusing
+// ----------------------------------------------------------------------------
+
+void WXDLLEXPORT wxMutexGuiEnter()
+{
+    // this would dead lock everything...
+    wxASSERT_MSG( !wxThread::IsMain(),
+                  "main thread doesn't want to block in wxMutexGuiEnter()!" );
+
+    // the order in which we enter the critical sections here is crucial!!
+
+    // set the flag telling to the main thread that we want to do some GUI
+    {
+        wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
+
+        s_nWaitingForGui++;
+    }
+
+    wxWakeUpMainThread();
+
+    // now we may block here because the main thread will soon let us in
+    // (during the next iteration of OnIdle())
+    s_critsectGui->Enter();
+}
+
+void WXDLLEXPORT wxMutexGuiLeave()
+{
+    wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
+
+    if ( wxThread::IsMain() )
+    {
+        s_bGuiOwnedByMainThread = FALSE;
+    }
+    else
+    {
+        // decrement the number of waiters now
+        wxASSERT_MSG( s_nWaitingForGui > 0,
+                      "calling wxMutexGuiLeave() without entering it first?" );
+
+        s_nWaitingForGui--;
+
+        wxWakeUpMainThread();
+    }
+
+    s_critsectGui->Leave();
+}
+
+void WXDLLEXPORT wxMutexGuiLeaveOrEnter()
+{
+    wxASSERT_MSG( wxThread::IsMain(),
+                  "only main thread may call wxMutexGuiLeaveOrEnter()!" );
+
+    wxCriticalSectionLocker enter(*s_critsectWaitingForGui);
+
+    if ( s_nWaitingForGui == 0 )
+    {
+        // no threads are waiting for GUI - so we may acquire the lock without
+        // any danger (but only if we don't already have it)
+        if ( !wxGuiOwnedByMainThread() )
+        {
+            s_critsectGui->Enter();
+
+            s_bGuiOwnedByMainThread = TRUE;
+        }
+        //else: already have it, nothing to do
+    }
+    else
+    {
+        // some threads are waiting, release the GUI lock if we have it
+        if ( wxGuiOwnedByMainThread() )
+        {
+            wxMutexGuiLeave();
+        }
+        //else: some other worker thread is doing GUI
+    }
+}
+
+bool WXDLLEXPORT wxGuiOwnedByMainThread()
+{
+    return s_bGuiOwnedByMainThread;
+}
+
+// wake up the main thread if it's in ::GetMessage()
+void WXDLLEXPORT wxWakeUpMainThread()
+{
+    // sending any message would do - hopefully WM_NULL is harmless enough
+    if ( !::PostThreadMessage(s_idMainThread, WM_NULL, 0, 0) )
+    {
+        // should never happen
+        wxLogLastError("PostThreadMessage(WM_NULL)");
+    }
+}
+
+bool WXDLLEXPORT wxIsWaitingForThread()
+{
+    return s_waitingForThread;
+}
+
+#endif // wxUSE_THREADS