]> git.saurik.com Git - wxWidgets.git/blobdiff - src/unix/threadpsx.cpp
some really ancient tips updated, mention make problems and flex version minimal...
[wxWidgets.git] / src / unix / threadpsx.cpp
index b30021a122799480fbd6f9a00ca2dc77d2662cee..f097dd3af2d9a25631be4240c5a5ce6bf04b7b32 100644 (file)
@@ -7,7 +7,7 @@
 // RCS-ID:      $Id$
 // Copyright:   (c) Wolfram Gloger (1996, 1997)
 //                  Guilhem Lavaux (1998)
-//                  Vadim Zeitlin (1999)
+//                  Vadim Zeitlin (1999-2002)
 //                  Robert Roebling (1999)
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
@@ -40,7 +40,6 @@
 #include <pthread.h>
 #include <errno.h>
 #include <time.h>
-
 #if HAVE_SCHED_H
     #include <sched.h>
 #endif
@@ -73,6 +72,15 @@ static const wxThread::ExitCode EXITCODE_CANCELLED = (wxThread::ExitCode)-1;
 // our trace mask
 #define TRACE_THREADS   _T("thread")
 
+// ----------------------------------------------------------------------------
+// pseudo template types
+// ----------------------------------------------------------------------------
+
+WX_DECLARE_LIST(pthread_mutex_t, wxMutexList);
+
+#include "wx/listimpl.cpp"
+WX_DEFINE_LIST(wxMutexList);
+
 // ----------------------------------------------------------------------------
 // private functions
 // ----------------------------------------------------------------------------
@@ -147,73 +155,180 @@ static wxCondition *gs_condAllDeleted = (wxCondition *)NULL;
 #endif // wxUSE_GUI
 
 // ============================================================================
-// implementation
+// wxMutex implementation
 // ============================================================================
 
-//--------------------------------------------------------------------
-// wxMutex (Posix implementation)
-//--------------------------------------------------------------------
+// ----------------------------------------------------------------------------
+// wxMutexInternal
+// ----------------------------------------------------------------------------
 
 class wxMutexInternal
 {
 public:
+    wxMutexInternal();
+    ~wxMutexInternal();
+
+    wxMutexError Lock();
+    wxMutexError TryLock();
+    wxMutexError Unlock();
+
+private:
     pthread_mutex_t m_mutex;
 };
 
+wxMutexInternal::wxMutexInternal()
+{
+    // support recursive locks like Win32, i.e. a thread can lock a mutex which
+    // it had itself already locked
+    //
+    // but initialization of recursive mutexes is non portable <sigh>, so try
+    // several methods
+#ifdef HAVE_PTHREAD_MUTEXATTR_T
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+
+    pthread_mutex_init(&m_mutex, &attr);
+#elif defined(HAVE_PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
+    // we can use this only as initializer so we have to assign it first to a
+    // temp var - assigning directly to m_mutex wouldn't even compile
+    pthread_mutex_t mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
+    m_mutex = mutex;
+#else // no recursive mutexes
+    pthread_mutex_init(&m_mutex, NULL);
+
+    // used by TryLock() below
+    #define NO_RECURSIVE_MUTEXES
+#endif // HAVE_PTHREAD_MUTEXATTR_T/...
+}
+
+wxMutexInternal::~wxMutexInternal()
+{
+    pthread_mutex_destroy(&m_mutex);
+}
+
+wxMutexError wxMutexInternal::Lock()
+{
+    int err = pthread_mutex_lock(&m_mutex);
+    switch ( err )
+    {
+        case EDEADLK:
+            wxLogDebug(wxT("Locking this mutex would lead to deadlock!"));
+            return wxMUTEX_DEAD_LOCK;
+
+        default:
+            wxFAIL_MSG( _T("unexpected pthread_mutex_lock() return") );
+            // fall through
+
+        case EINVAL:
+            wxLogDebug(_T("Failed to lock the mutex."));
+            return wxMUTEX_MISC_ERROR;
+
+        case 0:
+            return wxMUTEX_NO_ERROR;
+    }
+}
+
+wxMutexError wxMutexInternal::TryLock()
+{
+    int err = pthread_mutex_trylock(&m_mutex);
+    switch ( err )
+    {
+        case EBUSY:
+            return wxMUTEX_BUSY;
+
+        default:
+            wxFAIL_MSG( _T("unexpected pthread_mutex_trylock() return") );
+            // fall through
+
+        case EINVAL:
+            wxLogDebug(_T("Failed to try to lock the mutex."));
+            return wxMUTEX_MISC_ERROR;
+
+        case 0:
+            return wxMUTEX_NO_ERROR;
+    }
+}
+
+wxMutexError wxMutexInternal::Unlock()
+{
+    int err = pthread_mutex_unlock(&m_mutex);
+    switch ( err )
+    {
+        case EPERM:
+            // we don't own the mutex
+            return wxMUTEX_UNLOCKED;
+
+        default:
+            wxFAIL_MSG( _T("unexpected pthread_mutex_unlock() return") );
+            // fall through
+
+        case EINVAL:
+            wxLogDebug(_T("Failed to unlock the mutex."));
+            return wxMUTEX_MISC_ERROR;
+
+        case 0:
+            return wxMUTEX_NO_ERROR;
+    }
+}
+
+// ----------------------------------------------------------------------------
+// wxMutex
+// ----------------------------------------------------------------------------
+
+// TODO: this is completely generic, move it to common code?
+
 wxMutex::wxMutex()
 {
     m_internal = new wxMutexInternal;
 
-    pthread_mutex_init(&(m_internal->m_mutex),
-                       (pthread_mutexattr_t*) NULL );
     m_locked = 0;
 }
 
 wxMutex::~wxMutex()
 {
-    if (m_locked > 0)
+    if ( m_locked > 0 )
         wxLogDebug(wxT("Freeing a locked mutex (%d locks)"), m_locked);
 
-    pthread_mutex_destroy( &(m_internal->m_mutex) );
     delete m_internal;
 }
 
 wxMutexError wxMutex::Lock()
 {
-    int err = pthread_mutex_lock( &(m_internal->m_mutex) );
-    if (err == EDEADLK)
-    {
-        wxLogDebug(wxT("Locking this mutex would lead to deadlock!"));
+    wxMutexError err = m_internal->Lock();
 
-        return wxMUTEX_DEAD_LOCK;
+    if ( !err )
+    {
+        m_locked++;
     }
 
-    m_locked++;
-
-    return wxMUTEX_NO_ERROR;
+    return err;
 }
 
 wxMutexError wxMutex::TryLock()
 {
-    if (m_locked)
+    if ( m_locked )
     {
-        return wxMUTEX_BUSY;
+#ifdef NO_RECURSIVE_MUTEXES
+        return wxMUTEX_DEAD_LOCK;
+#else // have recursive mutexes on this platform
+        // we will succeed in locking it when we have it already locked
+        return wxMUTEX_NO_ERROR;
+#endif // recursive/non-recursive mutexes
     }
 
-    int err = pthread_mutex_trylock( &(m_internal->m_mutex) );
-    switch (err)
+    wxMutexError err = m_internal->TryLock();
+    if ( !err )
     {
-        case EBUSY: return wxMUTEX_BUSY;
+        m_locked++;
     }
 
-    m_locked++;
-
-    return wxMUTEX_NO_ERROR;
+    return err;
 }
 
 wxMutexError wxMutex::Unlock()
 {
-    if (m_locked > 0)
+    if ( m_locked > 0 )
     {
         m_locked--;
     }
@@ -224,52 +339,67 @@ wxMutexError wxMutex::Unlock()
         return wxMUTEX_UNLOCKED;
     }
 
-    pthread_mutex_unlock( &(m_internal->m_mutex) );
-
-    return wxMUTEX_NO_ERROR;
+    return m_internal->Unlock();
 }
 
-//--------------------------------------------------------------------
-// wxCondition (Posix implementation)
-//--------------------------------------------------------------------
+// ============================================================================
+// wxCondition implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wxConditionInternal
+// ----------------------------------------------------------------------------
 
 // The native POSIX condition variables are dumb: if the condition is signaled
 // before another thread starts to wait on it, the signal is lost and so this
 // other thread will be never woken up. It's much more convenient to us to
 // remember that the condition was signaled and to return from Wait()
 // immediately in this case (this is more like Win32 automatic event objects)
-
 class wxConditionInternal
 {
 public:
     wxConditionInternal();
     ~wxConditionInternal();
 
-    void Wait();
-    bool WaitWithTimeout(const timespec* ts);
-
-    void Signal();
-    void Broadcast();
+    // wait with the given timeout or indefinitely if NULL
+    bool Wait(const timespec* ts = NULL);
 
-    void WaitDone();
-    bool ShouldWait();
-    bool HasWaiters();
+    void Signal(bool all = FALSE);
 
 private:
-    bool m_wasSignaled;             // TRUE if condition was signaled while
-                                    // nobody waited for it
-    size_t m_nWaiters;              // TRUE if someone already waits for us
-
-    pthread_mutex_t m_mutexProtect; // protects access to vars above
-
-    pthread_mutex_t m_mutex;        // the mutex used with the condition
-    pthread_cond_t m_condition;     // the condition itself
+    // the number of Signal() calls queued
+    //
+    // changed by Signal(), accessed by Wait()
+    //
+    // protected by m_mutexSignalCount
+    size_t m_nSignalsMissed;
+
+    // protects access to m_nSignalsMissed
+    pthread_mutex_t m_mutexSignalCount;
+
+    // serializes Broadcast() and/or Signal() calls
+    //
+    // TODO: I'm not sure if this is really needed but it shouldn't harm
+    //       neither (except for efficiency condierations). However MSW doesn't
+    //       do this so maybe we shouldn't do it here neither? (VZ)
+    pthread_mutex_t m_mutexSignal;
+
+    // a condition variable must be always used with a mutex and so we maintain
+    // a list of mutexes - one for each thread that calls Wait().
+    //
+    // access to this list must be protected by m_mutexListContents
+    wxMutexList m_mutexes;
+
+    // the condition itself
+    pthread_cond_t m_condition;
+
+    // protects all accesses to m_mutexes list
+    pthread_mutex_t m_mutexListContents;
 };
 
 wxConditionInternal::wxConditionInternal()
 {
-    m_wasSignaled = FALSE;
-    m_nWaiters = 0;
+    m_nSignalsMissed = 0;
 
     if ( pthread_cond_init(&m_condition, (pthread_condattr_t *)NULL) != 0 )
     {
@@ -277,19 +407,13 @@ wxConditionInternal::wxConditionInternal()
         wxFAIL_MSG( _T("pthread_cond_init() failed") );
     }
 
-    if ( pthread_mutex_init(&m_mutex, (pthread_mutexattr_t *)NULL) != 0 ||
-         pthread_mutex_init(&m_mutexProtect, NULL) != 0 )
+    if ( pthread_mutex_init(&m_mutexSignalCount, NULL) != 0 ||
+         pthread_mutex_init(&m_mutexListContents, NULL) != 0 ||
+         pthread_mutex_init(&m_mutexSignal, NULL) != 0 )
     {
         // neither this
         wxFAIL_MSG( _T("wxCondition: pthread_mutex_init() failed") );
     }
-
-    // initially the mutex is locked, so no thread can Signal() or Broadcast()
-    // until another thread starts to Wait()
-    if ( pthread_mutex_lock(&m_mutex) != 0 )
-    {
-        wxFAIL_MSG( _T("wxCondition: pthread_mutex_lock() failed") );
-    }
 }
 
 wxConditionInternal::~wxConditionInternal()
@@ -300,139 +424,171 @@ wxConditionInternal::~wxConditionInternal()
                       "threads are probably still waiting on it?)"));
     }
 
-    if ( pthread_mutex_unlock( &m_mutex ) != 0 )
-    {
-        wxLogDebug(_T("wxCondition: failed to unlock the mutex"));
-    }
+    // the list of waiters mutexes must be empty by now
+    wxASSERT_MSG( !m_mutexes.GetFirst(),
+                  _T("deleting condition someone is still waiting on?") );
 
-    if ( pthread_mutex_destroy( &m_mutex ) != 0 ||
-         pthread_mutex_destroy( &m_mutexProtect ) != 0 )
+    if ( pthread_mutex_destroy( &m_mutexSignalCount ) != 0 || 
+         pthread_mutex_destroy( &m_mutexListContents ) != 0 ||
+         pthread_mutex_destroy( &m_mutexSignal ) != 0 )
     {
         wxLogDebug(_T("Failed to destroy mutex (it is probably locked)"));
     }
 }
 
-void wxConditionInternal::WaitDone()
+bool wxConditionInternal::Wait(const timespec* ts)
 {
-    MutexLock lock(m_mutexProtect);
+    {
+        wxLogTrace(TRACE_THREADS,
+                   _T("wxCondition(%08x)::Wait: about to lock missed signal counter"),
+                   this);
 
-    m_wasSignaled = FALSE;
-    m_nWaiters--;
-}
+        MutexLock lock(m_mutexSignalCount);
 
-bool wxConditionInternal::ShouldWait()
-{
-    MutexLock lock(m_mutexProtect);
+        if ( m_nSignalsMissed )
+        {
+            // the condition was signaled before we started to wait, just
+            // decrease the number of queued signals and return
+            m_nSignalsMissed--;
 
-    if ( m_wasSignaled )
-    {
-        // the condition was signaled before we started to wait, reset the
-        // flag and return
-        m_wasSignaled = FALSE;
+            wxLogTrace(TRACE_THREADS,
+                       _T("wxCondition(%08x)::Wait: not waiting at all, count = %u"),
+                       this, m_nSignalsMissed);
 
-        return FALSE;
+            return TRUE;
+        }
     }
 
-    // we start to wait for it
-    m_nWaiters++;
-
-    return TRUE;
-}
+    // we need to really wait, create a new mutex for this
+    pthread_mutex_t *mutex = new pthread_mutex_t;
+    if ( pthread_mutex_init(mutex, (pthread_mutexattr_t *)NULL) != 0 )
+    {
+        // not supposed to happen
+        wxFAIL_MSG( _T("pthread_mutex_init() failed when starting waiting") );
+    }
 
-bool wxConditionInternal::HasWaiters()
-{
-    MutexLock lock(m_mutexProtect);
+    // lock the mutex before starting to wait on it
+    pthread_mutex_lock(mutex);
 
-    if ( m_nWaiters )
+    // lock the list before modifying it
+    wxMutexList::Node *mutexNode;
     {
-        // someone waits for us, signal the condition normally
-        return TRUE;
+        MutexLock lockList(m_mutexListContents);
+
+        mutexNode = m_mutexes.Append(mutex);
     }
 
-    // nobody waits for us and may be never will - so just remember that the
-    // condition was signaled and don't do anything else
-    m_wasSignaled = TRUE;
+    // calling wait function below unlocks the mutex and Signal() or
+    // Broadcast() will be able to continue to run now if they were
+    // blocking for it in the loop locking all mutexes)
+    wxLogTrace(TRACE_THREADS,
+               _T("wxCondition(%08x)::Wait(): starting to wait"), this);
+    int err = ts ? pthread_cond_timedwait(&m_condition, mutex, ts)
+                 : pthread_cond_wait(&m_condition, mutex);
+    switch ( err )
+    {
+        case 0:
+            // condition was signaled
+            wxLogTrace(TRACE_THREADS,
+                       _T("wxCondition(%08x)::Wait(): ok"), this);
+            break;
 
-    return FALSE;
-}
+        default:
+            wxLogDebug(_T("unexpected pthread_cond_[timed]wait() return"));
+            // fall through
 
-void wxConditionInternal::Wait()
-{
-    if ( ShouldWait() )
+        case ETIMEDOUT:
+        case EINTR:
+            // wait interrupted or timeout elapsed
+            wxLogTrace(TRACE_THREADS,
+                       _T("wxCondition(%08x)::Wait(): timeout/intr"), this);
+    }
+
+    // delete the mutex we had used for waiting
     {
-        if ( pthread_cond_wait( &m_condition, &m_mutex ) != 0 )
-        {
-            // not supposed to ever happen
-            wxFAIL_MSG( _T("pthread_cond_wait() failed") );
-        }
+        MutexLock lock(m_mutexListContents);
+
+        pthread_mutex_t *m = mutexNode->GetData();
+        pthread_mutex_unlock(m);
+        pthread_mutex_destroy(m);
+        delete m;
+
+        m_mutexes.DeleteNode(mutexNode);
     }
 
-    WaitDone();
+    return err == 0;
 }
 
-bool wxConditionInternal::WaitWithTimeout(const timespec* ts)
+void wxConditionInternal::Signal(bool all)
 {
-    bool ok;
+    // make sure that only one Signal() or Broadcast() is in progress
+    MutexLock lock(m_mutexSignal);
+
+    // this mutex has to be locked as well, so that during the entire Signal()
+    // call, no new Wait() is going to wreak havoc (it will block in the very
+    // beginning on this mutex instead)
+    MutexLock lockSignalCount(m_mutexSignalCount);
+
+    wxLogTrace(TRACE_THREADS,
+               _T("wxCondition(%08x)::Signal(): got signal count mutex"),
+               this);
 
-    if ( ShouldWait() )
     {
-        switch ( pthread_cond_timedwait( &m_condition, &m_mutex, ts ) )
-        {
-            case 0:
-                // condition signaled
-                ok = TRUE;
-                break;
+        MutexLock lockList(m_mutexListContents);
 
-            default:
-                wxLogDebug(_T("pthread_cond_timedwait() failed"));
+        if ( !m_mutexes.GetFirst() )
+        {
+            // nobody is waiting for us, just remember that the condition was
+            // signaled and don't do anything else for now
+            m_nSignalsMissed++;
 
-                // fall through
+            wxLogTrace(TRACE_THREADS,
+                       _T("wxCondition(%08x)::Signal(): no waiters, count = %u"),
+                       this, m_nSignalsMissed);
 
-            case ETIMEDOUT:
-            case EINTR:
-                // wait interrupted or timeout elapsed
-                ok = FALSE;
+            return;
         }
     }
-    else
+
+    wxLogTrace(TRACE_THREADS,
+               _T("wxCondition(%08x)::Signal(): acquiring all mutexes"), this);
+
+    // All mutexes on the list have to be locked. This means that execution of
+    // Signal() goes on as soon as all pending Wait() calls have called
+    // pthread_cond_wait() (where the mutex gets unlocked internally)
+    wxMutexList::Node *node;
+    for ( node = m_mutexes.GetFirst(); node; node = node->GetNext() )
     {
-        // the condition had already been signaled before
-        ok = TRUE;
+        pthread_mutex_lock(node->GetData());
     }
 
-    WaitDone();
-
-    return ok;
-}
+    // now we can finally signal it
+    wxLogTrace(TRACE_THREADS, _T("wxCondition(%08x)::Signal(): preparing to %s"),
+               this, all ? _T("broadcast") : _T("signal"));
 
-void wxConditionInternal::Signal()
-{
-    if ( HasWaiters() )
+    int err = all ? pthread_cond_broadcast(&m_condition)
+                  : pthread_cond_signal(&m_condition);
+    if ( err )
     {
-        MutexLock lock(m_mutex);
-
-        if ( pthread_cond_signal( &m_condition ) != 0 )
-        {
-            // shouldn't ever happen
-            wxFAIL_MSG(_T("pthread_cond_signal() failed"));
-        }
+        // shouldn't ever happen
+        wxFAIL_MSG(_T("pthread_cond_{broadcast|signal}() failed"));
     }
-}
 
-void wxConditionInternal::Broadcast()
-{
-    if ( HasWaiters() )
+    // unlock all mutexes so that the threads blocking in their Wait()s could
+    // continue running
+    for ( node = m_mutexes.GetFirst(); node; node = node->GetNext() )
     {
-        MutexLock lock(m_mutex);
-
-        if ( pthread_cond_broadcast( &m_condition ) != 0 )
-        {
-            // shouldn't ever happen
-            wxFAIL_MSG(_T("pthread_cond_broadcast() failed"));
-        }
+        pthread_mutex_unlock(node->GetData());
     }
+
+    wxLogTrace(TRACE_THREADS,
+               _T("wxCondition(%08x)::Signal(): exiting"), this);
 }
 
+// ----------------------------------------------------------------------------
+// wxCondition
+// ----------------------------------------------------------------------------
+
 wxCondition::wxCondition()
 {
     m_internal = new wxConditionInternal;
@@ -445,7 +601,7 @@ wxCondition::~wxCondition()
 
 void wxCondition::Wait()
 {
-    m_internal->Wait();
+    (void)m_internal->Wait();
 }
 
 bool wxCondition::Wait(unsigned long sec, unsigned long nsec)
@@ -455,7 +611,7 @@ bool wxCondition::Wait(unsigned long sec, unsigned long nsec)
     tspec.tv_sec = time(0L) + sec;  // FIXME is time(0) correct here?
     tspec.tv_nsec = nsec;
 
-    return m_internal->WaitWithTimeout(&tspec);
+    return m_internal->Wait(&tspec);
 }
 
 void wxCondition::Signal()
@@ -465,12 +621,29 @@ void wxCondition::Signal()
 
 void wxCondition::Broadcast()
 {
-    m_internal->Broadcast();
+    m_internal->Signal(TRUE /* all */);
 }
 
-//--------------------------------------------------------------------
-// wxThread (Posix implementation)
-//--------------------------------------------------------------------
+// ============================================================================
+// wxThread implementation
+// ============================================================================
+
+// the thread callback functions must have the C linkage
+extern "C"
+{
+
+#if HAVE_THREAD_CLEANUP_FUNCTIONS
+    // thread exit function
+    void wxPthreadCleanup(void *ptr);
+#endif // HAVE_THREAD_CLEANUP_FUNCTIONS
+
+void *wxPthreadStart(void *ptr);
+
+} // extern "C"
+
+// ----------------------------------------------------------------------------
+// wxThreadInternal
+// ----------------------------------------------------------------------------
 
 class wxThreadInternal
 {
@@ -479,12 +652,7 @@ public:
     ~wxThreadInternal();
 
     // thread entry function
-    static void *PthreadStart(void *ptr);
-
-#if HAVE_THREAD_CLEANUP_FUNCTIONS
-    // thread exit function
-    static void PthreadCleanup(void *ptr);
-#endif
+    static void *PthreadStart(wxThread *thread);
 
     // thread actions
         // start the thread
@@ -531,6 +699,11 @@ public:
         // sometimes - tell the thread that it should do it
     void Notify() { m_shouldBroadcast = TRUE; }
 
+#if HAVE_THREAD_CLEANUP_FUNCTIONS
+    // this is used by wxPthreadCleanup() only
+    static void Cleanup(wxThread *thread);
+#endif // HAVE_THREAD_CLEANUP_FUNCTIONS
+
 private:
     pthread_t     m_threadId;   // id of the thread
     wxThreadState m_state;      // see wxThreadState enum
@@ -575,11 +748,17 @@ private:
 // thread startup and exit functions
 // ----------------------------------------------------------------------------
 
-void *wxThreadInternal::PthreadStart(void *ptr)
+void *wxPthreadStart(void *ptr)
+{
+    return wxThreadInternal::PthreadStart((wxThread *)ptr);
+}
+
+void *wxThreadInternal::PthreadStart(wxThread *thread)
 {
-    wxThread *thread = (wxThread *)ptr;
     wxThreadInternal *pthread = thread->m_internal;
 
+    wxLogTrace(TRACE_THREADS, _T("Thread %ld started."), pthread->GetId());
+
     // associate the thread pointer with the newly created thread so that
     // wxThread::This() will work
     int rc = pthread_setspecific(gs_keySelf, thread);
@@ -597,7 +776,7 @@ void *wxThreadInternal::PthreadStart(void *ptr)
 #if HAVE_THREAD_CLEANUP_FUNCTIONS
     // install the cleanup handler which will be called if the thread is
     // cancelled
-    pthread_cleanup_push(wxThreadInternal::PthreadCleanup, ptr);
+    pthread_cleanup_push(wxPthreadCleanup, thread);
 #endif // HAVE_THREAD_CLEANUP_FUNCTIONS
 
     // wait for the condition to be signaled from Run()
@@ -627,7 +806,7 @@ void *wxThreadInternal::PthreadStart(void *ptr)
                        pthread->GetId());
 
             // change the state of the thread to "exited" so that
-            // PthreadCleanup handler won't do anything from now (if it's
+            // wxPthreadCleanup handler won't do anything from now (if it's
             // called before we do pthread_cleanup_pop below)
             pthread->SetState(STATE_EXITED);
         }
@@ -661,10 +840,13 @@ void *wxThreadInternal::PthreadStart(void *ptr)
 #if HAVE_THREAD_CLEANUP_FUNCTIONS
 
 // this handler is called when the thread is cancelled
-void wxThreadInternal::PthreadCleanup(void *ptr)
+extern "C" void wxPthreadCleanup(void *ptr)
 {
-    wxThread *thread = (wxThread *) ptr;
+    wxThreadInternal::Cleanup((wxThread *)ptr);
+}
 
+void wxThreadInternal::Cleanup(wxThread *thread)
+{
     {
         wxCriticalSectionLocker lock(thread->m_critsect);
         if ( thread->m_internal->GetState() == STATE_EXITED )
@@ -725,9 +907,10 @@ void wxThreadInternal::Wait()
         wxMutexGuiLeave();
 
     bool isDetached = m_isDetached;
-    long id = (long)GetId();
-    wxLogTrace(TRACE_THREADS, _T("Starting to wait for thread %ld to exit."),
-               id);
+    wxThreadIdType id = GetId();
+
+    wxLogTrace(TRACE_THREADS,
+               _T("Starting to wait for thread %ld to exit."), id);
 
     // wait until the thread terminates (we're blocking in _another_ thread,
     // of course)
@@ -835,7 +1018,9 @@ bool wxThread::IsMain()
 
 void wxThread::Yield()
 {
+#ifdef HAVE_SCHED_YIELD
     sched_yield();
+#endif
 }
 
 void wxThread::Sleep(unsigned long milliseconds)
@@ -845,7 +1030,7 @@ void wxThread::Sleep(unsigned long milliseconds)
 
 int wxThread::GetCPUCount()
 {
-#if defined(__LINUX__)
+#if defined(__LINUX__) && wxUSE_FFILE
     // read from proc (can't use wxTextFile here because it's a special file:
     // it has 0 size but still can be read from)
     wxLogNull nolog;
@@ -884,6 +1069,19 @@ int wxThread::GetCPUCount()
     return -1;
 }
 
+#ifdef __VMS
+  // VMS is a 64 bit system and threads have 64 bit pointers.
+  // ??? also needed for other systems????
+unsigned long long wxThread::GetCurrentId()
+{
+    return (unsigned long long)pthread_self();
+#else
+unsigned long wxThread::GetCurrentId()
+{
+    return (unsigned long)pthread_self();
+#endif
+}
+
 bool wxThread::SetConcurrency(size_t level)
 {
 #ifdef HAVE_THR_SETCONCURRENCY
@@ -914,7 +1112,7 @@ wxThread::wxThread(wxThreadKind kind)
     m_isDetached = kind == wxTHREAD_DETACHED;
 }
 
-wxThreadError wxThread::Create()
+wxThreadError wxThread::Create(unsigned int WXUNUSED(stackSize))
 {
     if ( m_internal->GetState() != STATE_NEW )
     {
@@ -942,7 +1140,7 @@ wxThreadError wxThread::Create()
 #define sched_get_priority_min(_pol_) \
      (_pol_ == SCHED_OTHER ? PRI_FG_MIN_NP : PRI_FIFO_MIN)
 #endif
-   
+
     int max_prio = sched_get_priority_max(policy),
         min_prio = sched_get_priority_min(policy),
         prio = m_internal->GetPriority();
@@ -1008,7 +1206,7 @@ wxThreadError wxThread::Create()
              (
                 m_internal->GetIdPtr(),
                 &attr,
-                wxThreadInternal::PthreadStart,
+                wxPthreadStart,
                 (void *)this
              );
 
@@ -1085,9 +1283,9 @@ unsigned int wxThread::GetPriority() const
     return m_internal->GetPriority();
 }
 
-unsigned long wxThread::GetId() const
+wxThreadIdType wxThread::GetId() const
 {
-    return (unsigned long)m_internal->GetId();
+    return m_internal->GetId();
 }
 
 // -----------------------------------------------------------------------------
@@ -1254,11 +1452,12 @@ wxThreadError wxThread::Kill()
             if ( m_isDetached )
             {
                 // if we use cleanup function, this will be done from
-                // PthreadCleanup()
+                // wxPthreadCleanup()
 #if !HAVE_THREAD_CLEANUP_FUNCTIONS
                 ScheduleThreadForDeletion();
 
-                OnExit();
+                // 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 // HAVE_THREAD_CLEANUP_FUNCTIONS