X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/df744f4d6d1f9d093822980915b7802f95cb98fa..3a0a5ada86913e591479c1150d23135b0fe5e7e6:/src/unix/threadpsx.cpp

diff --git a/src/unix/threadpsx.cpp b/src/unix/threadpsx.cpp
index 5e8ba13423..72be919335 100644
--- a/src/unix/threadpsx.cpp
+++ b/src/unix/threadpsx.cpp
@@ -2,13 +2,14 @@
 // Name:        threadpsx.cpp
 // Purpose:     wxThread (Posix) Implementation
 // Author:      Original from Wolfram Gloger/Guilhem Lavaux
-// Modified by:
+// Modified by: K. S. Sreeram (2002): POSIXified wxCondition, added wxSemaphore
 // Created:     04/22/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Wolfram Gloger (1996, 1997)
 //                  Guilhem Lavaux (1998)
 //                  Vadim Zeitlin (1999-2002)
 //                  Robert Roebling (1999)
+//                  K. S. Sreeram (2002)
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
@@ -34,6 +35,7 @@
 #include "wx/log.h"
 #include "wx/intl.h"
 #include "wx/dynarray.h"
+#include "wx/timer.h"
 
 #include <stdio.h>
 #include <unistd.h>
@@ -72,15 +74,6 @@ 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
 // ----------------------------------------------------------------------------
@@ -88,35 +81,6 @@ WX_DEFINE_LIST(wxMutexList);
 static void ScheduleThreadForDeletion();
 static void DeleteThread(wxThread *This);
 
-// ----------------------------------------------------------------------------
-// private classes
-// ----------------------------------------------------------------------------
-
-// same as wxMutexLocker but for "native" mutex
-class MutexLock
-{
-public:
-    MutexLock(pthread_mutex_t& mutex)
-    {
-        m_mutex = &mutex;
-        if ( pthread_mutex_lock(m_mutex) != 0 )
-        {
-            wxLogDebug(_T("pthread_mutex_lock() failed"));
-        }
-    }
-
-    ~MutexLock()
-    {
-        if ( pthread_mutex_unlock(m_mutex) != 0 )
-        {
-            wxLogDebug(_T("pthread_mutex_unlock() failed"));
-        }
-    }
-
-private:
-    pthread_mutex_t *m_mutex;
-};
-
 // ----------------------------------------------------------------------------
 // types
 // ----------------------------------------------------------------------------
@@ -143,7 +107,7 @@ static pthread_key_t gs_keySelf;
 static size_t gs_nThreadsBeingDeleted = 0;
 
 // a mutex to protect gs_nThreadsBeingDeleted
-static pthread_mutex_t gs_mutexDeleteThread;
+static wxMutex *gs_mutexDeleteThread = (wxMutex *)NULL;
 
 // and a condition variable which will be signaled when all
 // gs_nThreadsBeingDeleted will have been deleted
@@ -174,6 +138,8 @@ public:
 
 private:
     pthread_mutex_t m_mutex;
+
+    friend class wxConditionInternal;
 };
 
 wxMutexInternal::wxMutexInternal()
@@ -342,209 +308,368 @@ wxMutexError wxMutex::Unlock()
     return m_internal->Unlock();
 }
 
-// ============================================================================
+// ===========================================================================
 // 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(wxMutex& mutex);
     ~wxConditionInternal();
 
-    // wait with the given timeout or indefinitely if NULL
-    bool Wait(const timespec* ts = NULL);
+    void Wait();
 
-    void Signal(bool all = FALSE);
+    bool Wait( const timespec *ts );
 
-private:
-    // the number of Signal() calls we "missed", i.e. which were done while
-    // there were no threads to wait for them
-    size_t m_nQueuedSignals;
+    void Signal();
 
-    // counts all pending waiters
-    size_t m_nWaiters;
+    void Broadcast();
 
-    // the condition itself
-    pthread_cond_t m_condition;
+private:
+    // get the POSIX mutex associated with us
+    pthread_mutex_t *GetMutex() const { return &m_mutex.m_internal->m_mutex; }
 
-    // the mutex used with the conditon: it also protects the counters above
-    pthread_mutex_t m_mutex;
+    wxMutex& m_mutex;
+    pthread_cond_t m_cond;
 };
 
-wxConditionInternal::wxConditionInternal()
+wxConditionInternal::wxConditionInternal(wxMutex& mutex)
+                   : m_mutex(mutex)
 {
-    m_nQueuedSignals =
-    m_nWaiters = 0;
-
-    if ( pthread_cond_init(&m_condition, (pthread_condattr_t *)NULL) != 0 )
-    {
-        // this is supposed to never happen
-        wxFAIL_MSG( _T("pthread_cond_init() failed") );
-    }
-
-    if ( pthread_mutex_init(&m_mutex, NULL) != 0 )
+    if ( pthread_cond_init( &m_cond, NULL ) != 0 )
     {
-        // neither this
-        wxFAIL_MSG( _T("wxCondition: pthread_mutex_init() failed") );
+        wxLogDebug(_T("pthread_cond_init() failed"));
     }
 }
 
 wxConditionInternal::~wxConditionInternal()
 {
-    if ( pthread_cond_destroy( &m_condition ) != 0 )
+    if ( pthread_cond_destroy( &m_cond ) != 0 )
     {
-        wxLogDebug(_T("Failed to destroy condition variable (some "
-                      "threads are probably still waiting on it?)"));
+        wxLogDebug(_T("pthread_cond_destroy() failed"));
     }
+}
 
-    if ( pthread_mutex_destroy( &m_mutex ) != 0 ) 
+void wxConditionInternal::Wait()
+{
+    if ( pthread_cond_wait( &m_cond, GetMutex() ) != 0 )
     {
-        wxLogDebug(_T("Failed to destroy mutex (it is probably locked)"));
+        wxLogDebug(_T("pthread_cond_wait() failed"));
     }
 }
 
-bool wxConditionInternal::Wait(const timespec* ts)
+bool wxConditionInternal::Wait( const timespec *ts )
 {
-    MutexLock lock(m_mutex);
+    int result = pthread_cond_timedwait( &m_cond, GetMutex(), ts );
+    if ( result == ETIMEDOUT )
+        return FALSE;
 
-    if ( m_nQueuedSignals )
+    if ( result != 0 )
     {
-        m_nQueuedSignals--;
+        wxLogDebug(_T("pthread_cond_timedwait() failed"));
+    }
 
-        wxLogTrace(TRACE_THREADS,
-                   _T("wxCondition(%08x)::Wait(): Has been signaled before"),
-                   this);
+    return TRUE;
+}
 
-        return TRUE;
+void wxConditionInternal::Signal()
+{
+    int result = pthread_cond_signal( &m_cond );
+    if ( result != 0 )
+{
+        wxFAIL_MSG( _T("pthread_cond_signal() failed") );
     }
+}
 
-    // there are no queued signals, so start really waiting
-    m_nWaiters++;
+void wxConditionInternal::Broadcast()
+{
+    int result = pthread_cond_broadcast( &m_cond );
+    if ( result != 0 )
+{
+        wxFAIL_MSG( _T("pthread_cond_broadcast() failed") );
+    }
+}
 
-    // 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, &m_mutex, ts)
-                 : pthread_cond_wait(&m_condition, &m_mutex);
-    switch ( err )
-    {
-        case 0:
-            // condition was signaled
-            wxLogTrace(TRACE_THREADS,
-                       _T("wxCondition(%08x)::Wait(): ok"), this);
-            break;
+// ---------------------------------------------------------------------------
+// wxCondition
+// ---------------------------------------------------------------------------
 
-        default:
-            wxLogDebug(_T("unexpected pthread_cond_[timed]wait() return"));
-            // fall through
+wxCondition::wxCondition(wxMutex& mutex)
+{
+    m_internal = new wxConditionInternal( mutex );
+}
 
-        case ETIMEDOUT:
-        case EINTR:
-            // The condition has not been signaled, so we have to
-            // decrement the counter manually
-            --m_nWaiters;
+wxCondition::~wxCondition()
+{
+    delete m_internal;
+}
 
-            // wait interrupted or timeout elapsed
-            wxLogTrace(TRACE_THREADS,
-                       _T("wxCondition(%08x)::Wait(): timeout/intr"), this);
-    }
+void wxCondition::Wait()
+{
+    m_internal->Wait();
+}
+
+bool wxCondition::Wait( unsigned long timeout_millis )
+{
+    wxLongLong curtime = wxGetLocalTimeMillis();
+    curtime += timeout_millis;
+    wxLongLong temp = curtime / 1000;
+    int sec = temp.GetLo();
+    temp = temp * 1000;
+    temp = curtime - temp;
+    int millis = temp.GetLo();
+
+    timespec tspec;
 
-    return err == 0;
+    tspec.tv_sec = sec;
+    tspec.tv_nsec = millis * 1000L * 1000L;
+
+    return m_internal->Wait(&tspec);
 }
 
-void wxConditionInternal::Signal(bool all)
+void wxCondition::Signal()
 {
-    // make sure that only one Signal() or Broadcast() is in progress
-    MutexLock lock(m_mutex);
+    m_internal->Signal();
+}
 
-    // Are there any waiters?
-    if ( m_nWaiters == 0 )
-    {
-        // No, there are not, so don't signal but keep in mind for the next
-        // Wait()
-        m_nQueuedSignals++;
+void wxCondition::Broadcast()
+{
+    m_internal->Broadcast();
+}
+
+// ===========================================================================
+// wxSemaphore implementation
+// ===========================================================================
+
+// ---------------------------------------------------------------------------
+// wxSemaphoreInternal
+// ---------------------------------------------------------------------------
+
+class wxSemaphoreInternal
+{
+public:
+    wxSemaphoreInternal( int initialcount, int maxcount );
+
+    void Wait();
+    bool TryWait();
+
+    bool Wait( unsigned long timeout_millis );
+
+    void Post();
+
+private:
+    wxMutex m_mutex;
+    wxCondition m_cond;
+
+    int count,
+        maxcount;
+};
+
+wxSemaphoreInternal::wxSemaphoreInternal( int initialcount, int maxcount )
+                   : m_cond(m_mutex)
+{
 
-        return;
+    if ( (initialcount < 0) || ((maxcount > 0) && (initialcount > maxcount)) )
+    {
+        wxFAIL_MSG( _T("wxSemaphore: invalid initial count") );
     }
 
-    // now we can finally signal it
-    wxLogTrace(TRACE_THREADS, _T("wxCondition(%08x)::Signal(): preparing to %s"),
-               this, all ? _T("broadcast") : _T("signal"));
+    maxcount = maxcount;
+    count = initialcount;
+}
 
-    int err = all ? pthread_cond_broadcast(&m_condition)
-                  : pthread_cond_signal(&m_condition);
+void wxSemaphoreInternal::Wait()
+{
+    wxMutexLocker locker(m_mutex);
 
-    if ( all )
+    while ( count <= 0 )
     {
-        m_nWaiters = 0;
+        m_cond.Wait();
     }
-    else
+
+    count--;
+}
+
+bool wxSemaphoreInternal::TryWait()
+{
+    wxMutexLocker locker(m_mutex);
+
+    if ( count <= 0 )
+        return FALSE;
+
+    count--;
+
+    return TRUE;
+}
+
+bool wxSemaphoreInternal::Wait( unsigned long timeout_millis )
+{
+    wxMutexLocker locker(m_mutex);
+
+    wxLongLong startTime = wxGetLocalTimeMillis();
+
+    while ( count <= 0 )
     {
-        --m_nWaiters;
+        wxLongLong elapsed = wxGetLocalTimeMillis() - startTime;
+        long remainingTime = (long)timeout_millis - (long)elapsed.GetLo();
+        if ( remainingTime <= 0 )
+            return FALSE;
+
+        bool result = m_cond.Wait( remainingTime );
+        if ( !result )
+            return FALSE;
     }
 
-    if ( err )
+    count--;
+
+    return TRUE;
+}
+
+void wxSemaphoreInternal::Post()
+{
+    wxMutexLocker locker(m_mutex);
+
+    if ( maxcount > 0 && count == maxcount )
     {
-        // shouldn't ever happen
-        wxFAIL_MSG(_T("pthread_cond_{broadcast|signal}() failed"));
+        wxFAIL_MSG( _T("wxSemaphore::Post() overflow") );
     }
+
+    count++;
+
+    m_cond.Signal();
 }
 
-// ----------------------------------------------------------------------------
-// wxCondition
-// ----------------------------------------------------------------------------
+// --------------------------------------------------------------------------
+// wxSemaphore
+// --------------------------------------------------------------------------
 
-wxCondition::wxCondition()
+wxSemaphore::wxSemaphore( int initialcount, int maxcount )
 {
-    m_internal = new wxConditionInternal;
+    m_internal = new wxSemaphoreInternal( initialcount, maxcount );
 }
 
-wxCondition::~wxCondition()
+wxSemaphore::~wxSemaphore()
 {
     delete m_internal;
 }
 
-void wxCondition::Wait()
+void wxSemaphore::Wait()
 {
-    (void)m_internal->Wait();
+    m_internal->Wait();
 }
 
-bool wxCondition::Wait(unsigned long sec, unsigned long nsec)
+bool wxSemaphore::TryWait()
 {
-    timespec tspec;
-
-    tspec.tv_sec = time(0L) + sec;  // FIXME is time(0) correct here?
-    tspec.tv_nsec = nsec;
-
-    return m_internal->Wait(&tspec);
+    return m_internal->TryWait();
 }
 
-void wxCondition::Signal()
+bool wxSemaphore::Wait( unsigned long timeout_millis )
 {
-    m_internal->Signal();
+    return m_internal->Wait( timeout_millis );
 }
 
-void wxCondition::Broadcast()
+void wxSemaphore::Post()
 {
-    m_internal->Signal(TRUE /* all */);
+    m_internal->Post();
 }
 
-// ============================================================================
+// This class is used by wxThreadInternal to support Delete() on
+// a detached thread
+class wxRefCountedCondition
+{
+public:
+    // start with a initial reference count of 1
+    wxRefCountedCondition()
+    {
+        m_refCount = 1;
+        m_signaled = FALSE;
+
+        m_mutex = new wxMutex();
+        m_cond = new wxCondition( *m_mutex );
+    }
+
+    // increment the reference count
+    void AddRef()
+    {
+        wxMutexLocker locker( *m_mutex );
+
+        m_refCount++;
+    }
+
+    // decrement the reference count if reference count is zero then delete the
+    // object
+    void DeleteRef()
+    {
+        bool shouldDelete = FALSE;
+
+        m_mutex->Lock();
+
+        if ( --m_refCount == 0 )
+        {
+            shouldDelete = TRUE;
+        }
+
+        m_mutex->Unlock();
+
+        if ( shouldDelete )
+        {
+            delete this;
+        }
+    }
+
+
+    // sets the object to signaled this signal will be a persistent signal all
+    // further Wait()s on the object will return without blocking
+    void SetSignaled()
+    {
+        wxMutexLocker locker( *m_mutex );
+
+        m_signaled = TRUE;
+
+        m_cond->Broadcast();
+    }
+
+    // wait till the object is signaled if the object was already signaled then
+    // return immediately
+    void Wait()
+    {
+        wxMutexLocker locker( *m_mutex );
+
+        if ( !m_signaled )
+        {
+            m_cond->Wait();
+        }
+    }
+
+private:
+    int m_refCount;
+
+    wxMutex *m_mutex;
+    wxCondition *m_cond;
+
+    bool m_signaled;
+
+    // Cannot delete this object directly, call DeleteRef() instead
+    ~wxRefCountedCondition()
+    {
+        delete m_cond;
+        delete m_mutex;
+    }
+
+    // suppress gcc warning about the class having private dtor and not having
+    // friend (so what??)
+    friend class wxDummyFriend;
+};
+
+// ===========================================================================
 // wxThread implementation
-// ============================================================================
+// ===========================================================================
 
 // the thread callback functions must have the C linkage
 extern "C"
@@ -580,7 +705,7 @@ public:
         // wake up threads waiting for our termination
     void SignalExit();
         // wake up threads waiting for our start
-    void SignalRun() { m_condRun.Signal(); }
+    void SignalRun() { m_semRun.Post(); }
         // go to sleep until Resume() is called
     void Pause();
         // resume the thread
@@ -630,7 +755,7 @@ private:
     // this flag is set when the thread should terminate
     bool m_cancelled;
 
-    // this flag is set when the thread is blocking on m_condSuspend
+    // this flag is set when the thread is blocking on m_semSuspend
     bool m_isPaused;
 
     // the thread exit code - only used for joinable (!detached) threads and
@@ -644,22 +769,18 @@ private:
     bool m_shouldBroadcast;
     bool m_isDetached;
 
-    // VZ: it's possible that we might do with less than three different
-    //     condition objects - for example, m_condRun and m_condEnd a priori
-    //     won't be used in the same time. But for now I prefer this may be a
-    //     bit less efficient but safer solution of having distinct condition
-    //     variables for each purpose.
-
-    // this condition is signaled by Run() and the threads Entry() is not
+    // this semaphore is posted by Run() and the threads Entry() is not
     // called before it is done
-    wxCondition m_condRun;
+    wxSemaphore m_semRun;
 
     // this one is signaled when the thread should resume after having been
     // Pause()d
-    wxCondition m_condSuspend;
+    wxSemaphore m_semSuspend;
 
     // finally this one is signalled when the thread exits
-    wxCondition m_condEnd;
+    // we are using a reference counted condition to support
+    // Delete() for a detached thread
+    wxRefCountedCondition *m_condEnd;
 };
 
 // ----------------------------------------------------------------------------
@@ -697,8 +818,8 @@ void *wxThreadInternal::PthreadStart(wxThread *thread)
     pthread_cleanup_push(wxPthreadCleanup, thread);
 #endif // HAVE_THREAD_CLEANUP_FUNCTIONS
 
-    // wait for the condition to be signaled from Run()
-    pthread->m_condRun.Wait();
+    // wait for the semaphore to be posted from Run()
+    pthread->m_semRun.Wait();
 
     // test whether we should run the run at all - may be it was deleted
     // before it started to Run()?
@@ -792,17 +913,20 @@ wxThreadInternal::wxThreadInternal()
     m_threadId = 0;
     m_exitcode = 0;
 
-    // set to TRUE only when the thread starts waiting on m_condSuspend
+    // set to TRUE only when the thread starts waiting on m_semSuspend
     m_isPaused = FALSE;
 
     // defaults for joinable threads
     m_shouldBeJoined = TRUE;
     m_shouldBroadcast = TRUE;
     m_isDetached = FALSE;
+
+    m_condEnd = new wxRefCountedCondition();
 }
 
 wxThreadInternal::~wxThreadInternal()
 {
+    m_condEnd->DeleteRef();
 }
 
 wxThreadError wxThreadInternal::Run()
@@ -832,7 +956,15 @@ void wxThreadInternal::Wait()
 
     // wait until the thread terminates (we're blocking in _another_ thread,
     // of course)
-    m_condEnd.Wait();
+
+    // a reference counting condition is used to handle the
+    // case where a detached thread deletes itself
+    // before m_condEnd->Wait() returns
+    // in this case the deletion of the condition object is deferred until
+    // all Wait()ing threads have finished calling DeleteRef()
+    m_condEnd->AddRef();
+    m_condEnd->Wait();
+    m_condEnd->DeleteRef();
 
     wxLogTrace(TRACE_THREADS, _T("Finished waiting for thread %ld."), id);
 
@@ -877,7 +1009,7 @@ void wxThreadInternal::SignalExit()
         wxLogTrace(TRACE_THREADS, _T("Thread %ld signals end condition."),
                    GetId());
 
-        m_condEnd.Broadcast();
+        m_condEnd->SetSignaled();
     }
 }
 
@@ -890,8 +1022,8 @@ void wxThreadInternal::Pause()
 
     wxLogTrace(TRACE_THREADS, _T("Thread %ld goes to sleep."), GetId());
 
-    // wait until the condition is signaled from Resume()
-    m_condSuspend.Wait();
+    // wait until the semaphore is Post()ed from Resume()
+    m_semSuspend.Wait();
 }
 
 void wxThreadInternal::Resume()
@@ -906,7 +1038,7 @@ void wxThreadInternal::Resume()
         wxLogTrace(TRACE_THREADS, _T("Waking up thread %ld"), GetId());
 
         // wake up Pause()
-        m_condSuspend.Signal();
+        m_semSuspend.Post();
 
         // reset the flag
         SetReallyPaused(FALSE);
@@ -1307,7 +1439,7 @@ wxThreadError wxThread::Delete(ExitCode *rc)
     {
         case STATE_NEW:
             // we need to wake up the thread so that PthreadStart() will
-            // terminate - right now it's blocking on m_condRun
+            // terminate - right now it's blocking on m_semRun
             m_internal->SignalRun();
 
             // fall through
@@ -1490,7 +1622,8 @@ wxThread::~wxThread()
     // is not called for the joinable threads, so do it here
     if ( !m_isDetached )
     {
-        MutexLock lock(gs_mutexDeleteThread);
+        wxMutexLocker lock( *gs_mutexDeleteThread );
+
         gs_nThreadsBeingDeleted--;
 
         wxLogTrace(TRACE_THREADS, _T("%u scheduled for deletion threads left."),
@@ -1566,9 +1699,8 @@ bool wxThreadModule::OnInit()
     gs_mutexGui->Lock();
 #endif // wxUSE_GUI
 
-    // under Solaris we get a warning from CC when using
-    // PTHREAD_MUTEX_INITIALIZER, so do it dynamically
-    pthread_mutex_init(&gs_mutexDeleteThread, NULL);
+    gs_mutexDeleteThread = new wxMutex();
+    gs_condAllDeleted = new wxCondition( *gs_mutexDeleteThread );
 
     return TRUE;
 }
@@ -1579,18 +1711,19 @@ void wxThreadModule::OnExit()
 
     // are there any threads left which are being deleted right now?
     size_t nThreadsBeingDeleted;
+
     {
-        MutexLock lock(gs_mutexDeleteThread);
+        wxMutexLocker lock( *gs_mutexDeleteThread );
         nThreadsBeingDeleted = gs_nThreadsBeingDeleted;
-    }
 
-    if ( nThreadsBeingDeleted > 0 )
-    {
-        wxLogTrace(TRACE_THREADS, _T("Waiting for %u threads to disappear"),
-                   nThreadsBeingDeleted);
+        if ( nThreadsBeingDeleted > 0 )
+{
+            wxLogTrace(TRACE_THREADS, _T("Waiting for %u threads to disappear"),
+                           nThreadsBeingDeleted);
 
-        // have to wait until all of them disappear
-        gs_condAllDeleted->Wait();
+            // have to wait until all of them disappear
+            gs_condAllDeleted->Wait();
+        }
     }
 
     // terminate any threads left
@@ -1617,6 +1750,9 @@ void wxThreadModule::OnExit()
 
     // and free TLD slot
     (void)pthread_key_delete(gs_keySelf);
+
+    delete gs_condAllDeleted;
+    delete gs_mutexDeleteThread;
 }
 
 // ----------------------------------------------------------------------------
@@ -1625,12 +1761,7 @@ void wxThreadModule::OnExit()
 
 static void ScheduleThreadForDeletion()
 {
-    MutexLock lock(gs_mutexDeleteThread);
-
-    if ( gs_nThreadsBeingDeleted == 0 )
-    {
-        gs_condAllDeleted = new wxCondition;
-    }
+    wxMutexLocker lock( *gs_mutexDeleteThread );
 
     gs_nThreadsBeingDeleted++;
 
@@ -1643,17 +1774,15 @@ static void DeleteThread(wxThread *This)
 {
     // gs_mutexDeleteThread should be unlocked before signalling the condition
     // or wxThreadModule::OnExit() would deadlock
-    {
-        MutexLock lock(gs_mutexDeleteThread);
+    wxMutexLocker locker( *gs_mutexDeleteThread );
 
-        wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId());
+    wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId());
 
-        delete This;
+    delete This;
 
-        wxCHECK_RET( gs_nThreadsBeingDeleted > 0,
+    wxCHECK_RET( gs_nThreadsBeingDeleted > 0,
                      _T("no threads scheduled for deletion, yet we delete "
                         "one?") );
-    }
 
     wxLogTrace(TRACE_THREADS, _T("%u scheduled for deletion threads left."),
                gs_nThreadsBeingDeleted - 1);
@@ -1662,9 +1791,6 @@ static void DeleteThread(wxThread *This)
     {
         // no more threads left, signal it
         gs_condAllDeleted->Signal();
-
-        delete gs_condAllDeleted;
-        gs_condAllDeleted = (wxCondition *)NULL;
     }
 }