added wxSemaphore (with docs), new version of wxCondition and bug fixes to wxThread...

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14907 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/docs/latex/wx/category.tex b/docs/latex/wx/category.tex
index a3d8afe9a2360a8509e6c41cd1e45ff8541b5d9c..a0c874f5cfbb67612da373e9a79bcc39096313c6 100644 (file)
--- a/docs/latex/wx/category.tex
+++ b/docs/latex/wx/category.tex
@@ -505,6 +505,7 @@ capabilities of the various platforms.
 \twocolitem{\helpref{wxCriticalSection}{wxcriticalsection}}{Critical section class}
 \twocolitem{\helpref{wxCriticalSectionLocker}{wxcriticalsectionlocker}}{Critical section locker utility class}
 \twocolitem{\helpref{wxCondition}{wxcondition}}{Condition class}
 \twocolitem{\helpref{wxCriticalSection}{wxcriticalsection}}{Critical section class}
 \twocolitem{\helpref{wxCriticalSectionLocker}{wxcriticalsectionlocker}}{Critical section locker utility class}
 \twocolitem{\helpref{wxCondition}{wxcondition}}{Condition class}

+\twocolitem{\helpref{wxSemaphore}{wxsemaphore}}{Semaphore class}

 \end{twocollist}
 
 {\large {\bf HTML classes}}
 \end{twocollist}
 
 {\large {\bf HTML classes}}

diff --git a/docs/latex/wx/classes.tex b/docs/latex/wx/classes.tex
index bc7e82b9585ac8bda711345e964ff910b6a0135e..9ec19fa7760a5c1e526a895ab7be15f97c4d1fca 100644 (file)
--- a/docs/latex/wx/classes.tex
+++ b/docs/latex/wx/classes.tex
@@ -270,6 +270,7 @@
 \input scrolwin.tex
 \input scrlwevt.tex
 \input scrolevt.tex
 \input scrolwin.tex
 \input scrlwevt.tex
 \input scrolevt.tex

+\input semaphor.tex

 \input hprovsmp.tex
 \input sngchdlg.tex
 \input snglinst.tex
 \input hprovsmp.tex
 \input sngchdlg.tex
 \input snglinst.tex

diff --git a/docs/latex/wx/conditn.tex b/docs/latex/wx/conditn.tex
index 88b04eeb289e3870c86d28d97960011e28080d2b..bb71a7e7d70671685ed1760b45d0319f7ea952ed 100644 (file)
--- a/docs/latex/wx/conditn.tex
+++ b/docs/latex/wx/conditn.tex
@@ -12,28 +12,22 @@ perfect because in this particular case it would be much better to just
 worker threads it already makes much more sense).
 
 Note that a call to \helpref{Signal()}{wxconditionsignal} may happen before the
 worker threads it already makes much more sense).
 
 Note that a call to \helpref{Signal()}{wxconditionsignal} may happen before the

-other thread calls \helpref{Wait()}{wxconditionwait} but, in marked contrast
-with the pthread conditions, this will still work as the missed signals are
-queued and \helpref{Wait()}{wxconditionwait} simply returns immediately if
-there are ny pending signals.
-
-However, the calls to \helpref{Broadcast()}{wxconditionbroadcast} are {\bf not} 
-queued and so it will only wake up the threads already waiting on the
-condition. Accordingly, you will probably want to use a mutex to ensure that
-the thread(s) you want to be waken up have indeed started to wait before
-calling \helpref{Broadcast()}{wxconditionbroadcast}.
+other thread calls \helpref{Wait()}{wxconditionwait} and, just as with the
+pthread conditions, the signal is then lost and so if you want to be sure to
+get it you must use a mutex together with the condition variable.

 
 \wxheading{Example}
 
 
 \wxheading{Example}
 

-This example shows how a main thread may launch a worker thread and wait until
-it starts running:
+This example shows how a main thread may launch a worker thread which starts
+running and then waits until the main thread signals it to continue:

 
 \begin{verbatim}
 class MyWaitingThread : public wxThread
 {
 public:
 
 \begin{verbatim}
 class MyWaitingThread : public wxThread
 {
 public:

-    MyWaitingThread(wxCondition *condition)
+    MyWaitingThread(wxMutex *mutex, wxCondition *condition)

     {
     {

+        m_mutex = mutex;

         m_condition = condition;
 
         Create();
         m_condition = condition;
 
         Create();


@@ -41,8 +35,11 @@ public:
 
     virtual ExitCode Entry()
     {
 
     virtual ExitCode Entry()
     {

-        // let the main thread know that we started running
+        // wait for the signal from the main thread: it is absolutely necessary
+        // to look the mutex before doing it!
+        m_mutex->Lock();

         m_condition->Signal();
         m_condition->Signal();

+        m_mutex->Unlock();

 
         ... do our job ...
 
 
         ... do our job ...
 


@@ -55,15 +52,23 @@ private:
 
 int main()
 {
 
 int main()
 {

-    wxCondition condition;
-    MyWaitingThread *thread - new MyWaitingThread(&condition);
+    wxMutex mutex;
+    wxCondition condition(&mutex);
+
+    for ( int i = 0; i < 10; i++ )
+    {
+        MyWaitingThread *thread = new MyWaitingThread(&mutex, &condition);

 
 

-    thread->Run();
+        thread->Run();
+    }

 
 

-    // wait until the thread really starts running
-    condition.Wait();
+    // wake up one of the threads
+    condition.Signal();

 
 

-    ...
+    // wake up all the other ones
+    condition.Broadcast();
+
+    ... wait until they terminate or do something else ...

 
     return 0;
 }
 
     return 0;
 }


@@ -85,37 +90,57 @@ None.
 
 \membersection{wxCondition::wxCondition}\label{wxconditionconstr}
 
 
 \membersection{wxCondition::wxCondition}\label{wxconditionconstr}
 

-\func{}{wxCondition}{\void}
+\func{}{wxCondition}{\param{wxMutex }{*mutex}}

 
 

-Default constructor.
+Default and only constructor. The {\it mutex} must be non {\tt NULL}.

 
 \membersection{wxCondition::\destruct{wxCondition}}
 
 \func{}{\destruct{wxCondition}}{\void}
 
 
 \membersection{wxCondition::\destruct{wxCondition}}
 
 \func{}{\destruct{wxCondition}}{\void}
 

-Destroys the wxCondition object.
+Destroys the wxCondition object. The destructor is not virtual so this class
+should not be used polymorphically.

 
 \membersection{wxCondition::Broadcast}\label{wxconditionbroadcast}
 
 \func{void}{Broadcast}{\void}
 
 
 \membersection{wxCondition::Broadcast}\label{wxconditionbroadcast}
 
 \func{void}{Broadcast}{\void}
 

-Broadcasts to all waiting objects.
+Broadcasts to all waiting threads, waking all of them up. Note that this method
+may be called whether the mutex associated with this condition is locked or
+not.
+
+\wxheading{See also}
+
+\helpref{wxCondition::Signal}{wxconditionsignal}

 
 \membersection{wxCondition::Signal}\label{wxconditionsignal}
 
 \func{void}{Signal}{\void}
 
 
 \membersection{wxCondition::Signal}\label{wxconditionsignal}
 
 \func{void}{Signal}{\void}
 

-Signals the object.
+Signals the object waking up at most one thread. If several threads are waiting
+on the same condition, the exact thread which is woken up is undefined. If no
+threads are waiting, the signal is lost and the condition would have to be
+signalled again to wake up any thread which may start waiting on it later.
+
+Note that this method may be called whether the mutex associated with this
+condition is locked or not.
+
+\wxheading{See also}
+
+\helpref{wxCondition::Broadcast}{wxconditionbroadcast}

 
 \membersection{wxCondition::Wait}\label{wxconditionwait}
 
 \func{void}{Wait}{\void}
 
 
 \membersection{wxCondition::Wait}\label{wxconditionwait}
 
 \func{void}{Wait}{\void}
 

-Waits indefinitely.
+Waits until the condition is signalled.

 
 \func{bool}{Wait}{\param{unsigned long}{ sec}, \param{unsigned long}{ nsec}}
 
 
 \func{bool}{Wait}{\param{unsigned long}{ sec}, \param{unsigned long}{ nsec}}
 

-Waits until a signal is raised or the timeout has elapsed.
+Waits until the condition is signalled or the timeout has elapsed.
+
+Note that the mutex associated with this condition {\bf must} be acquired by
+the thread before calling this method.

 
 \wxheading{Parameters}
 
 
 \wxheading{Parameters}
 


@@ -125,5 +150,7 @@ Waits until a signal is raised or the timeout has elapsed.
 
 \wxheading{Return value}
 
 
 \wxheading{Return value}
 

-The second form returns if the signal was raised, or FALSE if there was a timeout.
+The second form returns {\tt TRUE} if the condition has been signalled, or
+{\tt FALSE} if it returned because the timeout has elapsed.
+

 
 

diff --git a/docs/latex/wx/semaphor.tex b/docs/latex/wx/semaphor.tex
new file mode 100644 (file)
index 0000000..3193828
--- /dev/null
+++ b/docs/latex/wx/semaphor.tex
@@ -0,0 +1,84 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Name:        semaphore.tex
+%% Purpose:     wxSemaphore documentation
+%% Author:      Vadim Zeitlin
+%% Modified by:
+%% Created:     02.04.02
+%% RCS-ID:      $Id$
+%% Copyright:   (c) 2002 Vadim Zeitlin
+%% License:     wxWindows license
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\section{\class{wxSemaphore}}\label{wxsemaphore}
+
+wxSemaphore is a counter limiting the number of threads concurrently accessing
+a shared resource. This counter is always between $0$ and the maximum value
+specified during the semaphore creation. When the counter is strictly greater
+than $0$, a call to \helpref{Wait}{wxsemaphorewait} returns immediately and
+decrements the counter. As soon as it reaches $0$, any subsequent calls to
+\helpref{Wait}{wxsemaphorewait} block and only return when the semaphore
+counter becomes strictly positive again as the result of calling 
+\helpref{Post}{wxsemaphorepost} which increments the counter.
+
+In general, the semaphores are useful to restict access to a shared resource
+which can only be accessed by some fixed number of clients at once. For
+example, when modeling a hotel reservation system a semaphore with the counter
+equal to the total number of available rooms could be created. Each time a room
+is reserved, the semaphore should be acquired by calling 
+\helpref{Wait}{wxsemaphorewait} and each time a room is freed it should be
+released by calling \helpref{Post}{wxsemaphorepost}.
+
+\wxheading{Derived from}
+
+No base class
+
+\wxheading{Include files}
+
+<wx/thread.h>
+
+\latexignore{\rtfignore{\wxheading{Members}}}
+
+\membersection{wxSemaphore::wxSemaphore}\label{wxsemaphorewxsemaphore}
+
+\func{}{wxSemaphore}{\param{int }{initialcount = 0}, \param{int }{maxcount = 0}}
+
+Specifying a {\it maxcount} of $0$ actually makes wxSemaphore behave as if
+there is no upper limit. If maxcount is $1$ the semaphore behaves exactly as a
+mutex.
+
+{\it initialcount} is the initial value of the semaphore which must be between
+$0$ and {\it maxcount} (if it is not set to $0$).
+
+\membersection{wxSemaphore::\destruct{wxSemaphore}}\label{wxsemaphoredtor}
+
+\func{}{\destruct{wxSemaphore}}{\void}
+
+Destructor is not virtual, don't use this class polymorphically.
+
+\membersection{wxSemaphore::Post}\label{wxsemaphorepost}
+
+\func{void}{Post}{\void}
+
+Increments the semaphore count and signals one of the waiting threads in an
+atomic way.
+
+\membersection{wxSemaphore::TryWait}\label{wxsemaphoretrywait}
+
+\func{bool}{TryWait}{\void}
+
+Same as \helpref{Wait()}{wxsemaphorewait}, but does not block, returns
+{\tt TRUE} if the semaphore was successfully acquired and {\tt FALSE} if the
+count is zero and it couldn't be done.
+
+\membersection{wxSemaphore::Wait}\label{wxsemaphorewait}
+
+\func{void}{Wait}{\void}
+
+Wait indefinitely until the semaphore count becomes strictly positive
+and then decrement it and return.
+
+\func{bool}{Wait}{\param{unsigned long }{timeout\_millis}}
+
+Same as the version above, but with a timeout limit: returns {\tt TRUE| if the
+semaphore was acquired and {\tt FALSE} if the timeout has ellapsed
+

diff --git a/include/wx/thread.h b/include/wx/thread.h
index 7dd5cfa6212558f56a0b1c83ab69e6eaf5bf77e8..ff789112718ea35c026265a30bd6ea9a5f561108 100644 (file)
--- a/include/wx/thread.h
+++ b/include/wx/thread.h
@@ -80,6 +80,7 @@ enum
 
 // you should consider wxMutexLocker whenever possible instead of directly
 // working with wxMutex class - it is safer
 
 // you should consider wxMutexLocker whenever possible instead of directly
 // working with wxMutex class - it is safer

+class WXDLLEXPORT wxConditionInternal;

 class WXDLLEXPORT wxMutexInternal;
 class WXDLLEXPORT wxMutex
 {
 class WXDLLEXPORT wxMutexInternal;
 class WXDLLEXPORT wxMutex
 {


@@ -105,6 +106,8 @@ protected:
 
     int m_locked;
     wxMutexInternal *m_internal;
 
     int m_locked;
     wxMutexInternal *m_internal;

+
+    friend class wxConditionInternal;

 };
 
 // a helper class which locks the mutex in the ctor and unlocks it in the dtor:
 };
 
 // a helper class which locks the mutex in the ctor and unlocks it in the dtor:


@@ -211,41 +214,97 @@ private:
 };
 
 // ----------------------------------------------------------------------------
 };
 
 // ----------------------------------------------------------------------------

-// Condition variable: allows to block the thread execution until something
-// happens (== condition is signaled)
+// wxCondition models a POSIX condition variable which allows one (or more)
+// thread(s) to wait until some condition is fulfilled

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-class wxConditionInternal;

 class WXDLLEXPORT wxCondition
 {
 public:
 class WXDLLEXPORT wxCondition
 {
 public:

-    // constructor & destructor
-    wxCondition();
+    // constructor and destructor
+
+    // Each wxCondition object is associated with with a wxMutex object The
+    // mutex object MUST be locked before calling Wait()
+    wxCondition( wxMutex *mutex );
+
+    // dtor is not virtual, don't use this class polymorphically

     ~wxCondition();
 
     ~wxCondition();
 

-    // wait until the condition is signaled
-        // waits indefinitely.
+    // NB: the associated mutex MUST be locked beforehand by the calling thread
+    // 
+    // it atomically releases the lock on the associated mutex
+    // and starts waiting to be woken up by a Signal()/Broadcast()
+    // once its signaled, then it will wait until it can reacquire
+    // the lock on the associated mutex object, before returning.

     void Wait();
     void Wait();

-        // waits until a signal is raised or the timeout elapses
-    bool Wait(unsigned long sec, unsigned long nsec);

 
 

-    // signal the condition
-        // wakes up one (and only one) of the waiting threads
+    // exactly as Wait() except that it may also return if the specified
+    // timeout ellapses even if the condition hasn't been signalled: in this
+    // case, the return value is FALSE, otherwise (i.e. in case of a normal
+    // return) it is TRUE
+    // 
+    // the timeeout parameter specifies a interval that needs to be waited in
+    // milliseconds
+    bool Wait( unsigned long timeout_millis );
+
+    // NB: the associated mutex may or may not be locked by the calling thread
+    //
+    // this method unblocks one thread if any are blocking on the condition.
+    // if no thread is blocking in Wait(), then the signal is NOT remembered
+    // The thread which was blocking on Wait(), will then reacquire the lock
+    // on the associated mutex object before returning

     void Signal();
     void Signal();

-        // wakes up all threads waiting on this condition
-    void Broadcast();

 
 

-#ifdef __WXDEBUG__
-    // for debugging purposes only
-    void *GetId() const { return m_internal; }
-#endif // __WXDEBUG__
+    // NB: the associated mutex may or may not be locked by the calling thread
+    //
+    // this method unblocks all threads if any are blocking on the condition.
+    // if no thread is blocking in Wait(), then the signal is NOT remembered
+    // The threads which were blocking on Wait(), will then reacquire the lock
+    // on the associated mutex object before returning.
+    void Broadcast();

 
 private:
     wxConditionInternal *m_internal;
 };
 
 // ----------------------------------------------------------------------------
 
 private:
     wxConditionInternal *m_internal;
 };
 
 // ----------------------------------------------------------------------------

-// Thread class
+// wxSemaphore: a counter limiting the number of threads concurrently accessing
+//              a shared resource
+// ----------------------------------------------------------------------------
+
+class WXDLLEXPORT wxSemaphoreInternal;
+class WXDLLEXPORT wxSemaphore
+{
+public:
+    // specifying a maxcount of 0 actually makes wxSemaphore behave as if there
+    // is no upper limit, if maxcount is 1 the semaphore behaves as a mutex
+    wxSemaphore( int initialcount = 0, int maxcount = 0 );
+
+    // dtor is not virtual, don't use this class polymorphically
+    ~wxSemaphore();
+
+    // wait indefinitely, until the semaphore count goes beyond 0
+    // and then decrement it and return (this method might have been called
+    // Acquire())
+    void Wait();
+
+    // same as Wait(), but does not block, returns TRUE if successful and
+    // FALSE if the count is zero
+    bool TryWait();
+
+    // same as Wait(), but as a timeout limit, returns TRUE if the semaphore
+    // was acquired and FALSE if the timeout has ellapsed
+    bool Wait( unsigned long timeout_millis );
+
+    // increments the semaphore count and signals one of the waiting threads
+    void Post();
+
+private:
+    wxSemaphoreInternal *m_internal;
+};
+
+// ----------------------------------------------------------------------------
+// wxThread: class encpasulating a thread of execution

 // ----------------------------------------------------------------------------
 
 // there are two different kinds of threads: joinable and detached (default)
 // ----------------------------------------------------------------------------
 
 // there are two different kinds of threads: joinable and detached (default)


@@ -540,4 +599,3 @@ public:
 
 #endif // __THREADH__
 
 
 #endif // __THREADH__
 

-// vi:sts=4:sw=4:et

diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp
index b654353bfce9748f5248201b11732b31b2737a8e..ec70911da4b7417af88215ff9c3a05923646b1c2 100644 (file)
--- a/src/msw/thread.cpp
+++ b/src/msw/thread.cpp
@@ -146,7 +146,7 @@ public:
         }
     }
 
         }
     }
 

-    ~wxMutexInternal() { if ( m_mutex ) CloseHandle(m_mutex); }
+    ~wxMutexInternal() { if ( m_mutex ) ::CloseHandle(m_mutex); }

 
 public:
     HANDLE m_mutex;
 
 public:
     HANDLE m_mutex;


@@ -223,97 +223,284 @@ wxMutexError wxMutex::Unlock()
     return wxMUTEX_NO_ERROR;
 }
 
     return wxMUTEX_NO_ERROR;
 }
 

-// ----------------------------------------------------------------------------
-// wxCondition implementation
-// ----------------------------------------------------------------------------
+// ==========================================================================
+// wxSemaphore
+// ==========================================================================

 
 

-class wxConditionInternal
+// --------------------------------------------------------------------------
+// wxSemaphoreInternal
+// --------------------------------------------------------------------------
+
+class wxSemaphoreInternal

 {
 public:
 {
 public:

-    wxConditionInternal()
+    wxSemaphoreInternal( int initialcount = 0, int maxcount = 0 );
+    ~wxSemaphoreInternal();
+
+    void Wait();
+    bool TryWait();
+
+    bool Wait( unsigned long timeout_millis );
+
+    void Post();
+
+private:
+    HANDLE m_semaphore;
+};
+
+wxSemaphoreInternal::wxSemaphoreInternal( int initialcount, int maxcount )
+{
+    if ( maxcount == 0 )

     {
     {

-        m_hEvent = ::CreateEvent(
-                                 NULL,   // default secutiry
-                                 FALSE,  // not manual reset
-                                 FALSE,  // nonsignaled initially
-                                 NULL    // nameless event
-                                );
-        if ( !m_hEvent )
-        {
-            wxLogSysError(_("Can not create event object."));
-        }
+        // make it practically infinite
+        maxcount = INT_MAX;
+    }

 
 

-        // nobody waits for us yet
-        m_nWaiters = 0;
+    m_semaphore = ::CreateSemaphore( NULL, initialcount, maxcount, NULL );
+    if ( !m_semaphore )
+    {
+        wxLogLastError(_T("CreateSemaphore()"));

     }
     }

+}
+
+wxSemaphoreInternal::~wxSemaphoreInternal()
+{
+    CloseHandle( m_semaphore );
+}

 
 

-    bool Wait(DWORD timeout)
+void wxSemaphoreInternal::Wait()
+{
+    if ( ::WaitForSingleObject( m_semaphore, INFINITE ) != WAIT_OBJECT_0 )

     {
     {

-        // as m_nWaiters variable is accessed from multiple waiting threads
-        // (and possibly from the broadcasting thread), we need to change its
-        // value atomically
-        ::InterlockedIncrement(&m_nWaiters);
+        wxLogLastError(_T("WaitForSingleObject"));
+    }
+}

 
 

-        // FIXME this should be MsgWaitForMultipleObjects() as we want to keep
-        //       processing Windows messages while waiting (or don't we?)
-        DWORD rc = ::WaitForSingleObject(m_hEvent, timeout);
+bool wxSemaphoreInternal::TryWait()
+{
+    return Wait(0);
+}
+
+bool wxSemaphoreInternal::Wait( unsigned long timeout_millis )
+{
+    DWORD result = ::WaitForSingleObject( m_semaphore, timeout_millis );
+
+    switch ( result )
+    {
+        case WAIT_OBJECT_0:
+           return TRUE;

 
 

-        ::InterlockedDecrement(&m_nWaiters);
+        case WAIT_TIMEOUT:
+           break;

 
 

-        return rc != WAIT_TIMEOUT;
+        default:
+            wxLogLastError(_T("WaitForSingleObject()"));

     }
 
     }
 

-    void Signal()
+    return FALSE;
+}
+
+void wxSemaphoreInternal::Post()
+{
+    if ( !::ReleaseSemaphore( m_semaphore, 1, NULL ) )

     {
     {

-        // set the event to signaled: if a thread is already waiting on it, it
-        // will be woken up, otherwise the event will remain in the signaled
-        // state until someone waits on it. In any case, the system will return
-        // it to a non signalled state afterwards. If multiple threads are
-        // waiting, only one will be woken up.
-        if ( !::SetEvent(m_hEvent) )
-        {
-            wxLogLastError(wxT("SetEvent"));
-        }
+        wxLogLastError(_T("ReleaseSemaphore"));

     }
     }

+}
+
+// --------------------------------------------------------------------------
+// wxSemaphore
+// --------------------------------------------------------------------------
+
+wxSemaphore::wxSemaphore( int initialcount, int maxcount )
+{
+    m_internal = new wxSemaphoreInternal( initialcount, maxcount );
+}
+
+wxSemaphore::~wxSemaphore()
+{
+    delete m_internal;
+}
+
+void wxSemaphore::Wait()
+{
+    m_internal->Wait();
+}
+
+bool wxSemaphore::TryWait()
+{
+    return m_internal->TryWait();
+}
+
+bool wxSemaphore::Wait( unsigned long timeout_millis )
+{
+    return m_internal->Wait( timeout_millis );
+}
+
+void wxSemaphore::Post()
+{
+    m_internal->Post();
+}
+
+
+// ==========================================================================
+// wxCondition
+// ==========================================================================
+
+// --------------------------------------------------------------------------
+// wxConditionInternal
+// --------------------------------------------------------------------------

 
 

-    void Broadcast()
+class wxConditionInternal
+{
+public:
+    wxConditionInternal( wxMutex *mutex );
+    ~wxConditionInternal();
+
+    void Wait();
+
+    bool Wait( unsigned long timeout_millis );
+
+    void Signal();
+
+    void Broadcast();
+
+private:
+    int m_numWaiters;
+    wxMutex m_mutexNumWaiters;
+
+    wxMutex *m_mutex;
+
+    wxSemaphore m_semaphore;
+};
+
+wxConditionInternal::wxConditionInternal( wxMutex *mutex )
+{
+    m_mutex = mutex;
+
+    m_numWaiters = 0;
+}
+
+wxConditionInternal::~wxConditionInternal()
+{
+}
+
+void wxConditionInternal::Wait()
+{
+    // increment the number of waiters
+    m_mutexNumWaiters.Lock();
+    m_numWaiters++;
+    m_mutexNumWaiters.Unlock();
+
+    m_mutex->Unlock();
+
+    // a potential race condition can occur here
+    //
+    // after a thread increments nwaiters, and unlocks the mutex and before the
+    // semaphore.Wait() is called, if another thread can cause a signal to be
+    // generated
+    //
+    // this race condition is handled by using a semaphore and incrementing the
+    // semaphore only if 'nwaiters' is greater that zero since the semaphore,
+    // can 'remember' signals the race condition will not occur
+
+    // wait ( if necessary ) and decrement semaphore
+    m_semaphore.Wait();
+
+    m_mutex->Lock();
+}
+
+bool wxConditionInternal::Wait( unsigned long timeout_millis )
+{
+    m_mutexNumWaiters.Lock();
+    m_numWaiters++;
+    m_mutexNumWaiters.Unlock();
+
+    m_mutex->Unlock();
+
+    // a race condition can occur at this point in the code
+    //
+    // please see the comments in Wait(), for details
+
+    bool success = TRUE;
+
+    bool result = m_semaphore.Wait( timeout_millis );
+
+    if ( !result )

     {
     {

-        // we need to save the original value as m_nWaiters is goign to be
-        // decreased by the signalled thread resulting in the loop being
-        // executed less times than needed
-        LONG nWaiters = m_nWaiters;
-
-        // this works because all these threads are already waiting and so each
-        // SetEvent() inside Signal() is really a PulseEvent() because the
-        // event state is immediately returned to non-signaled
-        for ( LONG n = 0; n < nWaiters; n++ )
+        // another potential race condition exists here it is caused when a
+        // 'waiting' thread timesout, and returns from WaitForSingleObject, but
+        // has not yet decremented 'nwaiters'.
+        //
+        // at this point if another thread calls signal() then the semaphore
+        // will be incremented, but the waiting thread will miss it.
+        //
+        // to handle this particular case, the waiting thread calls
+        // WaitForSingleObject again with a timeout of 0, after locking
+        // 'nwaiters_mutex'. this call does not block because of the zero
+        // timeout, but will allow the waiting thread to catch the missed
+        // signals.
+        m_mutexNumWaiters.Lock();
+        result = m_semaphore.Wait( 0 );
+
+        if ( !result )

         {
         {

-            Signal();
+            m_numWaiters--;
+            success = FALSE;

         }
         }

+
+        m_mutexNumWaiters.Unlock();

     }
 
     }
 

-    ~wxConditionInternal()
+    m_mutex->Lock();
+
+    return success;
+}
+
+void wxConditionInternal::Signal()
+{
+    m_mutexNumWaiters.Lock();
+
+    if ( m_numWaiters > 0 )

     {
     {

-        if ( m_hEvent )
-        {
-            if ( !::CloseHandle(m_hEvent) )
-            {
-                wxLogLastError(wxT("CloseHandle(event)"));
-            }
-        }
+        // increment the semaphore by 1
+        m_semaphore.Post();
+
+        m_numWaiters--;

     }
 
     }
 

-private:
-    // the Win32 synchronization object corresponding to this event
-    HANDLE m_hEvent;
+    m_mutexNumWaiters.Unlock();
+}

 
 

-    // number of threads waiting for this condition
-    LONG m_nWaiters;
-};
+void wxConditionInternal::Broadcast()
+{
+    m_mutexNumWaiters.Lock();

 
 

-wxCondition::wxCondition()
+    while ( m_numWaiters > 0 )
+    {
+        m_semaphore.Post();
+        m_numWaiters--;
+    }
+
+    m_mutexNumWaiters.Unlock();
+}
+
+// ----------------------------------------------------------------------------
+// wxCondition implementation
+// ----------------------------------------------------------------------------
+
+wxCondition::wxCondition( wxMutex *mutex )

 {
 {

-    m_internal = new wxConditionInternal;
+    if ( !mutex )
+    {
+        wxFAIL_MSG( _T("NULL mutex in wxCondition ctor") );
+
+        m_internal = NULL;
+    }
+    else
+    {
+        m_internal = new wxConditionInternal( mutex );
+    }

 }
 
 wxCondition::~wxCondition()
 }
 
 wxCondition::~wxCondition()


@@ -323,23 +510,25 @@ wxCondition::~wxCondition()
 
 void wxCondition::Wait()
 {
 
 void wxCondition::Wait()
 {

-    (void)m_internal->Wait(INFINITE);
+    if ( m_internal )
+        m_internal->Wait();

 }
 
 }
 

-bool wxCondition::Wait(unsigned long sec,
-                       unsigned long nsec)
+bool wxCondition::Wait( unsigned long timeout_millis )

 {
 {

-    return m_internal->Wait(sec*1000 + nsec/1000000);
+    return m_internal ? m_internal->Wait(timeout_millis) : FALSE;

 }
 
 void wxCondition::Signal()
 {
 }
 
 void wxCondition::Signal()
 {

-    m_internal->Signal();
+    if ( m_internal )
+        m_internal->Signal();

 }
 
 void wxCondition::Broadcast()
 {
 }
 
 void wxCondition::Broadcast()
 {

-    m_internal->Broadcast();
+    if ( m_internal )
+        m_internal->Broadcast();

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------


@@ -350,7 +539,7 @@ wxCriticalSection::wxCriticalSection()
 {
 #ifdef __WXDEBUG__
     // Done this way to stop warnings during compilation about statement
 {
 #ifdef __WXDEBUG__
     // Done this way to stop warnings during compilation about statement

-    // always being false
+    // always being FALSE

     int csSize = sizeof(CRITICAL_SECTION);
     int bSize  = sizeof(m_buffer);
     wxASSERT_MSG( csSize <= bSize,
     int csSize = sizeof(CRITICAL_SECTION);
     int bSize  = sizeof(m_buffer);
     wxASSERT_MSG( csSize <= bSize,

diff --git a/src/unix/threadpsx.cpp b/src/unix/threadpsx.cpp
index 5e8ba134236f1b5b4b89bf2642aff45488963a77..4524bae5b8a06f05f5e22b0fd1188dfaed0df523 100644 (file)
--- 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
 // 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)
 // 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
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 


@@ -34,6 +35,7 @@
 #include "wx/log.h"
 #include "wx/intl.h"
 #include "wx/dynarray.h"
 #include "wx/log.h"
 #include "wx/intl.h"
 #include "wx/dynarray.h"

+#include "wx/timer.h"

 
 #include <stdio.h>
 #include <unistd.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")
 
 // 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
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // private functions
 // ----------------------------------------------------------------------------


@@ -88,35 +81,6 @@ WX_DEFINE_LIST(wxMutexList);
 static void ScheduleThreadForDeletion();
 static void DeleteThread(wxThread *This);
 
 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
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // types
 // ----------------------------------------------------------------------------


@@ -143,7 +107,7 @@ static pthread_key_t gs_keySelf;
 static size_t gs_nThreadsBeingDeleted = 0;
 
 // a mutex to protect gs_nThreadsBeingDeleted
 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
 
 // 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;
 
 private:
     pthread_mutex_t m_mutex;

+
+    friend class wxConditionInternal;

 };
 
 wxMutexInternal::wxMutexInternal()
 };
 
 wxMutexInternal::wxMutexInternal()


@@ -342,209 +308,379 @@ wxMutexError wxMutex::Unlock()
     return m_internal->Unlock();
 }
 
     return m_internal->Unlock();
 }
 

-// ============================================================================
+// ===========================================================================

 // wxCondition implementation
 // wxCondition implementation

-// ============================================================================
+// ===========================================================================

 
 

-// ----------------------------------------------------------------------------
+// ---------------------------------------------------------------------------

 // wxConditionInternal
 // 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:
 class wxConditionInternal
 {
 public:

-    wxConditionInternal();
+    wxConditionInternal( wxMutex *mutex );

     ~wxConditionInternal();
 
     ~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:

 
 

-    // 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_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 )
+    m_mutex = mutex;
+    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()
 {
     }
 }
 
 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, &(m_mutex->m_internal->m_mutex) ) != 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,
+                                         &(m_mutex->m_internal->m_mutex),
+                                         ts );
+    if ( result == ETIMEDOUT )
+        return FALSE;

 
 

-    if ( m_nQueuedSignals )
-    {
-        m_nQueuedSignals--;
+    wxASSERT_MSG( result == 0, _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 )
+// ---------------------------------------------------------------------------
+// wxCondition
+// ---------------------------------------------------------------------------
+
+wxCondition::wxCondition( wxMutex *mutex )
+{
+    if ( !mutex )

     {
     {

-        case 0:
-            // condition was signaled
-            wxLogTrace(TRACE_THREADS,
-                       _T("wxCondition(%08x)::Wait(): ok"), this);
-            break;
+        wxFAIL_MSG( _T("NULL mutex in wxCondition ctor") );

 
 

-        default:
-            wxLogDebug(_T("unexpected pthread_cond_[timed]wait() return"));
-            // fall through
+        m_internal = NULL;
+    }
+    else
+    {
+        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()
+{
+    if ( m_internal )
+        m_internal->Wait();
+}
+
+bool wxCondition::Wait( unsigned long timeout_millis )
+{
+    wxCHECK_MSG( m_internal, FALSE, _T("can't wait on uninitalized condition") );
+
+    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;
+
+    tspec.tv_sec = sec;
+    tspec.tv_nsec = millis * 1000L * 1000L;

 
 

-    return err == 0;
+    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);
+    if ( m_internal )
+        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()
+{
+    if ( m_internal )
+        m_internal->Broadcast();
+}
+
+// ===========================================================================
+// wxSemaphore implementation
+// ===========================================================================

 
 

-        return;
+// ---------------------------------------------------------------------------
+// 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)
+{
+
+    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;
 }
 
 {
     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
 // wxThread implementation

-// ============================================================================
+// ===========================================================================

 
 // the thread callback functions must have the C linkage
 extern "C"
 
 // the thread callback functions must have the C linkage
 extern "C"


@@ -580,7 +716,7 @@ public:
         // wake up threads waiting for our termination
     void SignalExit();
         // wake up threads waiting for our start
         // 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
         // go to sleep until Resume() is called
     void Pause();
         // resume the thread


@@ -630,7 +766,7 @@ private:
     // this flag is set when the thread should terminate
     bool m_cancelled;
 
     // 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
     bool m_isPaused;
 
     // the thread exit code - only used for joinable (!detached) threads and


@@ -644,22 +780,18 @@ private:
     bool m_shouldBroadcast;
     bool m_isDetached;
 
     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
     // 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
 
     // 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
 
     // 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 +829,8 @@ void *wxThreadInternal::PthreadStart(wxThread *thread)
     pthread_cleanup_push(wxPthreadCleanup, thread);
 #endif // HAVE_THREAD_CLEANUP_FUNCTIONS
 
     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()?
 
     // test whether we should run the run at all - may be it was deleted
     // before it started to Run()?


@@ -792,17 +924,20 @@ wxThreadInternal::wxThreadInternal()
     m_threadId = 0;
     m_exitcode = 0;
 
     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_isPaused = FALSE;
 
     // defaults for joinable threads
     m_shouldBeJoined = TRUE;
     m_shouldBroadcast = TRUE;
     m_isDetached = FALSE;

+
+    m_condEnd = new wxRefCountedCondition();

 }
 
 wxThreadInternal::~wxThreadInternal()
 {
 }
 
 wxThreadInternal::~wxThreadInternal()
 {

+    m_condEnd->DeleteRef();

 }
 
 wxThreadError wxThreadInternal::Run()
 }
 
 wxThreadError wxThreadInternal::Run()


@@ -832,7 +967,15 @@ void wxThreadInternal::Wait()
 
     // wait until the thread terminates (we're blocking in _another_ thread,
     // of course)
 
     // 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);
 
 
     wxLogTrace(TRACE_THREADS, _T("Finished waiting for thread %ld."), id);
 


@@ -877,7 +1020,7 @@ void wxThreadInternal::SignalExit()
         wxLogTrace(TRACE_THREADS, _T("Thread %ld signals end condition."),
                    GetId());
 
         wxLogTrace(TRACE_THREADS, _T("Thread %ld signals end condition."),
                    GetId());
 

-        m_condEnd.Broadcast();
+        m_condEnd->SetSignaled();

     }
 }
 
     }
 }
 


@@ -890,8 +1033,8 @@ void wxThreadInternal::Pause()
 
     wxLogTrace(TRACE_THREADS, _T("Thread %ld goes to sleep."), GetId());
 
 
     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()
 }
 
 void wxThreadInternal::Resume()


@@ -906,7 +1049,7 @@ void wxThreadInternal::Resume()
         wxLogTrace(TRACE_THREADS, _T("Waking up thread %ld"), GetId());
 
         // wake up Pause()
         wxLogTrace(TRACE_THREADS, _T("Waking up thread %ld"), GetId());
 
         // wake up Pause()

-        m_condSuspend.Signal();
+        m_semSuspend.Post();

 
         // reset the flag
         SetReallyPaused(FALSE);
 
         // reset the flag
         SetReallyPaused(FALSE);


@@ -1307,7 +1450,7 @@ wxThreadError wxThread::Delete(ExitCode *rc)
     {
         case STATE_NEW:
             // we need to wake up the thread so that PthreadStart() will
     {
         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
             m_internal->SignalRun();
 
             // fall through


@@ -1490,7 +1633,8 @@ wxThread::~wxThread()
     // is not called for the joinable threads, so do it here
     if ( !m_isDetached )
     {
     // 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."),
         gs_nThreadsBeingDeleted--;
 
         wxLogTrace(TRACE_THREADS, _T("%u scheduled for deletion threads left."),


@@ -1566,9 +1710,8 @@ bool wxThreadModule::OnInit()
     gs_mutexGui->Lock();
 #endif // wxUSE_GUI
 
     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;
 }
 
     return TRUE;
 }


@@ -1579,18 +1722,19 @@ void wxThreadModule::OnExit()
 
     // are there any threads left which are being deleted right now?
     size_t nThreadsBeingDeleted;
 
     // 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;
         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
     }
 
     // terminate any threads left


@@ -1617,6 +1761,9 @@ void wxThreadModule::OnExit()
 
     // and free TLD slot
     (void)pthread_key_delete(gs_keySelf);
 
     // and free TLD slot
     (void)pthread_key_delete(gs_keySelf);

+
+    delete gs_condAllDeleted;
+    delete gs_mutexDeleteThread;

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------


@@ -1625,12 +1772,7 @@ void wxThreadModule::OnExit()
 
 static void ScheduleThreadForDeletion()
 {
 
 static void ScheduleThreadForDeletion()
 {

-    MutexLock lock(gs_mutexDeleteThread);
-
-    if ( gs_nThreadsBeingDeleted == 0 )
-    {
-        gs_condAllDeleted = new wxCondition;
-    }
+    wxMutexLocker lock( *gs_mutexDeleteThread );

 
     gs_nThreadsBeingDeleted++;
 
 
     gs_nThreadsBeingDeleted++;
 


@@ -1643,17 +1785,15 @@ static void DeleteThread(wxThread *This)
 {
     // gs_mutexDeleteThread should be unlocked before signalling the condition
     // or wxThreadModule::OnExit() would deadlock
 {
     // 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?") );
                      _T("no threads scheduled for deletion, yet we delete "
                         "one?") );

-    }

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


@@ -1662,9 +1802,6 @@ static void DeleteThread(wxThread *This)
     {
         // no more threads left, signal it
         gs_condAllDeleted->Signal();
     {
         // no more threads left, signal it
         gs_condAllDeleted->Signal();

-
-        delete gs_condAllDeleted;
-        gs_condAllDeleted = (wxCondition *)NULL;

     }
 }
 
     }
 }