On screens with restricted space, it's useful to be able to add controls

[wxWidgets.git] / include / wx / thread.h

diff --git a/include/wx/thread.h b/include/wx/thread.h
index 3f1415adc7830ec7563d2bd61b7104a36f084dbc..3ef7e47adec2666aa96d50e4c9877a035fa5dcc1 100644 (file)
--- a/include/wx/thread.h
+++ b/include/wx/thread.h
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        thread.h
+// Name:        wx/thread.h

 // Purpose:     Thread API
 // Author:      Guilhem Lavaux
 // Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
 // Purpose:     Thread API
 // Author:      Guilhem Lavaux
 // Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads


@@ -10,51 +10,63 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 

-#ifndef __THREADH__
-#define __THREADH__
+#ifndef _WX_THREAD_H_
+#define _WX_THREAD_H_

 
 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------
 
 // get the value of wxUSE_THREADS configuration flag
 
 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------
 
 // get the value of wxUSE_THREADS configuration flag

-#include "wx/setup.h"
+#include "wx/defs.h"

 
 #if wxUSE_THREADS
 
 
 #if wxUSE_THREADS
 

-// only for wxUSE_THREADS - otherwise we'd get undefined symbols
-#ifdef __GNUG__
-    #pragma interface "thread.h"
-#endif
-

 // Windows headers define it
 #ifdef Yield
     #undef Yield
 #endif
 
 // Windows headers define it
 #ifdef Yield
     #undef Yield
 #endif
 

-#include "wx/module.h"
-

 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 
 enum wxMutexError
 {
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 
 enum wxMutexError
 {

-  wxMUTEX_NO_ERROR = 0,
-  wxMUTEX_DEAD_LOCK,      // Mutex has been already locked by THE CALLING thread
-  wxMUTEX_BUSY,           // Mutex has been already locked by ONE thread
-  wxMUTEX_UNLOCKED,
-  wxMUTEX_MISC_ERROR
+    wxMUTEX_NO_ERROR = 0,   // operation completed successfully
+    wxMUTEX_INVALID,        // mutex hasn't been initialized
+    wxMUTEX_DEAD_LOCK,      // mutex is already locked by the calling thread
+    wxMUTEX_BUSY,           // mutex is already locked by another thread
+    wxMUTEX_UNLOCKED,       // attempt to unlock a mutex which is not locked
+    wxMUTEX_MISC_ERROR      // any other error
+};
+
+enum wxCondError
+{
+    wxCOND_NO_ERROR = 0,
+    wxCOND_INVALID,
+    wxCOND_TIMEOUT,         // WaitTimeout() has timed out
+    wxCOND_MISC_ERROR
+};
+
+enum wxSemaError
+{
+    wxSEMA_NO_ERROR = 0,
+    wxSEMA_INVALID,         // semaphore hasn't been initialized successfully
+    wxSEMA_BUSY,            // returned by TryWait() if Wait() would block
+    wxSEMA_TIMEOUT,         // returned by WaitTimeout()
+    wxSEMA_OVERFLOW,        // Post() would increase counter past the max
+    wxSEMA_MISC_ERROR

 };
 
 enum wxThreadError
 {
 };
 
 enum wxThreadError
 {

-  wxTHREAD_NO_ERROR = 0,      // No error
-  wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread
-  wxTHREAD_RUNNING,           // The thread is already running
-  wxTHREAD_NOT_RUNNING,       // The thread isn't running
-  wxTHREAD_KILLED,            // Thread we waited for had to be killed
-  wxTHREAD_MISC_ERROR         // Some other error
+    wxTHREAD_NO_ERROR = 0,      // No error
+    wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread
+    wxTHREAD_RUNNING,           // The thread is already running
+    wxTHREAD_NOT_RUNNING,       // The thread isn't running
+    wxTHREAD_KILLED,            // Thread we waited for had to be killed
+    wxTHREAD_MISC_ERROR         // Some other error

 };
 
 enum wxThreadKind
 };
 
 enum wxThreadKind


@@ -71,6 +83,38 @@ enum
     WXTHREAD_MAX_PRIORITY      = 100u
 };
 
     WXTHREAD_MAX_PRIORITY      = 100u
 };
 

+// There are 2 types of mutexes: normal mutexes and recursive ones. The attempt
+// to lock a normal mutex by a thread which already owns it results in
+// undefined behaviour (it always works under Windows, it will almost always
+// result in a deadlock under Unix). Locking a recursive mutex in such
+// situation always succeeds and it must be unlocked as many times as it has
+// been locked.
+//
+// However recursive mutexes have several important drawbacks: first, in the
+// POSIX implementation, they're less efficient. Second, and more importantly,
+// they CAN NOT BE USED WITH CONDITION VARIABLES under Unix! Using them with
+// wxCondition will work under Windows and some Unices (notably Linux) but will
+// deadlock under other Unix versions (e.g. Solaris). As it might be difficult
+// to ensure that a recursive mutex is not used with wxCondition, it is a good
+// idea to avoid using recursive mutexes at all. Also, the last problem with
+// them is that some (older) Unix versions don't support this at all -- which
+// results in a configure warning when building and a deadlock when using them.
+enum wxMutexType
+{
+    // normal mutex: try to always use this one
+    wxMUTEX_DEFAULT,
+
+    // recursive mutex: don't use these ones with wxCondition
+    wxMUTEX_RECURSIVE
+};
+
+// forward declarations
+class WXDLLIMPEXP_BASE wxThreadHelper;
+class WXDLLIMPEXP_BASE wxConditionInternal;
+class WXDLLIMPEXP_BASE wxMutexInternal;
+class WXDLLIMPEXP_BASE wxSemaphoreInternal;
+class WXDLLIMPEXP_BASE wxThreadInternal;
+

 // ----------------------------------------------------------------------------
 // A mutex object is a synchronization object whose state is set to signaled
 // when it is not owned by any thread, and nonsignaled when it is owned. Its
 // ----------------------------------------------------------------------------
 // A mutex object is a synchronization object whose state is set to signaled
 // when it is not owned by any thread, and nonsignaled when it is owned. Its


@@ -80,46 +124,58 @@ 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 wxMutexInternal;
-class WXDLLEXPORT wxMutex
+class WXDLLIMPEXP_BASE wxMutex

 {
 public:
     // constructor & destructor
 {
 public:
     // constructor & destructor

-    wxMutex();
+    // ------------------------
+
+    // create either default (always safe) or recursive mutex
+    wxMutex(wxMutexType mutexType = wxMUTEX_DEFAULT);
+
+    // destroys the mutex kernel object

     ~wxMutex();
 
     ~wxMutex();
 

-    // Lock the mutex.
+    // test if the mutex has been created successfully
+    bool IsOk() const;
+
+    // mutex operations
+    // ----------------
+
+    // Lock the mutex, blocking on it until it is unlocked by the other thread.
+    // The result of locking a mutex already locked by the current thread
+    // depend on the mutex type.
+    //
+    // The caller must call Unlock() later if Lock() returned wxMUTEX_NO_ERROR.

     wxMutexError Lock();
     wxMutexError Lock();

-    // Try to lock the mutex: if it can't, returns immediately with an error.
+
+    // Try to lock the mutex: if it is currently locked, return immediately
+    // with an error. Otherwise the caller must call Unlock().

     wxMutexError TryLock();
     wxMutexError TryLock();

-    // Unlock the mutex.
-    wxMutexError Unlock();

 
 

-    // Returns true if the mutex is locked.
-    bool IsLocked() const { return (m_locked > 0); }
+    // Unlock the mutex. It is an error to unlock an already unlocked mutex
+    wxMutexError Unlock();

 
 protected:
 
 protected:

-    friend class wxCondition;
+    wxMutexInternal *m_internal;

 
 

-    // no assignment operator nor copy ctor
-    wxMutex(const wxMutex&);
-    wxMutex& operator=(const wxMutex&);
+    friend class wxConditionInternal;

 
 

-    int m_locked;
-    wxMutexInternal *p_internal;
+    DECLARE_NO_COPY_CLASS(wxMutex)

 };
 
 // a helper class which locks the mutex in the ctor and unlocks it in the dtor:
 // this ensures that mutex is always unlocked, even if the function returns or
 // throws an exception before it reaches the end
 };
 
 // a helper class which locks the mutex in the ctor and unlocks it in the dtor:
 // this ensures that mutex is always unlocked, even if the function returns or
 // throws an exception before it reaches the end

-class WXDLLEXPORT wxMutexLocker
+class WXDLLIMPEXP_BASE wxMutexLocker

 {
 public:
     // lock the mutex in the ctor
 {
 public:
     // lock the mutex in the ctor

-    wxMutexLocker(wxMutex& mutex) : m_mutex(mutex)
-        { m_isOk = m_mutex.Lock() == wxMUTEX_NO_ERROR; }
+    wxMutexLocker(wxMutex& mutex)
+        : m_isOk(false), m_mutex(mutex)
+        { m_isOk = ( m_mutex.Lock() == wxMUTEX_NO_ERROR ); }

 
 

-    // returns TRUE if mutex was successfully locked in ctor
+    // returns true if mutex was successfully locked in ctor

     bool IsOk() const
         { return m_isOk; }
 
     bool IsOk() const
         { return m_isOk; }
 


@@ -146,99 +202,205 @@ private:
 //     which makes it possible to have static globals of this class
 // ----------------------------------------------------------------------------
 
 //     which makes it possible to have static globals of this class
 // ----------------------------------------------------------------------------
 

-class WXDLLEXPORT wxCriticalSectionInternal;
-

 // in order to avoid any overhead under platforms where critical sections are
 // just mutexes make all wxCriticalSection class functions inline
 // in order to avoid any overhead under platforms where critical sections are
 // just mutexes make all wxCriticalSection class functions inline

-#if !defined(__WXMSW__) && !defined(__WXPM__) && !defined(__WXMAC__)
-    #define WXCRITICAL_INLINE   inline
-
+#if !defined(__WXMSW__) && !defined(__WXMAC__)

     #define wxCRITSECT_IS_MUTEX 1
     #define wxCRITSECT_IS_MUTEX 1

-#else // MSW || Mac || OS2
-    #define WXCRITICAL_INLINE

 
 

+    #define wxCRITSECT_INLINE inline
+#else // MSW

     #define wxCRITSECT_IS_MUTEX 0
     #define wxCRITSECT_IS_MUTEX 0

+
+    #define wxCRITSECT_INLINE

 #endif // MSW/!MSW
 
 // you should consider wxCriticalSectionLocker whenever possible instead of
 // directly working with wxCriticalSection class - it is safer
 #endif // MSW/!MSW
 
 // you should consider wxCriticalSectionLocker whenever possible instead of
 // directly working with wxCriticalSection class - it is safer

-class WXDLLEXPORT wxCriticalSection
+class WXDLLIMPEXP_BASE wxCriticalSection

 {
 public:
     // ctor & dtor
 {
 public:
     // ctor & dtor

-    WXCRITICAL_INLINE wxCriticalSection();
-    WXCRITICAL_INLINE ~wxCriticalSection();
+    wxCRITSECT_INLINE wxCriticalSection();
+    wxCRITSECT_INLINE ~wxCriticalSection();

 
     // enter the section (the same as locking a mutex)
 
     // enter the section (the same as locking a mutex)

-    WXCRITICAL_INLINE void Enter();
+    wxCRITSECT_INLINE void Enter();
+

     // leave the critical section (same as unlocking a mutex)
     // leave the critical section (same as unlocking a mutex)

-    WXCRITICAL_INLINE void Leave();
+    wxCRITSECT_INLINE void Leave();

 
 private:
 
 private:

-    // no assignment operator nor copy ctor
-    wxCriticalSection(const wxCriticalSection&);
-    wxCriticalSection& operator=(const wxCriticalSection&);
-

 #if wxCRITSECT_IS_MUTEX
     wxMutex m_mutex;
 #elif defined(__WXMSW__)
     // we can't allocate any memory in the ctor, so use placement new -
     // unfortunately, we have to hardcode the sizeof() here because we can't
 #if wxCRITSECT_IS_MUTEX
     wxMutex m_mutex;
 #elif defined(__WXMSW__)
     // we can't allocate any memory in the ctor, so use placement new -
     // unfortunately, we have to hardcode the sizeof() here because we can't

-    // include windows.h from this public header
-    char m_buffer[24];
-#elif !defined(__WXPM__)
-    wxCriticalSectionInternal *m_critsect;
-#else
-    // nothing for OS/2
-#endif // !Unix/Unix
+    // include windows.h from this public header and we also have to use the
+    // union to force the correct (i.e. maximal) alignment
+    //
+    // if CRITICAL_SECTION size changes in Windows, you'll get an assert from
+    // thread.cpp and will need to increase the buffer size
+    //
+    // finally, we need this typedef instead of declaring m_buffer directly
+    // because otherwise the assert mentioned above wouldn't compile with some
+    // compilers (notably CodeWarrior 8)
+#ifdef __WIN64__
+    typedef char wxCritSectBuffer[40];
+#else // __WIN32__
+    typedef char wxCritSectBuffer[24];
+#endif
+    union
+    {
+        unsigned long m_dummy1;
+        void *m_dummy2;
+
+        wxCritSectBuffer m_buffer;
+    };
+#elif defined(__WXMAC__)
+    void *m_critRegion ;
+#endif // Unix&OS2/Win32
+
+    DECLARE_NO_COPY_CLASS(wxCriticalSection)

 };
 
 };
 

-// keep your preprocessor name space clean
-#undef WXCRITICAL_INLINE
+#if wxCRITSECT_IS_MUTEX
+    // implement wxCriticalSection using mutexes
+    inline wxCriticalSection::wxCriticalSection() { }
+    inline wxCriticalSection::~wxCriticalSection() { }
+
+    inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
+    inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
+#endif // wxCRITSECT_IS_MUTEX
+
+#undef wxCRITSECT_INLINE
+#undef wxCRITSECT_IS_MUTEX

 
 // wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
 
 // wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is

-// to th mutexes
-class WXDLLEXPORT wxCriticalSectionLocker
+// to mutexes
+class WXDLLIMPEXP_BASE wxCriticalSectionLocker

 {
 public:
 {
 public:

-    inline wxCriticalSectionLocker(wxCriticalSection& critsect);
-    inline ~wxCriticalSectionLocker();
+    wxCriticalSectionLocker(wxCriticalSection& cs)
+        : m_critsect(cs)
+    {
+        m_critsect.Enter();
+    }

 
 

-private:
-    // no assignment operator nor copy ctor
-    wxCriticalSectionLocker(const wxCriticalSectionLocker&);
-    wxCriticalSectionLocker& operator=(const wxCriticalSectionLocker&);
+    ~wxCriticalSectionLocker()
+    {
+        m_critsect.Leave();
+    }

 
 

+private:

     wxCriticalSection& m_critsect;
     wxCriticalSection& m_critsect;

+
+    DECLARE_NO_COPY_CLASS(wxCriticalSectionLocker)
+};
+
+// ----------------------------------------------------------------------------
+// wxCondition models a POSIX condition variable which allows one (or more)
+// thread(s) to wait until some condition is fulfilled
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxCondition
+{
+public:
+    // Each wxCondition object is associated with a (single) 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();
+
+    // return true if the condition has been created successfully
+    bool IsOk() const;
+
+    // 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.
+    wxCondError Wait();
+
+    // exactly as Wait() except that it may also return if the specified
+    // timeout elapses 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 timeout parameter specifies an interval that needs to be waited for
+    // in milliseconds
+    wxCondError WaitTimeout(unsigned long milliseconds);
+
+    // 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
+    wxCondError Signal();
+
+    // 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.
+    wxCondError Broadcast();
+
+
+    // deprecated version, don't use
+    bool Wait(unsigned long milliseconds)
+        { return WaitTimeout(milliseconds) == wxCOND_NO_ERROR; }
+
+private:
+    wxConditionInternal *m_internal;
+
+    DECLARE_NO_COPY_CLASS(wxCondition)

 };
 
 // ----------------------------------------------------------------------------
 };
 
 // ----------------------------------------------------------------------------

-// Condition handler.
+// wxSemaphore: a counter limiting the number of threads concurrently accessing
+//              a shared resource

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

-class wxConditionInternal;
-class WXDLLEXPORT wxCondition
+class WXDLLIMPEXP_BASE wxSemaphore

 {
 public:
 {
 public:

-  // constructor & destructor
-  wxCondition();
-  ~wxCondition();
-
-  // Waits indefinitely.
-  void Wait(wxMutex& mutex);
-  // Waits until a signal is raised or the timeout is elapsed.
-  bool Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec);
-  // Raises a signal: only one "Waiter" is released.
-  void Signal();
-  // Broadcasts to all "Waiters".
-  void Broadcast();
+    // 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();
+
+    // return true if the semaphore has been created successfully
+    bool IsOk() const;
+
+    // wait indefinitely, until the semaphore count goes beyond 0
+    // and then decrement it and return (this method might have been called
+    // Acquire())
+    wxSemaError Wait();
+
+    // same as Wait(), but does not block, returns wxSEMA_NO_ERROR if
+    // successful and wxSEMA_BUSY if the count is currently zero
+    wxSemaError TryWait();
+
+    // same as Wait(), but as a timeout limit, returns wxSEMA_NO_ERROR if the
+    // semaphore was acquired and wxSEMA_TIMEOUT if the timeout has elapsed
+    wxSemaError WaitTimeout(unsigned long milliseconds);
+
+    // increments the semaphore count and signals one of the waiting threads
+    wxSemaError Post();

 
 private:
 
 private:

-  wxConditionInternal *p_internal;
+    wxSemaphoreInternal *m_internal;
+
+    DECLARE_NO_COPY_CLASS(wxSemaphore)

 };
 
 // ----------------------------------------------------------------------------
 };
 
 // ----------------------------------------------------------------------------

-// Thread class
+// wxThread: class encapsulating 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)


@@ -250,8 +412,14 @@ private:
 //     created by the wxThread object while "main thread" is the thread created
 //     during the process initialization (a.k.a. the GUI thread)
 
 //     created by the wxThread object while "main thread" is the thread created
 //     during the process initialization (a.k.a. the GUI thread)
 

-class wxThreadInternal;
-class WXDLLEXPORT wxThread
+// On VMS thread pointers are 64 bits (also needed for other systems???
+#ifdef __VMS
+   typedef unsigned long long wxThreadIdType;
+#else
+   typedef unsigned long wxThreadIdType;
+#endif
+
+class WXDLLIMPEXP_BASE wxThread

 {
 public:
     // the return type for the thread function
 {
 public:
     // the return type for the thread function


@@ -268,7 +436,7 @@ public:
         // Returns true if current thread is the main thread.
     static bool IsMain();
 
         // Returns true if current thread is the main thread.
     static bool IsMain();
 

-        // Release the rest of our time slice leting the other threads run
+        // Release the rest of our time slice letting the other threads run

     static void Yield();
 
         // Sleep during the specified period of time in milliseconds
     static void Yield();
 
         // Sleep during the specified period of time in milliseconds


@@ -276,6 +444,26 @@ public:
         // NB: at least under MSW worker threads can not call ::wxSleep()!
     static void Sleep(unsigned long milliseconds);
 
         // NB: at least under MSW worker threads can not call ::wxSleep()!
     static void Sleep(unsigned long milliseconds);
 

+        // get the number of system CPUs - useful with SetConcurrency()
+        // (the "best" value for it is usually number of CPUs + 1)
+        //
+        // Returns -1 if unknown, number of CPUs otherwise
+    static int GetCPUCount();
+
+        // Get the platform specific thread ID and return as a long.  This
+        // can be used to uniquely identify threads, even if they are not
+        // wxThreads.  This is used by wxPython.
+   static wxThreadIdType GetCurrentId();
+
+        // sets the concurrency level: this is, roughly, the number of threads
+        // the system tries to schedule to run in parallel. 0 means the
+        // default value (usually acceptable, but may not yield the best
+        // performance for this process)
+        //
+        // Returns true on success, false otherwise (if not implemented, for
+        // example)
+    static bool SetConcurrency(size_t level);
+

     // constructor only creates the C++ thread object and doesn't create (or
     // start) the real thread
     wxThread(wxThreadKind kind = wxTHREAD_DETACHED);
     // constructor only creates the C++ thread object and doesn't create (or
     // start) the real thread
     wxThread(wxThreadKind kind = wxTHREAD_DETACHED);


@@ -284,8 +472,11 @@ public:
     // from _another_ thread (typically the thread that created this one, e.g.
     // the main thread), not from the thread itself
 
     // from _another_ thread (typically the thread that created this one, e.g.
     // the main thread), not from the thread itself
 

-        // create a new thread - call Run() to start it
-    wxThreadError Create();
+        // create a new thread and optionally set the stack size on
+        // platforms that support that - call Run() to start it
+        // (special cased for watcom which won't accept 0 default)
+
+    wxThreadError Create(unsigned int stackSize = 0);

 
         // starts execution of the thread - from the moment Run() is called
         // the execution of wxThread::Entry() may start at any moment, caller
 
         // starts execution of the thread - from the moment Run() is called
         // the execution of wxThread::Entry() may start at any moment, caller


@@ -311,9 +502,9 @@ public:
     ExitCode Wait();
 
         // kills the thread without giving it any chance to clean up - should
     ExitCode Wait();
 
         // kills the thread without giving it any chance to clean up - should

-        // not be used in normal circumstances, use Delete() instead. It is a
-        // dangerous function that should only be used in the most extreme
-        // cases!
+        // not be used under normal circumstances, use Delete() instead.
+        // It is a dangerous function that should only be used in the most
+        // extreme cases!

         //
         // The wxThread object is deleted by Kill() if the thread is
         // detachable, but you still have to delete it manually for joinable
         //
         // The wxThread object is deleted by Kill() if the thread is
         // detachable, but you still have to delete it manually for joinable


@@ -349,23 +540,23 @@ public:
 
     // Get the thread ID - a platform dependent number which uniquely
     // identifies a thread inside a process
 
     // Get the thread ID - a platform dependent number which uniquely
     // identifies a thread inside a process

-    unsigned long GetId() const;
+    wxThreadIdType GetId() const;

 
     // called when the thread exits - in the context of this thread
     //
     // NB: this function will not be called if the thread is Kill()ed
     virtual void OnExit() { }
 
 
     // called when the thread exits - in the context of this thread
     //
     // NB: this function will not be called if the thread is Kill()ed
     virtual void OnExit() { }
 

+    // Returns true if the thread was asked to terminate: this function should
+    // be called by the thread from time to time, otherwise the main thread
+    // will be left forever in Delete()!
+    virtual bool TestDestroy();
+

     // dtor is public, but the detached threads should never be deleted - use
     // Delete() instead (or leave the thread terminate by itself)
     virtual ~wxThread();
 
 protected:
     // dtor is public, but the detached threads should never be deleted - use
     // Delete() instead (or leave the thread terminate by itself)
     virtual ~wxThread();
 
 protected:

-    // Returns TRUE if the thread was asked to terminate: this function should
-    // be called by the thread from time to time, otherwise the main thread
-    // will be left forever in Delete()!
-    bool TestDestroy();
-

     // exits from the current thread - can be called only from this thread
     void Exit(ExitCode exitcode = 0);
 
     // exits from the current thread - can be called only from this thread
     void Exit(ExitCode exitcode = 0);
 


@@ -381,7 +572,7 @@ private:
     friend class wxThreadInternal;
 
     // the (platform-dependent) thread class implementation
     friend class wxThreadInternal;
 
     // the (platform-dependent) thread class implementation

-    wxThreadInternal *p_internal;
+    wxThreadInternal *m_internal;

 
     // protects access to any methods of wxThreadInternal object
     wxCriticalSection m_critsect;
 
     // protects access to any methods of wxThreadInternal object
     wxCriticalSection m_critsect;


@@ -390,38 +581,146 @@ private:
     bool m_isDetached;
 };
 
     bool m_isDetached;
 };
 

+// wxThreadHelperThread class
+// --------------------------
+
+class WXDLLIMPEXP_BASE wxThreadHelperThread : public wxThread
+{
+public:
+    // constructor only creates the C++ thread object and doesn't create (or
+    // start) the real thread
+    wxThreadHelperThread(wxThreadHelper& owner)
+        : wxThread(wxTHREAD_JOINABLE), m_owner(owner)
+        { }
+
+protected:
+    // entry point for the thread -- calls Entry() in owner.
+    virtual void *Entry();
+
+private:
+    // the owner of the thread
+    wxThreadHelper& m_owner;
+
+    // no copy ctor/assignment operator
+    wxThreadHelperThread(const wxThreadHelperThread&);
+    wxThreadHelperThread& operator=(const wxThreadHelperThread&);
+};
+
+// ----------------------------------------------------------------------------
+// wxThreadHelper: this class implements the threading logic to run a
+// background task in another object (such as a window).  It is a mix-in: just
+// derive from it to implement a threading background task in your class.
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_BASE wxThreadHelper
+{
+private:
+    void KillThread()
+    {
+        if ( m_thread )
+        {
+            m_thread->Kill();
+            delete m_thread;
+        }
+    }
+
+public:
+    // constructor only initializes m_thread to NULL
+    wxThreadHelper() : m_thread(NULL) { }
+
+    // destructor deletes m_thread
+    virtual ~wxThreadHelper() { KillThread(); }
+
+    // create a new thread (and optionally set the stack size on platforms that
+    // support/need that), call Run() to start it
+    wxThreadError Create(unsigned int stackSize = 0)
+    {
+        KillThread();
+
+        m_thread = new wxThreadHelperThread(*this);
+
+        return m_thread->Create(stackSize);
+    }
+
+    // entry point for the thread - called by Run() and executes in the context
+    // of this thread.
+    virtual void *Entry() = 0;
+
+    // returns a pointer to the thread which can be used to call Run()
+    wxThread *GetThread() const { return m_thread; }
+
+protected:
+    wxThread *m_thread;
+};
+
+// call Entry() in owner, put it down here to avoid circular declarations
+inline void *wxThreadHelperThread::Entry()
+{
+    return m_owner.Entry();
+}
+

 // ----------------------------------------------------------------------------
 // Automatic initialization
 // ----------------------------------------------------------------------------
 
 // GUI mutex handling.
 // ----------------------------------------------------------------------------
 // Automatic initialization
 // ----------------------------------------------------------------------------
 
 // GUI mutex handling.

-void WXDLLEXPORT wxMutexGuiEnter();
-void WXDLLEXPORT wxMutexGuiLeave();
+void WXDLLIMPEXP_BASE wxMutexGuiEnter();
+void WXDLLIMPEXP_BASE wxMutexGuiLeave();

 
 // macros for entering/leaving critical sections which may be used without
 // having to take them inside "#if wxUSE_THREADS"
 #define wxENTER_CRIT_SECT(cs)   (cs).Enter()
 #define wxLEAVE_CRIT_SECT(cs)   (cs).Leave()
 
 // macros for entering/leaving critical sections which may be used without
 // having to take them inside "#if wxUSE_THREADS"
 #define wxENTER_CRIT_SECT(cs)   (cs).Enter()
 #define wxLEAVE_CRIT_SECT(cs)   (cs).Leave()

+#define wxCRIT_SECT_DECLARE(cs) static wxCriticalSection cs
+#define wxCRIT_SECT_DECLARE_MEMBER(cs) wxCriticalSection cs

 #define wxCRIT_SECT_LOCKER(name, cs)  wxCriticalSectionLocker name(cs)
 
 #define wxCRIT_SECT_LOCKER(name, cs)  wxCriticalSectionLocker name(cs)
 

-#else // !wxUSE_THREADS
+// function for checking if we're in the main thread which may be used whether
+// wxUSE_THREADS is 0 or 1
+inline bool wxIsMainThread() { return wxThread::IsMain(); }

 
 

-#include "wx/defs.h" // for WXDLLEXPORT
+#else // !wxUSE_THREADS

 
 // no thread support
 
 // no thread support

-inline void WXDLLEXPORT wxMutexGuiEnter() { }
-inline void WXDLLEXPORT wxMutexGuiLeave() { }
+inline void WXDLLIMPEXP_BASE wxMutexGuiEnter() { }
+inline void WXDLLIMPEXP_BASE wxMutexGuiLeave() { }

 
 // macros for entering/leaving critical sections which may be used without
 // having to take them inside "#if wxUSE_THREADS"
 #define wxENTER_CRIT_SECT(cs)
 #define wxLEAVE_CRIT_SECT(cs)
 
 // macros for entering/leaving critical sections which may be used without
 // having to take them inside "#if wxUSE_THREADS"
 #define wxENTER_CRIT_SECT(cs)
 #define wxLEAVE_CRIT_SECT(cs)

+#define wxCRIT_SECT_DECLARE(cs)
+#define wxCRIT_SECT_DECLARE_MEMBER(cs)

 #define wxCRIT_SECT_LOCKER(name, cs)
 
 #define wxCRIT_SECT_LOCKER(name, cs)
 

-#endif // wxUSE_THREADS
+// if there is only one thread, it is always the main one
+inline bool wxIsMainThread() { return true; }
+
+#endif // wxUSE_THREADS/!wxUSE_THREADS

 
 

-// automatically unlock GUI mutex in dtor
-class WXDLLEXPORT wxMutexGuiLocker
+// mark part of code as being a critical section: this macro declares a
+// critical section with the given name and enters it immediately and leaves
+// it at the end of the current scope
+//
+// example:
+//
+//      int Count()
+//      {
+//          static int s_counter = 0;
+//
+//          wxCRITICAL_SECTION(counter);
+//
+//          return ++s_counter;
+//      }
+//
+// this function is MT-safe in presence of the threads but there is no
+// overhead when the library is compiled without threads
+#define wxCRITICAL_SECTION(name) \
+    wxCRIT_SECT_DECLARE(s_cs##name);  \
+    wxCRIT_SECT_LOCKER(cs##name##Locker, s_cs##name)
+
+// automatically lock GUI mutex in ctor and unlock it in dtor
+class WXDLLIMPEXP_BASE wxMutexGuiLocker

 {
 public:
     wxMutexGuiLocker() { wxMutexGuiEnter(); }
 {
 public:
     wxMutexGuiLocker() { wxMutexGuiEnter(); }


@@ -434,62 +733,23 @@ public:
 
 #if wxUSE_THREADS
 
 
 #if wxUSE_THREADS
 

-#if defined(__WXMSW__)
+#if defined(__WXMSW__) || defined(__WXMAC__) || defined(__OS2__) || defined(__EMX__)

     // unlock GUI if there are threads waiting for and lock it back when
     // there are no more of them - should be called periodically by the main
     // thread
     // unlock GUI if there are threads waiting for and lock it back when
     // there are no more of them - should be called periodically by the main
     // thread

-    extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
-
-    // returns TRUE if the main thread has GUI lock
-    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+    extern void WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter();

 
 

-    // wakes up the main thread if it's sleeping inside ::GetMessage()
-    extern void WXDLLEXPORT wxWakeUpMainThread();
-
-    // return TRUE if the main thread is waiting for some other to terminate:
-    // wxApp then should block all "dangerous" messages
-    extern bool WXDLLEXPORT wxIsWaitingForThread();
-#elif defined(__WXMAC__)
-    extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
-
-    // returns TRUE if the main thread has GUI lock
-    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
+    // returns true if the main thread has GUI lock
+    extern bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread();

 
     // wakes up the main thread if it's sleeping inside ::GetMessage()
 
     // wakes up the main thread if it's sleeping inside ::GetMessage()

-    extern void WXDLLEXPORT wxWakeUpMainThread();
+    extern void WXDLLIMPEXP_BASE wxWakeUpMainThread();

 
 

-    // return TRUE if the main thread is waiting for some other to terminate:
+    // return true if the main thread is waiting for some other to terminate:

     // wxApp then should block all "dangerous" messages
     // wxApp then should block all "dangerous" messages

-    extern bool WXDLLEXPORT wxIsWaitingForThread();
-#elif defined(__WXPM__)
-    // unlock GUI if there are threads waiting for and lock it back when
-    // there are no more of them - should be called periodically by the main
-    // thread
-    extern void WXDLLEXPORT wxMutexGuiLeaveOrEnter();
-
-    // returns TRUE if the main thread has GUI lock
-    extern bool WXDLLEXPORT wxGuiOwnedByMainThread();
-
-    // return TRUE if the main thread is waiting for some other to terminate:
-    // wxApp then should block all "dangerous" messages
-    extern bool WXDLLEXPORT wxIsWaitingForThread();
-
-#else // !MSW && !PM
-    // implement wxCriticalSection using mutexes
-    inline wxCriticalSection::wxCriticalSection() { }
-    inline wxCriticalSection::~wxCriticalSection() { }
-
-    inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); }
-    inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); }
-#endif // MSW/!MSW
+    extern bool WXDLLIMPEXP_BASE wxIsWaitingForThread();
+#endif // MSW, Mac, OS/2

 
 

-    // we can define these inline functions now (they should be defined after
-    // wxCriticalSection::Enter/Leave)
-    inline
-    wxCriticalSectionLocker:: wxCriticalSectionLocker(wxCriticalSection& cs)
-        : m_critsect(cs) { m_critsect.Enter(); }
-    inline
-    wxCriticalSectionLocker::~wxCriticalSectionLocker() { m_critsect.Leave(); }

 #endif // wxUSE_THREADS
 
 #endif // wxUSE_THREADS
 

-#endif // __THREADH__
+#endif // _WX_THREAD_H_