wxGLCanvas works again

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

diff --git a/include/wx/thread.h b/include/wx/thread.h
index aa435992563832a4cc1945eb73f08a7190c17bf5..82c784744789605fc9f91a9661b09f75c71b3b13 100644 (file)
--- a/include/wx/thread.h
+++ b/include/wx/thread.h
@@ -2,7 +2,8 @@
 // Name:        thread.h
 // Purpose:     Thread API
 // Author:      Guilhem Lavaux
 // Name:        thread.h
 // Purpose:     Thread API
 // Author:      Guilhem Lavaux

-// Modified by:
+// Modified by: Vadim Zeitlin (modifications partly inspired by omnithreads
+//              package from Olivetti & Oracle Research Laboratory)

 // Created:     04/13/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
 // Created:     04/13/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux


@@ -12,28 +13,40 @@
 #ifndef __THREADH__
 #define __THREADH__
 
 #ifndef __THREADH__
 #define __THREADH__
 

+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// get the value of wxUSE_THREADS configuration flag
+#include "wx/setup.h"
+
+#if wxUSE_THREADS
+/* otherwise we get undefined references for non-thread case (KB)*/

 #ifdef __GNUG__
 #ifdef __GNUG__

-#pragma interface "thread.h"
+    #pragma interface "thread.h"
+#endif
+
+// Windows headers define it
+#ifdef Yield
+    #undef Yield

 #endif
 
 #endif
 

-#include "wx/object.h"
-#include "wx/setup.h"

 #include "wx/module.h"
 
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 
 #include "wx/module.h"
 
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 

-typedef enum 
+typedef enum

 {
   wxMUTEX_NO_ERROR = 0,
 {
   wxMUTEX_NO_ERROR = 0,

-  wxMUTEX_DEAD_LOCK,      // Mutex has been already locked by THE CALLING thread 
+  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
 } wxMutexError;
 
   wxMUTEX_BUSY,           // Mutex has been already locked by ONE thread
   wxMUTEX_UNLOCKED,
   wxMUTEX_MISC_ERROR
 } wxMutexError;
 

-typedef enum 
+typedef enum

 {
   wxTHREAD_NO_ERROR = 0,      // No error
   wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread
 {
   wxTHREAD_NO_ERROR = 0,      // No error
   wxTHREAD_NO_RESOURCE,       // No resource left to create a new thread


@@ -42,45 +55,137 @@ typedef enum
   wxTHREAD_MISC_ERROR         // Some other error
 } wxThreadError;
 
   wxTHREAD_MISC_ERROR         // Some other error
 } wxThreadError;
 

-/* defines the interval of priority. */
-#define WXTHREAD_MIN_PRIORITY     0
-#define WXTHREAD_DEFAULT_PRIORITY 50
-#define WXTHREAD_MAX_PRIORITY     100
+// defines the interval of priority
+#define WXTHREAD_MIN_PRIORITY     0u
+#define WXTHREAD_DEFAULT_PRIORITY 50u
+#define WXTHREAD_MAX_PRIORITY     100u

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

-// GUI mutex handling.
+// 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
+// name comes from its usefulness in coordinating mutually-exclusive access to
+// a shared resource. Only one thread at a time can own a mutex object.

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

-void WXDLLEXPORT wxMutexGuiEnter();
-void WXDLLEXPORT wxMutexGuiLeave();
+// you should consider wxMutexLocker whenever possible instead of directly
+// working with wxMutex class - it is safer
+class WXDLLEXPORT wxMutexInternal;
+class WXDLLEXPORT wxMutex
+{
+public:
+    // constructor & destructor
+    wxMutex();
+    ~wxMutex();
+
+    // Lock the mutex.
+    wxMutexError Lock();
+    // Try to lock the mutex: if it can't, returns immediately with an error.
+    wxMutexError TryLock();
+    // Unlock the mutex.
+    wxMutexError Unlock();
+
+    // Returns true if the mutex is locked.
+    bool IsLocked() const { return (m_locked > 0); }
+
+protected:
+    friend class wxCondition;
+
+    // no assignment operator nor copy ctor
+    wxMutex(const wxMutex&);
+    wxMutex& operator=(const wxMutex&);
+
+    int m_locked;
+    wxMutexInternal *p_internal;
+};
+
+// 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
+{
+public:
+    // lock the mutex in the ctor
+    wxMutexLocker(wxMutex& mutex) : m_mutex(mutex)
+        { m_isOk = m_mutex.Lock() == wxMUTEX_NO_ERROR; }
+
+    // returns TRUE if mutex was successfully locked in ctor
+    bool IsOk() const
+        { return m_isOk; }
+
+    // unlock the mutex in dtor
+    ~wxMutexLocker()
+        { if ( IsOk() ) m_mutex.Unlock(); }
+
+private:
+    // no assignment operator nor copy ctor
+    wxMutexLocker(const wxMutexLocker&);
+    wxMutexLocker& operator=(const wxMutexLocker&);
+
+    bool     m_isOk;
+    wxMutex& m_mutex;
+};

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

-// Mutex handler
+// Critical section: this is the same as mutex but is only visible to the
+// threads of the same process. For the platforms which don't have native
+// support for critical sections, they're implemented entirely in terms of
+// mutexes

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

-class WXDLLEXPORT wxMutexInternal;
-class WXDLLEXPORT wxMutex 
+// in order to avoid any overhead under !MSW make all wxCriticalSection class
+// functions inline - but this can't be done under MSW
+#ifdef __WXMSW__
+    class WXDLLEXPORT wxCriticalSectionInternal;
+    #define WXCRITICAL_INLINE
+#else // !MSW
+    #define WXCRITICAL_INLINE   inline
+#endif // MSW/!MSW
+
+// you should consider wxCriticalSectionLocker whenever possible instead of
+// directly working with wxCriticalSection class - it is safer
+class WXDLLEXPORT wxCriticalSection

 {
 public:
 {
 public:

-  // constructor & destructor 
-  wxMutex();
-  ~wxMutex();
+    // ctor & dtor
+    WXCRITICAL_INLINE wxCriticalSection();
+    WXCRITICAL_INLINE ~wxCriticalSection();

 
 

-  // Lock the mutex.
-  wxMutexError Lock();
-  // Try to lock the mutex: if it can't, returns immediately with an error.
-  wxMutexError TryLock();
-  // Unlock the mutex.
-  wxMutexError Unlock();
+    // enter the section (the same as locking a mutex)
+    WXCRITICAL_INLINE void Enter();
+    // leave the critical section (same as unlocking a mutex)
+    WXCRITICAL_INLINE void Leave();

 
 

-  // Returns true if the mutex is locked.
-  bool IsLocked() const { return (m_locked > 0); }
+private:
+    // no assignment operator nor copy ctor
+    wxCriticalSection(const wxCriticalSection&);
+    wxCriticalSection& operator=(const wxCriticalSection&);
+
+#ifdef __WXMSW__
+    wxCriticalSectionInternal *m_critsect;
+#else // !MSW
+    wxMutex m_mutex;
+#endif // MSW/!MSW
+};

 
 

-protected:
-  friend class wxCondition;
+// keep your preprocessor name space clean
+#undef WXCRITICAL_INLINE

 
 

-  int m_locked;
-  wxMutexInternal *p_internal;
+// wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
+// to th mutexes
+class WXDLLEXPORT wxCriticalSectionLocker
+{
+public:
+    wxCriticalSectionLocker(wxCriticalSection& critsect) : m_critsect(critsect)
+        { m_critsect.Enter(); }
+    ~wxCriticalSectionLocker()
+        { m_critsect.Leave(); }
+
+private:
+    // no assignment operator nor copy ctor
+    wxCriticalSectionLocker(const wxCriticalSectionLocker&);
+    wxCriticalSectionLocker& operator=(const wxCriticalSectionLocker&);
+
+    wxCriticalSection& m_critsect;

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


@@ -88,7 +193,7 @@ protected:
 // ----------------------------------------------------------------------------
 
 class wxConditionInternal;
 // ----------------------------------------------------------------------------
 
 class wxConditionInternal;

-class WXDLLEXPORT wxCondition 
+class WXDLLEXPORT wxCondition

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


@@ -112,86 +217,184 @@ private:
 // Thread management class
 // ----------------------------------------------------------------------------
 
 // Thread management class
 // ----------------------------------------------------------------------------
 

+// FIXME Thread termination model is still unclear. Delete() should probably
+//       have a timeout after which the thread must be Kill()ed.
+
+// NB: in the function descriptions the words "this thread" mean the 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 wxThreadInternal;

-class WXDLLEXPORT wxThread 
+class WXDLLEXPORT wxThread

 {
 public:
 {
 public:

-  // constructor & destructor.
-  wxThread();
-  virtual ~wxThread();
-
-  // Create a new thread, this method should check there is only one thread
-  // running by object.
-  wxThreadError Create();
-
-  // Destroys the thread immediately if the defer flag isn't true.
-  wxThreadError Destroy();
+    // the return type for the thread function
+    typedef void *ExitCode;
+
+    // static functions
+        // Returns the wxThread object for the calling thread. NULL is returned
+        // if the caller is the main thread (but it's recommended to use
+        // IsMain() and only call This() for threads other than the main one
+        // because NULL is also returned on error). If the thread wasn't
+        // created with wxThread class, the returned value is undefined.
+    static wxThread *This();
+
+        // Returns true if current thread is the main thread.
+    static bool IsMain();
+
+        // Release the rest of our time slice leting the other threads run
+    static void Yield();
+
+        // Sleep during the specified period of time in milliseconds
+        //
+        // NB: at least under MSW worker threads can not call ::wxSleep()!
+    static void Sleep(unsigned long milliseconds);
+
+    // default constructor
+    wxThread();
+
+    // function that change the thread state
+        // create a new thread - call Run() to start it
+    wxThreadError Create();
+
+        // starts execution of the thread - from the moment Run() is called the
+        // execution of wxThread::Entry() may start at any moment, caller
+        // shouldn't suppose that it starts after (or before) Run() returns.
+    wxThreadError Run();
+
+        // stops the thread if it's running and deletes the wxThread object
+        // freeing its memory. This function should also be called if the
+        // Create() or Run() fails to free memory (otherwise it will be done by
+        // the thread itself when it terminates). The return value is the
+        // thread exit code if the thread was gracefully terminated, 0 if it
+        // wasn't running and -1 if an error occured.
+    ExitCode Delete();
+
+        // 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! The wxThread object is deleted by Kill() if thread was
+        // killed (i.e. no errors occured).
+    wxThreadError Kill();
+
+        // pause a running thread
+    wxThreadError Pause();
+
+        // resume a paused thread
+    wxThreadError Resume();
+
+    // priority
+        // Sets the priority to "prio": see WXTHREAD_XXX_PRIORITY constants
+        //
+        // NB: the priority can only be set before the thread is created
+    void SetPriority(unsigned int prio);
+
+        // Get the current priority.
+    unsigned int GetPriority() const;
+
+    // Get the thread ID - a platform dependent number which uniquely
+    // identifies a thread inside a process
+    unsigned long GetID() const;
+
+    // thread status inquiries
+        // Returns true if the thread is alive: i.e. running or suspended
+    bool IsAlive() const;
+        // Returns true if the thread is running (not paused, not killed).
+    bool IsRunning() const;
+        // Returns true if the thread is suspended
+    bool IsPaused() const { return IsAlive() && !IsRunning(); }
+
+    // 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() { }

 
 

-  // Pause a running thread
-  wxThreadError Pause();
+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();

 
 

-  // Resume a paused thread
-  wxThreadError Resume();
+    // exits from the current thread - can be called only from this thread
+    void Exit(void *exitcode = 0);

 
 

-  // Switches on the defer flag.
-  void DeferDestroy(bool on);
+    // destructor is private - user code can't delete thread objects, they will
+    // auto-delete themselves (and thus must be always allocated on the heap).
+    // Use Delete() or Kill() instead.
+    //
+    // NB: derived classes dtors shouldn't be public neither!
+    virtual ~wxThread();

 
 

-  // Waits for the termination of the thread.
-  void *Join();
+    // entry point for the thread - called by Run() and executes in the context
+    // of this thread.
+    virtual void *Entry() = 0;

 
 

-  // Sets the priority to "prio". (Warning: The priority can only be set before
-  // the thread is created)
-  void SetPriority(int prio);
-  // Get the current priority.
-  int GetPriority() const;
+private:
+    // no copy ctor/assignment operator
+    wxThread(const wxThread&);
+    wxThread& operator=(const wxThread&);

 
 

-  // Get the thread ID
-  unsigned long GetID() const;
+    friend class wxThreadInternal;

 
 

-  // Returns true if the thread is alive.
-  bool IsAlive() const;
-  // Returns true if the thread is running (not paused, not killed).
-  bool IsRunning() const;
-  // Returns true if the thread is suspended
-  bool IsPaused() const { return IsAlive() && !IsRunning(); }
+    // the (platform-dependent) thread class implementation
+    wxThreadInternal *p_internal;

 
 

-  // Returns true if the thread is the main thread (aka the GUI thread).
-  static bool IsMain();
+    // protects access to any methods of wxThreadInternal object
+    wxCriticalSection m_critsect;
+};

 
 

-  // Called when thread exits.
-  virtual void OnExit();
+// ----------------------------------------------------------------------------
+// Automatic initialization
+// ----------------------------------------------------------------------------

 
 

-protected:
-  // In case, the DIFFER flag is true, enables another thread to kill this one.
-  void TestDestroy();
-  // Exits from the current thread.
-  void Exit(void *status = NULL);
+// GUI mutex handling.
+void WXDLLEXPORT wxMutexGuiEnter();
+void WXDLLEXPORT wxMutexGuiLeave();

 
 

-private:
-  // Entry point for the thread.
-  virtual void *Entry() = 0;
+#else // !wxUSE_THREADS

 
 

-private:
-  friend class wxThreadInternal;
+#include <wx/defs.h> // for WXDLLEXPORT

 
 

-  wxThreadInternal *p_internal;
-};
+// no thread support
+inline void WXDLLEXPORT wxMutexGuiEnter() { }
+inline void WXDLLEXPORT wxMutexGuiLeave() { }

 
 

-// ----------------------------------------------------------------------------
-// Automatic initialization
-// ----------------------------------------------------------------------------
+#endif // wxUSE_THREADS

 
 

-class wxThreadModule : public wxModule 
+// automatically unlock GUI mutex in dtor
+class WXDLLEXPORT wxMutexGuiLocker

 {
 {

-  DECLARE_DYNAMIC_CLASS(wxThreadModule)
-  

 public:
 public:

-  wxThreadModule() {}
-
-  virtual bool OnInit();
-  virtual void OnExit();
+    wxMutexGuiLocker() { wxMutexGuiEnter(); }
+   ~wxMutexGuiLocker() { wxMutexGuiLeave(); }

 };
 
 };
 

-
+// -----------------------------------------------------------------------------
+// implementation only until the end of file
+// -----------------------------------------------------------------------------
+#if wxUSE_THREADS
+#ifdef __WXMSW__
+    // 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();
+
+    // 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();
+#else // !MSW
+    // 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
+#endif // wxUSE_THREADS

 
 #endif // __THREADH__
 
 #endif // __THREADH__