// 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
#define __THREADH__
#ifdef __GNUG__
-#pragma interface "thread.h"
+ #pragma interface "thread.h"
#endif
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
+
+// get the value of wxUSE_THREADS configuration flag
#include "wx/setup.h"
#if wxUSE_THREADS
+
+// Windows headers define it
+#ifdef Yield
+ #undef Yield
+#endif
+
#include "wx/module.h"
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
-typedef enum
+typedef enum
{
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;
-typedef enum
+typedef enum
{
wxTHREAD_NO_ERROR = 0, // No error
wxTHREAD_NO_RESOURCE, // No resource left to create a new thread
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
// ----------------------------------------------------------------------------
// A mutex object is a synchronization object whose state is set to signaled
// you should consider wxMutexLocker whenever possible instead of directly
// working with wxMutex class - it is safer
class WXDLLEXPORT wxMutexInternal;
-class WXDLLEXPORT wxMutex
+class WXDLLEXPORT wxMutex
{
public:
- // constructor & destructor
+ // constructor & destructor
wxMutex();
~wxMutex();
{
public:
// lock the mutex in the ctor
- wxMutexLocker(wxMutex *mutex)
- { m_isOk = mutex && ((m_mutex = mutex)->Lock() == wxMUTEX_NO_ERROR); }
+ 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; }
+ bool IsOk() const
+ { return m_isOk; }
// unlock the mutex in dtor
- ~wxMutexLocker() { if ( IsOk() ) m_mutex->Unlock(); }
+ ~wxMutexLocker()
+ { if ( IsOk() ) m_mutex.Unlock(); }
private:
// no assignment operator nor copy ctor
wxMutexLocker& operator=(const wxMutexLocker&);
bool m_isOk;
- wxMutex *m_mutex;
+ wxMutex& m_mutex;
};
// ----------------------------------------------------------------------------
// mutexes
// ----------------------------------------------------------------------------
-// you should consider wxCriticalSectionLocker whenever possible instead of
-// directly working with wxCriticalSection class - it is safer
+// 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:
#endif // MSW/!MSW
};
+// keep your preprocessor name space clean
+#undef WXCRITICAL_INLINE
+
// wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is
// to th mutexes
class WXDLLEXPORT wxCriticalSectionLocker
// ----------------------------------------------------------------------------
class wxConditionInternal;
-class WXDLLEXPORT wxCondition
+class WXDLLEXPORT wxCondition
{
public:
// constructor & destructor
// 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 WXDLLEXPORT wxThread
+class WXDLLEXPORT wxThread
{
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();
-
- // Resume a paused thread
- wxThreadError Resume();
-
- // Switches on the defer flag.
- void DeferDestroy(bool on);
-
- // Waits for the termination of the thread.
- void *Join();
-
- // 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;
-
- // Get the thread ID
- unsigned long GetID() const;
-
- // 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(); }
-
- // Returns true if current thread is the main thread (aka the GUI thread)
- static bool IsMain();
+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();
- // Called when thread exits.
- virtual void OnExit();
+ // exits from the current thread - can be called only from this thread
+ void Exit(void *exitcode = 0);
-protected:
- // Returns TRUE if the thread was asked to terminate
- bool TestDestroy();
+ // 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();
- // Exits from the current thread.
- void Exit(void *status = NULL);
+ // entry point for the thread - called by Run() and executes in the context
+ // of this thread.
+ virtual void *Entry() = 0;
private:
- // Entry point for the thread.
- virtual void *Entry() = 0;
+ // no copy ctor/assignment operator
+ wxThread(const wxThread&);
+ wxThread& operator=(const wxThread&);
-private:
- friend class wxThreadInternal;
+ friend class wxThreadInternal;
- wxThreadInternal *p_internal;
+ // the (platform-dependent) thread class implementation
+ wxThreadInternal *p_internal;
+
+ // protects access to any methods of wxThreadInternal object
+ wxCriticalSection m_critsect;
};
// ----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// implementation only until the end of file
// -----------------------------------------------------------------------------
-#ifdef wxUSE_THREADS
+#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
// 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() { }
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