X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/d1bab566475b6573c1c0c982eec395c6d8eef13a..21d0340384a484e3c8e04280de90c0fb8e261006:/include/wx/thread.h diff --git a/include/wx/thread.h b/include/wx/thread.h index b3cc0a45f0..6806d82fea 100644 --- a/include/wx/thread.h +++ b/include/wx/thread.h @@ -5,7 +5,6 @@ // 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 // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// @@ -22,16 +21,6 @@ #if wxUSE_THREADS -// only for wxUSE_THREADS - otherwise we'd get undefined symbols -#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA) - #pragma interface "thread.h" -#endif - -// Windows headers define it -#ifdef Yield - #undef Yield -#endif - // ---------------------------------------------------------------------------- // constants // ---------------------------------------------------------------------------- @@ -43,6 +32,7 @@ enum wxMutexError 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_TIMEOUT, // LockTimeout() has timed out wxMUTEX_MISC_ERROR // any other error }; @@ -80,12 +70,27 @@ enum wxThreadKind wxTHREAD_JOINABLE }; -// defines the interval of priority +enum wxThreadWait +{ + wxTHREAD_WAIT_BLOCK, + wxTHREAD_WAIT_YIELD, // process events while waiting; MSW only + + // For compatibility reasons we use wxTHREAD_WAIT_YIELD by default as this + // was the default behaviour of wxMSW 2.8 but it should be avoided as it's + // dangerous and not portable. +#if WXWIN_COMPATIBILITY_2_8 + wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_YIELD +#else + wxTHREAD_WAIT_DEFAULT = wxTHREAD_WAIT_BLOCK +#endif +}; + +// Obsolete synonyms for wxPRIORITY_XXX for backwards compatibility-only enum { - WXTHREAD_MIN_PRIORITY = 0u, - WXTHREAD_DEFAULT_PRIORITY = 50u, - WXTHREAD_MAX_PRIORITY = 100u + WXTHREAD_MIN_PRIORITY = wxPRIORITY_MIN, + WXTHREAD_DEFAULT_PRIORITY = wxPRIORITY_DEFAULT, + WXTHREAD_MAX_PRIORITY = wxPRIORITY_MAX }; // There are 2 types of mutexes: normal mutexes and recursive ones. The attempt @@ -114,11 +119,11 @@ enum wxMutexType }; // forward declarations -class WXDLLIMPEXP_BASE wxThreadHelper; -class WXDLLIMPEXP_BASE wxConditionInternal; -class WXDLLIMPEXP_BASE wxMutexInternal; -class WXDLLIMPEXP_BASE wxSemaphoreInternal; -class WXDLLIMPEXP_BASE wxThreadInternal; +class WXDLLIMPEXP_FWD_BASE wxThreadHelper; +class WXDLLIMPEXP_FWD_BASE wxConditionInternal; +class WXDLLIMPEXP_FWD_BASE wxMutexInternal; +class WXDLLIMPEXP_FWD_BASE wxSemaphoreInternal; +class WXDLLIMPEXP_FWD_BASE wxThreadInternal; // ---------------------------------------------------------------------------- // A mutex object is a synchronization object whose state is set to signaled @@ -154,6 +159,10 @@ public: // The caller must call Unlock() later if Lock() returned wxMUTEX_NO_ERROR. wxMutexError Lock(); + // Same as Lock() but return wxMUTEX_TIMEOUT if the mutex can't be locked + // during the given number of milliseconds + wxMutexError LockTimeout(unsigned long ms); + // Try to lock the mutex: if it is currently locked, return immediately // with an error. Otherwise the caller must call Unlock(). wxMutexError TryLock(); @@ -166,7 +175,7 @@ protected: friend class wxConditionInternal; - DECLARE_NO_COPY_CLASS(wxMutex) + wxDECLARE_NO_COPY_CLASS(wxMutex); }; // a helper class which locks the mutex in the ctor and unlocks it in the dtor: @@ -177,10 +186,10 @@ class WXDLLIMPEXP_BASE wxMutexLocker public: // lock the mutex in the ctor wxMutexLocker(wxMutex& mutex) - : m_isOk(FALSE), m_mutex(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; } @@ -209,35 +218,46 @@ private: // in order to avoid any overhead under platforms where critical sections are // just mutexes make all wxCriticalSection class functions inline -#if !defined(__WXMSW__) +#if !defined(__WINDOWS__) #define wxCRITSECT_IS_MUTEX 1 - #define wxCRITSECT_INLINE inline + #define wxCRITSECT_INLINE WXEXPORT inline #else // MSW #define wxCRITSECT_IS_MUTEX 0 #define wxCRITSECT_INLINE #endif // MSW/!MSW +enum wxCriticalSectionType +{ + // recursive critical section + wxCRITSEC_DEFAULT, + + // non-recursive critical section + wxCRITSEC_NON_RECURSIVE +}; + // you should consider wxCriticalSectionLocker whenever possible instead of // directly working with wxCriticalSection class - it is safer class WXDLLIMPEXP_BASE wxCriticalSection { public: // ctor & dtor - wxCRITSECT_INLINE wxCriticalSection(); + wxCRITSECT_INLINE wxCriticalSection( wxCriticalSectionType critSecType = wxCRITSEC_DEFAULT ); wxCRITSECT_INLINE ~wxCriticalSection(); - // enter the section (the same as locking a mutex) wxCRITSECT_INLINE void Enter(); + // try to enter the section (the same as trying to lock a mutex) + wxCRITSECT_INLINE bool TryEnter(); + // leave the critical section (same as unlocking a mutex) wxCRITSECT_INLINE void Leave(); private: #if wxCRITSECT_IS_MUTEX wxMutex m_mutex; -#elif defined(__WXMSW__) +#elif defined(__WINDOWS__) // 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 and we also have to use the @@ -245,11 +265,11 @@ private: // // 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; @@ -259,15 +279,17 @@ private: }; #endif // Unix&OS2/Win32 - DECLARE_NO_COPY_CLASS(wxCriticalSection) + wxDECLARE_NO_COPY_CLASS(wxCriticalSection); }; #if wxCRITSECT_IS_MUTEX // implement wxCriticalSection using mutexes - inline wxCriticalSection::wxCriticalSection() { } + inline wxCriticalSection::wxCriticalSection( wxCriticalSectionType critSecType ) + : m_mutex( critSecType == wxCRITSEC_DEFAULT ? wxMUTEX_RECURSIVE : wxMUTEX_DEFAULT ) { } inline wxCriticalSection::~wxCriticalSection() { } inline void wxCriticalSection::Enter() { (void)m_mutex.Lock(); } + inline bool wxCriticalSection::TryEnter() { return m_mutex.TryLock() == wxMUTEX_NO_ERROR; } inline void wxCriticalSection::Leave() { (void)m_mutex.Unlock(); } #endif // wxCRITSECT_IS_MUTEX @@ -275,7 +297,7 @@ private: #undef wxCRITSECT_IS_MUTEX // wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is -// to th mutexes +// to mutexes class WXDLLIMPEXP_BASE wxCriticalSectionLocker { public: @@ -293,7 +315,7 @@ public: private: wxCriticalSection& m_critsect; - DECLARE_NO_COPY_CLASS(wxCriticalSectionLocker) + wxDECLARE_NO_COPY_CLASS(wxCriticalSectionLocker); }; // ---------------------------------------------------------------------------- @@ -311,31 +333,44 @@ public: // dtor is not virtual, don't use this class polymorphically ~wxCondition(); - // return TRUE if the condition has been created successfully + // 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(); + // std::condition_variable-like variant that evaluates the associated condition + template + wxCondError Wait(const Functor& predicate) + { + while ( !predicate() ) + { + wxCondError e = Wait(); + if ( e != wxCOND_NO_ERROR ) + return e; + } + return wxCOND_NO_ERROR; + } + // 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 + // timeout elapses even if the condition hasn't been signalled: in this + // case, the return value is wxCOND_TIMEOUT, otherwise (i.e. in case of a + // normal return) it is wxCOND_NO_ERROR. + // + // 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 + // The thread which was blocking on Wait() will then reacquire the lock // on the associated mutex object before returning wxCondError Signal(); @@ -343,21 +378,27 @@ public: // // 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 + // The threads which were blocking on Wait() will then reacquire the lock // on the associated mutex object before returning. wxCondError Broadcast(); +#if WXWIN_COMPATIBILITY_2_6 // deprecated version, don't use - bool Wait(unsigned long milliseconds) - { return WaitTimeout(milliseconds) == wxCOND_NO_ERROR; } + wxDEPRECATED( bool Wait(unsigned long milliseconds) ); +#endif // WXWIN_COMPATIBILITY_2_6 private: wxConditionInternal *m_internal; - DECLARE_NO_COPY_CLASS(wxCondition) + wxDECLARE_NO_COPY_CLASS(wxCondition); }; +#if WXWIN_COMPATIBILITY_2_6 + inline bool wxCondition::Wait(unsigned long milliseconds) + { return WaitTimeout(milliseconds) == wxCOND_NO_ERROR; } +#endif // WXWIN_COMPATIBILITY_2_6 + // ---------------------------------------------------------------------------- // wxSemaphore: a counter limiting the number of threads concurrently accessing // a shared resource @@ -373,7 +414,7 @@ public: // dtor is not virtual, don't use this class polymorphically ~wxSemaphore(); - // return TRUE if the semaphore has been created successfully + // return true if the semaphore has been created successfully bool IsOk() const; // wait indefinitely, until the semaphore count goes beyond 0 @@ -386,7 +427,7 @@ public: 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 ellapsed + // 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 @@ -395,11 +436,11 @@ public: private: wxSemaphoreInternal *m_internal; - DECLARE_NO_COPY_CLASS(wxSemaphore) + wxDECLARE_NO_COPY_CLASS(wxSemaphore); }; // ---------------------------------------------------------------------------- -// wxThread: class encpasulating a thread of execution +// wxThread: class encapsulating a thread of execution // ---------------------------------------------------------------------------- // there are two different kinds of threads: joinable and detached (default) @@ -433,14 +474,24 @@ public: static wxThread *This(); // Returns true if current thread is the main thread. - static bool IsMain(); + // + // Notice that it also returns true if main thread id hadn't been + // initialized yet on the assumption that it's too early in wx startup + // process for any other threads to have been created in this case. + static bool IsMain() + { + return !ms_idMainThread || GetCurrentId() == ms_idMainThread; + } - // Release the rest of our time slice leting the other threads run + // Return the main thread id + static wxThreadIdType GetMainId() { return ms_idMainThread; } + + // Release the rest of our time slice letting 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()! + // This is the same as wxMilliSleep(). static void Sleep(unsigned long milliseconds); // get the number of system CPUs - useful with SetConcurrency() @@ -452,14 +503,14 @@ public: // 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(); + 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 + // Returns true on success, false otherwise (if not implemented, for // example) static bool SetConcurrency(size_t level); @@ -492,18 +543,19 @@ public: // does it! // // will fill the rc pointer with the thread exit code if it's !NULL - wxThreadError Delete(ExitCode *rc = (ExitCode *)NULL); + wxThreadError Delete(ExitCode *rc = NULL, + wxThreadWait waitMode = wxTHREAD_WAIT_DEFAULT); // waits for a joinable thread to finish and returns its exit code // // Returns (ExitCode)-1 on error (for example, if the thread is not // joinable) - ExitCode Wait(); + ExitCode Wait(wxThreadWait waitMode = wxTHREAD_WAIT_DEFAULT); // 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 @@ -518,7 +570,8 @@ public: wxThreadError Resume(); // priority - // Sets the priority to "prio": see WXTHREAD_XXX_PRIORITY constants + // Sets the priority to "prio" which must be in 0..100 range (see + // also wxPRIORITY_XXX constants). // // NB: the priority can only be set before the thread is created void SetPriority(unsigned int prio); @@ -541,21 +594,19 @@ public: // identifies a thread inside a process 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() { } + wxThreadKind GetKind() const + { return m_isDetached ? wxTHREAD_DETACHED : wxTHREAD_JOINABLE; } + + // 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: - // 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); @@ -563,12 +614,37 @@ protected: // of this thread. virtual void *Entry() = 0; + // use this to call the Entry() virtual method + void *CallEntry(); + + // Callbacks which may be overridden by the derived class to perform some + // specific actions when the thread is deleted or killed. By default they + // do nothing. + + // This one is called by Delete() before actually deleting the thread and + // is executed in the context of the thread that called Delete(). + virtual void OnDelete() {} + + // This one is called by Kill() before killing the thread and is executed + // in the context of the thread that called Kill(). + virtual void OnKill() {} + private: // no copy ctor/assignment operator wxThread(const wxThread&); wxThread& operator=(const wxThread&); + // 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() { } + friend class wxThreadInternal; + friend class wxThreadModule; + + + // the main thread identifier, should be set on startup + static wxThreadIdType ms_idMainThread; // the (platform-dependent) thread class implementation wxThreadInternal *m_internal; @@ -588,8 +664,8 @@ 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) + wxThreadHelperThread(wxThreadHelper& owner, wxThreadKind kind) + : wxThread(kind), m_owner(owner) { } protected: @@ -616,27 +692,44 @@ class WXDLLIMPEXP_BASE wxThreadHelper private: void KillThread() { + // If wxThreadHelperThread is detached and is about to finish, it will + // set m_thread to NULL so don't delete it then. + // But if KillThread is called before wxThreadHelperThread (in detached mode) + // sets it to NULL, then the thread object still exists and can be killed + wxCriticalSectionLocker locker(m_critSection); + if ( m_thread ) { m_thread->Kill(); - delete m_thread; + + if ( m_kind == wxTHREAD_JOINABLE ) + delete m_thread; + + m_thread = NULL; } } public: // constructor only initializes m_thread to NULL - wxThreadHelper() : m_thread(NULL) { } + wxThreadHelper(wxThreadKind kind = wxTHREAD_JOINABLE) + : m_thread(NULL), m_kind(kind) { } // destructor deletes m_thread virtual ~wxThreadHelper() { KillThread(); } +#if WXWIN_COMPATIBILITY_2_8 + wxDEPRECATED( wxThreadError Create(unsigned int stackSize = 0) ); +#endif + // 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) + wxThreadError CreateThread(wxThreadKind kind = wxTHREAD_JOINABLE, + unsigned int stackSize = 0) { KillThread(); - m_thread = new wxThreadHelperThread(*this); + m_kind = kind; + m_thread = new wxThreadHelperThread(*this, m_kind); return m_thread->Create(stackSize); } @@ -646,16 +739,43 @@ public: virtual void *Entry() = 0; // returns a pointer to the thread which can be used to call Run() - wxThread *GetThread() const { return m_thread; } + wxThread *GetThread() const + { + wxCriticalSectionLocker locker((wxCriticalSection&)m_critSection); + + wxThread* thread = m_thread; + + return thread; + } protected: wxThread *m_thread; + wxThreadKind m_kind; + wxCriticalSection m_critSection; // To guard the m_thread variable + + friend class wxThreadHelperThread; }; +#if WXWIN_COMPATIBILITY_2_8 +inline wxThreadError wxThreadHelper::Create(unsigned int stackSize) +{ return CreateThread(m_kind, stackSize); } +#endif + // call Entry() in owner, put it down here to avoid circular declarations inline void *wxThreadHelperThread::Entry() { - return m_owner.Entry(); + void * const result = m_owner.Entry(); + + wxCriticalSectionLocker locker(m_owner.m_critSection); + + // Detached thread will be deleted after returning, so make sure + // wxThreadHelper::GetThread will not return an invalid pointer. + // And that wxThreadHelper::KillThread will not try to kill + // an already deleted thread + if ( m_owner.m_kind == wxTHREAD_DETACHED ) + m_owner.m_thread = NULL; + + return result; } // ---------------------------------------------------------------------------- @@ -681,16 +801,19 @@ inline bool wxIsMainThread() { return wxThread::IsMain(); } #else // !wxUSE_THREADS // no thread support -inline void WXDLLIMPEXP_BASE wxMutexGuiEnter() { } -inline void WXDLLIMPEXP_BASE wxMutexGuiLeave() { } +inline void wxMutexGuiEnter() { } +inline void 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) -#define wxCRIT_SECT_DECLARE(cs) -#define wxCRIT_SECT_DECLARE_MEMBER(cs) -#define wxCRIT_SECT_LOCKER(name, cs) +// (the implementation uses dummy structs to force semicolon after the macro; +// also notice that Watcom doesn't like declaring a struct as a member so we +// need to actually define it in wxCRIT_SECT_DECLARE_MEMBER) +#define wxENTER_CRIT_SECT(cs) do {} while (0) +#define wxLEAVE_CRIT_SECT(cs) do {} while (0) +#define wxCRIT_SECT_DECLARE(cs) struct wxDummyCS##cs +#define wxCRIT_SECT_DECLARE_MEMBER(cs) struct wxDummyCSMember##cs { } +#define wxCRIT_SECT_LOCKER(name, cs) struct wxDummyCSLocker##name // if there is only one thread, it is always the main one inline bool wxIsMainThread() { return true; } @@ -732,26 +855,25 @@ public: #if wxUSE_THREADS -#if defined(__WXMSW__) || defined(__WXMAC__) || defined(__WXPM__) +#if defined(__WINDOWS__) || defined(__OS2__) || defined(__EMX__) || defined(__DARWIN__) // 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 WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter(); - // returns TRUE if the main thread has GUI lock + // returns true if the main thread has GUI lock extern bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread(); -#ifndef __WXPM__ // wakes up the main thread if it's sleeping inside ::GetMessage() extern void WXDLLIMPEXP_BASE wxWakeUpMainThread(); -#endif // !OS/2 - // return TRUE if the main thread is waiting for some other to terminate: +#ifndef __DARWIN__ + // return true if the main thread is waiting for some other to terminate: // wxApp then should block all "dangerous" messages extern bool WXDLLIMPEXP_BASE wxIsWaitingForThread(); -#endif // MSW, Mac, OS/2 +#endif +#endif // MSW, OS/2 #endif // wxUSE_THREADS #endif // _WX_THREAD_H_ -