X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/c2dd8380badebac8dc01f8948288235ae91056ed..a7689c49fe02c0c065facf736ab28b19f5997b7c:/include/wx/thread.h diff --git a/include/wx/thread.h b/include/wx/thread.h index 9700b4ddfd..1cc9857b65 100644 --- a/include/wx/thread.h +++ b/include/wx/thread.h @@ -1,158 +1,864 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: thread.h +// Name: wx/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 // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// -#ifndef __THREADH__ -#define __THREADH__ +#ifndef _WX_THREAD_H_ +#define _WX_THREAD_H_ -#ifdef __GNUG__ -#pragma interface "thread.h" +// ---------------------------------------------------------------------------- +// headers +// ---------------------------------------------------------------------------- + +// get the value of wxUSE_THREADS configuration flag +#include "wx/defs.h" + +#if wxUSE_THREADS + +// ---------------------------------------------------------------------------- +// constants +// ---------------------------------------------------------------------------- + +enum wxMutexError +{ + 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_TIMEOUT, // LockTimeout() has timed out + 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 +{ + 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 +{ + wxTHREAD_DETACHED, + wxTHREAD_JOINABLE +}; + +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 +}; + +// defines the interval of priority +enum +{ + WXTHREAD_MIN_PRIORITY = 0u, + WXTHREAD_DEFAULT_PRIORITY = 50u, + 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_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 +// 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. +// ---------------------------------------------------------------------------- -#include "wx/object.h" -#include "wx/setup.h" - -typedef enum { - MUTEX_NO_ERROR=0, - MUTEX_DEAD_LOCK, // Mutex has been already locked by THE CALLING thread - MUTEX_BUSY, // Mutex has been already locked by ONE thread - MUTEX_UNLOCKED -} wxMutexError; - -typedef enum { - THREAD_NO_ERROR=0, // No error - THREAD_NO_RESOURCE, // No resource left to create a new thread - THREAD_RUNNING, // The thread is already running - THREAD_NOT_RUNNING, // The thread isn't running - THREAD_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 - -// --------------------------------------------------------------------------- -// Mutex handler -class WXDLLEXPORT wxMutexInternal; -class WXDLLEXPORT wxMutex { +// you should consider wxMutexLocker whenever possible instead of directly +// working with wxMutex class - it is safer +class WXDLLIMPEXP_BASE 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); } + // constructor & destructor + // ------------------------ + + // create either default (always safe) or recursive mutex + wxMutex(wxMutexType mutexType = wxMUTEX_DEFAULT); + + // destroys the mutex kernel object + ~wxMutex(); + + // 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(); + + // 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(); + + // Unlock the mutex. It is an error to unlock an already unlocked mutex + wxMutexError Unlock(); + protected: - friend class wxCondition; + wxMutexInternal *m_internal; + + friend class wxConditionInternal; + + wxDECLARE_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 +class WXDLLIMPEXP_BASE wxMutexLocker +{ +public: + // lock the mutex in the ctor + 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 + 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; +}; + +// ---------------------------------------------------------------------------- +// 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. +// +// NB: wxCriticalSection object does not allocate any memory in its ctor +// which makes it possible to have static globals of this class +// ---------------------------------------------------------------------------- + +// in order to avoid any overhead under platforms where critical sections are +// just mutexes make all wxCriticalSection class functions inline +#if !defined(__WINDOWS__) + #define wxCRITSECT_IS_MUTEX 1 - int m_locked; - wxMutexInternal *p_internal; + #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 }; -// --------------------------------------------------------------------------- -// Condition handler. -class wxConditionInternal; -class WXDLLEXPORT wxCondition { +// you should consider wxCriticalSectionLocker whenever possible instead of +// directly working with wxCriticalSection class - it is safer +class WXDLLIMPEXP_BASE wxCriticalSection +{ 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(); + // ctor & dtor + 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: - wxConditionInternal *p_internal; +#if wxCRITSECT_IS_MUTEX + wxMutex m_mutex; +#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 + // 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 +#ifdef __WIN64__ + typedef char wxCritSectBuffer[40]; +#else // __WIN32__ + typedef char wxCritSectBuffer[24]; +#endif + union + { + unsigned long m_dummy1; + void *m_dummy2; + + wxCritSectBuffer m_buffer; + }; +#endif // Unix&OS2/Win32 + + wxDECLARE_NO_COPY_CLASS(wxCriticalSection); }; -// --------------------------------------------------------------------------- -// Thread management class -class wxThreadInternal; -class WXDLLEXPORT wxThread { +#if wxCRITSECT_IS_MUTEX + // implement wxCriticalSection using mutexes + 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 + +#undef wxCRITSECT_INLINE +#undef wxCRITSECT_IS_MUTEX + +// wxCriticalSectionLocker is the same to critical sections as wxMutexLocker is +// to mutexes +class WXDLLIMPEXP_BASE wxCriticalSectionLocker +{ public: - // constructor & destructor. - wxThread(); - virtual ~wxThread(); + wxCriticalSectionLocker(wxCriticalSection& cs) + : m_critsect(cs) + { + m_critsect.Enter(); + } - // Create a new thread, this method should check there is only one thread - // running by object. - wxThreadError Create(); + ~wxCriticalSectionLocker() + { + m_critsect.Leave(); + } - // Destroys the thread immediately if the defer flag isn't true. - wxThreadError Destroy(); +private: + wxCriticalSection& m_critsect; + + wxDECLARE_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); - // Pause a running thread - wxThreadError Pause(); + // dtor is not virtual, don't use this class polymorphically + ~wxCondition(); - // Resume a paused thread - wxThreadError Resume(); + // return true if the condition has been created successfully + bool IsOk() const; - // Switches on the defer flag. - void DeferDestroy(bool on); + // 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(); - // Waits for the termination of the thread. - void *Join(); + // 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); - // 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; + // 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(); + + +#if WXWIN_COMPATIBILITY_2_6 + // deprecated version, don't use + wxDEPRECATED( bool Wait(unsigned long milliseconds) ); +#endif // WXWIN_COMPATIBILITY_2_6 + +private: + wxConditionInternal *m_internal; - // Get the thread ID - unsigned long GetID() const; + 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 +// ---------------------------------------------------------------------------- + +class WXDLLIMPEXP_BASE 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(); + + // 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: + wxSemaphoreInternal *m_internal; + + wxDECLARE_NO_COPY_CLASS(wxSemaphore); +}; + +// ---------------------------------------------------------------------------- +// wxThread: class encapsulating a thread of execution +// ---------------------------------------------------------------------------- + +// there are two different kinds of threads: joinable and detached (default) +// ones. Only joinable threads can return a return code and only detached +// threads auto-delete themselves - the user should delete the joinable +// threads manually. + +// 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) + +// 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 + typedef void *ExitCode; - // 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 the main thread (aka the GUI thread). - static bool IsMain(); + // 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(); - // Called when thread exits. - virtual void OnExit(); + // Returns true if current thread is the main thread. + // + // 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; + } + + // 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 + // + // This is the same as wxMilliSleep(). + 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); + + // functions that change the thread state: all these can only be called + // from _another_ thread (typically the thread that created this one, e.g. + // the main thread), not from the thread itself + + // 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 + // 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 if + // this is a detached thread freeing its memory - otherwise (for + // joinable threads) you still need to delete wxThread object + // yourself. + // + // this function only works if the thread calls TestDestroy() + // periodically - the thread will only be deleted the next time it + // does it! + // + // will fill the rc pointer with the thread exit code if it's !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(wxThreadWait waitMode = wxTHREAD_WAIT_DEFAULT); + + // kills the thread without giving it any chance to clean up - should + // 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 + // threads. + wxThreadError Kill(); + + // pause a running thread: as Delete(), this only works if the thread + // calls TestDestroy() regularly + 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; + + // 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; + + // is the thread of detached kind? + bool IsDetached() const { return m_isDetached; } + + // Get the thread ID - a platform dependent number which uniquely + // identifies a thread inside a process + wxThreadIdType GetId() const; + + 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(); - // Returns the wxThread object which corresponds to the ID. - static wxThread *GetThreadFromID(unsigned long id); 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); + // exits from the current thread - can be called only from this thread + void Exit(ExitCode exitcode = 0); + + // entry point for the thread - called by Run() and executes in the context + // of this thread. + virtual void *Entry() = 0; + + + // 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: - // Entry point for the thread. - virtual void *Entry() = 0; + // 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; + + // protects access to any methods of wxThreadInternal object + wxCriticalSection m_critsect; + + // true if the thread is detached, false if it is joinable + 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, wxThreadKind kind) + : wxThread(kind), m_owner(owner) + { } + +protected: + // entry point for the thread -- calls Entry() in owner. + virtual void *Entry(); private: - friend class wxThreadInternal; + // the owner of the thread + wxThreadHelper& m_owner; - wxThreadInternal *p_internal; + // no copy ctor/assignment operator + wxThreadHelperThread(const wxThreadHelperThread&); + wxThreadHelperThread& operator=(const wxThreadHelperThread&); }; -// --------------------------------------------------------------------------- -// Global variables +// ---------------------------------------------------------------------------- +// 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 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); -// GUI mutex. -WXDLLEXPORT_DATA(extern wxMutex) wxMainMutex; + if ( m_thread ) + { + m_thread->Kill(); + if ( m_kind == wxTHREAD_JOINABLE ) + delete m_thread; + + m_thread = NULL; + } + } + +public: + // constructor only initializes m_thread to 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 CreateThread(wxThreadKind kind = wxTHREAD_JOINABLE, + unsigned int stackSize = 0) + { + KillThread(); + + m_kind = kind; + m_thread = new wxThreadHelperThread(*this, m_kind); + + 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 + { + 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() +{ + 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; +} + +// ---------------------------------------------------------------------------- +// Automatic initialization +// ---------------------------------------------------------------------------- + +// GUI mutex handling. +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() +#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) + +// 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(); } + +#else // !wxUSE_THREADS + +// no thread support +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" +// (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; } + +#endif // wxUSE_THREADS/!wxUSE_THREADS + +// 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(); } + ~wxMutexGuiLocker() { wxMutexGuiLeave(); } +}; + +// ----------------------------------------------------------------------------- +// implementation only until the end of file +// ----------------------------------------------------------------------------- + +#if wxUSE_THREADS + +#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 + extern bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread(); + + // wakes up the main thread if it's sleeping inside ::GetMessage() + extern void WXDLLIMPEXP_BASE wxWakeUpMainThread(); + +#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 +#endif // MSW, OS/2 + +#endif // wxUSE_THREADS + +#endif // _WX_THREAD_H_