X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/fae05df5a988883e9c6683ccded766dfb7b84b1b..8b34993daa0cef2a4c2b5a49236c3dcd70737c26:/src/unix/threadpsx.cpp diff --git a/src/unix/threadpsx.cpp b/src/unix/threadpsx.cpp index a6f79d8db1..3da088548d 100644 --- a/src/unix/threadpsx.cpp +++ b/src/unix/threadpsx.cpp @@ -2,13 +2,14 @@ // Name: threadpsx.cpp // Purpose: wxThread (Posix) Implementation // Author: Original from Wolfram Gloger/Guilhem Lavaux -// Modified by: +// Modified by: K. S. Sreeram (2002): POSIXified wxCondition, added wxSemaphore // Created: 04/22/98 // RCS-ID: $Id$ // Copyright: (c) Wolfram Gloger (1996, 1997) // Guilhem Lavaux (1998) -// Vadim Zeitlin (1999) +// Vadim Zeitlin (1999-2002) // Robert Roebling (1999) +// K. S. Sreeram (2002) // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// @@ -20,13 +21,12 @@ // headers // ---------------------------------------------------------------------------- -#ifdef __GNUG__ +#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA) #pragma implementation "thread.h" #endif -// With simple makefiles, we must ignore the file body if not using -// threads. -#include "wx/setup.h" +// for compilers that support precompilation, includes "wx.h". +#include "wx/wxprec.h" #if wxUSE_THREADS @@ -36,17 +36,35 @@ #include "wx/log.h" #include "wx/intl.h" #include "wx/dynarray.h" +#include "wx/timer.h" #include #include #include #include #include - #if HAVE_SCHED_H #include #endif +#ifdef HAVE_THR_SETCONCURRENCY + #include +#endif + +// we use wxFFile under Linux in GetCPUCount() +#ifdef __LINUX__ + #include "wx/ffile.h" + // For setpriority. + #include + #include +#endif + +#ifdef __VMS + #define THR_ID(thr) ((long long)(thr)->GetId()) +#else + #define THR_ID(thr) ((long)(thr)->GetId()) +#endif + // ---------------------------------------------------------------------------- // constants // ---------------------------------------------------------------------------- @@ -60,12 +78,31 @@ enum wxThreadState STATE_EXITED // thread doesn't exist any more }; +// the exit value of a thread which has been cancelled +static const wxThread::ExitCode EXITCODE_CANCELLED = (wxThread::ExitCode)-1; + +// trace mask for wxThread operations +#define TRACE_THREADS _T("thread") + +// you can get additional debugging messages for the semaphore operations +#define TRACE_SEMA _T("semaphore") + +// ---------------------------------------------------------------------------- +// private functions +// ---------------------------------------------------------------------------- + +static void ScheduleThreadForDeletion(); +static void DeleteThread(wxThread *This); + // ---------------------------------------------------------------------------- -// types +// private classes // ---------------------------------------------------------------------------- +// an (non owning) array of pointers to threads WX_DEFINE_ARRAY(wxThread *, wxArrayThread); +// an entry for a thread we can wait for + // ----------------------------------------------------------------------------- // global data // ----------------------------------------------------------------------------- @@ -76,145 +113,495 @@ WX_DEFINE_ARRAY(wxThread *, wxArrayThread); static wxArrayThread gs_allThreads; // the id of the main thread -static pthread_t gs_tidMain; +static pthread_t gs_tidMain = (pthread_t)-1; // the key for the pointer to the associated wxThread object static pthread_key_t gs_keySelf; +// the number of threads which are being deleted - the program won't exit +// until there are any left +static size_t gs_nThreadsBeingDeleted = 0; + +// a mutex to protect gs_nThreadsBeingDeleted +static wxMutex *gs_mutexDeleteThread = (wxMutex *)NULL; + +// and a condition variable which will be signaled when all +// gs_nThreadsBeingDeleted will have been deleted +static wxCondition *gs_condAllDeleted = (wxCondition *)NULL; + // this mutex must be acquired before any call to a GUI function -static wxMutex *gs_mutexGui; +// (it's not inside #if wxUSE_GUI because this file is compiled as part +// of wxBase) +static wxMutex *gs_mutexGui = NULL; + +// when we wait for a thread to exit, we're blocking on a condition which the +// thread signals in its SignalExit() method -- but this condition can't be a +// member of the thread itself as a detached thread may delete itself at any +// moment and accessing the condition member of the thread after this would +// result in a disaster +// +// so instead we maintain a global list of the structs below for the threads +// we're interested in waiting on // ============================================================================ -// implementation +// wxMutex implementation // ============================================================================ -//-------------------------------------------------------------------- -// wxMutex (Posix implementation) -//-------------------------------------------------------------------- +// ---------------------------------------------------------------------------- +// wxMutexInternal +// ---------------------------------------------------------------------------- +// this is a simple wrapper around pthread_mutex_t which provides error +// checking class wxMutexInternal { public: - pthread_mutex_t p_mutex; + wxMutexInternal(wxMutexType mutexType); + ~wxMutexInternal(); + + wxMutexError Lock(); + wxMutexError TryLock(); + wxMutexError Unlock(); + + bool IsOk() const { return m_isOk; } + +private: + pthread_mutex_t m_mutex; + bool m_isOk; + + // wxConditionInternal uses our m_mutex + friend class wxConditionInternal; }; -wxMutex::wxMutex() +#ifdef HAVE_PTHREAD_MUTEXATTR_T +// on some systems pthread_mutexattr_settype() is not in the headers (but it is +// in the library, otherwise we wouldn't compile this code at all) +extern "C" int pthread_mutexattr_settype(pthread_mutexattr_t *, int); +#endif + +wxMutexInternal::wxMutexInternal(wxMutexType mutexType) { - p_internal = new wxMutexInternal; - pthread_mutex_init( &(p_internal->p_mutex), (const pthread_mutexattr_t*) NULL ); - m_locked = 0; + int err; + switch ( mutexType ) + { + case wxMUTEX_RECURSIVE: + // support recursive locks like Win32, i.e. a thread can lock a + // mutex which it had itself already locked + // + // unfortunately initialization of recursive mutexes is non + // portable, so try several methods +#ifdef HAVE_PTHREAD_MUTEXATTR_T + { + pthread_mutexattr_t attr; + pthread_mutexattr_init(&attr); + pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); + + err = pthread_mutex_init(&m_mutex, &attr); + } +#elif defined(HAVE_PTHREAD_RECURSIVE_MUTEX_INITIALIZER) + // we can use this only as initializer so we have to assign it + // first to a temp var - assigning directly to m_mutex wouldn't + // even compile + { + pthread_mutex_t mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; + m_mutex = mutex; + } +#else // no recursive mutexes + err = EINVAL; +#endif // HAVE_PTHREAD_MUTEXATTR_T/... + break; + + default: + wxFAIL_MSG( _T("unknown mutex type") ); + // fall through + + case wxMUTEX_DEFAULT: + err = pthread_mutex_init(&m_mutex, NULL); + break; + } + + m_isOk = err == 0; + if ( !m_isOk ) + { + wxLogApiError( wxT("pthread_mutex_init()"), err); + } } -wxMutex::~wxMutex() +wxMutexInternal::~wxMutexInternal() { - if (m_locked > 0) - wxLogDebug(_T("Freeing a locked mutex (%d locks)"), m_locked); + if ( m_isOk ) + { + int err = pthread_mutex_destroy(&m_mutex); + if ( err != 0 ) + { + wxLogApiError( wxT("pthread_mutex_destroy()"), err); + } + } +} - pthread_mutex_destroy( &(p_internal->p_mutex) ); - delete p_internal; +wxMutexError wxMutexInternal::Lock() +{ + int err = pthread_mutex_lock(&m_mutex); + switch ( err ) + { + case EDEADLK: + // only error checking mutexes return this value and so it's an + // unexpected situation -- hence use assert, not wxLogDebug + wxFAIL_MSG( _T("mutex deadlock prevented") ); + return wxMUTEX_DEAD_LOCK; + + case EINVAL: + wxLogDebug(_T("pthread_mutex_lock(): mutex not initialized.")); + break; + + case 0: + return wxMUTEX_NO_ERROR; + + default: + wxLogApiError(_T("pthread_mutex_lock()"), err); + } + + return wxMUTEX_MISC_ERROR; } -wxMutexError wxMutex::Lock() +wxMutexError wxMutexInternal::TryLock() { - int err = pthread_mutex_lock( &(p_internal->p_mutex) ); - if (err == EDEADLK) + int err = pthread_mutex_trylock(&m_mutex); + switch ( err ) { - wxLogDebug(_T("Locking this mutex would lead to deadlock!")); + case EBUSY: + // not an error: mutex is already locked, but we're prepared for + // this + return wxMUTEX_BUSY; + + case EINVAL: + wxLogDebug(_T("pthread_mutex_trylock(): mutex not initialized.")); + break; - return wxMUTEX_DEAD_LOCK; + case 0: + return wxMUTEX_NO_ERROR; + + default: + wxLogApiError(_T("pthread_mutex_trylock()"), err); } - m_locked++; + return wxMUTEX_MISC_ERROR; +} + +wxMutexError wxMutexInternal::Unlock() +{ + int err = pthread_mutex_unlock(&m_mutex); + switch ( err ) + { + case EPERM: + // we don't own the mutex + return wxMUTEX_UNLOCKED; - return wxMUTEX_NO_ERROR; + case EINVAL: + wxLogDebug(_T("pthread_mutex_unlock(): mutex not initialized.")); + break; + + case 0: + return wxMUTEX_NO_ERROR; + + default: + wxLogApiError(_T("pthread_mutex_unlock()"), err); + } + + return wxMUTEX_MISC_ERROR; } -wxMutexError wxMutex::TryLock() +// =========================================================================== +// wxCondition implementation +// =========================================================================== + +// --------------------------------------------------------------------------- +// wxConditionInternal +// --------------------------------------------------------------------------- + +// this is a wrapper around pthread_cond_t associated with a wxMutex (and hence +// with a pthread_mutex_t) +class wxConditionInternal +{ +public: + wxConditionInternal(wxMutex& mutex); + ~wxConditionInternal(); + + bool IsOk() const { return m_isOk && m_mutex.IsOk(); } + + wxCondError Wait(); + wxCondError WaitTimeout(unsigned long milliseconds); + + wxCondError Signal(); + wxCondError Broadcast(); + +private: + // get the POSIX mutex associated with us + pthread_mutex_t *GetPMutex() const { return &m_mutex.m_internal->m_mutex; } + + wxMutex& m_mutex; + pthread_cond_t m_cond; + + bool m_isOk; +}; + +wxConditionInternal::wxConditionInternal(wxMutex& mutex) + : m_mutex(mutex) { - if (m_locked) + int err = pthread_cond_init(&m_cond, NULL /* default attributes */); + + m_isOk = err == 0; + + if ( !m_isOk ) { - return wxMUTEX_BUSY; + wxLogApiError(_T("pthread_cond_init()"), err); } +} - int err = pthread_mutex_trylock( &(p_internal->p_mutex) ); - switch (err) +wxConditionInternal::~wxConditionInternal() +{ + if ( m_isOk ) { - case EBUSY: return wxMUTEX_BUSY; + int err = pthread_cond_destroy(&m_cond); + if ( err != 0 ) + { + wxLogApiError(_T("pthread_cond_destroy()"), err); + } } +} - m_locked++; +wxCondError wxConditionInternal::Wait() +{ + int err = pthread_cond_wait(&m_cond, GetPMutex()); + if ( err != 0 ) + { + wxLogApiError(_T("pthread_cond_wait()"), err); + + return wxCOND_MISC_ERROR; + } - return wxMUTEX_NO_ERROR; + return wxCOND_NO_ERROR; } -wxMutexError wxMutex::Unlock() +wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) { - if (m_locked > 0) + wxLongLong curtime = wxGetLocalTimeMillis(); + curtime += milliseconds; + wxLongLong temp = curtime / 1000; + int sec = temp.GetLo(); + temp *= 1000; + temp = curtime - temp; + int millis = temp.GetLo(); + + timespec tspec; + + tspec.tv_sec = sec; + tspec.tv_nsec = millis * 1000L * 1000L; + + int err = pthread_cond_timedwait( &m_cond, GetPMutex(), &tspec ); + switch ( err ) { - m_locked--; + case ETIMEDOUT: + return wxCOND_TIMEOUT; + + case 0: + return wxCOND_NO_ERROR; + + default: + wxLogApiError(_T("pthread_cond_timedwait()"), err); } - else + + return wxCOND_MISC_ERROR; +} + +wxCondError wxConditionInternal::Signal() +{ + int err = pthread_cond_signal(&m_cond); + if ( err != 0 ) { - wxLogDebug(_T("Unlocking not locked mutex.")); + wxLogApiError(_T("pthread_cond_signal()"), err); - return wxMUTEX_UNLOCKED; + return wxCOND_MISC_ERROR; } - pthread_mutex_unlock( &(p_internal->p_mutex) ); + return wxCOND_NO_ERROR; +} + +wxCondError wxConditionInternal::Broadcast() +{ + int err = pthread_cond_broadcast(&m_cond); + if ( err != 0 ) + { + wxLogApiError(_T("pthread_cond_broadcast()"), err); - return wxMUTEX_NO_ERROR; + return wxCOND_MISC_ERROR; + } + + return wxCOND_NO_ERROR; } -//-------------------------------------------------------------------- -// wxCondition (Posix implementation) -//-------------------------------------------------------------------- +// =========================================================================== +// wxSemaphore implementation +// =========================================================================== -class wxConditionInternal +// --------------------------------------------------------------------------- +// wxSemaphoreInternal +// --------------------------------------------------------------------------- + +// we implement the semaphores using mutexes and conditions instead of using +// the sem_xxx() POSIX functions because they're not widely available and also +// because it's impossible to implement WaitTimeout() using them +class wxSemaphoreInternal { public: - pthread_cond_t p_condition; + wxSemaphoreInternal(int initialcount, int maxcount); + + bool IsOk() const { return m_isOk; } + + wxSemaError Wait(); + wxSemaError TryWait(); + wxSemaError WaitTimeout(unsigned long milliseconds); + + wxSemaError Post(); + +private: + wxMutex m_mutex; + wxCondition m_cond; + + size_t m_count, + m_maxcount; + + bool m_isOk; }; -wxCondition::wxCondition() +wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount) + : m_cond(m_mutex) { - p_internal = new wxConditionInternal; - pthread_cond_init( &(p_internal->p_condition), (const pthread_condattr_t *) NULL ); + + if ( (initialcount < 0 || maxcount < 0) || + ((maxcount > 0) && (initialcount > maxcount)) ) + { + wxFAIL_MSG( _T("wxSemaphore: invalid initial or maximal count") ); + + m_isOk = FALSE; + } + else + { + m_maxcount = (size_t)maxcount; + m_count = (size_t)initialcount; + } + + m_isOk = m_mutex.IsOk() && m_cond.IsOk(); } -wxCondition::~wxCondition() +wxSemaError wxSemaphoreInternal::Wait() { - pthread_cond_destroy( &(p_internal->p_condition) ); + wxMutexLocker locker(m_mutex); - delete p_internal; + while ( m_count == 0 ) + { + wxLogTrace(TRACE_SEMA, + _T("Thread %ld waiting for semaphore to become signalled"), + wxThread::GetCurrentId()); + + if ( m_cond.Wait() != wxCOND_NO_ERROR ) + return wxSEMA_MISC_ERROR; + + wxLogTrace(TRACE_SEMA, + _T("Thread %ld finished waiting for semaphore, count = %lu"), + wxThread::GetCurrentId(), (unsigned long)m_count); + } + + m_count--; + + return wxSEMA_NO_ERROR; } -void wxCondition::Wait(wxMutex& mutex) +wxSemaError wxSemaphoreInternal::TryWait() { - pthread_cond_wait( &(p_internal->p_condition), &(mutex.p_internal->p_mutex) ); + wxMutexLocker locker(m_mutex); + + if ( m_count == 0 ) + return wxSEMA_BUSY; + + m_count--; + + return wxSEMA_NO_ERROR; } -bool wxCondition::Wait(wxMutex& mutex, unsigned long sec, unsigned long nsec) +wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long milliseconds) { - struct timespec tspec; + wxMutexLocker locker(m_mutex); + + wxLongLong startTime = wxGetLocalTimeMillis(); - tspec.tv_sec = time(0L)+sec; - tspec.tv_nsec = nsec; - return (pthread_cond_timedwait(&(p_internal->p_condition), &(mutex.p_internal->p_mutex), &tspec) != ETIMEDOUT); + while ( m_count == 0 ) + { + wxLongLong elapsed = wxGetLocalTimeMillis() - startTime; + long remainingTime = (long)milliseconds - (long)elapsed.GetLo(); + if ( remainingTime <= 0 ) + { + // timeout + return wxSEMA_TIMEOUT; + } + + switch ( m_cond.WaitTimeout(remainingTime) ) + { + case wxCOND_TIMEOUT: + return wxSEMA_TIMEOUT; + + default: + return wxSEMA_MISC_ERROR; + + case wxCOND_NO_ERROR: + ; + } + } + + m_count--; + + return wxSEMA_NO_ERROR; } -void wxCondition::Signal() +wxSemaError wxSemaphoreInternal::Post() { - pthread_cond_signal( &(p_internal->p_condition) ); + wxMutexLocker locker(m_mutex); + + if ( m_maxcount > 0 && m_count == m_maxcount ) + { + return wxSEMA_OVERFLOW; + } + + m_count++; + + wxLogTrace(TRACE_SEMA, + _T("Thread %ld about to signal semaphore, count = %lu"), + wxThread::GetCurrentId(), (unsigned long)m_count); + + return m_cond.Signal() == wxCOND_NO_ERROR ? wxSEMA_NO_ERROR + : wxSEMA_MISC_ERROR; } -void wxCondition::Broadcast() +// =========================================================================== +// wxThread implementation +// =========================================================================== + +// the thread callback functions must have the C linkage +extern "C" { - pthread_cond_broadcast( &(p_internal->p_condition) ); -} -//-------------------------------------------------------------------- -// wxThread (Posix implementation) -//-------------------------------------------------------------------- +#if HAVE_THREAD_CLEANUP_FUNCTIONS + // thread exit function + void wxPthreadCleanup(void *ptr); +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS + +void *wxPthreadStart(void *ptr); + +} // extern "C" + +// ---------------------------------------------------------------------------- +// wxThreadInternal +// ---------------------------------------------------------------------------- class wxThreadInternal { @@ -223,20 +610,15 @@ public: ~wxThreadInternal(); // thread entry function - static void *PthreadStart(void *ptr); - -#if HAVE_THREAD_CLEANUP_FUNCTIONS - // thread exit function - static void PthreadCleanup(void *ptr); -#endif + static void *PthreadStart(wxThread *thread); // thread actions // start the thread wxThreadError Run(); + // unblock the thread allowing it to run + void SignalRun() { m_semRun.Post(); } // ask the thread to terminate void Wait(); - // wake up threads waiting for our termination - void SignalExit(); // go to sleep until Resume() is called void Pause(); // resume the thread @@ -248,50 +630,98 @@ public: void SetPriority(int prio) { m_prio = prio; } // state wxThreadState GetState() const { return m_state; } - void SetState(wxThreadState state) { m_state = state; } + void SetState(wxThreadState state) + { +#ifdef __WXDEBUG__ + static const wxChar *stateNames[] = + { + _T("NEW"), + _T("RUNNING"), + _T("PAUSED"), + _T("EXITED"), + }; + + wxLogTrace(TRACE_THREADS, _T("Thread %ld: %s => %s."), + (long)GetId(), stateNames[m_state], stateNames[state]); +#endif // __WXDEBUG__ + + m_state = state; + } // id pthread_t GetId() const { return m_threadId; } pthread_t *GetIdPtr() { return &m_threadId; } // "cancelled" flag void SetCancelFlag() { m_cancelled = TRUE; } bool WasCancelled() const { return m_cancelled; } + // exit code + void SetExitCode(wxThread::ExitCode exitcode) { m_exitcode = exitcode; } + wxThread::ExitCode GetExitCode() const { return m_exitcode; } + + // the pause flag + void SetReallyPaused(bool paused) { m_isPaused = paused; } + bool IsReallyPaused() const { return m_isPaused; } + + // tell the thread that it is a detached one + void Detach() + { + wxCriticalSectionLocker lock(m_csJoinFlag); + + m_shouldBeJoined = FALSE; + m_isDetached = TRUE; + } + +#if HAVE_THREAD_CLEANUP_FUNCTIONS + // this is used by wxPthreadCleanup() only + static void Cleanup(wxThread *thread); +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS private: pthread_t m_threadId; // id of the thread wxThreadState m_state; // see wxThreadState enum - int m_prio; // in wxWindows units: from 0 to 100 + int m_prio; // in wxWidgets units: from 0 to 100 - // set when the thread should terminate + // this flag is set when the thread should terminate bool m_cancelled; - // this (mutex, cond) pair is used to synchronize the main thread and this - // thread in several situations: - // 1. The thread function blocks until condition is signaled by Run() when - // it's initially created - this allows thread creation in "suspended" - // state - // 2. The Delete() function blocks until the condition is signaled when the - // thread exits. - // GL: On Linux, this may fail because we can have a deadlock in either - // SignalExit() or Wait(): so we add m_end_mutex for the finalization. - wxMutex m_mutex, m_end_mutex; - wxCondition m_cond; + // this flag is set when the thread is blocking on m_semSuspend + bool m_isPaused; + + // the thread exit code - only used for joinable (!detached) threads and + // is only valid after the thread termination + wxThread::ExitCode m_exitcode; + + // many threads may call Wait(), but only one of them should call + // pthread_join(), so we have to keep track of this + wxCriticalSection m_csJoinFlag; + bool m_shouldBeJoined; + bool m_isDetached; - // another (mutex, cond) pair for Pause()/Resume() usage - // - // VZ: it's possible that we might reuse the mutex and condition from above - // for this too, but as I'm not at all sure that it won't create subtle - // problems with race conditions between, say, Pause() and Delete() I - // prefer this may be a bit less efficient but much safer solution - wxMutex m_mutexSuspend; - wxCondition m_condSuspend; + // this semaphore is posted by Run() and the threads Entry() is not + // called before it is done + wxSemaphore m_semRun; + + // this one is signaled when the thread should resume after having been + // Pause()d + wxSemaphore m_semSuspend; }; -void *wxThreadInternal::PthreadStart(void *ptr) +// ---------------------------------------------------------------------------- +// thread startup and exit functions +// ---------------------------------------------------------------------------- + +void *wxPthreadStart(void *ptr) +{ + return wxThreadInternal::PthreadStart((wxThread *)ptr); +} + +void *wxThreadInternal::PthreadStart(wxThread *thread) { - wxThread *thread = (wxThread *)ptr; - wxThreadInternal *pthread = thread->p_internal; - void *status; + wxThreadInternal *pthread = thread->m_internal; + wxLogTrace(TRACE_THREADS, _T("Thread %ld started."), THR_ID(pthread)); + + // associate the thread pointer with the newly created thread so that + // wxThread::This() will work int rc = pthread_setspecific(gs_keySelf, thread); if ( rc != 0 ) { @@ -299,184 +729,225 @@ void *wxThreadInternal::PthreadStart(void *ptr) return (void *)-1; } + + // have to declare this before pthread_cleanup_push() which defines a + // block! + bool dontRunAtAll; + #if HAVE_THREAD_CLEANUP_FUNCTIONS - // Install the cleanup handler. - pthread_cleanup_push(wxThreadInternal::PthreadCleanup, ptr); -#endif + // install the cleanup handler which will be called if the thread is + // cancelled + pthread_cleanup_push(wxPthreadCleanup, thread); +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS - // wait for the condition to be signaled from Run() - // mutex state: currently locked by the thread which created us - pthread->m_cond.Wait(pthread->m_mutex); - // mutex state: locked again on exit of Wait() + // wait for the semaphore to be posted from Run() + pthread->m_semRun.Wait(); - // call the main entry - status = thread->Entry(); + // test whether we should run the run at all - may be it was deleted + // before it started to Run()? + { + wxCriticalSectionLocker lock(thread->m_critsect); + dontRunAtAll = pthread->GetState() == STATE_NEW && + pthread->WasCancelled(); + } + + if ( !dontRunAtAll ) + { + // call the main entry + wxLogTrace(TRACE_THREADS, + _T("Thread %ld about to enter its Entry()."), + THR_ID(pthread)); + + pthread->m_exitcode = thread->Entry(); + + wxLogTrace(TRACE_THREADS, + _T("Thread %ld Entry() returned %lu."), + THR_ID(pthread), (unsigned long)pthread->m_exitcode); + + { + wxCriticalSectionLocker lock(thread->m_critsect); + + // change the state of the thread to "exited" so that + // wxPthreadCleanup handler won't do anything from now (if it's + // called before we do pthread_cleanup_pop below) + pthread->SetState(STATE_EXITED); + } + } + + // NB: at least under Linux, pthread_cleanup_push/pop are macros and pop + // contains the matching '}' for the '{' in push, so they must be used + // in the same block! #if HAVE_THREAD_CLEANUP_FUNCTIONS + // remove the cleanup handler without executing it pthread_cleanup_pop(FALSE); -#endif +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS - // terminate the thread - thread->Exit(status); + if ( dontRunAtAll ) + { + // FIXME: deleting a possibly joinable thread here??? + delete thread; + + return EXITCODE_CANCELLED; + } + else + { + // terminate the thread + thread->Exit(pthread->m_exitcode); - wxFAIL_MSG(_T("wxThread::Exit() can't return.")); + wxFAIL_MSG(wxT("wxThread::Exit() can't return.")); - return NULL; + return NULL; + } } #if HAVE_THREAD_CLEANUP_FUNCTIONS -// Only called when the thread is explicitely killed. -void wxThreadInternal::PthreadCleanup(void *ptr) +// this handler is called when the thread is cancelled +extern "C" void wxPthreadCleanup(void *ptr) { - wxThread *thread = (wxThread *) ptr; + wxThreadInternal::Cleanup((wxThread *)ptr); +} - // The thread is already considered as finished. - if (thread->p_internal->GetState() == STATE_EXITED) - return; +void wxThreadInternal::Cleanup(wxThread *thread) +{ + { + wxCriticalSectionLocker lock(thread->m_critsect); + if ( thread->m_internal->GetState() == STATE_EXITED ) + { + // thread is already considered as finished. + return; + } + } - // first call user-level clean up code - thread->OnExit(); + // exit the thread gracefully + thread->Exit(EXITCODE_CANCELLED); +} - // next wake up the threads waiting for us (OTOH, this function won't retur - // until someone waited for us!) - thread->p_internal->SetState(STATE_EXITED); +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS - thread->p_internal->SignalExit(); -} -#endif +// ---------------------------------------------------------------------------- +// wxThreadInternal +// ---------------------------------------------------------------------------- wxThreadInternal::wxThreadInternal() { m_state = STATE_NEW; m_cancelled = FALSE; + m_prio = WXTHREAD_DEFAULT_PRIORITY; + m_threadId = 0; + m_exitcode = 0; - // this mutex is locked during almost all thread lifetime - it will only be - // unlocked in the very end - m_mutex.Lock(); - - // this mutex is used by wxThreadInternal::Wait() and by - // wxThreadInternal::SignalExit(). We don't use m_mutex because of a - // possible deadlock in either Wait() or SignalExit(). - m_end_mutex.Lock(); + // set to TRUE only when the thread starts waiting on m_semSuspend + m_isPaused = FALSE; - // this mutex is used in Pause()/Resume() and is also locked all the time - // unless the thread is paused - m_mutexSuspend.Lock(); + // defaults for joinable threads + m_shouldBeJoined = TRUE; + m_isDetached = FALSE; } wxThreadInternal::~wxThreadInternal() { - // GL: moved to SignalExit - // m_mutexSuspend.Unlock(); - - // note that m_mutex will be unlocked by the thread which waits for our - // termination - - // In the case, we didn't start the thread, all these mutex are locked: - // we must unlock them. - if (m_mutex.IsLocked()) - m_mutex.Unlock(); - - if (m_end_mutex.IsLocked()) - m_end_mutex.Unlock(); - - if (m_mutexSuspend.IsLocked()) - m_mutexSuspend.Unlock(); } wxThreadError wxThreadInternal::Run() { wxCHECK_MSG( GetState() == STATE_NEW, wxTHREAD_RUNNING, - _T("thread may only be started once after successful Create()") ); + wxT("thread may only be started once after Create()") ); - // the mutex was locked on Create(), so we will be able to lock it again - // only when the thread really starts executing and enters the wait - - // otherwise we might signal the condition before anybody is waiting for it - wxMutexLocker lock(m_mutex); - m_cond.Signal(); + SetState(STATE_RUNNING); - m_state = STATE_RUNNING; + // wake up threads waiting for our start + SignalRun(); return wxTHREAD_NO_ERROR; - - // now the mutex is unlocked back - but just to allow Wait() function to - // terminate by relocking it, so the net result is that the worker thread - // starts executing and the mutex is still locked } void wxThreadInternal::Wait() { - wxCHECK_RET( WasCancelled(), _T("thread should have been cancelled first") ); + wxCHECK_RET( !m_isDetached, _T("can't wait for a detached thread") ); // if the thread we're waiting for is waiting for the GUI mutex, we will // deadlock so make sure we release it temporarily if ( wxThread::IsMain() ) wxMutexGuiLeave(); - // entering Wait() releases the mutex thus allowing SignalExit() to acquire - // it and to signal us its termination - m_cond.Wait(m_end_mutex); + wxLogTrace(TRACE_THREADS, + _T("Starting to wait for thread %ld to exit."), + THR_ID(this)); - // mutex is still in the locked state - relocked on exit from Wait(), so - // unlock it - we don't need it any more, the thread has already terminated - m_end_mutex.Unlock(); + // to avoid memory leaks we should call pthread_join(), but it must only be + // done once so use a critical section to serialize the code below + { + wxCriticalSectionLocker lock(m_csJoinFlag); + + if ( m_shouldBeJoined ) + { + // FIXME shouldn't we set cancellation type to DISABLED here? If + // we're cancelled inside pthread_join(), things will almost + // certainly break - but if we disable the cancellation, we + // might deadlock + if ( pthread_join(GetId(), &m_exitcode) != 0 ) + { + // this is a serious problem, so use wxLogError and not + // wxLogDebug: it is possible to bring the system to its knees + // by creating too many threads and not joining them quite + // easily + wxLogError(_("Failed to join a thread, potential memory leak detected - please restart the program")); + } - // After that, we wait for the real end of the other thread. - pthread_join(GetId(), NULL); + m_shouldBeJoined = FALSE; + } + } // reacquire GUI mutex if ( wxThread::IsMain() ) wxMutexGuiEnter(); } -void wxThreadInternal::SignalExit() -{ - // GL: Unlock mutexSuspend here. - m_mutexSuspend.Unlock(); - - // as mutex is currently locked, this will block until some other thread - // (normally the same which created this one) unlocks it by entering Wait() - m_end_mutex.Lock(); - - // wake up all the threads waiting for our termination - m_cond.Broadcast(); - - // after this call mutex will be finally unlocked - m_end_mutex.Unlock(); -} - void wxThreadInternal::Pause() { // the state is set from the thread which pauses us first, this function // is called later so the state should have been already set wxCHECK_RET( m_state == STATE_PAUSED, - _T("thread must first be paused with wxThread::Pause().") ); + wxT("thread must first be paused with wxThread::Pause().") ); - // don't pause the thread which is being terminated - this would lead to - // deadlock if the thread is paused after Delete() had called Resume() but - // before it had time to call Wait() - if ( WasCancelled() ) - return; + wxLogTrace(TRACE_THREADS, + _T("Thread %ld goes to sleep."), THR_ID(this)); - // wait until the condition is signaled from Resume() - m_condSuspend.Wait(m_mutexSuspend); + // wait until the semaphore is Post()ed from Resume() + m_semSuspend.Wait(); } void wxThreadInternal::Resume() { wxCHECK_RET( m_state == STATE_PAUSED, - _T("can't resume thread which is not suspended.") ); + wxT("can't resume thread which is not suspended.") ); + + // the thread might be not actually paused yet - if there were no call to + // TestDestroy() since the last call to Pause() for example + if ( IsReallyPaused() ) + { + wxLogTrace(TRACE_THREADS, + _T("Waking up thread %ld"), THR_ID(this)); - // we will be able to lock this mutex only when Pause() starts waiting - wxMutexLocker lock(m_mutexSuspend); - m_condSuspend.Signal(); + // wake up Pause() + m_semSuspend.Post(); + + // reset the flag + SetReallyPaused(FALSE); + } + else + { + wxLogTrace(TRACE_THREADS, + _T("Thread %ld is not yet really paused"), THR_ID(this)); + } SetState(STATE_RUNNING); } // ----------------------------------------------------------------------------- -// static functions +// wxThread static functions // ----------------------------------------------------------------------------- wxThread *wxThread::This() @@ -486,78 +957,217 @@ wxThread *wxThread::This() bool wxThread::IsMain() { - return (bool)pthread_equal(pthread_self(), gs_tidMain); + return (bool)pthread_equal(pthread_self(), gs_tidMain) || gs_tidMain == (pthread_t)-1; } void wxThread::Yield() { +#ifdef HAVE_SCHED_YIELD sched_yield(); +#endif } void wxThread::Sleep(unsigned long milliseconds) { - wxUsleep(milliseconds); + wxMilliSleep(milliseconds); +} + +int wxThread::GetCPUCount() +{ +#if defined(__LINUX__) && wxUSE_FFILE + // read from proc (can't use wxTextFile here because it's a special file: + // it has 0 size but still can be read from) + wxLogNull nolog; + + wxFFile file(_T("/proc/cpuinfo")); + if ( file.IsOpened() ) + { + // slurp the whole file + wxString s; + if ( file.ReadAll(&s) ) + { + // (ab)use Replace() to find the number of "processor: num" strings + size_t count = s.Replace(_T("processor\t:"), _T("")); + if ( count > 0 ) + { + return count; + } + + wxLogDebug(_T("failed to parse /proc/cpuinfo")); + } + else + { + wxLogDebug(_T("failed to read /proc/cpuinfo")); + } + } +#elif defined(_SC_NPROCESSORS_ONLN) + // this works for Solaris + int rc = sysconf(_SC_NPROCESSORS_ONLN); + if ( rc != -1 ) + { + return rc; + } +#endif // different ways to get number of CPUs + + // unknown + return -1; +} + +// VMS is a 64 bit system and threads have 64 bit pointers. +// FIXME: also needed for other systems???? +#ifdef __VMS +unsigned long long wxThread::GetCurrentId() +{ + return (unsigned long long)pthread_self(); +} + +#else // !__VMS + +unsigned long wxThread::GetCurrentId() +{ + return (unsigned long)pthread_self(); +} + +#endif // __VMS/!__VMS + + +bool wxThread::SetConcurrency(size_t level) +{ +#ifdef HAVE_THR_SETCONCURRENCY + int rc = thr_setconcurrency(level); + if ( rc != 0 ) + { + wxLogSysError(rc, _T("thr_setconcurrency() failed")); + } + + return rc == 0; +#else // !HAVE_THR_SETCONCURRENCY + // ok only for the default value + return level == 0; +#endif // HAVE_THR_SETCONCURRENCY/!HAVE_THR_SETCONCURRENCY } // ----------------------------------------------------------------------------- // creating thread // ----------------------------------------------------------------------------- -wxThread::wxThread() +wxThread::wxThread(wxThreadKind kind) { // add this thread to the global list of all threads gs_allThreads.Add(this); - p_internal = new wxThreadInternal(); + m_internal = new wxThreadInternal(); + + m_isDetached = kind == wxTHREAD_DETACHED; } -wxThreadError wxThread::Create() +wxThreadError wxThread::Create(unsigned int WXUNUSED(stackSize)) { - if (p_internal->GetState() != STATE_NEW) + if ( m_internal->GetState() != STATE_NEW ) + { + // don't recreate thread return wxTHREAD_RUNNING; + } // set up the thread attribute: right now, we only set thread priority pthread_attr_t attr; pthread_attr_init(&attr); #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS - int prio; - if ( pthread_attr_getschedpolicy(&attr, &prio) != 0 ) + int policy; + if ( pthread_attr_getschedpolicy(&attr, &policy) != 0 ) { wxLogError(_("Cannot retrieve thread scheduling policy.")); } - int min_prio = sched_get_priority_min(prio), - max_prio = sched_get_priority_max(prio); +#ifdef __VMS__ + /* the pthread.h contains too many spaces. This is a work-around */ +# undef sched_get_priority_max +#undef sched_get_priority_min +#define sched_get_priority_max(_pol_) \ + (_pol_ == SCHED_OTHER ? PRI_FG_MAX_NP : PRI_FIFO_MAX) +#define sched_get_priority_min(_pol_) \ + (_pol_ == SCHED_OTHER ? PRI_FG_MIN_NP : PRI_FIFO_MIN) +#endif + + int max_prio = sched_get_priority_max(policy), + min_prio = sched_get_priority_min(policy), + prio = m_internal->GetPriority(); if ( min_prio == -1 || max_prio == -1 ) { wxLogError(_("Cannot get priority range for scheduling policy %d."), - prio); + policy); + } + else if ( max_prio == min_prio ) + { + if ( prio != WXTHREAD_DEFAULT_PRIORITY ) + { + // notify the programmer that this doesn't work here + wxLogWarning(_("Thread priority setting is ignored.")); + } + //else: we have default priority, so don't complain + + // anyhow, don't do anything because priority is just ignored } else { struct sched_param sp; - pthread_attr_getschedparam(&attr, &sp); - sp.sched_priority = min_prio + - (p_internal->GetPriority()*(max_prio-min_prio))/100; - pthread_attr_setschedparam(&attr, &sp); + if ( pthread_attr_getschedparam(&attr, &sp) != 0 ) + { + wxFAIL_MSG(_T("pthread_attr_getschedparam() failed")); + } + + sp.sched_priority = min_prio + (prio*(max_prio - min_prio))/100; + + if ( pthread_attr_setschedparam(&attr, &sp) != 0 ) + { + wxFAIL_MSG(_T("pthread_attr_setschedparam(priority) failed")); + } } #endif // HAVE_THREAD_PRIORITY_FUNCTIONS #ifdef HAVE_PTHREAD_ATTR_SETSCOPE // this will make the threads created by this process really concurrent - pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM); + if ( pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) != 0 ) + { + wxFAIL_MSG(_T("pthread_attr_setscope(PTHREAD_SCOPE_SYSTEM) failed")); + } #endif // HAVE_PTHREAD_ATTR_SETSCOPE + // VZ: assume that this one is always available (it's rather fundamental), + // if this function is ever missing we should try to use + // pthread_detach() instead (after thread creation) + if ( m_isDetached ) + { + if ( pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0 ) + { + wxFAIL_MSG(_T("pthread_attr_setdetachstate(DETACHED) failed")); + } + + // never try to join detached threads + m_internal->Detach(); + } + //else: threads are created joinable by default, it's ok + // create the new OS thread object - int rc = pthread_create(p_internal->GetIdPtr(), &attr, - wxThreadInternal::PthreadStart, (void *)this); - pthread_attr_destroy(&attr); + int rc = pthread_create + ( + m_internal->GetIdPtr(), + &attr, + wxPthreadStart, + (void *)this + ); + + if ( pthread_attr_destroy(&attr) != 0 ) + { + wxFAIL_MSG(_T("pthread_attr_destroy() failed")); + } if ( rc != 0 ) { - p_internal->SetState(STATE_EXITED); + m_internal->SetState(STATE_EXITED); + return wxTHREAD_NO_RESOURCE; } @@ -566,7 +1176,12 @@ wxThreadError wxThread::Create() wxThreadError wxThread::Run() { - return p_internal->Run(); + wxCriticalSectionLocker lock(m_critsect); + + wxCHECK_MSG( m_internal->GetId(), wxTHREAD_MISC_ERROR, + wxT("must call wxThread::Create() first") ); + + return m_internal->Run(); } // ----------------------------------------------------------------------------- @@ -577,36 +1192,76 @@ void wxThread::SetPriority(unsigned int prio) { wxCHECK_RET( ((int)WXTHREAD_MIN_PRIORITY <= (int)prio) && ((int)prio <= (int)WXTHREAD_MAX_PRIORITY), - _T("invalid thread priority") ); + wxT("invalid thread priority") ); wxCriticalSectionLocker lock(m_critsect); - switch ( p_internal->GetState() ) + switch ( m_internal->GetState() ) { case STATE_NEW: // thread not yet started, priority will be set when it is - p_internal->SetPriority(prio); + m_internal->SetPriority(prio); break; case STATE_RUNNING: case STATE_PAUSED: #ifdef HAVE_THREAD_PRIORITY_FUNCTIONS +#if defined(__LINUX__) +// On Linux, pthread_setschedparam with SCHED_OTHER does not allow +// a priority other than 0. Instead, we use the BSD setpriority +// which alllows us to set a 'nice' value between 20 to -20. Only +// super user can set a value less than zero (more negative yields +// higher priority). setpriority set the static priority of a process, +// but this is OK since Linux is configured as a thread per process. + { + float fPrio; + float pSpan; + int iPrio; + + // Map Wx priorites (WXTHREAD_MIN_PRIORITY - + // WXTHREAD_MAX_PRIORITY) into BSD priorities (20 - -20). + // Do calculation of values instead of hard coding them + // to make maintenance easier. + + pSpan = ((float)(WXTHREAD_MAX_PRIORITY - WXTHREAD_MIN_PRIORITY)) / 2.0; + + // prio starts as ................... // value => (0) >= p <= (n) + + fPrio = ((float)prio) - pSpan; // value => (-n) >= p <= (+n) + + fPrio = 0.0 - fPrio; // value => (+n) <= p >= (-n) + + fPrio = fPrio * (20. / pSpan) + .5; // value => (20) <= p >= (-20) + + iPrio = (int)fPrio; + + // Clamp prio from 20 - -20; + iPrio = (iPrio > 20) ? 20 : iPrio; + iPrio = (iPrio < -20) ? -20 : iPrio; + + if (setpriority(PRIO_PROCESS, 0, iPrio) == -1) + { + wxLogError(_("Failed to set thread priority %d."), prio); + } + } +#else // __LINUX__ { struct sched_param sparam; sparam.sched_priority = prio; - if ( pthread_setschedparam(p_internal->GetId(), + if ( pthread_setschedparam(m_internal->GetId(), SCHED_OTHER, &sparam) != 0 ) { wxLogError(_("Failed to set thread priority %d."), prio); } } +#endif // __LINUX__ #endif // HAVE_THREAD_PRIORITY_FUNCTIONS break; case STATE_EXITED: default: - wxFAIL_MSG(_T("impossible to set thread priority in this state")); + wxFAIL_MSG(wxT("impossible to set thread priority in this state")); } } @@ -614,12 +1269,12 @@ unsigned int wxThread::GetPriority() const { wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); - return p_internal->GetPriority(); + return m_internal->GetPriority(); } -unsigned long wxThread::GetID() const +wxThreadIdType wxThread::GetId() const { - return (unsigned long)p_internal->GetId(); + return (wxThreadIdType) m_internal->GetId(); } // ----------------------------------------------------------------------------- @@ -628,37 +1283,53 @@ unsigned long wxThread::GetID() const wxThreadError wxThread::Pause() { + wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR, + _T("a thread can't pause itself") ); + wxCriticalSectionLocker lock(m_critsect); - if ( p_internal->GetState() != STATE_RUNNING ) + if ( m_internal->GetState() != STATE_RUNNING ) { - wxLogDebug(_T("Can't pause thread which is not running.")); + wxLogDebug(wxT("Can't pause thread which is not running.")); return wxTHREAD_NOT_RUNNING; } - p_internal->SetState(STATE_PAUSED); + // just set a flag, the thread will be really paused only during the next + // call to TestDestroy() + m_internal->SetState(STATE_PAUSED); return wxTHREAD_NO_ERROR; } wxThreadError wxThread::Resume() { + wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR, + _T("a thread can't resume itself") ); + wxCriticalSectionLocker lock(m_critsect); - if ( p_internal->GetState() == STATE_PAUSED ) - { - m_critsect.Leave(); - p_internal->Resume(); - m_critsect.Enter(); + wxThreadState state = m_internal->GetState(); - return wxTHREAD_NO_ERROR; - } - else + switch ( state ) { - wxLogDebug(_T("Attempt to resume a thread which is not paused.")); + case STATE_PAUSED: + wxLogTrace(TRACE_THREADS, _T("Thread %ld suspended, resuming."), + GetId()); + + m_internal->Resume(); + + return wxTHREAD_NO_ERROR; + + case STATE_EXITED: + wxLogTrace(TRACE_THREADS, _T("Thread %ld exited, won't resume."), + GetId()); + return wxTHREAD_NO_ERROR; + + default: + wxLogDebug(_T("Attempt to resume a thread which is not paused.")); - return wxTHREAD_MISC_ERROR; + return wxTHREAD_MISC_ERROR; } } @@ -666,51 +1337,92 @@ wxThreadError wxThread::Resume() // exiting thread // ----------------------------------------------------------------------------- -wxThread::ExitCode wxThread::Delete() +wxThread::ExitCode wxThread::Wait() +{ + wxCHECK_MSG( This() != this, (ExitCode)-1, + _T("a thread can't wait for itself") ); + + wxCHECK_MSG( !m_isDetached, (ExitCode)-1, + _T("can't wait for detached thread") ); + + m_internal->Wait(); + + return m_internal->GetExitCode(); +} + +wxThreadError wxThread::Delete(ExitCode *rc) { - if (IsPaused()) - Resume(); + wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR, + _T("a thread can't delete itself") ); + + bool isDetached = m_isDetached; m_critsect.Enter(); - wxThreadState state = p_internal->GetState(); + wxThreadState state = m_internal->GetState(); // ask the thread to stop - p_internal->SetCancelFlag(); + m_internal->SetCancelFlag(); m_critsect.Leave(); switch ( state ) { case STATE_NEW: + // we need to wake up the thread so that PthreadStart() will + // terminate - right now it's blocking on run semaphore in + // PthreadStart() + m_internal->SignalRun(); + + // fall through + case STATE_EXITED: // nothing to do break; case STATE_PAUSED: // resume the thread first - Resume(); + m_internal->Resume(); // fall through default: - // wait until the thread stops - p_internal->Wait(); + if ( !isDetached ) + { + // wait until the thread stops + m_internal->Wait(); + + if ( rc ) + { + // return the exit code of the thread + *rc = m_internal->GetExitCode(); + } + } + //else: can't wait for detached threads } - return NULL; + return wxTHREAD_NO_ERROR; } wxThreadError wxThread::Kill() { - switch ( p_internal->GetState() ) + wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR, + _T("a thread can't kill itself") ); + + switch ( m_internal->GetState() ) { case STATE_NEW: case STATE_EXITED: return wxTHREAD_NOT_RUNNING; + case STATE_PAUSED: + // resume the thread first + Resume(); + + // fall through + default: -#ifdef HAVE_PTHREAD_CANCEL - if ( pthread_cancel(p_internal->GetId()) != 0 ) +#ifdef HAVE_PTHREAD_CANCEL + if ( pthread_cancel(m_internal->GetId()) != 0 ) #endif { wxLogError(_("Failed to terminate a thread.")); @@ -718,57 +1430,111 @@ wxThreadError wxThread::Kill() return wxTHREAD_MISC_ERROR; } + if ( m_isDetached ) + { + // if we use cleanup function, this will be done from + // wxPthreadCleanup() +#if !HAVE_THREAD_CLEANUP_FUNCTIONS + ScheduleThreadForDeletion(); + + // don't call OnExit() here, it can only be called in the + // threads context and we're in the context of another thread + + DeleteThread(this); +#endif // HAVE_THREAD_CLEANUP_FUNCTIONS + } + else + { + m_internal->SetExitCode(EXITCODE_CANCELLED); + } + return wxTHREAD_NO_ERROR; } } -void wxThread::Exit(void *status) +void wxThread::Exit(ExitCode status) { - // first call user-level clean up code - OnExit(); + wxASSERT_MSG( This() == this, + _T("wxThread::Exit() can only be called in the context of the same thread") ); - // next wake up the threads waiting for us (OTOH, this function won't return - // until someone waited for us!) - p_internal->SignalExit(); + if ( m_isDetached ) + { + // from the moment we call OnExit(), the main program may terminate at + // any moment, so mark this thread as being already in process of being + // deleted or wxThreadModule::OnExit() will try to delete it again + ScheduleThreadForDeletion(); + } - p_internal->SetState(STATE_EXITED); + // don't enter m_critsect before calling OnExit() because the user code + // might deadlock if, for example, it signals a condition in OnExit() (a + // common case) while the main thread calls any of functions entering + // m_critsect on us (almost all of them do) + OnExit(); - // delete both C++ thread object and terminate the OS thread object - // GL: This is very ugly and buggy ... -// delete this; + // delete C++ thread object if this is a detached thread - user is + // responsible for doing this for joinable ones + if ( m_isDetached ) + { + // FIXME I'm feeling bad about it - what if another thread function is + // called (in another thread context) now? It will try to access + // half destroyed object which will probably result in something + // very bad - but we can't protect this by a crit section unless + // we make it a global object, but this would mean that we can + // only call one thread function at a time :-( + DeleteThread(this); + } + + // terminate the thread (pthread_exit() never returns) pthread_exit(status); + + wxFAIL_MSG(_T("pthread_exit() failed")); } // also test whether we were paused bool wxThread::TestDestroy() { - wxCriticalSectionLocker lock(m_critsect); + wxASSERT_MSG( This() == this, + _T("wxThread::TestDestroy() can only be called in the context of the same thread") ); - if ( p_internal->GetState() == STATE_PAUSED ) + m_critsect.Enter(); + + if ( m_internal->GetState() == STATE_PAUSED ) { - // leave the crit section or the other threads will stop too if they try - // to call any of (seemingly harmless) IsXXX() functions while we sleep - m_critsect.Leave(); + m_internal->SetReallyPaused(TRUE); - p_internal->Pause(); + // leave the crit section or the other threads will stop too if they + // try to call any of (seemingly harmless) IsXXX() functions while we + // sleep + m_critsect.Leave(); - // enter it back before it's finally left in lock object dtor - m_critsect.Enter(); + m_internal->Pause(); + } + else + { + // thread wasn't requested to pause, nothing to do + m_critsect.Leave(); } - return p_internal->WasCancelled(); + return m_internal->WasCancelled(); } wxThread::~wxThread() { +#ifdef __WXDEBUG__ m_critsect.Enter(); - if (p_internal->GetState() != STATE_EXITED && - p_internal->GetState() != STATE_NEW) - wxLogDebug(_T("The thread is being destroyed althought it is still running ! The application may crash.")); + + // check that the thread either exited or couldn't be created + if ( m_internal->GetState() != STATE_EXITED && + m_internal->GetState() != STATE_NEW ) + { + wxLogDebug(_T("The thread %ld is being destroyed although it is still running! The application may crash."), GetId()); + } m_critsect.Leave(); +#endif // __WXDEBUG__ + + delete m_internal; - delete p_internal; // remove this thread from the global array gs_allThreads.Remove(this); } @@ -781,14 +1547,14 @@ bool wxThread::IsRunning() const { wxCriticalSectionLocker lock((wxCriticalSection &)m_critsect); - return p_internal->GetState() == STATE_RUNNING; + return m_internal->GetState() == STATE_RUNNING; } bool wxThread::IsAlive() const { wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect); - switch ( p_internal->GetState() ) + switch ( m_internal->GetState() ) { case STATE_RUNNING: case STATE_PAUSED: @@ -803,7 +1569,7 @@ bool wxThread::IsPaused() const { wxCriticalSectionLocker lock((wxCriticalSection&)m_critsect); - return (p_internal->GetState() == STATE_PAUSED); + return (m_internal->GetState() == STATE_PAUSED); } //-------------------------------------------------------------------- @@ -827,57 +1593,123 @@ bool wxThreadModule::OnInit() int rc = pthread_key_create(&gs_keySelf, NULL /* dtor function */); if ( rc != 0 ) { - wxLogSysError(rc, _("Thread module initialization failed: " - "failed to create thread key")); + wxLogSysError(rc, _("Thread module initialization failed: failed to create thread key")); return FALSE; } - gs_mutexGui = new wxMutex(); - gs_tidMain = pthread_self(); + gs_mutexGui = new wxMutex(); gs_mutexGui->Lock(); + gs_mutexDeleteThread = new wxMutex(); + gs_condAllDeleted = new wxCondition( *gs_mutexDeleteThread ); + return TRUE; } void wxThreadModule::OnExit() { - wxASSERT_MSG( wxThread::IsMain(), _T("only main thread can be here") ); + wxASSERT_MSG( wxThread::IsMain(), wxT("only main thread can be here") ); + + // are there any threads left which are being deleted right now? + size_t nThreadsBeingDeleted; + + { + wxMutexLocker lock( *gs_mutexDeleteThread ); + nThreadsBeingDeleted = gs_nThreadsBeingDeleted; + + if ( nThreadsBeingDeleted > 0 ) + { + wxLogTrace(TRACE_THREADS, + _T("Waiting for %lu threads to disappear"), + (unsigned long)nThreadsBeingDeleted); + + // have to wait until all of them disappear + gs_condAllDeleted->Wait(); + } + } // terminate any threads left size_t count = gs_allThreads.GetCount(); if ( count != 0u ) - wxLogDebug(_T("Some threads were not terminated by the application.")); + { + wxLogDebug(wxT("%lu threads were not terminated by the application."), + (unsigned long)count); + } for ( size_t n = 0u; n < count; n++ ) { - gs_allThreads[n]->Delete(); + // Delete calls the destructor which removes the current entry. We + // should only delete the first one each time. + gs_allThreads[0]->Delete(); } // destroy GUI mutex gs_mutexGui->Unlock(); - delete gs_mutexGui; // and free TLD slot (void)pthread_key_delete(gs_keySelf); + + delete gs_condAllDeleted; + delete gs_mutexDeleteThread; } // ---------------------------------------------------------------------------- // global functions // ---------------------------------------------------------------------------- +static void ScheduleThreadForDeletion() +{ + wxMutexLocker lock( *gs_mutexDeleteThread ); + + gs_nThreadsBeingDeleted++; + + wxLogTrace(TRACE_THREADS, _T("%lu thread%s waiting to be deleted"), + (unsigned long)gs_nThreadsBeingDeleted, + gs_nThreadsBeingDeleted == 1 ? "" : "s"); +} + +static void DeleteThread(wxThread *This) +{ + // gs_mutexDeleteThread should be unlocked before signalling the condition + // or wxThreadModule::OnExit() would deadlock + wxMutexLocker locker( *gs_mutexDeleteThread ); + + wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId()); + + delete This; + + wxCHECK_RET( gs_nThreadsBeingDeleted > 0, + _T("no threads scheduled for deletion, yet we delete one?") ); + + wxLogTrace(TRACE_THREADS, _T("%lu scheduled for deletion threads left."), + (unsigned long)gs_nThreadsBeingDeleted - 1); + + if ( !--gs_nThreadsBeingDeleted ) + { + // no more threads left, signal it + gs_condAllDeleted->Signal(); + } +} + void wxMutexGuiEnter() { - gs_mutexGui->Lock(); + gs_mutexGui->Lock(); } void wxMutexGuiLeave() { - gs_mutexGui->Unlock(); + gs_mutexGui->Unlock(); } -#endif - // wxUSE_THREADS +// ---------------------------------------------------------------------------- +// include common implementation code +// ---------------------------------------------------------------------------- + +#include "wx/thrimpl.cpp" + +#endif // wxUSE_THREADS +