X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/ef8d96c29c73b9da8cdaa2b8b4737862c85ccc20..11a2ce5ad289cb21b35cc21131b46f75dd4af060:/src/unix/threadpsx.cpp?ds=sidebyside diff --git a/src/unix/threadpsx.cpp b/src/unix/threadpsx.cpp index 34f3cd81b4..47e9a41e62 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 ///////////////////////////////////////////////////////////////////////////// @@ -34,13 +35,13 @@ #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 @@ -52,6 +53,9 @@ // we use wxFFile under Linux in GetCPUCount() #ifdef __LINUX__ #include "wx/ffile.h" + // For setpriority. + #include + #include #endif // ---------------------------------------------------------------------------- @@ -70,9 +74,12 @@ enum wxThreadState // the exit value of a thread which has been cancelled static const wxThread::ExitCode EXITCODE_CANCELLED = (wxThread::ExitCode)-1; -// our trace mask +// 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 // ---------------------------------------------------------------------------- @@ -84,37 +91,11 @@ static void DeleteThread(wxThread *This); // private classes // ---------------------------------------------------------------------------- -// same as wxMutexLocker but for "native" mutex -class MutexLock -{ -public: - MutexLock(pthread_mutex_t& mutex) - { - m_mutex = &mutex; - if ( pthread_mutex_lock(m_mutex) != 0 ) - { - wxLogDebug(_T("pthread_mutex_lock() failed")); - } - } - - ~MutexLock() - { - if ( pthread_mutex_unlock(m_mutex) != 0 ) - { - wxLogDebug(_T("pthread_mutex_unlock() failed")); - } - } - -private: - pthread_mutex_t *m_mutex; -}; - -// ---------------------------------------------------------------------------- -// types -// ---------------------------------------------------------------------------- - +// an (non owning) array of pointers to threads WX_DEFINE_ARRAY(wxThread *, wxArrayThread); +// an entry for a thread we can wait for + // ----------------------------------------------------------------------------- // global data // ----------------------------------------------------------------------------- @@ -135,7 +116,7 @@ static pthread_key_t gs_keySelf; static size_t gs_nThreadsBeingDeleted = 0; // a mutex to protect gs_nThreadsBeingDeleted -static pthread_mutex_t gs_mutexDeleteThread = PTHREAD_MUTEX_INITIALIZER; +static wxMutex *gs_mutexDeleteThread = (wxMutex *)NULL; // and a condition variable which will be signaled when all // gs_nThreadsBeingDeleted will have been deleted @@ -146,331 +127,459 @@ static wxCondition *gs_condAllDeleted = (wxCondition *)NULL; static wxMutex *gs_mutexGui; #endif // wxUSE_GUI +// 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: + 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() +wxMutexInternal::wxMutexInternal(wxMutexType mutexType) { - m_internal = new wxMutexInternal; + 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); - pthread_mutex_init(&(m_internal->m_mutex), - (pthread_mutexattr_t*) NULL ); - m_locked = 0; + 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(wxT("Freeing a locked mutex (%d locks)"), m_locked); - - pthread_mutex_destroy( &(m_internal->m_mutex) ); - delete m_internal; + if ( m_isOk ) + { + int err = pthread_mutex_destroy(&m_mutex); + if ( err != 0 ) + { + wxLogApiError( wxT("pthread_mutex_destroy()"), err); + } + } } -wxMutexError wxMutex::Lock() +wxMutexError wxMutexInternal::Lock() { - int err = pthread_mutex_lock( &(m_internal->m_mutex) ); - if (err == EDEADLK) + int err = pthread_mutex_lock(&m_mutex); + switch ( err ) { - wxLogDebug(wxT("Locking this mutex would lead to deadlock!")); + 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; - return wxMUTEX_DEAD_LOCK; - } + case 0: + return wxMUTEX_NO_ERROR; - m_locked++; + default: + wxLogApiError(_T("pthread_mutex_lock()"), err); + } - return wxMUTEX_NO_ERROR; + return wxMUTEX_MISC_ERROR; } -wxMutexError wxMutex::TryLock() +wxMutexError wxMutexInternal::TryLock() { - if (m_locked) + int err = pthread_mutex_trylock(&m_mutex); + switch ( err ) { - return wxMUTEX_BUSY; - } + case EBUSY: + // not an error: mutex is already locked, but we're prepared for + // this + return wxMUTEX_BUSY; - int err = pthread_mutex_trylock( &(m_internal->m_mutex) ); - switch (err) - { - case EBUSY: return wxMUTEX_BUSY; - } + case EINVAL: + wxLogDebug(_T("pthread_mutex_trylock(): mutex not initialized.")); + break; + + case 0: + return wxMUTEX_NO_ERROR; - m_locked++; + default: + wxLogApiError(_T("pthread_mutex_trylock()"), err); + } - return wxMUTEX_NO_ERROR; + return wxMUTEX_MISC_ERROR; } -wxMutexError wxMutex::Unlock() +wxMutexError wxMutexInternal::Unlock() { - if (m_locked > 0) + int err = pthread_mutex_unlock(&m_mutex); + switch ( err ) { - m_locked--; - } - else - { - wxLogDebug(wxT("Unlocking not locked mutex.")); + case EPERM: + // we don't own the mutex + return wxMUTEX_UNLOCKED; - return wxMUTEX_UNLOCKED; - } + case EINVAL: + wxLogDebug(_T("pthread_mutex_unlock(): mutex not initialized.")); + break; - pthread_mutex_unlock( &(m_internal->m_mutex) ); + case 0: + return wxMUTEX_NO_ERROR; - return wxMUTEX_NO_ERROR; + default: + wxLogApiError(_T("pthread_mutex_unlock()"), err); + } + + return wxMUTEX_MISC_ERROR; } -//-------------------------------------------------------------------- -// wxCondition (Posix implementation) -//-------------------------------------------------------------------- +// =========================================================================== +// wxCondition implementation +// =========================================================================== -// The native POSIX condition variables are dumb: if the condition is signaled -// before another thread starts to wait on it, the signal is lost and so this -// other thread will be never woken up. It's much more convenient to us to -// remember that the condition was signaled and to return from Wait() -// immediately in this case (this is more like Win32 automatic event objects) +// --------------------------------------------------------------------------- +// wxConditionInternal +// --------------------------------------------------------------------------- +// this is a wrapper around pthread_cond_t associated with a wxMutex (and hence +// with a pthread_mutex_t) class wxConditionInternal { public: - wxConditionInternal(); + wxConditionInternal(wxMutex& mutex); ~wxConditionInternal(); - void Wait(); - bool WaitWithTimeout(const timespec* ts); + bool IsOk() const { return m_isOk && m_mutex.IsOk(); } - void Signal(); - void Broadcast(); + wxCondError Wait(); + wxCondError WaitTimeout(unsigned long milliseconds); - void WaitDone(); - bool ShouldWait(); - bool HasWaiters(); + wxCondError Signal(); + wxCondError Broadcast(); private: - bool m_wasSignaled; // TRUE if condition was signaled while - // nobody waited for it - size_t m_nWaiters; // TRUE if someone already waits for us + // get the POSIX mutex associated with us + pthread_mutex_t *GetPMutex() const { return &m_mutex.m_internal->m_mutex; } - pthread_mutex_t m_mutexProtect; // protects access to vars above + wxMutex& m_mutex; + pthread_cond_t m_cond; - pthread_mutex_t m_mutex; // the mutex used with the condition - pthread_cond_t m_condition; // the condition itself + bool m_isOk; }; -wxConditionInternal::wxConditionInternal() +wxConditionInternal::wxConditionInternal(wxMutex& mutex) + : m_mutex(mutex) { - m_wasSignaled = FALSE; - m_nWaiters = 0; + int err = pthread_cond_init(&m_cond, NULL /* default attributes */); - if ( pthread_cond_init(&m_condition, (pthread_condattr_t *)NULL) != 0 ) - { - // this is supposed to never happen - wxFAIL_MSG( _T("pthread_cond_init() failed") ); - } + m_isOk = err == 0; - if ( pthread_mutex_init(&m_mutex, (pthread_mutexattr_t *)NULL) != 0 || - pthread_mutex_init(&m_mutexProtect, NULL) != 0 ) + if ( !m_isOk ) { - // neither this - wxFAIL_MSG( _T("wxCondition: pthread_mutex_init() failed") ); - } - - // initially the mutex is locked, so no thread can Signal() or Broadcast() - // until another thread starts to Wait() - if ( pthread_mutex_lock(&m_mutex) != 0 ) - { - wxFAIL_MSG( _T("wxCondition: pthread_mutex_lock() failed") ); + wxLogApiError(_T("pthread_cond_init()"), err); } } wxConditionInternal::~wxConditionInternal() { - if ( pthread_cond_destroy( &m_condition ) != 0 ) + if ( m_isOk ) { - wxLogDebug(_T("Failed to destroy condition variable (some " - "threads are probably still waiting on it?)")); + int err = pthread_cond_destroy(&m_cond); + if ( err != 0 ) + { + wxLogApiError(_T("pthread_cond_destroy()"), err); + } } +} - if ( pthread_mutex_unlock( &m_mutex ) != 0 ) +wxCondError wxConditionInternal::Wait() +{ + int err = pthread_cond_wait(&m_cond, GetPMutex()); + if ( err != 0 ) { - wxLogDebug(_T("wxCondition: failed to unlock the mutex")); - } + wxLogApiError(_T("pthread_cond_wait()"), err); - if ( pthread_mutex_destroy( &m_mutex ) != 0 || - pthread_mutex_destroy( &m_mutexProtect ) != 0 ) - { - wxLogDebug(_T("Failed to destroy mutex (it is probably locked)")); + return wxCOND_MISC_ERROR; } + + return wxCOND_NO_ERROR; } -void wxConditionInternal::WaitDone() +wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) { - MutexLock lock(m_mutexProtect); + wxLongLong curtime = wxGetLocalTimeMillis(); + curtime += milliseconds; + wxLongLong temp = curtime / 1000; + int sec = temp.GetLo(); + temp *= 1000; + temp = curtime - temp; + int millis = temp.GetLo(); - m_wasSignaled = FALSE; - m_nWaiters--; -} + timespec tspec; -bool wxConditionInternal::ShouldWait() -{ - MutexLock lock(m_mutexProtect); + tspec.tv_sec = sec; + tspec.tv_nsec = millis * 1000L * 1000L; - if ( m_wasSignaled ) + int err = pthread_cond_timedwait( &m_cond, GetPMutex(), &tspec ); + switch ( err ) { - // the condition was signaled before we started to wait, reset the - // flag and return - m_wasSignaled = FALSE; + case ETIMEDOUT: + return wxCOND_TIMEOUT; - return FALSE; - } + case 0: + return wxCOND_NO_ERROR; - // we start to wait for it - m_nWaiters++; + default: + wxLogApiError(_T("pthread_cond_timedwait()"), err); + } - return TRUE; + return wxCOND_MISC_ERROR; } -bool wxConditionInternal::HasWaiters() +wxCondError wxConditionInternal::Signal() { - MutexLock lock(m_mutexProtect); - - if ( m_nWaiters ) + int err = pthread_cond_signal(&m_cond); + if ( err != 0 ) { - // someone waits for us, signal the condition normally - return TRUE; - } + wxLogApiError(_T("pthread_cond_signal()"), err); - // nobody waits for us and may be never will - so just remember that the - // condition was signaled and don't do anything else - m_wasSignaled = TRUE; + return wxCOND_MISC_ERROR; + } - return FALSE; + return wxCOND_NO_ERROR; } -void wxConditionInternal::Wait() +wxCondError wxConditionInternal::Broadcast() { - if ( ShouldWait() ) + int err = pthread_cond_broadcast(&m_cond); + if ( err != 0 ) { - if ( pthread_cond_wait( &m_condition, &m_mutex ) != 0 ) - { - // not supposed to ever happen - wxFAIL_MSG( _T("pthread_cond_wait() failed") ); - } + wxLogApiError(_T("pthread_cond_broadcast()"), err); + + return wxCOND_MISC_ERROR; } - WaitDone(); + return wxCOND_NO_ERROR; } -bool wxConditionInternal::WaitWithTimeout(const timespec* ts) +// =========================================================================== +// wxSemaphore implementation +// =========================================================================== + +// --------------------------------------------------------------------------- +// 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 { - bool ok; +public: + wxSemaphoreInternal(int initialcount, int maxcount); - if ( ShouldWait() ) - { - switch ( pthread_cond_timedwait( &m_condition, &m_mutex, ts ) ) - { - case 0: - // condition signaled - ok = TRUE; - break; + bool IsOk() const { return m_isOk; } - default: - wxLogDebug(_T("pthread_cond_timedwait() failed")); + wxSemaError Wait(); + wxSemaError TryWait(); + wxSemaError WaitTimeout(unsigned long milliseconds); - // fall through + wxSemaError Post(); - case ETIMEDOUT: - case EINTR: - // wait interrupted or timeout elapsed - ok = FALSE; - } +private: + wxMutex m_mutex; + wxCondition m_cond; + + size_t m_count, + m_maxcount; + + bool m_isOk; +}; + +wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount) + : m_cond(m_mutex) +{ + + if ( (initialcount < 0 || maxcount < 0) || + ((maxcount > 0) && (initialcount > maxcount)) ) + { + wxFAIL_MSG( _T("wxSemaphore: invalid initial or maximal count") ); + + m_isOk = FALSE; } else { - // the condition had already been signaled before - ok = TRUE; + m_maxcount = (size_t)maxcount; + m_count = (size_t)initialcount; } - WaitDone(); - - return ok; + m_isOk = m_mutex.IsOk() && m_cond.IsOk(); } -void wxConditionInternal::Signal() +wxSemaError wxSemaphoreInternal::Wait() { - if ( HasWaiters() ) + wxMutexLocker locker(m_mutex); + + while ( m_count == 0 ) { - MutexLock lock(m_mutex); + wxLogTrace(TRACE_SEMA, + "Thread %ld waiting for semaphore to become signalled", + wxThread::GetCurrentId()); - if ( pthread_cond_signal( &m_condition ) != 0 ) - { - // shouldn't ever happen - wxFAIL_MSG(_T("pthread_cond_signal() failed")); - } + if ( m_cond.Wait() != wxCOND_NO_ERROR ) + return wxSEMA_MISC_ERROR; + + wxLogTrace(TRACE_SEMA, + "Thread %ld finished waiting for semaphore, count = %u", + wxThread::GetCurrentId(), m_count); } + + m_count--; + + return wxSEMA_NO_ERROR; } -void wxConditionInternal::Broadcast() +wxSemaError wxSemaphoreInternal::TryWait() { - if ( HasWaiters() ) - { - MutexLock lock(m_mutex); + wxMutexLocker locker(m_mutex); + + if ( m_count == 0 ) + return wxSEMA_BUSY; + + m_count--; + + return wxSEMA_NO_ERROR; +} + +wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long milliseconds) +{ + wxMutexLocker locker(m_mutex); + + wxLongLong startTime = wxGetLocalTimeMillis(); - if ( pthread_cond_broadcast( &m_condition ) != 0 ) + while ( m_count == 0 ) + { + wxLongLong elapsed = wxGetLocalTimeMillis() - startTime; + long remainingTime = (long)milliseconds - (long)elapsed.GetLo(); + if ( remainingTime <= 0 ) { - // shouldn't ever happen - wxFAIL_MSG(_T("pthread_cond_broadcast() failed")); + // timeout + return wxSEMA_TIMEOUT; } + + if ( m_cond.Wait(remainingTime) != wxCOND_NO_ERROR ) + return wxSEMA_MISC_ERROR; } -} -wxCondition::wxCondition() -{ - m_internal = new wxConditionInternal; -} + m_count--; -wxCondition::~wxCondition() -{ - delete m_internal; + return wxSEMA_NO_ERROR; } -void wxCondition::Wait() +wxSemaError wxSemaphoreInternal::Post() { - m_internal->Wait(); -} + wxMutexLocker locker(m_mutex); -bool wxCondition::Wait(unsigned long sec, unsigned long nsec) -{ - timespec tspec; + if ( m_maxcount > 0 && m_count == m_maxcount ) + { + return wxSEMA_OVERFLOW; + } - tspec.tv_sec = time(0L) + sec; // FIXME is time(0) correct here? - tspec.tv_nsec = nsec; + m_count++; - return m_internal->WaitWithTimeout(&tspec); + wxLogTrace(TRACE_SEMA, + "Thread %ld about to signal semaphore, count = %u", + wxThread::GetCurrentId(), m_count); + + return m_cond.Signal() == wxCOND_NO_ERROR ? wxSEMA_NO_ERROR + : wxSEMA_MISC_ERROR; } -void wxCondition::Signal() -{ - m_internal->Signal(); -} +// =========================================================================== +// wxThread implementation +// =========================================================================== -void wxCondition::Broadcast() +// the thread callback functions must have the C linkage +extern "C" { - m_internal->Broadcast(); -} -//-------------------------------------------------------------------- -// 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 { @@ -479,22 +588,15 @@ 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(); - // wake up threads waiting for our start - void SignalRun() { m_condRun.Signal(); } // go to sleep until Resume() is called void Pause(); // resume the thread @@ -506,7 +608,23 @@ 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."), + 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; } @@ -524,12 +642,16 @@ public: // tell the thread that it is a detached one void Detach() { - m_shouldBeJoined = m_shouldBroadcast = FALSE; + wxCriticalSectionLocker lock(m_csJoinFlag); + + m_shouldBeJoined = FALSE; m_isDetached = TRUE; } - // but even detached threads need to notifyus about their termination - // sometimes - tell the thread that it should do it - void Notify() { m_shouldBroadcast = 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 @@ -539,7 +661,7 @@ private: // this flag is set when the thread should terminate bool m_cancelled; - // this flag is set when the thread is blocking on m_condSuspend + // 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 @@ -550,36 +672,32 @@ private: // pthread_join(), so we have to keep track of this wxCriticalSection m_csJoinFlag; bool m_shouldBeJoined; - bool m_shouldBroadcast; bool m_isDetached; - // VZ: it's possible that we might do with less than three different - // condition objects - for example, m_condRun and m_condEnd a priori - // won't be used in the same time. But for now I prefer this may be a - // bit less efficient but safer solution of having distinct condition - // variables for each purpose. - - // this condition is signaled by Run() and the threads Entry() is not + // this semaphore is posted by Run() and the threads Entry() is not // called before it is done - wxCondition m_condRun; + wxSemaphore m_semRun; // this one is signaled when the thread should resume after having been // Pause()d - wxCondition m_condSuspend; - - // finally this one is signalled when the thread exits - wxCondition m_condEnd; + wxSemaphore m_semSuspend; }; // ---------------------------------------------------------------------------- // thread startup and exit functions // ---------------------------------------------------------------------------- -void *wxThreadInternal::PthreadStart(void *ptr) +void *wxPthreadStart(void *ptr) +{ + return wxThreadInternal::PthreadStart((wxThread *)ptr); +} + +void *wxThreadInternal::PthreadStart(wxThread *thread) { - wxThread *thread = (wxThread *)ptr; wxThreadInternal *pthread = thread->m_internal; + wxLogTrace(TRACE_THREADS, _T("Thread %ld started."), pthread->GetId()); + // associate the thread pointer with the newly created thread so that // wxThread::This() will work int rc = pthread_setspecific(gs_keySelf, thread); @@ -597,11 +715,11 @@ void *wxThreadInternal::PthreadStart(void *ptr) #if HAVE_THREAD_CLEANUP_FUNCTIONS // install the cleanup handler which will be called if the thread is // cancelled - pthread_cleanup_push(wxThreadInternal::PthreadCleanup, ptr); + pthread_cleanup_push(wxPthreadCleanup, thread); #endif // HAVE_THREAD_CLEANUP_FUNCTIONS - // wait for the condition to be signaled from Run() - pthread->m_condRun.Wait(); + // wait for the semaphore to be posted from Run() + pthread->m_semRun.Wait(); // test whether we should run the run at all - may be it was deleted // before it started to Run()? @@ -615,19 +733,19 @@ void *wxThreadInternal::PthreadStart(void *ptr) if ( !dontRunAtAll ) { // call the main entry + wxLogTrace(TRACE_THREADS, _T("Thread %ld about to enter its Entry()."), + pthread->GetId()); + pthread->m_exitcode = thread->Entry(); - wxLogTrace(TRACE_THREADS, _T("Thread %ld left its Entry()."), - pthread->GetId()); + wxLogTrace(TRACE_THREADS, _T("Thread %ld Entry() returned %lu."), + pthread->GetId(), (unsigned long)pthread->m_exitcode); { wxCriticalSectionLocker lock(thread->m_critsect); - wxLogTrace(TRACE_THREADS, _T("Thread %ld changes state to EXITED."), - pthread->GetId()); - // change the state of the thread to "exited" so that - // PthreadCleanup handler won't do anything from now (if it's + // wxPthreadCleanup handler won't do anything from now (if it's // called before we do pthread_cleanup_pop below) pthread->SetState(STATE_EXITED); } @@ -643,6 +761,7 @@ void *wxThreadInternal::PthreadStart(void *ptr) if ( dontRunAtAll ) { + // FIXME: deleting a possibly joinable thread here??? delete thread; return EXITCODE_CANCELLED; @@ -661,10 +780,13 @@ void *wxThreadInternal::PthreadStart(void *ptr) #if HAVE_THREAD_CLEANUP_FUNCTIONS // this handler is called when the thread is cancelled -void wxThreadInternal::PthreadCleanup(void *ptr) +extern "C" void wxPthreadCleanup(void *ptr) { - wxThread *thread = (wxThread *) ptr; + wxThreadInternal::Cleanup((wxThread *)ptr); +} +void wxThreadInternal::Cleanup(wxThread *thread) +{ { wxCriticalSectionLocker lock(thread->m_critsect); if ( thread->m_internal->GetState() == STATE_EXITED ) @@ -692,12 +814,11 @@ wxThreadInternal::wxThreadInternal() m_threadId = 0; m_exitcode = 0; - // set to TRUE only when the thread starts waiting on m_condSuspend + // set to TRUE only when the thread starts waiting on m_semSuspend m_isPaused = FALSE; // defaults for joinable threads m_shouldBeJoined = TRUE; - m_shouldBroadcast = TRUE; m_isDetached = FALSE; } @@ -710,37 +831,29 @@ wxThreadError wxThreadInternal::Run() wxCHECK_MSG( GetState() == STATE_NEW, wxTHREAD_RUNNING, wxT("thread may only be started once after Create()") ); - SignalRun(); - SetState(STATE_RUNNING); + // wake up threads waiting for our start + SignalRun(); + return wxTHREAD_NO_ERROR; } void wxThreadInternal::Wait() { + 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(); - bool isDetached = m_isDetached; - long id = GetId(); - wxLogTrace(TRACE_THREADS, _T("Starting to wait for thread %ld to exit."), - id); - - // wait until the thread terminates (we're blocking in _another_ thread, - // of course) - m_condEnd.Wait(); + wxLogTrace(TRACE_THREADS, + _T("Starting to wait for thread %ld to exit."), GetId()); - wxLogTrace(TRACE_THREADS, _T("Finished waiting for thread %ld."), id); - - // we can't use any member variables any more if the thread is detached - // because it could be already deleted - if ( !isDetached ) + // 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 { - // to avoid memory leaks we should call pthread_join(), but it must - // only be done once wxCriticalSectionLocker lock(m_csJoinFlag); if ( m_shouldBeJoined ) @@ -749,8 +862,12 @@ void wxThreadInternal::Wait() // we're cancelled inside pthread_join(), things will almost // certainly break - but if we disable the cancellation, we // might deadlock - if ( pthread_join(id, &m_exitcode) != 0 ) + if ( pthread_join((pthread_t)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")); } @@ -764,22 +881,6 @@ void wxThreadInternal::Wait() wxMutexGuiEnter(); } -void wxThreadInternal::SignalExit() -{ - wxLogTrace(TRACE_THREADS, _T("Thread %ld about to exit."), GetId()); - - SetState(STATE_EXITED); - - // wake up all the threads waiting for our termination - if there are any - if ( m_shouldBroadcast ) - { - wxLogTrace(TRACE_THREADS, _T("Thread %ld signals end condition."), - GetId()); - - m_condEnd.Broadcast(); - } -} - void wxThreadInternal::Pause() { // the state is set from the thread which pauses us first, this function @@ -789,8 +890,8 @@ void wxThreadInternal::Pause() wxLogTrace(TRACE_THREADS, _T("Thread %ld goes to sleep."), GetId()); - // wait until the condition is signaled from Resume() - m_condSuspend.Wait(); + // wait until the semaphore is Post()ed from Resume() + m_semSuspend.Wait(); } void wxThreadInternal::Resume() @@ -805,7 +906,7 @@ void wxThreadInternal::Resume() wxLogTrace(TRACE_THREADS, _T("Waking up thread %ld"), GetId()); // wake up Pause() - m_condSuspend.Signal(); + m_semSuspend.Post(); // reset the flag SetReallyPaused(FALSE); @@ -835,7 +936,9 @@ bool wxThread::IsMain() void wxThread::Yield() { +#ifdef HAVE_SCHED_YIELD sched_yield(); +#endif } void wxThread::Sleep(unsigned long milliseconds) @@ -845,7 +948,7 @@ void wxThread::Sleep(unsigned long milliseconds) int wxThread::GetCPUCount() { -#if defined(__LINUX__) +#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; @@ -884,6 +987,19 @@ int wxThread::GetCPUCount() return -1; } +#ifdef __VMS + // VMS is a 64 bit system and threads have 64 bit pointers. + // ??? also needed for other systems???? +unsigned long long wxThread::GetCurrentId() +{ + return (unsigned long long)pthread_self(); +#else +unsigned long wxThread::GetCurrentId() +{ + return (unsigned long)pthread_self(); +#endif +} + bool wxThread::SetConcurrency(size_t level) { #ifdef HAVE_THR_SETCONCURRENCY @@ -914,7 +1030,7 @@ wxThread::wxThread(wxThreadKind kind) m_isDetached = kind == wxTHREAD_DETACHED; } -wxThreadError wxThread::Create() +wxThreadError wxThread::Create(unsigned int WXUNUSED(stackSize)) { if ( m_internal->GetState() != STATE_NEW ) { @@ -933,8 +1049,18 @@ wxThreadError wxThread::Create() wxLogError(_("Cannot retrieve thread scheduling policy.")); } - int min_prio = sched_get_priority_min(policy), - max_prio = sched_get_priority_max(policy), +#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 ) @@ -998,7 +1124,7 @@ wxThreadError wxThread::Create() ( m_internal->GetIdPtr(), &attr, - wxThreadInternal::PthreadStart, + wxPthreadStart, (void *)this ); @@ -1049,6 +1175,45 @@ void wxThread::SetPriority(unsigned int prio) 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; @@ -1059,6 +1224,7 @@ void wxThread::SetPriority(unsigned int prio) wxLogError(_("Failed to set thread priority %d."), prio); } } +#endif // __LINUX__ #endif // HAVE_THREAD_PRIORITY_FUNCTIONS break; @@ -1075,9 +1241,9 @@ unsigned int wxThread::GetPriority() const return m_internal->GetPriority(); } -unsigned long wxThread::GetId() const +wxThreadIdType wxThread::GetId() const { - return (unsigned long)m_internal->GetId(); + return (wxThreadIdType) m_internal->GetId(); } // ----------------------------------------------------------------------------- @@ -1098,9 +1264,6 @@ wxThreadError wxThread::Pause() return wxTHREAD_NOT_RUNNING; } - wxLogTrace(TRACE_THREADS, _T("Asking thread %ld to pause."), - GetId()); - // just set a flag, the thread will be really paused only during the next // call to TestDestroy() m_internal->SetState(STATE_PAUSED); @@ -1161,27 +1324,22 @@ wxThreadError wxThread::Delete(ExitCode *rc) wxCHECK_MSG( This() != this, wxTHREAD_MISC_ERROR, _T("a thread can't delete itself") ); + bool isDetached = m_isDetached; + m_critsect.Enter(); wxThreadState state = m_internal->GetState(); // ask the thread to stop m_internal->SetCancelFlag(); - if ( m_isDetached ) - { - // detached threads won't broadcast about their termination by default - // because usually nobody waits for them - but here we do, so ask the - // thread to notify us - m_internal->Notify(); - } - 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 m_condRun + // terminate - right now it's blocking on run semaphore in + // PthreadStart() m_internal->SignalRun(); // fall through @@ -1191,24 +1349,24 @@ wxThreadError wxThread::Delete(ExitCode *rc) break; case STATE_PAUSED: - // resume the thread first (don't call our Resume() because this - // would dead lock when it tries to enter m_critsect) + // resume the thread first m_internal->Resume(); // fall through default: - // wait until the thread stops - m_internal->Wait(); - - if ( rc ) + if ( !isDetached ) { - wxASSERT_MSG( !m_isDetached, - _T("no return code for detached threads") ); + // wait until the thread stops + m_internal->Wait(); - // if it's a joinable thread, it's not deleted yet - *rc = m_internal->GetExitCode(); + if ( rc ) + { + // return the exit code of the thread + *rc = m_internal->GetExitCode(); + } } + //else: can't wait for detached threads } return wxTHREAD_NO_ERROR; @@ -1244,11 +1402,12 @@ wxThreadError wxThread::Kill() if ( m_isDetached ) { // if we use cleanup function, this will be done from - // PthreadCleanup() + // wxPthreadCleanup() #if !HAVE_THREAD_CLEANUP_FUNCTIONS ScheduleThreadForDeletion(); - OnExit(); + // 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 @@ -1268,10 +1427,13 @@ void wxThread::Exit(ExitCode status) _T("wxThread::Exit() can only be called in the " "context of the same thread") ); - // 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(); + 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(); + } // don't enter m_critsect before calling OnExit() because the user code // might deadlock if, for example, it signals a condition in OnExit() (a @@ -1279,17 +1441,6 @@ void wxThread::Exit(ExitCode status) // m_critsect on us (almost all of them do) OnExit(); - // now do enter it because SignalExit() will change our state - m_critsect.Enter(); - - // next wake up the threads waiting for us (OTOH, this function won't return - // until someone waited for us!) - m_internal->SignalExit(); - - // leave the critical section before entering the dtor which tries to - // enter it - m_critsect.Leave(); - // delete C++ thread object if this is a detached thread - user is // responsible for doing this for joinable ones if ( m_isDetached ) @@ -1358,17 +1509,6 @@ wxThread::~wxThread() // remove this thread from the global array gs_allThreads.Remove(this); - - // detached thread will decrement this counter in DeleteThread(), but it - // is not called for the joinable threads, so do it here - if ( !m_isDetached ) - { - MutexLock lock(gs_mutexDeleteThread); - gs_nThreadsBeingDeleted--; - - wxLogTrace(TRACE_THREADS, _T("%u scheduled for deletion threads left."), - gs_nThreadsBeingDeleted - 1); - } } // ----------------------------------------------------------------------------- @@ -1439,6 +1579,9 @@ bool wxThreadModule::OnInit() gs_mutexGui->Lock(); #endif // wxUSE_GUI + gs_mutexDeleteThread = new wxMutex(); + gs_condAllDeleted = new wxCondition( *gs_mutexDeleteThread ); + return TRUE; } @@ -1448,18 +1591,19 @@ void wxThreadModule::OnExit() // are there any threads left which are being deleted right now? size_t nThreadsBeingDeleted; + { - MutexLock lock(gs_mutexDeleteThread); + wxMutexLocker lock( *gs_mutexDeleteThread ); nThreadsBeingDeleted = gs_nThreadsBeingDeleted; - } - if ( nThreadsBeingDeleted > 0 ) - { - wxLogTrace(TRACE_THREADS, _T("Waiting for %u threads to disappear"), - nThreadsBeingDeleted); + if ( nThreadsBeingDeleted > 0 ) + { + wxLogTrace(TRACE_THREADS, _T("Waiting for %u threads to disappear"), + nThreadsBeingDeleted); - // have to wait until all of them disappear - gs_condAllDeleted->Wait(); + // have to wait until all of them disappear + gs_condAllDeleted->Wait(); + } } // terminate any threads left @@ -1486,6 +1630,9 @@ void wxThreadModule::OnExit() // and free TLD slot (void)pthread_key_delete(gs_keySelf); + + delete gs_condAllDeleted; + delete gs_mutexDeleteThread; } // ---------------------------------------------------------------------------- @@ -1494,12 +1641,7 @@ void wxThreadModule::OnExit() static void ScheduleThreadForDeletion() { - MutexLock lock(gs_mutexDeleteThread); - - if ( gs_nThreadsBeingDeleted == 0 ) - { - gs_condAllDeleted = new wxCondition; - } + wxMutexLocker lock( *gs_mutexDeleteThread ); gs_nThreadsBeingDeleted++; @@ -1512,17 +1654,14 @@ static void DeleteThread(wxThread *This) { // gs_mutexDeleteThread should be unlocked before signalling the condition // or wxThreadModule::OnExit() would deadlock - { - MutexLock lock(gs_mutexDeleteThread); + wxMutexLocker locker( *gs_mutexDeleteThread ); - wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId()); + wxLogTrace(TRACE_THREADS, _T("Thread %ld auto deletes."), This->GetId()); - delete This; + delete This; - wxCHECK_RET( gs_nThreadsBeingDeleted > 0, - _T("no threads scheduled for deletion, yet we delete " - "one?") ); - } + wxCHECK_RET( gs_nThreadsBeingDeleted > 0, + _T("no threads scheduled for deletion, yet we delete one?") ); wxLogTrace(TRACE_THREADS, _T("%u scheduled for deletion threads left."), gs_nThreadsBeingDeleted - 1); @@ -1531,9 +1670,6 @@ static void DeleteThread(wxThread *This) { // no more threads left, signal it gs_condAllDeleted->Signal(); - - delete gs_condAllDeleted; - gs_condAllDeleted = (wxCondition *)NULL; } } @@ -1551,5 +1687,11 @@ void wxMutexGuiLeave() #endif // wxUSE_GUI } -#endif - // wxUSE_THREADS +// ---------------------------------------------------------------------------- +// include common implementation code +// ---------------------------------------------------------------------------- + +#include "wx/thrimpl.cpp" + +#endif // wxUSE_THREADS +