X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/077309e1a38c65d7d236f06b4d54e67ffcf897bf..cb73e6001f891ae46b12a1e4ca39b93649cb6099:/src/msw/thread.cpp diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp index 2180ddd994..3f273a4600 100644 --- a/src/msw/thread.cpp +++ b/src/msw/thread.cpp @@ -10,7 +10,7 @@ // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// -#ifdef __GNUG__ +#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA) #pragma implementation "thread.h" #endif @@ -26,11 +26,14 @@ #endif #ifndef WX_PRECOMP -# include "wx/wx.h" + #include "wx/intl.h" + #include "wx/app.h" #endif #if wxUSE_THREADS +#include "wx/apptrait.h" + #include "wx/msw/private.h" #include "wx/msw/missing.h" @@ -61,10 +64,13 @@ (defined(__GNUG__) && defined(__MSVCRT__)) || \ defined(__WATCOMC__) || defined(__MWERKS__) +#ifndef __WXWINCE__ #undef wxUSE_BEGIN_THREAD #define wxUSE_BEGIN_THREAD #endif +#endif + #ifdef wxUSE_BEGIN_THREAD // this is where _beginthreadex() is declared #include @@ -174,6 +180,8 @@ private: wxMutexError LockTimeout(DWORD milliseconds); HANDLE m_mutex; + + DECLARE_NO_COPY_CLASS(wxMutexInternal) }; // all mutexes are recursive under Win32 so we don't use mutexType @@ -243,7 +251,7 @@ wxMutexError wxMutexInternal::Unlock() { if ( !::ReleaseMutex(m_mutex) ) { - wxLogLastError(_("ReleaseMutex()")); + wxLogLastError(_T("ReleaseMutex()")); return wxMUTEX_MISC_ERROR; } @@ -265,17 +273,29 @@ public: bool IsOk() const { return m_semaphore != NULL; } wxSemaError Wait() { return WaitTimeout(INFINITE); } - wxSemaError TryWait() { return WaitTimeout(0); } + + wxSemaError TryWait() + { + wxSemaError rc = WaitTimeout(0); + if ( rc == wxSEMA_TIMEOUT ) + rc = wxSEMA_BUSY; + + return rc; + } + wxSemaError WaitTimeout(unsigned long milliseconds); wxSemaError Post(); private: HANDLE m_semaphore; + + DECLARE_NO_COPY_CLASS(wxSemaphoreInternal) }; wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount) { +#ifndef __WXWINCE__ if ( maxcount == 0 ) { // make it practically infinite @@ -289,7 +309,7 @@ wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount) maxcount, NULL // no name ); - +#endif if ( !m_semaphore ) { wxLogLastError(_T("CreateSemaphore()")); @@ -317,7 +337,7 @@ wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long milliseconds) return wxSEMA_NO_ERROR; case WAIT_TIMEOUT: - return wxSEMA_BUSY; + return wxSEMA_TIMEOUT; default: wxLogLastError(_T("WaitForSingleObject(semaphore)")); @@ -328,7 +348,9 @@ wxSemaError wxSemaphoreInternal::WaitTimeout(unsigned long milliseconds) wxSemaError wxSemaphoreInternal::Post() { +#ifndef __WXWINCE__ if ( !::ReleaseSemaphore(m_semaphore, 1, NULL /* ptr to previous count */) ) +#endif { wxLogLastError(_T("ReleaseSemaphore")); @@ -338,141 +360,6 @@ wxSemaError wxSemaphoreInternal::Post() return wxSEMA_NO_ERROR; } -// -------------------------------------------------------------------------- -// wxCondition -// -------------------------------------------------------------------------- - -// Win32 doesn't have explicit support for the POSIX condition variables and -// the Win32 events have quite different semantics, so we reimplement the -// conditions from scratch using the mutexes and semaphores -class wxConditionInternal -{ -public: - wxConditionInternal(wxMutex& mutex); - - bool IsOk() const { return m_mutex.IsOk() && m_semaphore.IsOk(); } - - wxCondError Wait(); - wxCondError WaitTimeout(unsigned long milliseconds); - - wxCondError Signal(); - wxCondError Broadcast(); - -private: - // the number of threads currently waiting for this condition - LONG m_numWaiters; - - // the critical section protecting m_numWaiters - wxCriticalSection m_csWaiters; - - wxMutex& m_mutex; - wxSemaphore m_semaphore; -}; - -wxConditionInternal::wxConditionInternal(wxMutex& mutex) - : m_mutex(mutex) -{ - // another thread can't access it until we return from ctor, so no need to - // protect access to m_numWaiters here - m_numWaiters = 0; -} - -wxCondError wxConditionInternal::Wait() -{ - // increment the number of waiters - ::InterlockedIncrement(&m_numWaiters); - - m_mutex.Unlock(); - - // a potential race condition can occur here - // - // after a thread increments nwaiters, and unlocks the mutex and before the - // semaphore.Wait() is called, if another thread can cause a signal to be - // generated - // - // this race condition is handled by using a semaphore and incrementing the - // semaphore only if 'nwaiters' is greater that zero since the semaphore, - // can 'remember' signals the race condition will not occur - - // wait ( if necessary ) and decrement semaphore - wxSemaError err = m_semaphore.Wait(); - m_mutex.Lock(); - - return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR : wxCOND_MISC_ERROR; -} - -wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) -{ - ::InterlockedIncrement(&m_numWaiters); - - m_mutex.Unlock(); - - // a race condition can occur at this point in the code - // - // please see the comments in Wait(), for details - - wxSemaError err = m_semaphore.WaitTimeout(milliseconds); - - if ( err == wxSEMA_BUSY ) - { - // another potential race condition exists here it is caused when a - // 'waiting' thread timesout, and returns from WaitForSingleObject, but - // has not yet decremented 'nwaiters'. - // - // at this point if another thread calls signal() then the semaphore - // will be incremented, but the waiting thread will miss it. - // - // to handle this particular case, the waiting thread calls - // WaitForSingleObject again with a timeout of 0, after locking - // 'nwaiters_mutex'. this call does not block because of the zero - // timeout, but will allow the waiting thread to catch the missed - // signals. - wxCriticalSectionLocker lock(m_csWaiters); - - err = m_semaphore.WaitTimeout(0); - - if ( err != wxSEMA_NO_ERROR ) - { - m_numWaiters--; - } - } - - m_mutex.Lock(); - - return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR : wxCOND_MISC_ERROR; -} - -wxCondError wxConditionInternal::Signal() -{ - wxCriticalSectionLocker lock(m_csWaiters); - - if ( m_numWaiters > 0 ) - { - // increment the semaphore by 1 - if ( m_semaphore.Post() != wxSEMA_NO_ERROR ) - return wxCOND_MISC_ERROR; - - m_numWaiters--; - } - - return wxCOND_NO_ERROR; -} - -wxCondError wxConditionInternal::Broadcast() -{ - wxCriticalSectionLocker lock(m_csWaiters); - - while ( m_numWaiters > 0 ) - { - if ( m_semaphore.Post() != wxSEMA_NO_ERROR ) - return wxCOND_MISC_ERROR; - - m_numWaiters--; - } - - return wxCOND_NO_ERROR; -} - // ---------------------------------------------------------------------------- // wxThread implementation // ---------------------------------------------------------------------------- @@ -511,6 +398,15 @@ public: // create a new (suspended) thread (for the given thread object) bool Create(wxThread *thread, unsigned int stackSize); + // wait for the thread to terminate, either by itself, or by asking it + // (politely, this is not Kill()!) to do it + wxThreadError WaitForTerminate(bool shouldCancel, + wxCriticalSection& cs, + wxThread::ExitCode *pRc); + + // kill the thread unconditionally + wxThreadError Kill(); + // suspend/resume/terminate bool Suspend(); bool Resume(); @@ -536,6 +432,8 @@ private: wxThreadState m_state; // state, see wxThreadState enum unsigned int m_priority; // thread priority in "wx" units DWORD m_tid; // thread id + + DECLARE_NO_COPY_CLASS(wxThreadInternal) }; THREAD_RETVAL THREAD_CALLCONV wxThreadInternal::WinThreadStart(void *param) @@ -614,6 +512,9 @@ void wxThreadInternal::SetPriority(unsigned int priority) bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize) { + wxASSERT_MSG( m_state == STATE_NEW && !m_hThread, + _T("Create()ing thread twice?") ); + // for compilers which have it, we should use C RTL function for thread // creation instead of Win32 API one because otherwise we will have memory // leaks if the thread uses C RTL (and most threads do) @@ -662,6 +563,190 @@ bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize) return TRUE; } +wxThreadError wxThreadInternal::Kill() +{ + if ( !::TerminateThread(m_hThread, (DWORD)-1) ) + { + wxLogSysError(_("Couldn't terminate thread")); + + return wxTHREAD_MISC_ERROR; + } + + Free(); + + return wxTHREAD_NO_ERROR; +} + +wxThreadError +wxThreadInternal::WaitForTerminate(bool shouldCancel, + wxCriticalSection& cs, + wxThread::ExitCode *pRc) +{ + wxThread::ExitCode rc = 0; + + // Delete() is always safe to call, so consider all possible states + + // we might need to resume the thread, but we might also not need to cancel + // it if it doesn't run yet + bool shouldResume = FALSE, + isRunning = FALSE; + + // check if the thread already started to run + { + wxCriticalSectionLocker lock(cs); + + if ( m_state == STATE_NEW ) + { + if ( shouldCancel ) + { + // WinThreadStart() will see it and terminate immediately, no need + // to cancel the thread - but we still need to resume it to let it + // run + m_state = STATE_EXITED; + + Resume(); // it knows about STATE_EXITED special case + + shouldCancel = FALSE; + } + + isRunning = TRUE; + + // shouldResume is correctly set to FALSE here + } + else + { + shouldResume = m_state == STATE_PAUSED; + } + } + + // resume the thread if it is paused + if ( shouldResume ) + Resume(); + + // is it still running? + if ( isRunning || m_state == STATE_RUNNING ) + { + if ( wxThread::IsMain() ) + { + // set flag for wxIsWaitingForThread() + gs_waitingForThread = TRUE; + } + + // ask the thread to terminate + if ( shouldCancel ) + { + wxCriticalSectionLocker lock(cs); + + Cancel(); + } + + // we can't just wait for the thread to terminate because it might be + // calling some GUI functions and so it will never terminate before we + // process the Windows messages that result from these functions + // (note that even in console applications we might have to process + // messages if we use wxExecute() or timers or ...) + DWORD result = 0; // suppress warnings from broken compilers + do + { + if ( wxThread::IsMain() ) + { + // give the thread we're waiting for chance to do the GUI call + // it might be in + if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() ) + { + wxMutexGuiLeave(); + } + } + + result = ::MsgWaitForMultipleObjects + ( + 1, // number of objects to wait for + &m_hThread, // the objects + FALSE, // don't wait for all objects + INFINITE, // no timeout + QS_ALLINPUT | // return as soon as there are any events + QS_ALLPOSTMESSAGE + ); + + switch ( result ) + { + case 0xFFFFFFFF: + // error + wxLogSysError(_("Can not wait for thread termination")); + Kill(); + return wxTHREAD_KILLED; + + case WAIT_OBJECT_0: + // thread we're waiting for terminated + break; + + case WAIT_OBJECT_0 + 1: + // new message arrived, process it -- but only if we're the + // main thread as we don't support processing messages in + // the other ones + // + // NB: we still must include QS_ALLINPUT even when waiting + // in a secondary thread because if it had created some + // window somehow (possible not even using wxWindows) + // the system might dead lock then + if ( wxThread::IsMain() ) + { + // it looks that sometimes WAIT_OBJECT_0 + 1 is + // returned but there are no messages in the thread + // queue -- prevent DoMessageFromThreadWait() from + // blocking inside ::GetMessage() forever in this case + ::PostMessage(NULL, WM_NULL, 0, 0); + + wxAppTraits *traits = wxTheApp ? wxTheApp->GetTraits() + : NULL; + + if ( traits && !traits->DoMessageFromThreadWait() ) + { + // WM_QUIT received: kill the thread + Kill(); + + return wxTHREAD_KILLED; + } + } + break; + + default: + wxFAIL_MSG(wxT("unexpected result of MsgWaitForMultipleObject")); + } + } while ( result != WAIT_OBJECT_0 ); + + if ( wxThread::IsMain() ) + { + gs_waitingForThread = FALSE; + } + } + + // although the thread might be already in the EXITED state it might not + // have terminated yet and so we are not sure that it has actually + // terminated if the "if" above hadn't been taken + do + { + if ( !::GetExitCodeThread(m_hThread, (LPDWORD)&rc) ) + { + wxLogLastError(wxT("GetExitCodeThread")); + + rc = (wxThread::ExitCode)-1; + } + } while ( (DWORD)rc == STILL_ACTIVE ); + + if ( pRc ) + *pRc = rc; + + // we don't need the thread handle any more + Free(); + + wxCriticalSectionLocker lock(cs); + SetState(STATE_EXITED); + + return rc == (wxThread::ExitCode)-1 ? wxTHREAD_MISC_ERROR + : wxTHREAD_NO_ERROR; +} + bool wxThreadInternal::Suspend() { DWORD nSuspendCount = ::SuspendThread(m_hThread); @@ -721,10 +806,6 @@ bool wxThread::IsMain() return ::GetCurrentThreadId() == gs_idMainThread; } -#ifdef Yield -#undef Yield -#endif - void wxThread::Yield() { // 0 argument to Sleep() is special and means to just give away the rest of @@ -752,6 +833,7 @@ unsigned long wxThread::GetCurrentId() bool wxThread::SetConcurrency(size_t level) { +#ifndef __WXWINCE__ wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") ); // ok only for the default one @@ -841,7 +923,7 @@ bool wxThread::SetConcurrency(size_t level) return FALSE; } - +#endif return TRUE; } @@ -912,206 +994,18 @@ wxThread::ExitCode wxThread::Wait() // although under Windows we can wait for any thread, it's an error to // wait for a detached one in wxWin API wxCHECK_MSG( !IsDetached(), (ExitCode)-1, - _T("can't wait for detached thread") ); + _T("wxThread::Wait(): can't wait for detached thread") ); ExitCode rc = (ExitCode)-1; - (void)Delete(&rc); - - m_internal->Free(); + (void)m_internal->WaitForTerminate(false, m_critsect, &rc); return rc; } wxThreadError wxThread::Delete(ExitCode *pRc) { - ExitCode rc = 0; - - // Delete() is always safe to call, so consider all possible states - - // we might need to resume the thread, but we might also not need to cancel - // it if it doesn't run yet - bool shouldResume = FALSE, - shouldCancel = TRUE, - isRunning = FALSE; - - // check if the thread already started to run - { - wxCriticalSectionLocker lock(m_critsect); - - if ( m_internal->GetState() == STATE_NEW ) - { - // WinThreadStart() will see it and terminate immediately, no need - // to cancel the thread - but we still need to resume it to let it - // run - m_internal->SetState(STATE_EXITED); - - Resume(); // it knows about STATE_EXITED special case - - shouldCancel = FALSE; - isRunning = TRUE; - - // shouldResume is correctly set to FALSE here - } - else - { - shouldResume = IsPaused(); - } - } - - // resume the thread if it is paused - if ( shouldResume ) - Resume(); - - HANDLE hThread = m_internal->GetHandle(); - - // Check if thread is really still running. There is a - // race condition in WinThreadStart between the time the - // m_internal->m_state is set to STATE_EXITED and the win32 - // thread actually exits. It can be flagged as STATE_EXITED - // and then we don't wait for it to exit. This will cause - // GetExitCodeThread to return STILL_ACTIVE. - if ( !isRunning ) - { - if ( !IsRunning() ) - { - if ( ::GetExitCodeThread(hThread, (LPDWORD)&rc) ) - { - if ((DWORD)rc == STILL_ACTIVE) - isRunning = TRUE; - } - } - else - { - isRunning = TRUE; - } - } - - // does it still run? - if ( isRunning ) - { - if ( IsMain() ) - { - // set flag for wxIsWaitingForThread() - gs_waitingForThread = TRUE; - } - - // ask the thread to terminate - if ( shouldCancel ) - { - wxCriticalSectionLocker lock(m_critsect); - - m_internal->Cancel(); - } - -#if wxUSE_GUI - // we can't just wait for the thread to terminate because it might be - // calling some GUI functions and so it will never terminate before we - // process the Windows messages that result from these functions - DWORD result = 0; // suppress warnings from broken compilers - do - { - if ( IsMain() ) - { - // give the thread we're waiting for chance to do the GUI call - // it might be in - if ( (gs_nWaitingForGui > 0) && wxGuiOwnedByMainThread() ) - { - wxMutexGuiLeave(); - } - } - - result = ::MsgWaitForMultipleObjects - ( - 1, // number of objects to wait for - &hThread, // the objects - FALSE, // don't wait for all objects - INFINITE, // no timeout - QS_ALLINPUT | // return as soon as there are any events - QS_ALLPOSTMESSAGE - ); - - switch ( result ) - { - case 0xFFFFFFFF: - // error - wxLogSysError(_("Can not wait for thread termination")); - Kill(); - return wxTHREAD_KILLED; - - case WAIT_OBJECT_0: - // thread we're waiting for terminated - break; - - case WAIT_OBJECT_0 + 1: - { - MSG peekMsg; - // Check if a new message has really arrived. - // MsgWaitForMultipleObjects can indicate that a message - // is ready for processing, but this message may be sucked - // up by GetMessage and then GetMessage will hang and not - // allow us to process the actual thread exit event. - if (::PeekMessage(&peekMsg, (HWND) NULL, 0, 0, PM_NOREMOVE)) - { - // new message arrived, process it - if ( !wxTheApp->DoMessage() ) - { - // WM_QUIT received: kill the thread - Kill(); - - return wxTHREAD_KILLED; - } - } - } - break; - - default: - wxFAIL_MSG(wxT("unexpected result of MsgWaitForMultipleObject")); - } - } while ( result != WAIT_OBJECT_0 ); -#else // !wxUSE_GUI - // simply wait for the thread to terminate - // - // OTOH, even console apps create windows (in wxExecute, for WinSock - // &c), so may be use MsgWaitForMultipleObject() too here? - if ( WaitForSingleObject(hThread, INFINITE) != WAIT_OBJECT_0 ) - { - wxFAIL_MSG(wxT("unexpected result of WaitForSingleObject")); - } -#endif // wxUSE_GUI/!wxUSE_GUI - - if ( IsMain() ) - { - gs_waitingForThread = FALSE; - } - } - - // although the thread might be already in the EXITED state it might not - // have terminated yet and so we are not sure that it has actually - // terminated if the "if" above hadn't been taken - do - { - if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) ) - { - wxLogLastError(wxT("GetExitCodeThread")); - - rc = (ExitCode)-1; - } - } while ( (DWORD)rc == STILL_ACTIVE ); - - if ( IsDetached() ) - { - // if the thread exits normally, this is done in WinThreadStart, but in - // this case it would have been too early because - // MsgWaitForMultipleObject() would fail if the thread handle was - // closed while we were waiting on it, so we must do it here - delete this; - } - - if ( pRc ) - *pRc = rc; - - return rc == (ExitCode)-1 ? wxTHREAD_MISC_ERROR : wxTHREAD_NO_ERROR; + return m_internal->WaitForTerminate(true, m_critsect, pRc); } wxThreadError wxThread::Kill() @@ -1119,21 +1013,20 @@ wxThreadError wxThread::Kill() if ( !IsRunning() ) return wxTHREAD_NOT_RUNNING; - if ( !::TerminateThread(m_internal->GetHandle(), (DWORD)-1) ) - { - wxLogSysError(_("Couldn't terminate thread")); - - return wxTHREAD_MISC_ERROR; - } - - m_internal->Free(); + wxThreadError rc = m_internal->Kill(); if ( IsDetached() ) { delete this; } + else // joinable + { + // update the status of the joinable thread + wxCriticalSectionLocker lock(m_critsect); + m_internal->SetState(STATE_EXITED); + } - return wxTHREAD_NO_ERROR; + return rc; } void wxThread::Exit(ExitCode status) @@ -1144,6 +1037,12 @@ void wxThread::Exit(ExitCode status) { delete this; } + else // joinable + { + // update the status of the joinable thread + wxCriticalSectionLocker lock(m_critsect); + m_internal->SetState(STATE_EXITED); + } #ifdef wxUSE_BEGIN_THREAD _endthreadex((unsigned)status); @@ -1283,7 +1182,7 @@ void wxThreadModule::OnExit() // not a mutex, so the names are a bit confusing // ---------------------------------------------------------------------------- -void WXDLLEXPORT wxMutexGuiEnter() +void WXDLLIMPEXP_BASE wxMutexGuiEnter() { // this would dead lock everything... wxASSERT_MSG( !wxThread::IsMain(), @@ -1305,7 +1204,7 @@ void WXDLLEXPORT wxMutexGuiEnter() gs_critsectGui->Enter(); } -void WXDLLEXPORT wxMutexGuiLeave() +void WXDLLIMPEXP_BASE wxMutexGuiLeave() { wxCriticalSectionLocker enter(*gs_critsectWaitingForGui); @@ -1327,7 +1226,7 @@ void WXDLLEXPORT wxMutexGuiLeave() gs_critsectGui->Leave(); } -void WXDLLEXPORT wxMutexGuiLeaveOrEnter() +void WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter() { wxASSERT_MSG( wxThread::IsMain(), wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") ); @@ -1357,13 +1256,13 @@ void WXDLLEXPORT wxMutexGuiLeaveOrEnter() } } -bool WXDLLEXPORT wxGuiOwnedByMainThread() +bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread() { return gs_bGuiOwnedByMainThread; } // wake up the main thread if it's in ::GetMessage() -void WXDLLEXPORT wxWakeUpMainThread() +void WXDLLIMPEXP_BASE wxWakeUpMainThread() { // sending any message would do - hopefully WM_NULL is harmless enough if ( !::PostThreadMessage(gs_idMainThread, WM_NULL, 0, 0) ) @@ -1373,7 +1272,7 @@ void WXDLLEXPORT wxWakeUpMainThread() } } -bool WXDLLEXPORT wxIsWaitingForThread() +bool WXDLLIMPEXP_BASE wxIsWaitingForThread() { return gs_waitingForThread; }