X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/f0f044dcbe59a8085359073abcb41d250c18dac7..ab8576b4acbf68f0aba6feb1d7ba110588a47dfb:/include/wx/thrimpl.cpp diff --git a/include/wx/thrimpl.cpp b/include/wx/thrimpl.cpp index 60ead20789..ba4aa31bb7 100644 --- a/include/wx/thrimpl.cpp +++ b/include/wx/thrimpl.cpp @@ -64,19 +64,11 @@ wxMutexError wxMutex::Unlock() // wxConditionInternal // -------------------------------------------------------------------------- -#if defined(__WXMSW__) || defined(__WXPM__) || defined(__EMX__) // Win32 and OS/2 don't have explicit support for the POSIX condition // variables and their events/event semaphores have quite different semantics, // so we reimplement the conditions from scratch using the mutexes and // semaphores -#if defined(__WXPM__) || defined(__EMX__) -void InterlockedIncrement(LONG *num) -{ - ::DosEnterCritSec(); - (*num)++; - ::DosExitCritSec(); -} -#endif +#if defined(__WXMSW__) || defined(__OS2__) || defined(__EMX__) class wxConditionInternal { @@ -115,30 +107,41 @@ wxConditionInternal::wxConditionInternal(wxMutex& mutex) wxCondError wxConditionInternal::Wait() { // increment the number of waiters - ::InterlockedIncrement(&m_numWaiters); + { + wxCriticalSectionLocker lock(m_csWaiters); + 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 + // after a thread increments m_numWaiters, 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, + // semaphore only if m_numWaiters 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; + if ( err == wxSEMA_NO_ERROR ) + return wxCOND_NO_ERROR; + else if ( err == wxSEMA_TIMEOUT ) + return wxCOND_TIMEOUT; + else + return wxCOND_MISC_ERROR; } wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) { - ::InterlockedIncrement(&m_numWaiters); + { + wxCriticalSectionLocker lock(m_csWaiters); + m_numWaiters++; + } m_mutex.Unlock(); @@ -148,25 +151,25 @@ wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) wxSemaError err = m_semaphore.WaitTimeout(milliseconds); - if ( err == wxSEMA_BUSY ) + if ( err == wxSEMA_TIMEOUT ) { // another potential race condition exists here it is caused when a - // 'waiting' thread timesout, and returns from WaitForSingleObject, but - // has not yet decremented 'nwaiters'. + // 'waiting' thread times out, and returns from WaitForSingleObject, + // but has not yet decremented m_numWaiters // // 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 + // m_csWaiters. 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); + wxSemaError err2 = m_semaphore.WaitTimeout(0); - if ( err != wxSEMA_NO_ERROR ) + if ( err2 != wxSEMA_NO_ERROR ) { m_numWaiters--; } @@ -174,7 +177,9 @@ wxCondError wxConditionInternal::WaitTimeout(unsigned long milliseconds) m_mutex.Lock(); - return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR : wxCOND_MISC_ERROR; + return err == wxSEMA_NO_ERROR ? wxCOND_NO_ERROR + : err == wxSEMA_TIMEOUT ? wxCOND_TIMEOUT + : wxCOND_MISC_ERROR; } wxCondError wxConditionInternal::Signal() @@ -207,7 +212,8 @@ wxCondError wxConditionInternal::Broadcast() return wxCOND_NO_ERROR; } -#endif + +#endif // MSW or OS2 // ---------------------------------------------------------------------------- // wxCondition