// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-#ifdef __GNUG__
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation "thread.h"
#endif
(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 <process.h>
wxSemaphoreInternal::wxSemaphoreInternal(int initialcount, int maxcount)
{
+#ifndef __WXWINCE__
if ( maxcount == 0 )
{
// make it practically infinite
maxcount,
NULL // no name
);
-
+#endif
if ( !m_semaphore )
{
wxLogLastError(_T("CreateSemaphore()"));
wxSemaError wxSemaphoreInternal::Post()
{
+#ifndef __WXWINCE__
if ( !::ReleaseSemaphore(m_semaphore, 1, NULL /* ptr to previous count */) )
+#endif
{
wxLogLastError(_T("ReleaseSemaphore"));
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
// ----------------------------------------------------------------------------
// 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();
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);
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
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
return FALSE;
}
-
+#endif
return TRUE;
}
// 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();
-
- // does is still run?
- if ( isRunning || IsRunning() )
- {
- if ( IsMain() )
- {
- // set flag for wxIsWaitingForThread()
- gs_waitingForThread = TRUE;
- }
-
- // ask the thread to terminate
- if ( shouldCancel )
- {
- wxCriticalSectionLocker lock(m_critsect);
-
- m_internal->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 ( 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:
- // new message arrived, process it
- {
- 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 ( 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()
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() )
{
m_internal->SetState(STATE_EXITED);
}
- return wxTHREAD_NO_ERROR;
+ return rc;
}
void wxThread::Exit(ExitCode status)
projects / wxWidgets.git / blobdiff