#endif
#ifndef WX_PRECOMP
- #include "wx/wx.h"
+# include "wx/wx.h"
#endif
#if wxUSE_THREADS
#include "wx/module.h"
#include "wx/thread.h"
+#ifdef Yield
+# undef Yield
+#endif
+
// must have this symbol defined to get _beginthread/_endthread declarations
#ifndef _MT
#define _MT
#endif
-#ifdef __VISUALC__
+#if defined(__BORLANDC__)
+ #if !defined(__MT__)
+ // I can't set -tWM in the IDE (anyone?) so have to do this
+ #define __MT__
+ #endif
+
+ #if !defined(__MFC_COMPAT__)
+ // Needed to know about _beginthreadex etc..
+ #define __MFC_COMPAT__
+ #endif
+#endif // BC++
+
+// define wxUSE_BEGIN_THREAD if the compiler has _beginthreadex() function
+// which should be used instead of Win32 ::CreateThread() if possible
+#if defined(__VISUALC__) || \
+ (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \
+ (defined(__GNUG__) && defined(__MSVCRT__)) || \
+ defined(__WATCOMC__) || defined(__MWERKS__)
+
+ #undef wxUSE_BEGIN_THREAD
+ #define wxUSE_BEGIN_THREAD
+#endif
+
+#ifdef wxUSE_BEGIN_THREAD
+ // this is where _beginthreadex() is declared
#include <process.h>
+
+ // the return type of the thread function entry point
+ typedef unsigned THREAD_RETVAL;
+
+ // the calling convention of the thread function entry point
+ #define THREAD_CALLCONV __stdcall
+#else
+ // the settings for CreateThread()
+ typedef DWORD THREAD_RETVAL;
+ #define THREAD_CALLCONV WINAPI
#endif
// ----------------------------------------------------------------------------
}
}
- ~wxMutexInternal() { if ( m_mutex ) CloseHandle(m_mutex); }
+ ~wxMutexInternal() { if ( m_mutex ) ::CloseHandle(m_mutex); }
public:
HANDLE m_mutex;
return wxMUTEX_NO_ERROR;
}
-// ----------------------------------------------------------------------------
-// wxCondition implementation
-// ----------------------------------------------------------------------------
+// ==========================================================================
+// wxSemaphore
+// ==========================================================================
-class wxConditionInternal
+// --------------------------------------------------------------------------
+// wxSemaphoreInternal
+// --------------------------------------------------------------------------
+
+class wxSemaphoreInternal
{
public:
- wxConditionInternal()
+ wxSemaphoreInternal( int initialcount = 0, int maxcount = 0 );
+ ~wxSemaphoreInternal();
+
+ void Wait();
+ bool TryWait();
+
+ bool Wait( unsigned long timeout_millis );
+
+ void Post();
+
+private:
+ HANDLE m_semaphore;
+};
+
+wxSemaphoreInternal::wxSemaphoreInternal( int initialcount, int maxcount )
+{
+ if ( maxcount == 0 )
{
- event = ::CreateEvent(
- NULL, // default secutiry
- FALSE, // not manual reset
- FALSE, // nonsignaled initially
- NULL // nameless event
- );
- if ( !event )
- {
- wxLogSysError(_("Can not create event object."));
- }
- waiters = 0;
+ // make it practically infinite
+ maxcount = INT_MAX;
}
- bool Wait(DWORD timeout)
+ m_semaphore = ::CreateSemaphore( NULL, initialcount, maxcount, NULL );
+ if ( !m_semaphore )
{
- waiters++;
+ wxLogLastError(_T("CreateSemaphore()"));
+ }
+}
- // FIXME this should be MsgWaitForMultipleObjects() as well probably
- DWORD rc = ::WaitForSingleObject(event, timeout);
+wxSemaphoreInternal::~wxSemaphoreInternal()
+{
+ CloseHandle( m_semaphore );
+}
- waiters--;
+void wxSemaphoreInternal::Wait()
+{
+ if ( ::WaitForSingleObject( m_semaphore, INFINITE ) != WAIT_OBJECT_0 )
+ {
+ wxLogLastError(_T("WaitForSingleObject"));
+ }
+}
+
+bool wxSemaphoreInternal::TryWait()
+{
+ return Wait(0);
+}
+
+bool wxSemaphoreInternal::Wait( unsigned long timeout_millis )
+{
+ DWORD result = ::WaitForSingleObject( m_semaphore, timeout_millis );
+
+ switch ( result )
+ {
+ case WAIT_OBJECT_0:
+ return TRUE;
- return rc != WAIT_TIMEOUT;
+ case WAIT_TIMEOUT:
+ break;
+
+ default:
+ wxLogLastError(_T("WaitForSingleObject()"));
}
- ~wxConditionInternal()
+ return FALSE;
+}
+
+void wxSemaphoreInternal::Post()
+{
+ if ( !::ReleaseSemaphore( m_semaphore, 1, NULL ) )
{
- if ( event )
+ wxLogLastError(_T("ReleaseSemaphore"));
+ }
+}
+
+// --------------------------------------------------------------------------
+// wxSemaphore
+// --------------------------------------------------------------------------
+
+wxSemaphore::wxSemaphore( int initialcount, int maxcount )
+{
+ m_internal = new wxSemaphoreInternal( initialcount, maxcount );
+}
+
+wxSemaphore::~wxSemaphore()
+{
+ delete m_internal;
+}
+
+void wxSemaphore::Wait()
+{
+ m_internal->Wait();
+}
+
+bool wxSemaphore::TryWait()
+{
+ return m_internal->TryWait();
+}
+
+bool wxSemaphore::Wait( unsigned long timeout_millis )
+{
+ return m_internal->Wait( timeout_millis );
+}
+
+void wxSemaphore::Post()
+{
+ m_internal->Post();
+}
+
+
+// ==========================================================================
+// wxCondition
+// ==========================================================================
+
+// --------------------------------------------------------------------------
+// wxConditionInternal
+// --------------------------------------------------------------------------
+
+class wxConditionInternal
+{
+public:
+ wxConditionInternal(wxMutex& mutex);
+
+ void Wait();
+
+ bool Wait( unsigned long timeout_millis );
+
+ void Signal();
+
+ void Broadcast();
+
+private:
+ int m_numWaiters;
+ wxMutex m_mutexNumWaiters;
+
+ wxMutex& m_mutex;
+
+ wxSemaphore m_semaphore;
+
+ DECLARE_NO_COPY_CLASS(wxConditionInternal)
+};
+
+wxConditionInternal::wxConditionInternal(wxMutex& mutex)
+ : m_mutex(mutex)
+{
+
+ m_numWaiters = 0;
+}
+
+void wxConditionInternal::Wait()
+{
+ // increment the number of waiters
+ m_mutexNumWaiters.Lock();
+ m_numWaiters++;
+ m_mutexNumWaiters.Unlock();
+
+ 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
+ m_semaphore.Wait();
+
+ m_mutex.Lock();
+}
+
+bool wxConditionInternal::Wait( unsigned long timeout_millis )
+{
+ m_mutexNumWaiters.Lock();
+ m_numWaiters++;
+ m_mutexNumWaiters.Unlock();
+
+ m_mutex.Unlock();
+
+ // a race condition can occur at this point in the code
+ //
+ // please see the comments in Wait(), for details
+
+ bool success = TRUE;
+
+ bool result = m_semaphore.Wait( timeout_millis );
+
+ if ( !result )
+ {
+ // 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.
+ m_mutexNumWaiters.Lock();
+ result = m_semaphore.Wait( 0 );
+
+ if ( !result )
{
- if ( !::CloseHandle(event) )
- {
- wxLogLastError("CloseHandle(event)");
- }
+ m_numWaiters--;
+ success = FALSE;
}
+
+ m_mutexNumWaiters.Unlock();
}
- HANDLE event;
- int waiters;
-};
+ m_mutex.Lock();
+
+ return success;
+}
+
+void wxConditionInternal::Signal()
+{
+ m_mutexNumWaiters.Lock();
+
+ if ( m_numWaiters > 0 )
+ {
+ // increment the semaphore by 1
+ m_semaphore.Post();
+
+ m_numWaiters--;
+ }
+
+ m_mutexNumWaiters.Unlock();
+}
-wxCondition::wxCondition()
+void wxConditionInternal::Broadcast()
{
- m_internal = new wxConditionInternal;
+ m_mutexNumWaiters.Lock();
+
+ while ( m_numWaiters > 0 )
+ {
+ m_semaphore.Post();
+ m_numWaiters--;
+ }
+
+ m_mutexNumWaiters.Unlock();
+}
+
+// ----------------------------------------------------------------------------
+// wxCondition implementation
+// ----------------------------------------------------------------------------
+
+wxCondition::wxCondition(wxMutex& mutex)
+{
+ m_internal = new wxConditionInternal( mutex );
}
wxCondition::~wxCondition()
void wxCondition::Wait()
{
- (void)m_internal->Wait(INFINITE);
+ m_internal->Wait();
}
-bool wxCondition::Wait(unsigned long sec,
- unsigned long nsec)
+bool wxCondition::Wait( unsigned long timeout_millis )
{
- return m_internal->Wait(sec*1000 + nsec/1000000);
+ return m_internal->Wait(timeout_millis);
}
void wxCondition::Signal()
{
- // set the event to signaled: if a thread is already waiting on it, it will
- // be woken up, otherwise the event will remain in the signaled state until
- // someone waits on it. In any case, the system will return it to a non
- // signalled state afterwards. If multiple threads are waiting, only one
- // will be woken up.
- if ( !::SetEvent(m_internal->event) )
- {
- wxLogLastError("SetEvent");
- }
+ m_internal->Signal();
}
void wxCondition::Broadcast()
{
- // this works because all these threads are already waiting and so each
- // SetEvent() inside Signal() is really a PulseEvent() because the event
- // state is immediately returned to non-signaled
- for ( int i = 0; i < m_internal->waiters; i++ )
- {
- Signal();
- }
+ m_internal->Broadcast();
}
// ----------------------------------------------------------------------------
wxCriticalSection::wxCriticalSection()
{
- wxASSERT_MSG( sizeof(CRITICAL_SECTION) <= sizeof(m_buffer),
+#ifdef __WXDEBUG__
+ // Done this way to stop warnings during compilation about statement
+ // always being FALSE
+ int csSize = sizeof(CRITICAL_SECTION);
+ int bSize = sizeof(m_buffer);
+ wxASSERT_MSG( csSize <= bSize,
_T("must increase buffer size in wx/thread.h") );
+#endif
::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer);
}
{
if ( !::CloseHandle(m_hThread) )
{
- wxLogLastError("CloseHandle(thread)");
+ wxLogLastError(wxT("CloseHandle(thread)"));
}
m_hThread = 0;
}
// create a new (suspended) thread (for the given thread object)
- bool Create(wxThread *thread);
+ bool Create(wxThread *thread, unsigned int stackSize);
// suspend/resume/terminate
bool Suspend();
DWORD GetId() const { return m_tid; }
// thread function
- static DWORD WinThreadStart(wxThread *thread);
+ static THREAD_RETVAL THREAD_CALLCONV WinThreadStart(void *thread);
private:
HANDLE m_hThread; // handle of the thread
DWORD m_tid; // thread id
};
-DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
+THREAD_RETVAL THREAD_CALLCONV wxThreadInternal::WinThreadStart(void *param)
{
- // first of all, check whether we hadn't been cancelled already
+ THREAD_RETVAL rc;
+ bool wasCancelled;
+
+ // first of all, check whether we hadn't been cancelled already and don't
+ // start the user code at all then
+ wxThread *thread = (wxThread *)param;
if ( thread->m_internal->GetState() == STATE_EXITED )
{
- return (DWORD)-1;
+ rc = (THREAD_RETVAL)-1;
+ wasCancelled = TRUE;
}
-
- // store the thread object in the TLS
- if ( !::TlsSetValue(gs_tlsThisThread, thread) )
+ else // do run thread
{
- wxLogSysError(_("Can not start thread: error writing TLS."));
+ // store the thread object in the TLS
+ if ( !::TlsSetValue(gs_tlsThisThread, thread) )
+ {
+ wxLogSysError(_("Can not start thread: error writing TLS."));
- return (DWORD)-1;
- }
+ return (DWORD)-1;
+ }
- DWORD rc = (DWORD)thread->Entry();
+ rc = (THREAD_RETVAL)thread->Entry();
- // enter m_critsect before changing the thread state
- thread->m_critsect.Enter();
- bool wasCancelled = thread->m_internal->GetState() == STATE_CANCELED;
- thread->m_internal->SetState(STATE_EXITED);
- thread->m_critsect.Leave();
+ // enter m_critsect before changing the thread state
+ thread->m_critsect.Enter();
+ wasCancelled = thread->m_internal->GetState() == STATE_CANCELED;
+ thread->m_internal->SetState(STATE_EXITED);
+ thread->m_critsect.Leave();
+ }
thread->OnExit();
- // if the thread was cancelled (from Delete()), then it the handle is still
+ // if the thread was cancelled (from Delete()), then its handle is still
// needed there
if ( thread->IsDetached() && !wasCancelled )
{
}
}
-bool wxThreadInternal::Create(wxThread *thread)
+bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize)
{
// 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)
-#ifdef __VISUALC__
- typedef unsigned (__stdcall *RtlThreadStart)(void *);
-
- m_hThread = (HANDLE)_beginthreadex(NULL, 0,
- (RtlThreadStart)
- wxThreadInternal::WinThreadStart,
- thread, CREATE_SUSPENDED,
- (unsigned int *)&m_tid);
-#else // !VC++
+#ifdef wxUSE_BEGIN_THREAD
+
+ // Watcom is reported to not like 0 stack size (which means "use default"
+ // for the other compilers and is also the default value for stackSize)
+#ifdef __WATCOMC__
+ if ( !stackSize )
+ stackSize = 10240;
+#endif // __WATCOMC__
+
+ m_hThread = (HANDLE)_beginthreadex
+ (
+ NULL, // default security
+ stackSize,
+ wxThreadInternal::WinThreadStart, // entry point
+ thread,
+ CREATE_SUSPENDED,
+ (unsigned int *)&m_tid
+ );
+#else // compiler doesn't have _beginthreadex
m_hThread = ::CreateThread
(
NULL, // default security
- 0, // default stack size
- (LPTHREAD_START_ROUTINE) // thread entry point
- wxThreadInternal::WinThreadStart, //
+ stackSize, // stack size
+ wxThreadInternal::WinThreadStart, // thread entry point
(LPVOID)thread, // parameter
CREATE_SUSPENDED, // flags
&m_tid // [out] thread id
);
-#endif // VC++/!VC++
+#endif // _beginthreadex/CreateThread
if ( m_hThread == NULL )
{
return FALSE;
}
- m_state = STATE_RUNNING;
+ // don't change the state from STATE_EXITED because it's special and means
+ // we are going to terminate without running any user code - if we did it,
+ // the codei n Delete() wouldn't work
+ if ( m_state != STATE_EXITED )
+ {
+ m_state = STATE_RUNNING;
+ }
return TRUE;
}
return si.dwNumberOfProcessors;
}
+unsigned long wxThread::GetCurrentId()
+{
+ return (unsigned long)::GetCurrentThreadId();
+}
+
bool wxThread::SetConcurrency(size_t level)
{
wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );
if ( hModKernel )
{
pfnSetProcessAffinityMask = (SETPROCESSAFFINITYMASK)
- ::GetProcAddress(hModKernel, _T("SetProcessAffinityMask"));
+ ::GetProcAddress(hModKernel, "SetProcessAffinityMask");
}
// we've discovered a MT version of Win9x!
wxASSERT_MSG( pfnSetProcessAffinityMask,
- _T("this system has several CPUs but no "
- "SetProcessAffinityMask function?") );
+ _T("this system has several CPUs but no SetProcessAffinityMask function?") );
}
if ( !pfnSetProcessAffinityMask )
// create/start thread
// -------------------
-wxThreadError wxThread::Create()
+wxThreadError wxThread::Create(unsigned int stackSize)
{
wxCriticalSectionLocker lock(m_critsect);
- if ( !m_internal->Create(this) )
+ if ( !m_internal->Create(this, stackSize) )
return wxTHREAD_NO_RESOURCE;
return wxTHREAD_NO_ERROR;
// Delete() is always safe to call, so consider all possible states
- // has the thread started to run?
- bool shouldResume = FALSE;
+ // 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
+ // 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);
- shouldResume = TRUE;
+ Resume(); // it knows about STATE_EXITED special case
+
+ shouldCancel = FALSE;
+ isRunning = TRUE;
+
+ // shouldResume is correctly set to FALSE here
+ }
+ else
+ {
+ shouldResume = IsPaused();
}
}
- // is the thread paused?
- if ( shouldResume || IsPaused() )
+ // resume the thread if it is paused
+ if ( shouldResume )
Resume();
HANDLE hThread = m_internal->GetHandle();
// does is still run?
- if ( IsRunning() )
+ if ( isRunning || IsRunning() )
{
if ( IsMain() )
{
}
// ask the thread to terminate
+ if ( shouldCancel )
{
wxCriticalSectionLocker lock(m_critsect);
}
}
- if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
+ // 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
{
- wxLogLastError("GetExitCodeThread");
+ if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
+ {
+ wxLogLastError(wxT("GetExitCodeThread"));
- rc = (ExitCode)-1;
- }
+ 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 therad handle was
+ // MsgWaitForMultipleObject() would fail if the thread handle was
// closed while we were waiting on it, so we must do it here
delete this;
}
- wxASSERT_MSG( (DWORD)rc != STILL_ACTIVE,
- wxT("thread must be already terminated.") );
-
if ( pRc )
*pRc = rc;
delete this;
}
-#ifdef __VISUALC__
+#ifdef wxUSE_BEGIN_THREAD
_endthreadex((unsigned)status);
#else // !VC++
::ExitThread((DWORD)status);
// in normal circumstances it will only happen if all other
// TLS_MINIMUM_AVAILABLE (>= 64) indices are already taken - in other
// words, this should never happen
- wxLogSysError(_("Thread module initialization failed: "
- "impossible to allocate index in thread "
- "local storage"));
+ wxLogSysError(_("Thread module initialization failed: impossible to allocate index in thread local storage"));
return FALSE;
}
::TlsFree(gs_tlsThisThread);
gs_tlsThisThread = 0xFFFFFFFF;
- wxLogSysError(_("Thread module initialization failed: "
- "can not store value in thread local storage"));
+ wxLogSysError(_("Thread module initialization failed: can not store value in thread local storage"));
return FALSE;
}
{
if ( !::TlsFree(gs_tlsThisThread) )
{
- wxLogLastError("TlsFree failed.");
+ wxLogLastError(wxT("TlsFree failed."));
}
if ( gs_critsectGui )
}
else
{
- // decrement the number of waiters now
+ // decrement the number of threads waiting for GUI access now
wxASSERT_MSG( gs_nWaitingForGui > 0,
wxT("calling wxMutexGuiLeave() without entering it first?") );
if ( !::PostThreadMessage(gs_idMainThread, WM_NULL, 0, 0) )
{
// should never happen
- wxLogLastError("PostThreadMessage(WM_NULL)");
+ wxLogLastError(wxT("PostThreadMessage(WM_NULL)"));
}
}
}
#endif // wxUSE_THREADS
+
+// vi:sts=4:sw=4:et
projects / wxWidgets.git / blobdiff