typo fixed: should be lpthread, not -lpthread in THREAD_OPTS

[wxWidgets.git] / src / msw / thread.cpp

diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp
index 66efdf36ac33b01ec87a1a4c6c68611cebeef763..e2c76f9389403c4964138f1eb591905d9e6a4837 100644 (file)
--- a/src/msw/thread.cpp
+++ b/src/msw/thread.cpp
@@ -45,21 +45,42 @@
     #define _MT
 #endif
 
     #define _MT
 #endif
 

+#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)) || \
 #if defined(__VISUALC__) || \
     (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \

-    (defined(__GNUG__) && defined(__MSVCRT__))
-
-#if defined(__BORLANDC__) && !defined(__MT__)
-// I can't set -tWM in the IDE (anyone?) so have to do this
-#define __MT__
-#endif
+    (defined(__GNUG__) && defined(__MSVCRT__)) || \
+    defined(__WATCOMC__)

 
 

-#if defined(__BORLANDC__) && !defined(__MFC_COMPAT__)
-// Needed to know about _beginthreadex etc..
-#define __MFC_COMPAT__
+    #undef wxUSE_BEGIN_THREAD
+    #define wxUSE_BEGIN_THREAD

 #endif
 
 #endif
 

+#ifdef wxUSE_BEGIN_THREAD
+    // this is where _beginthreadex() is declared

     #include <process.h>
     #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
 
 // ----------------------------------------------------------------------------
 #endif
 
 // ----------------------------------------------------------------------------


@@ -125,7 +146,7 @@ public:
         }
     }
 
         }
     }
 

-    ~wxMutexInternal() { if ( m_mutex ) CloseHandle(m_mutex); }
+    ~wxMutexInternal() { if ( m_mutex ) ::CloseHandle(m_mutex); }

 
 public:
     HANDLE m_mutex;
 
 public:
     HANDLE m_mutex;


@@ -202,92 +223,272 @@ wxMutexError wxMutex::Unlock()
     return wxMUTEX_NO_ERROR;
 }
 
     return wxMUTEX_NO_ERROR;
 }
 

-// ----------------------------------------------------------------------------
-// wxCondition implementation
-// ----------------------------------------------------------------------------
+// ==========================================================================
+// wxSemaphore
+// ==========================================================================

 
 

-class wxConditionInternal
+// --------------------------------------------------------------------------
+// wxSemaphoreInternal
+// --------------------------------------------------------------------------
+
+class wxSemaphoreInternal

 {
 public:
 {
 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 )

     {
     {

-        m_hEvent = ::CreateEvent(
-                                 NULL,   // default secutiry
-                                 FALSE,  // not manual reset
-                                 FALSE,  // nonsignaled initially
-                                 NULL    // nameless event
-                                );
-        if ( !m_hEvent )
-        {
-            wxLogSysError(_("Can not create event object."));
-        }
+        // make it practically infinite
+        maxcount = INT_MAX;
+    }

 
 

-        // nobody waits for us yet
-        m_nWaiters = 0;
+    m_semaphore = ::CreateSemaphore( NULL, initialcount, maxcount, NULL );
+    if ( !m_semaphore )
+    {
+        wxLogLastError(_T("CreateSemaphore()"));

     }
     }

+}
+
+wxSemaphoreInternal::~wxSemaphoreInternal()
+{
+    CloseHandle( m_semaphore );
+}

 
 

-    bool Wait(DWORD timeout)
+void wxSemaphoreInternal::Wait()
+{
+    if ( ::WaitForSingleObject( m_semaphore, INFINITE ) != WAIT_OBJECT_0 )

     {
     {

-        // as m_nWaiters variable is accessed from multiple waiting threads
-        // (and possibly from the broadcasting thread), we need to change its
-        // value atomically
-        ::InterlockedIncrement(&m_nWaiters);
+        wxLogLastError(_T("WaitForSingleObject"));
+    }
+}

 
 

-        // FIXME this should be MsgWaitForMultipleObjects() as we want to keep
-        //       processing Windows messages while waiting (or don't we?)
-        DWORD rc = ::WaitForSingleObject(m_hEvent, timeout);
+bool wxSemaphoreInternal::TryWait()
+{
+    return Wait(0);
+}

 
 

-        ::InterlockedDecrement(&m_nWaiters);
+bool wxSemaphoreInternal::Wait( unsigned long timeout_millis )
+{
+    DWORD result = ::WaitForSingleObject( m_semaphore, timeout_millis );

 
 

-        return rc != WAIT_TIMEOUT;
+    switch ( result )
+    {
+        case WAIT_OBJECT_0:
+           return TRUE;
+
+        case WAIT_TIMEOUT:
+           break;
+
+        default:
+            wxLogLastError(_T("WaitForSingleObject()"));

     }
 
     }
 

-    void Signal()
+    return FALSE;
+}
+
+void wxSemaphoreInternal::Post()
+{
+    if ( !::ReleaseSemaphore( m_semaphore, 1, NULL ) )

     {
     {

-        // 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_hEvent) )
-        {
-            wxLogLastError(wxT("SetEvent"));
-        }
+        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
+// --------------------------------------------------------------------------

 
 

-    void Broadcast()
+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 )

     {
     {

-        // 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 ( LONG n = 0; n < m_nWaiters; n++ )
+        // 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 )

         {
         {

-            Signal();
+            m_numWaiters--;
+            success = FALSE;

         }
         }

+
+        m_mutexNumWaiters.Unlock();
+    }
+
+    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--;

     }
 
     }
 

-    ~wxConditionInternal()
+    m_mutexNumWaiters.Unlock();
+}
+
+void wxConditionInternal::Broadcast()
+{
+    m_mutexNumWaiters.Lock();
+
+    while ( m_numWaiters > 0 )

     {
     {

-        if ( m_hEvent )
-        {
-            if ( !::CloseHandle(m_hEvent) )
-            {
-                wxLogLastError(wxT("CloseHandle(event)"));
-            }
-        }
+        m_semaphore.Post();
+        m_numWaiters--;

     }
 
     }
 

-private:
-    // the Win32 synchronization object corresponding to this event
-    HANDLE m_hEvent;
+    m_mutexNumWaiters.Unlock();
+}

 
 

-    // number of threads waiting for this condition
-    LONG m_nWaiters;
-};
+// ----------------------------------------------------------------------------
+// wxCondition implementation
+// ----------------------------------------------------------------------------

 
 

-wxCondition::wxCondition()
+wxCondition::wxCondition(wxMutex& mutex)

 {
 {

-    m_internal = new wxConditionInternal;
+    m_internal = new wxConditionInternal( mutex );

 }
 
 wxCondition::~wxCondition()
 }
 
 wxCondition::~wxCondition()


@@ -297,13 +498,12 @@ wxCondition::~wxCondition()
 
 void wxCondition::Wait()
 {
 
 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()
 }
 
 void wxCondition::Signal()


@@ -322,8 +522,14 @@ void wxCondition::Broadcast()
 
 wxCriticalSection::wxCriticalSection()
 {
 
 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") );
                   _T("must increase buffer size in wx/thread.h") );

+#endif

 
     ::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer);
 }
 
     ::InitializeCriticalSection((CRITICAL_SECTION *)m_buffer);
 }


@@ -379,7 +585,7 @@ public:
     }
 
     // create a new (suspended) thread (for the given thread object)
     }
 
     // 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();
 
     // suspend/resume/terminate
     bool Suspend();


@@ -399,7 +605,7 @@ public:
     DWORD  GetId() const { return m_tid; }
 
     // thread function
     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
 
 private:
     HANDLE        m_hThread;    // handle of the thread


@@ -408,16 +614,17 @@ private:
     DWORD         m_tid;        // thread id
 };
 
     DWORD         m_tid;        // thread id
 };
 

-DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
+THREAD_RETVAL THREAD_CALLCONV wxThreadInternal::WinThreadStart(void *param)

 {
 {

-    DWORD rc;
+    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
     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 )
     {
     if ( thread->m_internal->GetState() == STATE_EXITED )
     {

-        rc = (DWORD)-1;
+        rc = (THREAD_RETVAL)-1;

         wasCancelled = TRUE;
     }
     else // do run thread
         wasCancelled = TRUE;
     }
     else // do run thread


@@ -430,7 +637,7 @@ DWORD wxThreadInternal::WinThreadStart(wxThread *thread)
             return (DWORD)-1;
         }
 
             return (DWORD)-1;
         }
 

-        rc = (DWORD)thread->Entry();
+        rc = (THREAD_RETVAL)thread->Entry();

 
         // enter m_critsect before changing the thread state
         thread->m_critsect.Enter();
 
         // enter m_critsect before changing the thread state
         thread->m_critsect.Enter();


@@ -481,28 +688,35 @@ void wxThreadInternal::SetPriority(unsigned int priority)
     }
 }
 
     }
 }
 

-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)
 {
     // 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)

-#if defined(__VISUALC__) || \
-    (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \
-    (defined(__GNUG__) && defined(__MSVCRT__))
-    typedef unsigned (__stdcall *RtlThreadStart)(void *);
-
-    m_hThread = (HANDLE)_beginthreadex(NULL, 0,
-                                       (RtlThreadStart)
-                                       wxThreadInternal::WinThreadStart,
-                                       thread, CREATE_SUSPENDED,
-                                       (unsigned int *)&m_tid);
+#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
 #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
                     (LPVOID)thread,                     // parameter
                     CREATE_SUSPENDED,                   // flags
                     &m_tid                              // [out] thread id


@@ -607,6 +821,11 @@ int wxThread::GetCPUCount()
     return si.dwNumberOfProcessors;
 }
 
     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") );
 bool wxThread::SetConcurrency(size_t level)
 {
     wxASSERT_MSG( IsMain(), _T("should only be called from the main thread") );


@@ -720,11 +939,11 @@ wxThread::~wxThread()
 // create/start thread
 // -------------------
 
 // create/start thread
 // -------------------
 

-wxThreadError wxThread::Create()
+wxThreadError wxThread::Create(unsigned int stackSize)

 {
     wxCriticalSectionLocker lock(m_critsect);
 
 {
     wxCriticalSectionLocker lock(m_critsect);
 

-    if ( !m_internal->Create(this) )
+    if ( !m_internal->Create(this, stackSize) )

         return wxTHREAD_NO_RESOURCE;
 
     return wxTHREAD_NO_ERROR;
         return wxTHREAD_NO_RESOURCE;
 
     return wxTHREAD_NO_ERROR;


@@ -918,12 +1137,18 @@ wxThreadError wxThread::Delete(ExitCode *pRc)
         }
     }
 
         }
     }
 

-    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(wxT("GetExitCodeThread"));
+        if ( !::GetExitCodeThread(hThread, (LPDWORD)&rc) )
+        {
+            wxLogLastError(wxT("GetExitCodeThread"));

 
 

-        rc = (ExitCode)-1;
-    }
+            rc = (ExitCode)-1;
+        }
+    } while ( (DWORD)rc == STILL_ACTIVE );

 
     if ( IsDetached() )
     {
 
     if ( IsDetached() )
     {


@@ -934,9 +1159,6 @@ wxThreadError wxThread::Delete(ExitCode *pRc)
         delete this;
     }
 
         delete this;
     }
 

-    wxASSERT_MSG( (DWORD)rc != STILL_ACTIVE,
-                  wxT("thread must be already terminated.") );
-

     if ( pRc )
         *pRc = rc;
 
     if ( pRc )
         *pRc = rc;
 


@@ -974,9 +1196,7 @@ void wxThread::Exit(ExitCode status)
         delete this;
     }
 
         delete this;
     }
 

-#if defined(__VISUALC__) || \
-    (defined(__BORLANDC__) && (__BORLANDC__ >= 0x500)) || \
-    (defined(__GNUG__) && defined(__MSVCRT__))
+#ifdef wxUSE_BEGIN_THREAD

     _endthreadex((unsigned)status);
 #else // !VC++
     ::ExitThread((DWORD)status);
     _endthreadex((unsigned)status);
 #else // !VC++
     ::ExitThread((DWORD)status);


@@ -1210,3 +1430,5 @@ bool WXDLLEXPORT wxIsWaitingForThread()
 }
 
 #endif // wxUSE_THREADS
 }
 
 #endif // wxUSE_THREADS

+
+// vi:sts=4:sw=4:et