Applied patch from Mark Armstrong <marka@availsolutions.com>

This patch fixes two problems.
The first is a race condition during a thread exit and a join.
The second is condition where a thread can hang during
msg/event processing.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16031 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/src/msw/thread.cpp b/src/msw/thread.cpp
index d93d017704c2d27c7abe938b44eee16dd8d89bc1..2180ddd994e8a548c97498fb39de7e8eb51b61aa 100644 (file)
--- a/src/msw/thread.cpp
+++ b/src/msw/thread.cpp
@@ -965,8 +965,30 @@ wxThreadError wxThread::Delete(ExitCode *pRc)
 
     HANDLE hThread = m_internal->GetHandle();
 
 
     HANDLE hThread = m_internal->GetHandle();
 

-    // does is still run?
-    if ( isRunning || IsRunning() )
+       // 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() )
         {
     {
         if ( IsMain() )
         {


@@ -1022,13 +1044,24 @@ wxThreadError wxThread::Delete(ExitCode *pRc)
                     break;
 
                 case WAIT_OBJECT_0 + 1:
                     break;
 
                 case WAIT_OBJECT_0 + 1:

-                    // new message arrived, process it
-                    if ( !wxTheApp->DoMessage() )

                     {
                     {

-                        // WM_QUIT received: kill the thread
-                        Kill();
-
-                        return wxTHREAD_KILLED;
+                        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;
 
                     }
                     break;