Cygwin/X: Store pthread_ids and chain IOError handlers to avoid longjmp across threads

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>

2 files changed, 53 insertions, 25 deletions

diff --git a/hw/xwin/winclipboardthread.c b/hw/xwin/winclipboardthread.c
index 9788d883b..ea9459910 100644
--- a/hw/xwin/winclipboardthread.c
+++ b/hw/xwin/winclipboardthread.c
@@ -58,6 +58,9 @@ extern Window		g_iClipboardWindow;
  */
 
 static jmp_buf			g_jmpEntry;
+static XIOErrorHandler g_winClipboardOldIOErrorHandler;
+static pthread_t g_winClipboardProcThread;
+
 Bool				g_fUnicodeSupport = FALSE;
 Bool				g_fUseUnicode = FALSE;
 
@@ -126,6 +129,11 @@ winClipboardProc (void *pvNotUsed)
       ErrorF ("winClipboardProc - Warning: Locale not supported by X.\n");
     }
 
+  /* Set error handler */
+  XSetErrorHandler (winClipboardErrorHandler);
+  g_winClipboardProcThread = pthread_self();
+  g_winClipboardOldIOErrorHandler = XSetIOErrorHandler (winClipboardIOErrorHandler);
+
   /* Set jump point for Error exits */
   iReturn = setjmp (g_jmpEntry);
   
@@ -148,10 +156,6 @@ winClipboardProc (void *pvNotUsed)
   /* Use our generated cookie for authentication */
   winSetAuthorization();
 
-  /* Set error handler */
-  XSetErrorHandler (winClipboardErrorHandler);
-  XSetIOErrorHandler (winClipboardIOErrorHandler);
-
   /* Initialize retry count */
   iRetries = 0;
 
@@ -462,9 +466,15 @@ winClipboardIOErrorHandler (Display *pDisplay)
 {
   ErrorF ("winClipboardIOErrorHandler!\n\n");
 
-  /* Restart at the main entry point */
-  longjmp (g_jmpEntry, WIN_JMP_ERROR_IO);
-  
+  if (pthread_equal(pthread_self(),g_winClipboardProcThread))
+    {
+      /* Restart at the main entry point */
+      longjmp (g_jmpEntry, WIN_JMP_ERROR_IO);
+    }
+
+  if (g_winClipboardOldIOErrorHandler)
+    g_winClipboardOldIOErrorHandler(pDisplay);
+
   return 0;
 }
 
diff --git a/hw/xwin/winmultiwindowwm.c b/hw/xwin/winmultiwindowwm.c
index 6c2812c6f..c507ca1b3 100644
--- a/hw/xwin/winmultiwindowwm.c
+++ b/hw/xwin/winmultiwindowwm.c
@@ -206,7 +206,11 @@ winUpdateWindowPosition (HWND hWnd, Bool reshape, HWND *zstyle);
  */
 
 static jmp_buf			g_jmpWMEntry;
+static XIOErrorHandler g_winMultiWindowWMOldIOErrorHandler;
+static pthread_t g_winMultiWindowWMThread;
 static jmp_buf			g_jmpXMsgProcEntry;
+static XIOErrorHandler g_winMultiWindowXMsgProcOldIOErrorHandler;
+static pthread_t g_winMultiWindowXMsgProcThread;
 static Bool			g_shutdown = FALSE;
 static Bool			redirectError = FALSE;
 static Bool			g_fAnotherWMRunning = FALSE;
@@ -910,9 +914,14 @@ winMultiWindowXMsgProc (void *pArg)
 
   ErrorF ("winMultiWindowXMsgProc - pthread_mutex_unlock () returned.\n");
 
+  /* Install our error handler */
+  XSetErrorHandler (winMultiWindowXMsgProcErrorHandler);
+  g_winMultiWindowXMsgProcThread = pthread_self();
+  g_winMultiWindowXMsgProcOldIOErrorHandler = XSetIOErrorHandler (winMultiWindowXMsgProcIOErrorHandler);
+
   /* Set jump point for IO Error exits */
   iReturn = setjmp (g_jmpXMsgProcEntry);
-  
+
   /* Check if we should continue operations */
   if (iReturn != WIN_JMP_ERROR_IO
       && iReturn != WIN_JMP_OKAY)
@@ -928,10 +937,6 @@ winMultiWindowXMsgProc (void *pArg)
       pthread_exit (NULL);
     }
 
-  /* Install our error handler */
-  XSetErrorHandler (winMultiWindowXMsgProcErrorHandler);
-  XSetIOErrorHandler (winMultiWindowXMsgProcIOErrorHandler);
-
   /* Setup the display connection string x */
   winGetDisplayName(pszDisplay, (int)pProcArg->dwScreen);
 
@@ -1292,9 +1297,14 @@ winInitMultiWindowWM (WMInfoPtr pWMInfo, WMProcArgPtr pProcArg)
 
   ErrorF ("winInitMultiWindowWM - pthread_mutex_unlock () returned.\n");
 
+  /* Install our error handler */
+  XSetErrorHandler (winMultiWindowWMErrorHandler);
+  g_winMultiWindowWMThread = pthread_self();
+  g_winMultiWindowWMOldIOErrorHandler = XSetIOErrorHandler (winMultiWindowWMIOErrorHandler);
+
   /* Set jump point for IO Error exits */
   iReturn = setjmp (g_jmpWMEntry);
-  
+
   /* Check if we should continue operations */
   if (iReturn != WIN_JMP_ERROR_IO
       && iReturn != WIN_JMP_OKAY)
@@ -1310,10 +1320,6 @@ winInitMultiWindowWM (WMInfoPtr pWMInfo, WMProcArgPtr pProcArg)
       pthread_exit (NULL);
     }
 
-  /* Install our error handler */
-  XSetErrorHandler (winMultiWindowWMErrorHandler);
-  XSetIOErrorHandler (winMultiWindowWMIOErrorHandler);
-
   /* Setup the display connection string x */
   winGetDisplayName(pszDisplay, (int)pProcArg->dwScreen);
 
@@ -1436,12 +1442,18 @@ winMultiWindowWMIOErrorHandler (Display *pDisplay)
 {
   ErrorF ("winMultiWindowWMIOErrorHandler!\n\n");
 
-  if (g_shutdown)
-    pthread_exit(NULL);
+  if (pthread_equal(pthread_self(),g_winMultiWindowWMThread))
+    {
+      if (g_shutdown)
+        pthread_exit(NULL);
+
+      /* Restart at the main entry point */
+      longjmp (g_jmpWMEntry, WIN_JMP_ERROR_IO);
+    }
+
+  if (g_winMultiWindowWMOldIOErrorHandler)
+    g_winMultiWindowWMOldIOErrorHandler(pDisplay);
 
-  /* Restart at the main entry point */
-  longjmp (g_jmpWMEntry, WIN_JMP_ERROR_IO);
-  
   return 0;
 }
 
@@ -1476,9 +1488,15 @@ winMultiWindowXMsgProcIOErrorHandler (Display *pDisplay)
 {
   ErrorF ("winMultiWindowXMsgProcIOErrorHandler!\n\n");
 
-  /* Restart at the main entry point */
-  longjmp (g_jmpXMsgProcEntry, WIN_JMP_ERROR_IO);
-  
+  if (pthread_equal(pthread_self(),g_winMultiWindowXMsgProcThread))
+    {
+      /* Restart at the main entry point */
+      longjmp (g_jmpXMsgProcEntry, WIN_JMP_ERROR_IO);
+    }
+
+  if (g_winMultiWindowXMsgProcOldIOErrorHandler)
+    g_winMultiWindowXMsgProcOldIOErrorHandler(pDisplay);
+
   return 0;
 }