1 files changed, 812 insertions, 0 deletions
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Reconnect.c b/nx-X11/programs/Xserver/hw/nxagent/Reconnect.c
new file mode 100644
index 000000000..90b80799c
--- /dev/null
+++ b/nx-X11/programs/Xserver/hw/nxagent/Reconnect.c
@@ -0,0 +1,812 @@
+/**************************************************************************/
+/*                                                                        */
+/* Copyright (c) 2001, 2011 NoMachine, http://www.nomachine.com/.         */
+/*                                                                        */
+/* NXAGENT, NX protocol compression and NX extensions to this software    */
+/* are copyright of NoMachine. Redistribution and use of the present      */
+/* software is allowed according to terms specified in the file LICENSE   */
+/* which comes in the source distribution.                                */
+/*                                                                        */
+/* Check http://www.nomachine.com/licensing.html for applicability.       */
+/*                                                                        */
+/* NX and NoMachine are trademarks of Medialogic S.p.A.                   */
+/*                                                                        */
+/* All rights reserved.                                                   */
+/*                                                                        */
+/**************************************************************************/
+
+#include <signal.h>
+
+#include "X.h"
+#include "Xproto.h"
+#include "Xpoll.h"
+#include "mi.h"
+#include "fb.h"
+#include "inputstr.h"
+
+#include "Agent.h"
+#include "Atoms.h"
+#include "Drawable.h"
+#include "Client.h"
+#include "Reconnect.h"
+#include "Display.h"
+#include "Dialog.h"
+#include "Screen.h"
+#include "Windows.h"
+#include "Events.h"
+#include "Dialog.h"
+#include "Args.h"
+#include "Font.h"
+#include "GCs.h"
+#include "Trap.h"
+#include "Keyboard.h"
+#include "Composite.h"
+#include "Millis.h"
+#include "Splash.h"
+#include "Error.h"
+
+#ifdef XKB
+#include "XKBsrv.h"
+#endif
+
+#include "NX.h"
+#include "NXlib.h"
+#include "NXalert.h"
+
+/*
+ * Set here the required log level.
+ */
+
+#define PANIC
+#define WARNING
+#undef  TEST
+#undef  DEBUG
+
+#define NXAGENT_RECONNECT_DEFAULT_MESSAGE_SIZE  32
+
+extern Bool nxagentReconnectAllCursor(void*);
+extern Bool nxagentReconnectAllColormap(void*);
+extern Bool nxagentReconnectAllWindows(void*);
+extern Bool nxagentReconnectAllGlyphSet(void*);
+extern Bool nxagentReconnectAllPictFormat(void*);
+extern Bool nxagentReconnectAllPicture(void*);
+
+extern Bool nxagentDisconnectAllPicture(void);
+extern Bool nxagentDisconnectAllWindows(void);
+extern Bool nxagentDisconnectAllCursor(void);
+
+extern Bool nxagentReconnectFailedFonts(void*);
+extern Bool nxagentInstallFontServerPath(void);
+extern Bool nxagentUninstallFontServerPath(void);
+
+extern void nxagentRemoveXConnection(void);
+
+extern void nxagentInitPointerMap(void);
+
+static char *nxagentGetReconnectError(void);
+
+void nxagentInitializeRecLossyLevel(void);
+
+static char *nxagentReconnectErrorMessage = NULL;
+static int  nxagentReconnectErrorId;
+
+extern Bool nxagentRenderEnable;
+
+extern char *nxagentKeyboard;
+
+enum SESSION_STATE nxagentSessionState = SESSION_STARTING;
+
+struct nxagentExceptionStruct nxagentException = {0, 0};
+
+enum RECONNECTION_STEP
+{
+  DISPLAY_STEP = 0,
+  SCREEN_STEP,
+  FONT_STEP,
+  PIXMAP_STEP,
+  GC_STEP,
+  CURSOR_STEP,
+  COLORMAP_STEP,
+  WINDOW_STEP,
+  GLYPHSET_STEP,
+  PICTFORMAT_STEP,
+  PICTURE_STEP,
+  STEP_NONE
+};
+
+void *reconnectLossyLevel[STEP_NONE];
+
+static enum RECONNECTION_STEP failedStep;
+
+int nxagentHandleConnectionStates(void)
+{
+  #ifdef TEST
+  fprintf(stderr, "nxagentHandleConnectionStates: Handling Exception with "
+              "state [%s] and transport [%d] and generation [%ld].\n",
+                  DECODE_SESSION_STATE(nxagentSessionState), NXTransRunning(NX_FD_ANY), serverGeneration);
+  fprintf(stderr, "nxagentHandleConnectionStates: Entering with nxagentException.sigHup = [%d], "
+              "nxagentException.ioError = [%d]\n",
+                  nxagentException.sigHup, nxagentException.ioError);
+  #endif
+
+  if (nxagentException.sigHup > 0)
+  {
+    #ifdef TEST
+    fprintf(stderr, "nxagentHandleConnectionStates: Got SIGHUP in the exception flags.\n");
+    #endif
+
+    nxagentException.sigHup = 0;
+
+    if (nxagentSessionState == SESSION_UP)
+    {
+      if (nxagentOption(Persistent))
+      {
+        nxagentSessionState = SESSION_GOING_DOWN;
+
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConnectionStates: Handling "
+                    "signal [SIGHUP] by disconnecting the agent.\n");
+
+        #endif
+
+      }
+      else
+      {
+        nxagentTerminateSession();
+      }
+    }
+    else if (nxagentSessionState == SESSION_STARTING)
+    {
+      nxagentTerminateSession();
+
+      #ifdef WARNING
+      fprintf(stderr, "nxagentHandleConnectionStates: Handling signal [SIGHUP] by terminating the agent.\n");
+      #endif
+    }
+    else if (nxagentSessionState == SESSION_DOWN &&
+                 NXTransRunning(NX_FD_ANY) == 0)
+    {
+      nxagentSessionState = SESSION_GOING_UP;
+
+      #ifdef TEST
+      fprintf(stderr, "nxagentHandleConnectionStates: Handling signal [SIGHUP] by reconnecting the agent.\n");
+      #endif
+    }
+    else
+    {
+      #ifdef TEST
+      fprintf(stderr, "nxagentHandleConnectionStates: Handling signal with state [%s] and exception [%d].\n",
+                  DECODE_SESSION_STATE(nxagentSessionState), dispatchException);
+      #endif
+    }
+  }
+
+  if (nxagentNeedConnectionChange() == 1)
+  {
+    #ifdef TEST
+    fprintf(stderr, "nxagentHandleConnectionStates: Calling nxagentHandleConnectionChanges "
+                "with ioError [%d] sigHup [%d].\n", nxagentException.ioError, nxagentException.sigHup);
+    #endif
+
+    nxagentHandleConnectionChanges();
+  }
+
+  if (nxagentException.ioError > 0)
+  {
+    #ifdef TEST
+    fprintf(stderr, "nxagentHandleConnectionStates: Got I/O error in the exception flags.\n");
+    #endif
+/*
+TODO: This should be reset only when
+      the state became SESSION_DOWN.
+*/
+    nxagentException.ioError = 0;
+
+    if (nxagentOption(Persistent) == 1 && nxagentSessionState != SESSION_STARTING)
+    {
+      if (nxagentSessionState == SESSION_UP)
+      {
+        if ((dispatchException & DE_TERMINATE) == 0)
+        {
+          fprintf(stderr, "Session: Display failure detected at '%s'.\n", GetTimeAsString());
+
+          fprintf(stderr, "Session: Suspending session at '%s'.\n", GetTimeAsString());
+        }
+
+        nxagentDisconnectSession();
+      }
+      else if (nxagentSessionState == SESSION_GOING_DOWN)
+      {
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConnectionStates: Got I/O error with session "
+                    "[SESSION_GOING_DOWN].\n");
+        #endif
+      }
+      else if (nxagentSessionState == SESSION_GOING_UP)
+      {
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConnectionStates: Got I/O error with session "
+                    "[SESSION_GOING_UP].\n");
+        #endif
+
+        nxagentSessionState = SESSION_GOING_DOWN;
+
+        nxagentSetReconnectError(FAILED_RESUME_DISPLAY_BROKEN_ALERT,
+                                     "Got I/O error during reconnect.");
+
+        nxagentChangeOption(Fullscreen, False);
+
+        return 1;
+      }
+      else if (nxagentSessionState == SESSION_DOWN)
+      {
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConnectionStates: Got I/O error with session "
+                    "[SESSION_DOWN]. Ignoring.\n");
+        #endif
+
+        return 1;
+      }
+      else
+      {
+        #ifdef TEST
+        fprintf(stderr, "nxagentHandleConnectionStates: Got I/O error with session "
+                    "[%d].\n", nxagentSessionState);
+        #endif
+      }
+
+      nxagentSessionState = SESSION_DOWN;
+
+      if ((dispatchException & DE_TERMINATE) == 0)
+      {
+        #ifdef NX_DEBUG_INPUT
+        fprintf(stderr, "Session: Session suspended at '%s' timestamp [%lu].\n", GetTimeAsString(), GetTimeInMillis());
+        #else
+        fprintf(stderr, "Session: Session suspended at '%s'.\n", GetTimeAsString());
+        #endif
+      }
+
+      nxagentResetDisplayHandlers();
+
+      return 1;
+    }
+
+    fprintf(stderr, "Info: Disconnected from display '%s'.\n", nxagentDisplayName);
+
+    nxagentTerminateSession();
+
+    return -1;
+  }
+
+  return 0;
+}
+
+void nxagentInitializeRecLossyLevel()
+{
+  *(int *)reconnectLossyLevel[DISPLAY_STEP]    = 0;
+  *(int *)reconnectLossyLevel[SCREEN_STEP]     = 0;
+  *(int *)reconnectLossyLevel[FONT_STEP]       = 0;
+  *(int *)reconnectLossyLevel[PIXMAP_STEP]     = 0;
+  *(int *)reconnectLossyLevel[GC_STEP]         = 0;
+  *(int *)reconnectLossyLevel[CURSOR_STEP]     = 0;
+  *(int *)reconnectLossyLevel[COLORMAP_STEP]   = 0;
+  *(int *)reconnectLossyLevel[WINDOW_STEP]     = 0;
+  *(int *)reconnectLossyLevel[GLYPHSET_STEP]   = 0;
+  *(int *)reconnectLossyLevel[PICTFORMAT_STEP] = 0;
+  *(int *)reconnectLossyLevel[PICTURE_STEP]    = 0;
+}
+
+void nxagentInitReconnector(void)
+{
+  nxagentReconnectTrap = 0;
+
+  reconnectLossyLevel[DISPLAY_STEP]    = xalloc(sizeof(int));
+  reconnectLossyLevel[SCREEN_STEP]     = xalloc(sizeof(int));
+  reconnectLossyLevel[FONT_STEP]       = xalloc(sizeof(int));
+  reconnectLossyLevel[PIXMAP_STEP]     = xalloc(sizeof(int));
+  reconnectLossyLevel[GC_STEP]         = xalloc(sizeof(int));
+  reconnectLossyLevel[CURSOR_STEP]     = xalloc(sizeof(int));
+  reconnectLossyLevel[COLORMAP_STEP]   = xalloc(sizeof(int));
+  reconnectLossyLevel[WINDOW_STEP]     = xalloc(sizeof(int));
+  reconnectLossyLevel[GLYPHSET_STEP]   = xalloc(sizeof(int));
+  reconnectLossyLevel[PICTFORMAT_STEP] = xalloc(sizeof(int));
+  reconnectLossyLevel[PICTURE_STEP]    = xalloc(sizeof(int));
+}
+
+void nxagentDisconnectSession(void)
+{
+  #ifdef TEST
+  fprintf(stderr, "nxagentDisconnectSession: Disconnecting session with state [%s].\n",
+              DECODE_SESSION_STATE(nxagentSessionState));
+  #endif
+
+  /*
+   * Force an I/O error on the display
+   * and wait until the NX transport
+   * is gone.
+   */
+
+  #ifdef TEST
+  fprintf(stderr, "nxagentDisconnectSession: Disconnecting the X display.\n");
+  #endif
+
+  nxagentWaitDisplay();
+
+  /*
+   * Prepare for the next reconnection.
+   */
+
+  #ifdef TEST
+  fprintf(stderr, "nxagentDisconnectSession: Disconnecting all X resources.\n");
+  #endif
+
+  nxagentInitializeRecLossyLevel();
+
+  nxagentBackupDisplayInfo();
+
+  if (nxagentOption(Rootless))
+  {
+    nxagentFreePropertyList();
+  }
+
+  if (nxagentRenderEnable)
+  {
+    nxagentDisconnectAllPicture();
+  }
+
+  nxagentEmptyAllBackingStoreRegions();
+
+  nxagentDisconnectAllWindows();
+  nxagentDisconnectAllCursor();
+  nxagentDisconnectAllPixmaps();
+  nxagentDisconnectAllGCs();
+  nxagentDisconnectDisplay();
+
+  nxagentWMIsRunning = 0;
+
+  #ifdef TEST
+  fprintf(stderr, "nxagentDisconnectSession: Disconnection completed. SigHup is [%d]. IoError is [%d].\n",
+              nxagentException.sigHup, nxagentException.ioError);
+  #endif
+}
+
+Bool nxagentReconnectSession(void)
+{
+  char *nxagentOldKeyboard = NULL;
+
+  nxagentResizeDesktopAtStartup = False;
+
+  /*
+   * The default is device settings have
+   * not to be propagated to the X server.
+   */
+
+  nxagentChangeOption(DeviceControl, False);
+
+  /*
+   * We need to zero out every new XID
+   * created by the disconnected display.
+   */
+
+  nxagentDisconnectSession();
+
+  /*
+   * Set this in order to let the screen
+   * function to behave differently at
+   * reconnection time.
+   */
+
+  nxagentReconnectTrap = True;
+
+  nxagentSetReconnectError(0, NULL);
+
+  if (nxagentKeyboard != NULL)
+  {
+    int size;
+
+    size = strlen(nxagentKeyboard);
+
+    if ((nxagentOldKeyboard = xalloc(size + 1)) != NULL)
+    {
+      strncpy(nxagentOldKeyboard, nxagentKeyboard, size);
+
+      nxagentOldKeyboard[size] = '\0';
+    }
+  }
+
+  if (nxagentKeyboard)
+  {
+    xfree(nxagentKeyboard);
+
+    nxagentKeyboard = NULL;
+  }
+
+  nxagentSaveOptions();
+
+  nxagentResetOptions();
+
+  nxagentProcessOptionsFile();
+
+  if (nxagentReconnectDisplay(reconnectLossyLevel[DISPLAY_STEP]) == 0)
+  {
+    failedStep = DISPLAY_STEP;
+
+    #ifdef TEST
+    fprintf(stderr, "nxagentReconnect: WARNING! Failed display reconnection.\n");
+    #endif
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentReconnectScreen(reconnectLossyLevel[SCREEN_STEP]) == 0)
+  {
+    failedStep = SCREEN_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  nxagentDisconnectAllFonts();
+
+  nxagentListRemoteFonts("*", nxagentMaxFontNames);
+
+  if (nxagentReconnectAllFonts(reconnectLossyLevel[FONT_STEP]) == 0)
+  {
+    if (nxagentReconnectFailedFonts(reconnectLossyLevel[FONT_STEP]) == 0)
+    {
+      failedStep = FONT_STEP;
+
+      goto nxagentReconnectError;
+    }
+    else
+    {
+      #ifdef WARNING
+      fprintf(stderr, "nxagentReconnect: WARNING! Unable to retrieve all the fonts currently in use. "
+                  "Missing fonts have been replaced.\n");
+      #endif
+
+      nxagentLaunchDialog(DIALOG_FONT_REPLACEMENT);
+    }
+  }
+
+  /*
+   * Map the main window and send a
+   * SetSelectionOwner request to
+   * notify of the agent start.
+   */
+
+  nxagentMapDefaultWindows();
+
+  /*
+   * Ensure that the SetSelectionOwner
+   * request is sent through the link.
+   */
+
+  XFlush(nxagentDisplay);
+
+  NXTransContinue(NULL);
+
+  nxagentEmptyBSPixmapList();
+
+  if (nxagentReconnectAllPixmaps(reconnectLossyLevel[PIXMAP_STEP]) == 0)
+  {
+    failedStep = PIXMAP_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentReconnectAllGCs(reconnectLossyLevel[GC_STEP]) == 0)
+  {
+    failedStep = GC_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentReconnectAllColormap(reconnectLossyLevel[COLORMAP_STEP]) == 0)
+  {
+    failedStep = COLORMAP_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentReconnectAllWindows(reconnectLossyLevel[WINDOW_STEP]) == 0)
+  {
+    failedStep = WINDOW_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentRenderEnable)
+  {
+    if (nxagentReconnectAllGlyphSet(reconnectLossyLevel[GLYPHSET_STEP]) == 0)
+    {
+      failedStep = GLYPHSET_STEP;
+
+      goto nxagentReconnectError;
+    }
+
+    if (nxagentReconnectAllPictFormat(reconnectLossyLevel[PICTFORMAT_STEP]) == 0)
+    {
+      failedStep = PICTFORMAT_STEP;
+
+      goto nxagentReconnectError;
+    }
+
+    if (nxagentReconnectAllPicture(reconnectLossyLevel[PICTURE_STEP]) == 0)
+    {
+      failedStep = PICTURE_STEP;
+
+      goto nxagentReconnectError;
+    }
+  }
+
+  if (nxagentReconnectAllCursor(reconnectLossyLevel[CURSOR_STEP]) == 0)
+  {
+    failedStep = CURSOR_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentSetWindowCursors(reconnectLossyLevel[WINDOW_STEP]) == 0)
+  {
+    failedStep = WINDOW_STEP;
+
+    goto nxagentReconnectError;
+  }
+
+  if (nxagentOption(ResetKeyboardAtResume) == 1 &&
+         (nxagentKeyboard  == NULL || nxagentOldKeyboard == NULL ||
+             strcmp(nxagentKeyboard, nxagentOldKeyboard) != 0 ||
+                 strcmp(nxagentKeyboard, "query") == 0))
+  {
+    if (nxagentResetKeyboard() == 0)
+    {
+      #ifdef WARNING
+      if (nxagentVerbose == 1)
+      {
+        fprintf(stderr, "nxagentReconnect: Failed to reset keyboard device.\n");
+      }
+      #endif
+
+      failedStep = WINDOW_STEP;
+
+      goto nxagentReconnectError;
+    }
+  }
+  else
+  {
+    nxagentResetKeycodeConversion();
+  }
+
+  nxagentXkbState.Initialized = 0;
+
+  if (nxagentOldKeyboard != NULL)
+  {
+    xfree(nxagentOldKeyboard);
+
+    nxagentOldKeyboard = NULL;
+  }
+
+  nxagentInitPointerMap();
+
+  nxagentDeactivatePointerGrab();
+
+  nxagentWakeupByReconnect();
+
+  nxagentFreeGCList();
+
+  nxagentRedirectDefaultWindows();
+
+  if (nxagentResizeDesktopAtStartup || nxagentOption(Rootless) == True)
+  {
+    nxagentChangeScreenConfig(0, nxagentOption(RootWidth),
+                                  nxagentOption(RootHeight), 0, 0);
+
+    nxagentResizeDesktopAtStartup = False;
+  }
+
+  nxagentReconnectTrap = False;
+
+  nxagentExposeArrayIsInitialized = False;
+
+  if (nxagentSessionState != SESSION_GOING_UP)
+  {
+    #ifdef WARNING
+    fprintf(stderr, "nxagentReconnect: WARNING! Unexpected session state [%s] while reconnecting.\n",
+                DECODE_SESSION_STATE(nxagentSessionState));
+    #endif
+
+    goto nxagentReconnectError;
+  }
+
+  #ifdef NX_DEBUG_INPUT
+  fprintf(stderr, "Session: Session resumed at '%s' timestamp [%lu].\n", GetTimeAsString(), GetTimeInMillis());
+  #else
+  fprintf(stderr, "Session: Session resumed at '%s'.\n", GetTimeAsString());
+  #endif
+
+  nxagentRemoveSplashWindow(NULL);
+
+  /*
+   * We let the proxy flush the link on our behalf
+   * after having opened the display. We are now
+   * entering again the dispatcher so can flush
+   * the link explicitly.
+   */
+
+  #ifdef TEST
+  fprintf(stderr, "nxagentReconnect: Setting the NX flush policy to deferred.\n");
+  #endif
+
+  NXSetDisplayPolicy(nxagentDisplay, NXPolicyDeferred);
+
+  nxagentCleanupBackupDisplayInfo();
+
+  return 1;
+
+nxagentReconnectError:
+
+  if (failedStep == DISPLAY_STEP)
+  {
+    #ifdef TEST
+    fprintf(stderr, "nxagentReconnect: Reconnection failed in display step. Restoring options.\n");
+    #endif
+
+    nxagentRestoreOptions();
+  }
+  else
+  {
+    nxagentCleanupBackupDisplayInfo();
+  }
+
+  if (*nxagentGetReconnectError() == '\0')
+  {
+    #ifdef WARNING
+    if (nxagentVerbose == 1)
+    {
+      fprintf(stderr, "nxagentReconnect: WARNING! The reconnect error message is not set. Failed step is [%d].\n",
+                  failedStep);
+    }
+    #endif
+
+    #ifdef TEST
+    fprintf(stderr, "nxagentReconnect: Reconnection failed due to a display error.\n");
+    #endif
+  }
+  else
+  {
+    #ifdef TEST
+    fprintf(stderr, "nxagentReconnect: Reconnection failed with reason '%s'\n",
+                nxagentGetReconnectError());
+    #endif
+  }
+
+  if (NXDisplayError(nxagentDisplay) == 0)
+  {
+    nxagentUnmapWindows();
+
+    nxagentFailedReconnectionDialog(nxagentReconnectErrorId, nxagentGetReconnectError());
+  }
+  #ifdef TEST
+  else
+  {
+    fprintf(stderr, "nxagentReconnect: Cannot launch the dialog without a valid display.\n");
+  }
+  #endif
+
+  if (failedStep == FONT_STEP)
+  {
+    *((int *) reconnectLossyLevel[FONT_STEP]) = 1;
+  }
+
+  if (nxagentDisplay == NULL)
+  {
+    nxagentDisconnectDisplay();
+  }
+
+  if (nxagentOldKeyboard != NULL)
+  {
+    xfree(nxagentOldKeyboard);
+
+    nxagentOldKeyboard = NULL;
+  }
+
+  return 0;
+}
+
+void nxagentSetReconnectError(int id, char *format, ...)
+{
+  static int size = 0;
+
+  va_list ap;
+  int n;
+
+  if (format == NULL)
+  {
+    nxagentSetReconnectError(id, "");
+
+    return;
+  }
+
+  nxagentReconnectErrorId = id;
+
+  while (1)
+  {
+    va_start (ap, format);
+
+    n = vsnprintf(nxagentReconnectErrorMessage, size, format, ap);
+
+    va_end(ap);
+
+    if (n > -1 && n < size)
+    {
+      break;
+    }
+    if (n > -1)
+    {
+      size = n + 1;
+    }
+    else
+    {
+      /*
+       * The vsnprintf() in glibc 2.0.6 would return
+       * -1 when the output was truncated. See section
+       * NOTES on printf(3).
+       */
+
+      size = (size ? size * 2 : NXAGENT_RECONNECT_DEFAULT_MESSAGE_SIZE);
+    }
+
+    nxagentReconnectErrorMessage = realloc(nxagentReconnectErrorMessage, size);
+
+    if (nxagentReconnectErrorMessage == NULL)
+    {
+      FatalError("realloc failed");
+    }
+  }
+
+  return;
+}
+
+static char* nxagentGetReconnectError()
+{
+  if (nxagentReconnectErrorMessage == NULL)
+  {
+    nxagentSetReconnectError(nxagentReconnectErrorId, "");
+  }
+
+  return nxagentReconnectErrorMessage;
+}
+
+void nxagentHandleConnectionChanges()
+{
+  #ifdef TEST
+  fprintf(stderr, "nxagentHandleConnectionChanges: Called.\n");
+  #endif
+
+  if (nxagentSessionState == SESSION_GOING_DOWN)
+  {
+    fprintf(stderr, "Session: Suspending session at '%s'.\n", GetTimeAsString());
+
+    nxagentDisconnectSession();
+  }
+  else if (nxagentSessionState == SESSION_GOING_UP)
+  {
+    fprintf(stderr, "Session: Resuming session at '%s'.\n", GetTimeAsString());
+
+    if (nxagentReconnectSession())
+    {
+      nxagentSessionState = SESSION_UP;
+    }
+    else
+    {
+      nxagentSessionState = SESSION_GOING_DOWN;
+
+      fprintf(stderr, "Session: Display failure detected at '%s'.\n", GetTimeAsString());
+
+      fprintf(stderr, "Session: Suspending session at '%s'.\n", GetTimeAsString());
+
+      nxagentDisconnectSession();
+    }
+  }
+}
+