vdagent-x11: Unify / share error handling between vdagent-x11 and randr code

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

3 files changed, 29 insertions, 34 deletions

diff --git a/src/vdagent-x11-priv.h b/src/vdagent-x11-priv.h
index d161f64..ee04b04 100644
--- a/src/vdagent-x11-priv.h
+++ b/src/vdagent-x11-priv.h
@@ -135,10 +135,17 @@ struct vdagent_x11 {
     int dont_send_guest_xorg_res;
 };
 
+extern int (*vdagent_x11_prev_error_handler)(Display *, XErrorEvent *);
+extern int vdagent_x11_caught_error;
+
 void vdagent_x11_randr_init(struct vdagent_x11 *x11);
 void vdagent_x11_send_daemon_guest_xorg_res(struct vdagent_x11 *x11,
                                             int update);
 void vdagent_x11_randr_handle_root_size_change(struct vdagent_x11 *x11,
                                                int width, int height);
 
+void vdagent_x11_set_error_handler(struct vdagent_x11 *x11,
+    int (*handler)(Display *, XErrorEvent *));
+int vdagent_x11_restore_error_handler(struct vdagent_x11 *x11);
+
 #endif // VDAGENT_X11_PRIV
diff --git a/src/vdagent-x11-randr.c b/src/vdagent-x11-randr.c
index 7738851..5a299d1 100644
--- a/src/vdagent-x11-randr.c
+++ b/src/vdagent-x11-randr.c
@@ -32,34 +32,12 @@
 #include "vdagent-x11.h"
 #include "vdagent-x11-priv.h"
 
-static int caught_error;
-static int (*old_error_handler)(Display *, XErrorEvent *);
-
 static int error_handler(Display *display, XErrorEvent *error)
 {
-    caught_error = 1;
+    vdagent_x11_caught_error = 1;
     return 0;
 }
 
-static void arm_error_handler(struct vdagent_x11 *x11)
-{
-    caught_error = 0;
-    XSync(x11->display, False);
-    old_error_handler = XSetErrorHandler(error_handler);
-}
-
-static int check_error_handler(struct vdagent_x11 *x11)
-{
-    int error;
-
-    XSync(x11->display, False);
-    XSetErrorHandler(old_error_handler);
-    error = caught_error;
-    caught_error = 0;
-
-    return error;
-}
-
 static XRRModeInfo *mode_from_id(struct vdagent_x11 *x11, int id)
 {
     int i;
@@ -237,12 +215,12 @@ static void delete_mode(struct vdagent_x11 *x11, int output_index,
             break;
     }
     if (m < x11->randr.res->nmode) {
-        arm_error_handler(x11);
+        vdagent_x11_set_error_handler(x11, error_handler);
         XRRDeleteOutputMode (x11->display, x11->randr.res->outputs[output_index],
                              mode->id);
         XRRDestroyMode (x11->display, mode->id);
 	// ignore race error, if mode is created by others
-	check_error_handler(x11);
+	vdagent_x11_restore_error_handler(x11);
     }
 
     /* silly to update everytime for more then one monitor */
@@ -337,10 +315,10 @@ static XRRModeInfo *create_new_mode(struct vdagent_x11 *x11, int output_index,
     set_reduced_cvt_mode(&mode, width, height);
     mode.modeFlags = 0;
     mode.id = 0;
-    arm_error_handler(x11);
+    vdagent_x11_set_error_handler(x11, error_handler);
     XRRCreateMode (x11->display, x11->root_window, &mode);
     // ignore race error, if mode is created by others
-    check_error_handler(x11);
+    vdagent_x11_restore_error_handler(x11);
 
     /* silly to update everytime for more then one monitor */
     update_randr_res(x11, 0);
@@ -786,11 +764,11 @@ void vdagent_x11_set_monitor_config(struct vdagent_x11 *x11,
         if (x11->debug)
             syslog(LOG_DEBUG, "Changing screen size to %dx%d",
                    primary_w, primary_h);
-        arm_error_handler(x11);
+        vdagent_x11_set_error_handler(x11, error_handler);
         XRRSetScreenSize(x11->display, x11->root_window, primary_w, primary_h,
                          DisplayWidthMM(x11->display, x11->screen),
                          DisplayHeightMM(x11->display, x11->screen));
-        if (check_error_handler(x11)) {
+        if (vdagent_x11_restore_error_handler(x11)) {
             syslog(LOG_ERR, "XRRSetScreenSize failed, not enough mem?");
             if (!fallback && curr) {
                 syslog(LOG_WARNING, "Restoring previous config");
diff --git a/src/vdagent-x11.c b/src/vdagent-x11.c
index 5e1cbb6..2cfbeab 100644
--- a/src/vdagent-x11.c
+++ b/src/vdagent-x11.c
@@ -46,7 +46,8 @@
 #include "vdagent-x11-priv.h"
 
 /* Stupid X11 API, there goes our encapsulate all data in a struct design */
-static int (*vdagent_x11_prev_error_handler)(Display *, XErrorEvent *);
+int (*vdagent_x11_prev_error_handler)(Display *, XErrorEvent *);
+int vdagent_x11_caught_error;
 
 static void vdagent_x11_handle_selection_notify(struct vdagent_x11 *x11,
                                                 XEvent *event, int incr);
@@ -88,15 +89,24 @@ static int vdagent_x11_ignore_bad_window_handler(
     return vdagent_x11_prev_error_handler(display, error);
 }
 
-static void vdagent_x11_set_error_handler(
+void vdagent_x11_set_error_handler(struct vdagent_x11 *x11,
     int (*handler)(Display *, XErrorEvent *))
 {
+    XSync(x11->display, False);
+    vdagent_x11_caught_error = 0;
     vdagent_x11_prev_error_handler = XSetErrorHandler(handler);
 }
 
-static void vdagent_x11_restore_error_handler(void)
+int vdagent_x11_restore_error_handler(struct vdagent_x11 *x11)
 {
+    int error;
+
+    XSync(x11->display, False);
     XSetErrorHandler(vdagent_x11_prev_error_handler);
+    error = vdagent_x11_caught_error;
+    vdagent_x11_caught_error = 0;
+
+    return error;
 }
 
 static void vdagent_x11_get_wm_name(struct vdagent_x11 *x11)
@@ -112,7 +122,7 @@ static void vdagent_x11_get_wm_name(struct vdagent_x11 *x11)
        _NET_SUPPORTING_WM_CHECK property, and the window manager running in
        the user session has not yet updated it to point to its window, so its
        pointing to a non existing window. */
-    vdagent_x11_set_error_handler(vdagent_x11_ignore_bad_window_handler);
+    vdagent_x11_set_error_handler(x11, vdagent_x11_ignore_bad_window_handler);
 
     /* Get the window manager SUPPORTING_WM_CHECK window */
     if (XGetWindowProperty(x11->display, x11->root_window,
@@ -158,7 +168,7 @@ static void vdagent_x11_get_wm_name(struct vdagent_x11 *x11)
         }
     }
 
-    vdagent_x11_restore_error_handler();
+    vdagent_x11_restore_error_handler(x11);
 }
 
 struct vdagent_x11 *vdagent_x11_create(struct udscs_connection *vdagentd,