chardev: new qemu_chr_be_update_read_handlers()

Add a wrapper for the chr_update_read_handler().

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1505975754-21555-2-git-send-email-peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

chardev/char-fe.c

@@ -253,15 +253,13 @@ void qemu_chr_fe_set_handlers(CharBackend *b,
                               bool set_open)
 {
     Chardev *s;
-    ChardevClass *cc;
     int fe_open;
 
     s = b->chr;
     if (!s) {
         return;
     }
 
-    cc = CHARDEV_GET_CLASS(s);
     if (!opaque && !fd_can_read && !fd_read && !fd_event) {
         fe_open = 0;
         remove_fd_in_watch(s);
@@ -273,9 +271,8 @@ void qemu_chr_fe_set_handlers(CharBackend *b,
     b->chr_event = fd_event;
     b->chr_be_change = be_change;
     b->opaque = opaque;
-    if (cc->chr_update_read_handler) {
-        cc->chr_update_read_handler(s, context);
-    }
+
+    qemu_chr_be_update_read_handlers(s, context);
 
     if (set_open) {
         qemu_chr_fe_set_open(b, fe_open);

chardev/char.c

@@ -180,6 +180,16 @@ void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
     }
 }
 
+void qemu_chr_be_update_read_handlers(Chardev *s,
+                                      GMainContext *context)
+{
+    ChardevClass *cc = CHARDEV_GET_CLASS(s);
+
+    if (cc->chr_update_read_handler) {
+        cc->chr_update_read_handler(s, context);
+    }
+}
+
 int qemu_chr_add_client(Chardev *s, int fd)
 {
     return CHARDEV_GET_CLASS(s)->chr_add_client ?

include/chardev/char.h

@@ -168,6 +168,16 @@ void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
  */
 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
 
+/**
+ * @qemu_chr_be_update_read_handlers:
+ *
+ * Invoked when frontend read handlers are setup
+ *
+ * @context the gcontext that will be used to attach the watch sources
+ */
+void qemu_chr_be_update_read_handlers(Chardev *s,
+                                      GMainContext *context);
+
 /**
  * @qemu_chr_be_event:
  *