From 90ab2f639a083754719c147a97631e2f8f1020a0 Mon Sep 17 00:00:00 2001
From: "Zeeshan Ali (Khattak)" <zeeshanak@gnome.org>
Date: Tue, 28 Jul 2015 16:37:48 +0100
Subject: [PATCH] ovirt: Wait machine to start before connecting to it

Apparently the starting process is asynchronous in the sense that even
after the async Ovirt.Vm.start_async() returns, the state change is not
not guaranteed to have taken place and communicated back from server.
This results in Boxes giving up on connecting on slower networks where
state change (and it's communication etc) can take a few seconds.

This patch tries to solve the issue by waiting for state change to
happen for 3 seconds (more specifically, for 1 second 3 times) before
giving up on the state change and hence connecting to it.

https://bugzilla.gnome.org/show_bug.cgi?id=752966
---
 src/ovirt-machine.vala | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/ovirt-machine.vala b/src/ovirt-machine.vala
index 6eae4b2..4d4449f 100644
--- a/src/ovirt-machine.vala
+++ b/src/ovirt-machine.vala
@@ -3,6 +3,11 @@
 using Gtk;
 
 private class Boxes.OvirtMachine: Boxes.Machine {
+    private const uint STATE_CHANGE_TIMEOUT = 1000; // 1 second
+    // We only try changing state once, this controls how many times we wait
+    // STATE_CHANGE_TIMEOUT miliseconds for state change to happen.
+    private const uint8 STATE_CHANGE_RETRIES = 3;
+
     private Ovirt.Vm vm;
     private Ovirt.Proxy proxy;
 
@@ -31,13 +36,14 @@ public override async void connect_display (Machine.ConnectFlags flags) throws G
         if (state == MachineState.STOPPED)
             try {
                 yield vm.start_async (proxy, connecting_cancellable);
-                this.update_state ();
             } catch (IOError.CANCELLED error) {
                 debug ("connection to %s was cancelled", name);
             } catch (GLib.Error error) {
                 throw new Boxes.Error.INVALID ("Couldn't start oVirt VM '%s': %s", vm.name, error.message);
             }
 
+        yield wait_for_state (MachineState.RUNNING, connecting_cancellable);
+
         if (state != MachineState.RUNNING)
             throw new Boxes.Error.INVALID ("oVirt VM '%s' is not RUNNING", vm.name);
 
@@ -100,6 +106,31 @@ private Display create_display_connection () throws GLib.Error {
             throw new Boxes.Error.INVALID ("unsupported display type %d for %s", vm.display.type, vm.name);
         }
     }
+
+    private async void wait_for_state (Machine.MachineState desired_state, Cancellable cancellable) {
+        for (var i = 0; i < STATE_CHANGE_RETRIES; i++) {
+            this.update_state ();
+
+            if (state == desired_state)
+                break;
+
+            SourceFunc callback = wait_for_state.callback;
+            Timeout.add (STATE_CHANGE_TIMEOUT, () => {
+                callback ();
+
+                return false;
+            });
+
+            yield;
+
+            if (cancellable.is_cancelled ()) {
+                debug ("connection to %s was cancelled", name);
+
+                return;
+            }
+        }
+    }
+
     private void update_state () {
         switch (vm.state) {
             case VmState.UP:
-- 
2.4.3