[folks] core: Force IndividualAggregator quiescence after a 5s timeout

[Philip Withnall <pwithnall src gnome org>]

commit b7bda06afca7ad5222e26e7ef6f9765162d38093
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sun Mar 4 14:29:27 2012 +0000

    core: Force IndividualAggregator quiescence after a 5s timeout
    
    This prevents clients being (too) adversely affected (e.g. not being able
    to do anything) by buggy Backends and PersonaStores which never reach
    quiescence.
    
    Note that this patches the symptoms, not the cause of the problem. Good as
    a safety net, though.
    
    Helps: https://bugzilla.gnome.org/show_bug.cgi?id=670191

 NEWS                             |    1 +
 folks/individual-aggregator.vala |   51 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index ba7442f..f4607a8 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,7 @@
 Overview of changes from libfolks 0.6.7 to libfolks 0.6.8
 =============================================================
 Bugs fixed:
+* Bug 670191 â IndividualAggregator::is-quiescent is never set to TRUE
 
 Overview of changes from libfolks 0.6.6 to libfolks 0.6.7
 =============================================================
diff --git a/folks/individual-aggregator.vala b/folks/individual-aggregator.vala
index 91f4172..aa3aeaa 100644
--- a/folks/individual-aggregator.vala
+++ b/folks/individual-aggregator.vala
@@ -100,6 +100,13 @@ public class Folks.IndividualAggregator : Object
   /* Same for backends. */
   private uint _non_quiescent_backend_count = 0;
   private bool _is_quiescent = false;
+  /* As a precaution against backends/persona stores which never reach
+   * quiescence (due to bugs), we implement a timeout after which we forcibly
+   * reach quiescence. */
+  private uint _quiescent_timeout_id = 0;
+
+  private static const uint _QUIESCENT_TIMEOUT = 5; /* seconds */
+
   /* We use this to know if the primary PersonaStore has been explicitly
    * set by the user (either via GConf or an env variable). If that is the
    * case, we don't want to override it with other PersonaStores that
@@ -359,6 +366,12 @@ public class Folks.IndividualAggregator : Object
     {
       debug ("Destroying IndividualAggregator %p", this);
 
+      if (this._quiescent_timeout_id != 0)
+        {
+          Source.remove (this._quiescent_timeout_id);
+          this._quiescent_timeout_id = 0;
+        }
+
       this._backend_store.backend_available.disconnect (
           this._backend_available_cb);
 
@@ -675,6 +688,15 @@ public class Folks.IndividualAggregator : Object
       if (backend.is_quiescent == false)
         {
           this._non_quiescent_backend_count++;
+
+          /* Start the timeout to force quiescence if the backend (or its
+           * persona stores) misbehave and don't reach quiescence. */
+          if (this._quiescent_timeout_id == 0)
+            {
+              this._quiescent_timeout_id =
+                  Timeout.add_seconds (this._QUIESCENT_TIMEOUT,
+                      this._quiescent_timeout_cb);
+            }
         }
 
       this._add_backend.begin (backend);
@@ -1455,7 +1477,36 @@ public class Folks.IndividualAggregator : Object
 
           this._is_quiescent = true;
           this.notify_property ("is-quiescent");
+
+          /* Remove the quiescence timeout, if it exists. */
+          if (this._quiescent_timeout_id != 0)
+            {
+              Source.remove (this._quiescent_timeout_id);
+              this._quiescent_timeout_id = 0;
+            }
+        }
+    }
+
+  private bool _quiescent_timeout_cb ()
+    {
+      /* If we're not quiescent by the time the timeout is triggered, force
+       * quiescence anyway, just so that we don't leave clients hanging if our
+       * backends have bugs. */
+      if (this._is_quiescent == false)
+        {
+          warning ("Failed to reach quiescence normally (%u backends and %u " +
+              "persona stores still haven't reached quiescence). Forcing " +
+              "IndividualAggregator quiescence due to reaching the timeout.",
+              this._non_quiescent_backend_count,
+              this._non_quiescent_persona_store_count);
+
+          this._is_quiescent = true;
+          this.notify_property ("is-quiescent");
         }
+
+      /* One-shot timeout */
+      this._quiescent_timeout_id = 0;
+      return false;
     }
 
   private void _persona_store_is_user_set_default_changed_cb (Object obj,