[geary/wip/789924-network-transition: 15/15] Add a IMAP pool stop timeout as well as a start to help prevent flapping.

[Michael Gratton <mjog src gnome org>]

commit 304fa9dcc2f184120b42c242c109a79a6c362527
Author: Michael James Gratton <mike vee net>
Date:   Sun Nov 12 22:10:11 2017 +1100

    Add a IMAP pool stop timeout as well as a start to help prevent flapping.
    
    * src/engine/imap/transport/imap-client-session-manager.vala
      (ClientSessionManager): Increase the start timeout and add a stop
      timeout to suppress connection flapping when e.g. the system is
      connecting to a network.

 .../transport/imap-client-session-manager.vala     |   19 ++++++++++++++-----
 1 files changed, 14 insertions(+), 5 deletions(-)
---
diff --git a/src/engine/imap/transport/imap-client-session-manager.vala 
b/src/engine/imap/transport/imap-client-session-manager.vala
index f75647f..ef87601 100644
--- a/src/engine/imap/transport/imap-client-session-manager.vala
+++ b/src/engine/imap/transport/imap-client-session-manager.vala
@@ -8,9 +8,10 @@
 
 public class Geary.Imap.ClientSessionManager : BaseObject {
     private const int DEFAULT_MIN_POOL_SIZE = 1;
-    private const int POOL_START_TIMEOUT_MS = 1000;
+    private const int POOL_START_TIMEOUT_SEC = 4;
     private const int POOL_RETRY_MIN_TIMEOUT_SEC = 1;
     private const int POOL_RETRY_MAX_TIMEOUT_SEC = 10;
+    private const int POOL_STOP_TIMEOUT_SEC = 1;
 
     /** Determines if the manager has been opened. */
     public bool is_open { get; private set; default = false; }
@@ -69,6 +70,7 @@ public class Geary.Imap.ClientSessionManager : BaseObject {
 
     private TimeoutManager pool_start;
     private TimeoutManager pool_retry;
+    private TimeoutManager pool_stop;
 
     /**
      * Fired after when the manager has a working connection.
@@ -93,8 +95,8 @@ public class Geary.Imap.ClientSessionManager : BaseObject {
         this.endpoint.notify[Endpoint.PROP_TRUST_UNTRUSTED_HOST].connect(on_imap_trust_untrusted_host);
         this.endpoint.untrusted_host.connect(on_imap_untrusted_host);
 
-        this.pool_start = new TimeoutManager.milliseconds(
-            POOL_START_TIMEOUT_MS,
+        this.pool_start = new TimeoutManager.seconds(
+            POOL_START_TIMEOUT_SEC,
             () => { this.adjust_session_pool.begin(); }
         );
 
@@ -102,6 +104,11 @@ public class Geary.Imap.ClientSessionManager : BaseObject {
             POOL_RETRY_MIN_TIMEOUT_SEC,
             () => { this.adjust_session_pool.begin(); }
         );
+
+        this.pool_stop = new TimeoutManager.seconds(
+            POOL_STOP_TIMEOUT_SEC,
+            () => { this.force_disconnect_all.begin(); }
+        );
     }
 
     ~ClientSessionManager() {
@@ -136,6 +143,7 @@ public class Geary.Imap.ClientSessionManager : BaseObject {
 
         this.pool_start.reset();
         this.pool_retry.reset();
+        this.pool_stop.reset();
 
                this.endpoint.connectivity.notify["is-reachable"].disconnect(on_connectivity_change);
 
@@ -552,13 +560,14 @@ public class Geary.Imap.ClientSessionManager : BaseObject {
                bool is_reachable = this.endpoint.connectivity.is_reachable;
                if (is_reachable) {
             this.pool_start.start();
+            this.pool_stop.reset();
                } else {
             // Get a ready signal again once we are back online
             this.is_ready = false;
             this.pool_start.reset();
-            this.pool_retry.reset();
-            this.force_disconnect_all.begin();
+            this.pool_stop.start();
         }
+        this.pool_retry.reset();
        }
 
     /**