[IMAPx] Connection could be used multiple times at once in certain cases

Sometimes, with a good thread interleaving, one connection could be
used by multiple threads at once, this resulted in runtime warnings like:
> Starting command ... while still processing ...
which is a safety check for these cases. This change makes sure that
the connections are reserved for one thread only.

2 files changed, 22 insertions, 4 deletions

diff --git a/camel/providers/imapx/camel-imapx-conn-manager.c b/camel/providers/imapx/camel-imapx-conn-manager.c
index b756d5c58..052080ef8 100644
--- a/camel/providers/imapx/camel-imapx-conn-manager.c
+++ b/camel/providers/imapx/camel-imapx-conn-manager.c
@@ -216,6 +216,25 @@ connection_info_unref (ConnectionInfo *cinfo)
 }
 
 static gboolean
+connection_info_try_reserve (ConnectionInfo *cinfo)
+{
+	gboolean reserved = FALSE;
+
+	g_return_val_if_fail (cinfo != NULL, FALSE);
+
+	g_mutex_lock (&cinfo->lock);
+
+	if (!cinfo->busy) {
+		cinfo->busy = TRUE;
+		reserved = TRUE;
+	}
+
+	g_mutex_unlock (&cinfo->lock);
+
+	return reserved;
+}
+
+static gboolean
 connection_info_get_busy (ConnectionInfo *cinfo)
 {
 	gboolean busy;
@@ -845,9 +864,8 @@ camel_imapx_conn_manager_ref_connection (CamelIMAPXConnManager *conn_man,
 			for (link = conn_man->priv->connections; link; link = g_list_next (link)) {
 				ConnectionInfo *candidate = link->data;
 
-				if (candidate && !connection_info_get_busy (candidate)) {
+				if (candidate && connection_info_try_reserve (candidate)) {
 					cinfo = connection_info_ref (candidate);
-					connection_info_set_busy (cinfo, TRUE);
 					break;
 				}
 			}
diff --git a/camel/providers/imapx/camel-imapx-server.c b/camel/providers/imapx/camel-imapx-server.c
index 582d6a4da..b28c4be38 100644
--- a/camel/providers/imapx/camel-imapx-server.c
+++ b/camel/providers/imapx/camel-imapx-server.c
@@ -3614,8 +3614,8 @@ camel_imapx_server_process_command_sync (CamelIMAPXServer *is,
 	COMMAND_LOCK (is);
 
 	if (is->priv->current_command != NULL) {
-		g_warning ("%s: Starting command %p (%s) while still processing %p (%s)", G_STRFUNC,
-			ic, camel_imapx_job_get_kind_name (ic->job_kind),
+		g_warning ("%s: [%c] %p: Starting command %p (%s) while still processing %p (%s)", G_STRFUNC,
+			is->priv->tagprefix, is, ic, camel_imapx_job_get_kind_name (ic->job_kind),
 			is->priv->current_command, camel_imapx_job_get_kind_name (is->priv->current_command->job_kind));
 	}