[evolution-data-server/gnome-3-20] [IMAPx] Add thread-safety locking around server's private 'changes' property

[Milan Crha <mcrha src gnome org>]

commit 9dc43f93b28ef7b3e0b3b013c0440345a94c4c15
Author: Milan Crha <mcrha redhat com>
Date:   Tue Apr 5 13:51:22 2016 +0200

    [IMAPx] Add thread-safety locking around server's private 'changes' property
    
    The 'changes' could be accessed from multiple threads, thus add
    thread safety to it by using a mutex when accessing it.

 camel/providers/imapx/camel-imapx-server.c |   87 +++++++++++++++++++++++-----
 1 files changed, 73 insertions(+), 14 deletions(-)
---
diff --git a/camel/providers/imapx/camel-imapx-server.c b/camel/providers/imapx/camel-imapx-server.c
index b491407..0881c06 100644
--- a/camel/providers/imapx/camel-imapx-server.c
+++ b/camel/providers/imapx/camel-imapx-server.c
@@ -255,6 +255,8 @@ struct _CamelIMAPXServerPrivate {
        GMutex select_lock;
        GWeakRef select_mailbox;
        GWeakRef select_pending;
+
+       GMutex changes_lock;
        CamelFolderChangeInfo *changes;
 
        /* Data items to request in STATUS commands:
@@ -760,14 +762,26 @@ imapx_expunge_uid_from_summary (CamelIMAPXServer *is,
        g_return_if_fail (is->priv->changes != NULL);
 
        camel_folder_summary_remove_uid (folder->summary, uid);
+
+       g_mutex_lock (&is->priv->changes_lock);
+
        camel_folder_change_info_remove_uid (is->priv->changes, uid);
 
        if (camel_imapx_server_is_in_idle (is)) {
+               CamelFolderChangeInfo *changes;
+
+               changes = is->priv->changes;
+               is->priv->changes = camel_folder_change_info_new ();
+
+               g_mutex_unlock (&is->priv->changes_lock);
+
                camel_folder_summary_save_to_db (folder->summary, NULL);
                imapx_update_store_summary (folder);
-               camel_folder_changed (folder, is->priv->changes);
+               camel_folder_changed (folder, changes);
 
-               camel_folder_change_info_clear (is->priv->changes);
+               camel_folder_change_info_free (changes);
+       } else {
+               g_mutex_unlock (&is->priv->changes_lock);
        }
 
        g_object_unref (folder);
@@ -938,6 +952,8 @@ imapx_untagged_vanished (CamelIMAPXServer *is,
 
        g_return_val_if_fail (is->priv->changes != NULL, FALSE);
 
+       g_mutex_lock (&is->priv->changes_lock);
+
        for (ii = 0; ii < uids->len; ii++) {
                guint32 uid;
                gchar *str;
@@ -951,22 +967,38 @@ imapx_untagged_vanished (CamelIMAPXServer *is,
                camel_folder_change_info_remove_uid (is->priv->changes, str);
        }
 
+       g_mutex_unlock (&is->priv->changes_lock);
+
        uid_list = g_list_reverse (uid_list);
        camel_folder_summary_remove_uids (folder->summary, uid_list);
 
-       COMMAND_LOCK (is);
-
        /* If the response is truly unsolicited (e.g. via NOTIFY)
         * then go ahead and emit the change notification now. */
-       if (!is->priv->current_command && is->priv->changes->uid_removed &&
-           is->priv->changes->uid_removed->len >= 100) {
-               camel_folder_summary_save_to_db (folder->summary, NULL);
-               imapx_update_store_summary (folder);
-               camel_folder_changed (folder, is->priv->changes);
-               camel_folder_change_info_clear (is->priv->changes);
-       }
+       COMMAND_LOCK (is);
+       if (!is->priv->current_command) {
+               COMMAND_UNLOCK (is);
 
-       COMMAND_UNLOCK (is);
+               g_mutex_lock (&is->priv->changes_lock);
+               if (is->priv->changes->uid_removed &&
+                   is->priv->changes->uid_removed->len >= 100) {
+                       CamelFolderChangeInfo *changes;
+
+                       changes = is->priv->changes;
+                       is->priv->changes = camel_folder_change_info_new ();
+
+                       g_mutex_unlock (&is->priv->changes_lock);
+
+                       camel_folder_summary_save_to_db (folder->summary, NULL);
+                       imapx_update_store_summary (folder);
+
+                       camel_folder_changed (folder, changes);
+                       camel_folder_change_info_free (changes);
+               } else {
+                       g_mutex_unlock (&is->priv->changes_lock);
+               }
+       } else {
+               COMMAND_UNLOCK (is);
+       }
 
        g_list_free_full (uid_list, (GDestroyNotify) g_free);
        g_array_free (uids, TRUE);
@@ -1232,15 +1264,22 @@ imapx_untagged_fetch (CamelIMAPXServer *is,
                        if (changed) {
                                g_return_val_if_fail (is->priv->changes != NULL, FALSE);
 
+                               g_mutex_lock (&is->priv->changes_lock);
                                camel_folder_change_info_change_uid (is->priv->changes, uid);
+                               g_mutex_unlock (&is->priv->changes_lock);
                        }
                        g_free (uid);
 
                        if (changed && camel_imapx_server_is_in_idle (is)) {
                                camel_folder_summary_save_to_db (select_folder->summary, NULL);
                                imapx_update_store_summary (select_folder);
+
+                               g_mutex_lock (&is->priv->changes_lock);
+
                                camel_folder_changed (select_folder, is->priv->changes);
                                camel_folder_change_info_clear (is->priv->changes);
+
+                               g_mutex_unlock (&is->priv->changes_lock);
                        }
 
                        if (mi)
@@ -1347,9 +1386,13 @@ imapx_untagged_fetch (CamelIMAPXServer *is,
                                imapx_set_message_info_flags_for_new_message (mi, server_flags, 
server_user_flags, FALSE, NULL, camel_imapx_mailbox_get_permanentflags (mailbox));
                                camel_folder_summary_add (folder->summary, mi);
 
+                               g_mutex_lock (&is->priv->changes_lock);
+
                                camel_folder_change_info_add_uid (is->priv->changes, mi->uid);
                                camel_folder_change_info_recent_uid (is->priv->changes, mi->uid);
 
+                               g_mutex_unlock (&is->priv->changes_lock);
+
                                if (messages > 0) {
                                        gint cnt = (camel_folder_summary_count (folder->summary) * 100) / 
messages;
 
@@ -2261,9 +2304,17 @@ imapx_completion (CamelIMAPXServer *is,
 
        c (is->priv->tagprefix, "Got completion response for command %05u '%s'\n", ic->tag, 
camel_imapx_job_get_kind_name (ic->job_kind));
 
+       g_mutex_lock (&is->priv->changes_lock);
+
        if (camel_folder_change_info_changed (is->priv->changes)) {
                CamelFolder *folder = NULL;
                CamelIMAPXMailbox *mailbox;
+               CamelFolderChangeInfo *changes;
+
+               changes = is->priv->changes;
+               is->priv->changes = camel_folder_change_info_new ();
+
+               g_mutex_unlock (&is->priv->changes_lock);
 
                mailbox = camel_imapx_server_ref_selected (is);
 
@@ -2276,13 +2327,15 @@ imapx_completion (CamelIMAPXServer *is,
                        camel_folder_summary_save_to_db (folder->summary, NULL);
 
                        imapx_update_store_summary (folder);
-                       camel_folder_changed (folder, is->priv->changes);
+                       camel_folder_changed (folder, changes);
                }
 
-               camel_folder_change_info_clear (is->priv->changes);
+               camel_folder_change_info_free (changes);
 
                g_clear_object (&folder);
                g_clear_object (&mailbox);
+       } else {
+               g_mutex_unlock (&is->priv->changes_lock);
        }
 
        if (g_list_next (ic->current_part) != NULL) {
@@ -3290,6 +3343,7 @@ imapx_server_finalize (GObject *object)
 
        g_mutex_clear (&is->priv->stream_lock);
        g_mutex_clear (&is->priv->select_lock);
+       g_mutex_clear (&is->priv->changes_lock);
 
        camel_folder_change_info_free (is->priv->changes);
        imapx_free_status (is->priv->copyuid_status);
@@ -3382,6 +3436,7 @@ camel_imapx_server_init (CamelIMAPXServer *is)
        g_mutex_init (&is->priv->stream_lock);
        g_mutex_init (&is->priv->inactivity_timeout_lock);
        g_mutex_init (&is->priv->select_lock);
+       g_mutex_init (&is->priv->changes_lock);
        g_mutex_init (&is->priv->search_results_lock);
        g_mutex_init (&is->priv->known_alerts_lock);
 
@@ -4593,7 +4648,9 @@ camel_imapx_server_append_message_sync (CamelIMAPXServer *is,
 
                                camel_folder_summary_add (folder->summary, mi);
 
+                               g_mutex_lock (&is->priv->changes_lock);
                                camel_folder_change_info_add_uid (is->priv->changes, mi->uid);
+                               g_mutex_unlock (&is->priv->changes_lock);
 
                                mi = NULL;
 
@@ -4736,7 +4793,9 @@ imapx_server_process_fetch_changes_infos (CamelIMAPXServer *is,
                        nfo->server_user_flags,
                        camel_imapx_mailbox_get_permanentflags (mailbox),
                        folder, FALSE)) {
+                       g_mutex_lock (&is->priv->changes_lock);
                        camel_folder_change_info_change_uid (is->priv->changes, camel_message_info_uid 
(minfo));
+                       g_mutex_unlock (&is->priv->changes_lock);
                }
 
                camel_message_info_unref (minfo);