[gnome-software/wip/kalev/appstream-silo-threadsafety: 3/3] shell-extensions: Add locking for XbSilo

[Kalev Lember <klember src gnome org>]

commit 02df9dbbc9831b419f9d13a270d48ea7bd52e5f1
Author: Kalev Lember <klember redhat com>
Date:   Fri May 10 14:50:01 2019 +0200

    shell-extensions: Add locking for XbSilo

 .../shell-extensions/gs-plugin-shell-extensions.c  | 28 +++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)
---
diff --git a/plugins/shell-extensions/gs-plugin-shell-extensions.c 
b/plugins/shell-extensions/gs-plugin-shell-extensions.c
index 628d046b..2b6411ba 100644
--- a/plugins/shell-extensions/gs-plugin-shell-extensions.c
+++ b/plugins/shell-extensions/gs-plugin-shell-extensions.c
@@ -36,6 +36,7 @@ struct GsPluginData {
        GsApp           *cached_origin;
        GSettings       *settings;
        XbSilo          *silo;
+       GRWLock          silo_lock;
 };
 
 typedef enum {
@@ -62,6 +63,10 @@ gs_plugin_initialize (GsPlugin *plugin)
 {
        GsPluginData *priv = gs_plugin_alloc_data (plugin, sizeof(GsPluginData));
 
+       /* XbSilo needs external locking as we destroy the silo and build a new
+        * one when something changes */
+       g_rw_lock_init (&priv->silo_lock);
+
        /* add source */
        priv->cached_origin = gs_app_new (gs_plugin_get_name (plugin));
        gs_app_set_kind (priv->cached_origin, AS_APP_KIND_SOURCE);
@@ -87,6 +92,7 @@ gs_plugin_destroy (GsPlugin *plugin)
                g_object_unref (priv->silo);
        g_object_unref (priv->cached_origin);
        g_object_unref (priv->settings);
+       g_rw_lock_clear (&priv->silo_lock);
 }
 
 void
@@ -413,6 +419,7 @@ gs_plugin_refine_app (GsPlugin *plugin,
        const gchar *uuid;
        g_autofree gchar *xpath = NULL;
        g_autoptr(GError) error_local = NULL;
+       g_autoptr(GRWLockReaderLocker) locker = NULL;
        g_autoptr(XbNode) component = NULL;
 
        /* repo not enabled */
@@ -446,9 +453,13 @@ gs_plugin_refine_app (GsPlugin *plugin,
                gs_app_set_size_download (app, GS_APP_SIZE_UNKNOWABLE);
 
 
-       /* find the component using the UUID */
+       /* check silo is valid */
        if (!_check_silo (plugin, cancellable, error))
                return FALSE;
+
+       locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
+
+       /* find the component using the UUID */
        xpath = g_strdup_printf ("components/component/custom/"
                                 "value[@key='shell-extensions::uuid'][text()='%s']/../..",
                                 uuid);
@@ -477,6 +488,7 @@ gs_plugin_refine_wildcard (GsPlugin *plugin,
        g_autofree gchar *xpath = NULL;
        g_autoptr(GError) error_local = NULL;
        g_autoptr(GPtrArray) components = NULL;
+       g_autoptr(GRWLockReaderLocker) locker = NULL;
 
        /* repo not enabled */
        if (!g_settings_get_boolean (priv->settings, "enable-shell-extensions-repo"))
@@ -491,6 +503,8 @@ gs_plugin_refine_wildcard (GsPlugin *plugin,
        if (id == NULL)
                return TRUE;
 
+       locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
+
        /* find all apps */
        xpath = g_strdup_printf ("components/component/id[text()='%s']/..", id);
        components = xb_silo_query (priv->silo, xpath, 0, &error_local);
@@ -757,6 +771,7 @@ gs_plugin_shell_extensions_refresh (GsPlugin *plugin,
        g_autofree gchar *fn = NULL;
        g_autofree gchar *uri = NULL;
        g_autoptr(GFile) file = NULL;
+       g_autoptr(GRWLockReaderLocker) locker = NULL;
        g_autoptr(GsApp) app_dl = gs_app_new (gs_plugin_get_name (plugin));
 
        /* get cache filename */
@@ -789,8 +804,10 @@ gs_plugin_shell_extensions_refresh (GsPlugin *plugin,
        }
 
        /* be explicit */
+       locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
        if (priv->silo != NULL)
                xb_silo_invalidate (priv->silo);
+
        return TRUE;
 }
 
@@ -803,16 +820,21 @@ _check_silo (GsPlugin *plugin, GCancellable *cancellable, GError **error)
        g_autoptr(GError) error_local = NULL;
        g_autoptr(GFile) blobfile = NULL;
        g_autoptr(GFile) file = NULL;
+       g_autoptr(GRWLockReaderLocker) reader_locker = NULL;
+       g_autoptr(GRWLockWriterLocker) writer_locker = NULL;
        g_autoptr(XbBuilder) builder = xb_builder_new ();
        g_autoptr(XbBuilderSource) source = xb_builder_source_new ();
 
+       reader_locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
        /* everything is okay */
        if (priv->silo != NULL && xb_silo_is_valid (priv->silo)) {
                g_debug ("silo already valid");
                return TRUE;
        }
+       g_clear_pointer (&reader_locker, g_rw_lock_reader_locker_free);
 
        /* drat! silo needs regenerating */
+       writer_locker = g_rw_lock_writer_locker_new (&priv->silo_lock);
        g_clear_object (&priv->silo);
 
        /* verbose profiling */
@@ -884,11 +906,13 @@ gs_plugin_add_search (GsPlugin *plugin, gchar **values, GsAppList *list,
                      GCancellable *cancellable, GError **error)
 {
        GsPluginData *priv = gs_plugin_get_data (plugin);
+       g_autoptr(GRWLockReaderLocker) locker = NULL;
        g_autoptr(GsAppList) list_tmp = gs_app_list_new ();
        if (!g_settings_get_boolean (priv->settings, "enable-shell-extensions-repo"))
                return TRUE;
        if (!_check_silo (plugin, cancellable, error))
                return FALSE;
+       locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
        if (!gs_appstream_search (plugin, priv->silo, values, list_tmp,
                                  cancellable, error))
                return FALSE;
@@ -902,11 +926,13 @@ gs_plugin_add_category_apps (GsPlugin *plugin, GsCategory *category, GsAppList *
                             GCancellable *cancellable, GError **error)
 {
        GsPluginData *priv = gs_plugin_get_data (plugin);
+       g_autoptr(GRWLockReaderLocker) locker = NULL;
        g_autoptr(GsAppList) list_tmp = gs_app_list_new ();
        if (!g_settings_get_boolean (priv->settings, "enable-shell-extensions-repo"))
                return TRUE;
        if (!_check_silo (plugin, cancellable, error))
                return FALSE;
+       locker = g_rw_lock_reader_locker_new (&priv->silo_lock);
        if (!gs_appstream_add_category_apps (plugin, priv->silo, category,
                                             list_tmp, cancellable, error))
                return FALSE;