[gnome-calendar/gbsneto/recurring-event-editing-fixes: 5/18] calendar-monitor: Move events hash table to shared section

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit a651e958bf08dc0e9f73abb76e360cb38700597c
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Oct 13 22:22:52 2022 -0300

    calendar-monitor: Move events hash table to shared section
    
    We'll start accessing the hash table from multiple threads, so
    it must be in the shared section of the structure, and it must
    be encapsulated by locking.

 src/core/gcal-calendar-monitor.c | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)
---
diff --git a/src/core/gcal-calendar-monitor.c b/src/core/gcal-calendar-monitor.c
index 8c558e45..0377dd0a 100644
--- a/src/core/gcal-calendar-monitor.c
+++ b/src/core/gcal-calendar-monitor.c
@@ -55,8 +55,6 @@ struct _GcalCalendarMonitor
   GMainContext       *thread_context;
   GMainContext       *main_context;
 
-  GHashTable         *events; /* gchar* -> GcalEvent* */
-
   GAsyncQueue        *messages;
   GcalCalendar       *calendar;
   gboolean            complete;
@@ -77,6 +75,7 @@ struct _GcalCalendarMonitor
    */
   struct {
     GRWLock           lock;
+    GHashTable       *events; /* gchar* -> GcalEvent* */
     GcalRange        *range;
     gchar            *filter;
   } shared;
@@ -830,12 +829,15 @@ static void
 remove_events_outside_range (GcalCalendarMonitor *self,
                              GcalRange           *range)
 {
+  g_autoptr (GRWLockWriterLocker) writer_locker = NULL;
   GHashTableIter iter;
   GcalEvent *event;
 
   GCAL_TRACE_MSG ("Removing events outside range from monitor");
 
-  g_hash_table_iter_init (&iter, self->events);
+  writer_locker = g_rw_lock_writer_locker_new (&self->shared.lock);
+
+  g_hash_table_iter_init (&iter, self->shared.events);
   while (g_hash_table_iter_next (&iter, NULL, (gpointer*) &event))
     {
       g_object_ref (event);
@@ -850,12 +852,15 @@ remove_events_outside_range (GcalCalendarMonitor *self,
 static void
 remove_all_events (GcalCalendarMonitor *self)
 {
+  g_autoptr (GRWLockWriterLocker) writer_locker = NULL;
   GHashTableIter iter;
   GcalEvent *event;
 
   GCAL_TRACE_MSG ("Removing all events from view");
 
-  g_hash_table_iter_init (&iter, self->events);
+  writer_locker = g_rw_lock_writer_locker_new (&self->shared.lock);
+
+  g_hash_table_iter_init (&iter, self->shared.events);
   while (g_hash_table_iter_next (&iter, NULL, (gpointer*) &event))
     {
       g_hash_table_iter_remove (&iter);
@@ -884,6 +889,7 @@ set_complete (GcalCalendarMonitor *self,
 static gboolean
 add_event_to_timeline_in_idle_cb (gpointer user_data)
 {
+  g_autoptr (GRWLockWriterLocker) writer_locker = NULL;
   GcalCalendarMonitor *self;
   GcalEvent *event;
   IdleData *idle_data;
@@ -897,7 +903,9 @@ add_event_to_timeline_in_idle_cb (gpointer user_data)
   g_assert (idle_data->event_id == NULL);
 
   event_id = gcal_event_get_uid (event);
-  if (g_hash_table_insert (self->events, g_strdup (event_id), g_object_ref (event)))
+
+  writer_locker = g_rw_lock_writer_locker_new (&self->shared.lock);
+  if (g_hash_table_insert (self->shared.events, g_strdup (event_id), g_object_ref (event)))
     g_signal_emit (self, signals[EVENT_ADDED], 0, event);
 
   GCAL_RETURN (G_SOURCE_REMOVE);
@@ -906,6 +914,7 @@ add_event_to_timeline_in_idle_cb (gpointer user_data)
 static gboolean
 update_event_in_idle_cb (gpointer user_data)
 {
+  g_autoptr (GRWLockWriterLocker) writer_locker = NULL;
   GcalCalendarMonitor *self;
   GcalEvent *old_event;
   GcalEvent *event;
@@ -920,10 +929,12 @@ update_event_in_idle_cb (gpointer user_data)
   g_assert (idle_data->event_id == NULL);
 
   event_id = gcal_event_get_uid (event);
-  old_event = g_hash_table_lookup (self->events, event_id);
+
+  writer_locker = g_rw_lock_writer_locker_new (&self->shared.lock);
+  old_event = g_hash_table_lookup (self->shared.events, event_id);
   if (old_event)
     {
-      g_hash_table_insert (self->events, g_strdup (event_id), g_object_ref (event));
+      g_hash_table_insert (self->shared.events, g_strdup (event_id), g_object_ref (event));
       g_signal_emit (self, signals[EVENT_UPDATED], 0, old_event, event);
     }
 
@@ -933,6 +944,7 @@ update_event_in_idle_cb (gpointer user_data)
 static gboolean
 remove_event_from_timeline_in_idle_cb (gpointer user_data)
 {
+  g_autoptr (GRWLockWriterLocker) writer_locker = NULL;
   g_autoptr (GcalEvent) event = NULL;
   GcalCalendarMonitor *self;
   IdleData *idle_data;
@@ -945,14 +957,15 @@ remove_event_from_timeline_in_idle_cb (gpointer user_data)
   g_assert (idle_data->event == NULL);
   event_id = idle_data->event_id;
 
-  event = g_hash_table_lookup (self->events, event_id);
+  writer_locker = g_rw_lock_writer_locker_new (&self->shared.lock);
+  event = g_hash_table_lookup (self->shared.events, event_id);
 
   if (event)
     {
       /* Keep the event alive until the signal is emitted */
       g_object_ref (event);
 
-      g_hash_table_remove (self->events, event_id);
+      g_hash_table_remove (self->shared.events, event_id);
       g_signal_emit (self, signals[EVENT_REMOVED], 0, event);
     }
 
@@ -1010,10 +1023,10 @@ gcal_calendar_monitor_finalize (GObject *object)
   remove_all_events (self);
 
   g_clear_object (&self->calendar);
-  g_clear_pointer (&self->events, g_hash_table_destroy);
   g_clear_pointer (&self->thread_context, g_main_context_unref);
   g_clear_pointer (&self->main_context, g_main_context_unref);
   g_clear_pointer (&self->messages, g_async_queue_unref);
+  g_clear_pointer (&self->shared.events, g_hash_table_destroy);
   g_clear_pointer (&self->shared.filter, g_free);
   g_clear_pointer (&self->shared.range, gcal_range_unref);
 
@@ -1121,7 +1134,7 @@ gcal_calendar_monitor_class_init (GcalCalendarMonitorClass *klass)
 static void
 gcal_calendar_monitor_init (GcalCalendarMonitor *self)
 {
-  self->events = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_object_unref);
+  self->shared.events = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_object_unref);
   self->thread_context = g_main_context_new ();
   self->main_context = g_main_context_ref_thread_default ();
   self->messages = g_async_queue_new ();
@@ -1200,7 +1213,9 @@ gcal_calendar_monitor_get_cached_event (GcalCalendarMonitor *self,
   g_return_val_if_fail (GCAL_IS_CALENDAR_MONITOR (self), NULL);
   g_return_val_if_fail (event_id, NULL);
 
-  event = g_hash_table_lookup (self->events, event_id);
+  g_rw_lock_reader_lock (&self->shared.lock);
+  event = g_hash_table_lookup (self->shared.events, event_id);
+  g_rw_lock_reader_unlock (&self->shared.lock);
 
   return event ? g_object_ref (event) : NULL;
 }