[libgda] GdaVconnectionDataModel: fix weak ref implementation

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit ae3dadff8a607e0f4fd8bc430aca6935f4827a2d
Author: Daniel Espinosa <esodan gmail com>
Date:   Wed Oct 9 18:56:12 2019 -0500

    GdaVconnectionDataModel: fix weak ref implementation
    
    Fixes on VContext->context_object to use just GWeakRef

 .../virtual/gda-vconnection-data-model-private.h   |   2 +-
 libgda/sqlite/virtual/gda-vconnection-data-model.c | 119 ++++++++++-----------
 2 files changed, 56 insertions(+), 65 deletions(-)
---
diff --git a/libgda/sqlite/virtual/gda-vconnection-data-model-private.h 
b/libgda/sqlite/virtual/gda-vconnection-data-model-private.h
index 90ddf2977..1d50290f1 100644
--- a/libgda/sqlite/virtual/gda-vconnection-data-model-private.h
+++ b/libgda/sqlite/virtual/gda-vconnection-data-model-private.h
@@ -40,7 +40,7 @@ typedef struct VirtualFilteredData VirtualFilteredData;
 
 struct VContext{
        GWeakRef                 context_object;
-       GPtrArray                  *context_data;
+       GPtrArray               *context_data;
        GdaVConnectionTableData *vtable;
 };
 
diff --git a/libgda/sqlite/virtual/gda-vconnection-data-model.c 
b/libgda/sqlite/virtual/gda-vconnection-data-model.c
index 1ef1130e1..823396049 100644
--- a/libgda/sqlite/virtual/gda-vconnection-data-model.c
+++ b/libgda/sqlite/virtual/gda-vconnection-data-model.c
@@ -1,9 +1,8 @@
 /*
- * Copyright (C) 2007 - 2014 Vivien Malerba <malerba gnome-db org>
+ * Copyright (C) 2007 - 2013 Vivien Malerba <malerba gnome-db org>
  * Copyright (C) 2008 - 2011 Murray Cumming <murrayc murrayc com>
  * Copyright (C) 2009 Bas Driessen <bas driessen xobas com>
  * Copyright (C) 2010 David King <davidk openismus com>
- * Copyright (C) 2018 Daniel Espinosa <esodan gmail com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -22,7 +21,6 @@
  */
 
 #include <glib/gi18n-lib.h>
-#include <glib.h>
 #include <string.h>
 #include "gda-vconnection-data-model.h"
 #include "gda-vconnection-data-model-private.h"
@@ -31,12 +29,13 @@
 #include <libgda/gda-connection-internal.h>
 #include "../gda-sqlite.h"
 
-
+static void gda_vconnection_data_model_class_init (GdaVconnectionDataModelClass *klass);
+static void gda_vconnection_data_model_init       (GdaVconnectionDataModel *cnc);
 static void gda_vconnection_data_model_dispose   (GObject *object);
 
+
 typedef struct {
-       GSList *table_data_list; /* list of GdaVConnectionTableData structures */
-       gboolean being_disposed;
+       GSList       *table_data_list; /* list of GdaVConnectionTableData structures */
 
        GMutex        lock_context;
        GdaStatement *executed_stmt;
@@ -44,6 +43,7 @@ typedef struct {
 
 G_DEFINE_TYPE_WITH_PRIVATE (GdaVconnectionDataModel, gda_vconnection_data_model, GDA_TYPE_VIRTUAL_CONNECTION)
 
+
 static gboolean get_rid_of_vtable (GdaVconnectionDataModel *cnc, GdaVConnectionTableData *td, gboolean 
force, GError **error);
 
 enum {
@@ -54,14 +54,15 @@ enum {
 
 static gint gda_vconnection_data_model_signals[LAST_SIGNAL] = { 0, 0 };
 
+static GObjectClass  *parent_class = NULL;
+
 #ifdef GDA_DEBUG_NO
 static void
 dump_all_tables (GdaVconnectionDataModel *cnc)
 {
-       GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
        GSList *list;
        g_print ("GdaVconnectionDataModel's tables:\n");
-       for (list = priv->table_data_list; list; list = list->next) {
+       for (list = cnc->priv->table_data_list; list; list = list->next) {
                GdaVConnectionTableData *td = (GdaVConnectionTableData *) list->data;
                g_print ("    table %s, td=%p, spec=%p\n", td->table_name, td, td->spec);
        }
@@ -81,13 +82,11 @@ static void
 vtable_dropped (GdaVconnectionDataModel *cnc, const gchar *table_name)
 {
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
-
        GdaVConnectionTableData *td;
        td = _gda_vconnection_get_table_data_by_name (cnc, table_name);
        if (td)
                priv->table_data_list = g_slist_remove (priv->table_data_list, td);
-       if (! priv->being_disposed)
-               _gda_connection_signal_meta_table_update ((GdaConnection *)cnc, table_name);
+       _gda_connection_signal_meta_table_update ((GdaConnection *)cnc, table_name);
 #ifdef GDA_DEBUG_NO
        dump_all_tables (cnc);
 #endif
@@ -101,6 +100,8 @@ gda_vconnection_data_model_class_init (GdaVconnectionDataModelClass *klass)
 {
        GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+       parent_class = g_type_class_peek_parent (klass);
+
        /**
         * GdaVconnectionDataModel::vtable-created
         * @cnc: the #GdaVconnectionDataModel connection
@@ -142,8 +143,8 @@ static void
 gda_vconnection_data_model_init (GdaVconnectionDataModel *cnc)
 {
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
+       priv = g_new (GdaVconnectionDataModelPrivate, 1);
        priv->table_data_list = NULL;
-       priv->being_disposed = FALSE;
        g_mutex_init (& (priv->lock_context));
 
        g_object_set (G_OBJECT (cnc), "cnc-string", "_IS_VIRTUAL=TRUE", NULL);
@@ -153,26 +154,22 @@ static void
 gda_vconnection_data_model_dispose (GObject *object)
 {
        GdaVconnectionDataModel *cnc = (GdaVconnectionDataModel *) object;
+       g_return_if_fail (GDA_IS_VCONNECTION_DATA_MODEL (cnc));
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
 
-       g_return_if_fail (GDA_IS_VCONNECTION_DATA_MODEL (cnc));
 
+       /* free memory */
        if (priv->table_data_list != NULL) {
-               /* free memory */
-               priv->being_disposed = TRUE;
                while (priv->table_data_list) {
                        GdaVConnectionTableData *td;
                        td = (GdaVConnectionTableData *) priv->table_data_list->data;
                        get_rid_of_vtable (cnc, td, TRUE, NULL);
                }
-               priv->table_data_list = NULL;
        }
-       gda_connection_close ((GdaConnection *) cnc, NULL);
-
-       g_mutex_clear (& (priv->lock_context));
+       g_mutex_clear (&(priv->lock_context));
 
        /* chain to parent class */
-       G_OBJECT_CLASS (gda_vconnection_data_model_parent_class)->dispose (object);
+       parent_class->dispose (object);
 }
 
 static void
@@ -217,13 +214,13 @@ gboolean
 gda_vconnection_data_model_add_model (GdaVconnectionDataModel *cnc, 
                                      GdaDataModel *model, const gchar *table_name, GError **error)
 {
+       g_return_val_if_fail (GDA_IS_DATA_MODEL (model), FALSE);
        GdaVconnectionDataModelSpec *spec;
        gboolean retval;
 
        spec = g_new0 (GdaVconnectionDataModelSpec, 1);
-       spec->data_model = model;
+       spec->data_model = g_object_ref (model);
        spec->create_columns_func = create_columns;
-       g_object_ref (model);
        retval = gda_vconnection_data_model_add (cnc, spec, (GDestroyNotify) spec_destroy_func, table_name, 
error);
 
        return retval;
@@ -233,7 +230,7 @@ gda_vconnection_data_model_add_model (GdaVconnectionDataModel *cnc,
  * gda_vconnection_data_model_add:
  * @cnc: a #GdaVconnectionDataModel connection
  * @spec: a #GdaVconnectionDataModelSpec structure, used AS IS (not copied) and can be modified
- * @spec_free_func: (nullable): function to call when freeing @spec, or %NULL
+ * @spec_free_func: (allow-none): function to call when freeing @spec, or %NULL
  * @table_name: the name of the table
  * @error: a place to store errors, or %NULL
  *
@@ -254,14 +251,12 @@ gboolean
 gda_vconnection_data_model_add (GdaVconnectionDataModel *cnc, GdaVconnectionDataModelSpec *spec, 
                                GDestroyNotify spec_free_func, const gchar *table_name, GError **error)
 {
-       GdaVirtualProvider *prov;
+       GdaSqliteProvider *prov;
        gchar *str;
        int rc;
        char *zErrMsg = NULL;
        gboolean retval = TRUE;
        SqliteConnectionData *scnc;
-       GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
-       GdaSqliteProvider *sprov = GDA_SQLITE_PROVIDER (gda_connection_get_provider (GDA_CONNECTION (cnc)));
 
        static gint counter = 0;
 
@@ -270,6 +265,8 @@ gda_vconnection_data_model_add (GdaVconnectionDataModel *cnc, GdaVconnectionData
        g_return_val_if_fail (spec, FALSE);
        g_return_val_if_fail (spec->data_model || (spec->create_columns_func && (spec->create_model_func || 
spec->create_filtered_model_func)), FALSE);
 
+       GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
+
        /* cleaning functions */
        if (spec->data_model) {
                g_return_val_if_fail (GDA_IS_DATA_MODEL (spec->data_model), FALSE);
@@ -299,15 +296,15 @@ gda_vconnection_data_model_add (GdaVconnectionDataModel *cnc, GdaVconnectionData
        priv->table_data_list = g_slist_append (priv->table_data_list, td);
 
        /* actually create the virtual table in @cnc */
-       prov = (GdaVirtualProvider *) gda_connection_get_provider (GDA_CONNECTION (cnc));
+       prov = (GdaSqliteProvider *) gda_connection_get_provider (GDA_CONNECTION (cnc));
        str = g_strdup_printf ("CREATE VIRTUAL TABLE %s USING %s ('%s')", td->table_name, G_OBJECT_TYPE_NAME 
(prov), td->unique_name);
-       rc = SQLITE3_CALL (sprov, sqlite3_exec) (scnc->connection, str, NULL, 0, &zErrMsg);
+       rc = SQLITE3_CALL (prov, sqlite3_exec) (scnc->connection, str, NULL, 0, &zErrMsg);
        g_free (str);
        if (rc != SQLITE_OK) {
                g_set_error (error, GDA_SERVER_PROVIDER_ERROR,
                             GDA_SERVER_PROVIDER_INTERNAL_ERROR,
-                            _("Internal Error: when trying to add data model spec for virtual connection: 
%s"), zErrMsg);
-               SQLITE3_CALL (sprov, sqlite3_free) (zErrMsg);
+                            "%s", zErrMsg);
+               SQLITE3_CALL (prov, sqlite3_free) (zErrMsg);
                _gda_vconnection_data_model_table_data_free (td);
                priv->table_data_list = g_slist_remove (priv->table_data_list, td);
                retval = FALSE;
@@ -328,13 +325,14 @@ get_rid_of_vtable (GdaVconnectionDataModel *cnc, GdaVConnectionTableData *td, gb
        int rc;
        char *zErrMsg = NULL;
        gboolean allok = TRUE;
+       GdaSqliteProvider *prov;
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
-       GdaSqliteProvider *prov = GDA_SQLITE_PROVIDER (gda_connection_get_provider (GDA_CONNECTION (cnc)));
 
        SqliteConnectionData *scnc;
        scnc = (SqliteConnectionData*) gda_connection_internal_get_provider_data_error ((GdaConnection *) 
cnc, error);
        if (!scnc && !force)
                return FALSE;
+       prov = (GdaSqliteProvider *) gda_connection_get_provider (GDA_CONNECTION (cnc));
 
        if (scnc) {
                str = g_strdup_printf ("DROP TABLE %s", td->table_name);
@@ -400,7 +398,7 @@ gda_vconnection_data_model_remove (GdaVconnectionDataModel *cnc, const gchar *ta
  * Find the #GdaVconnectionDataModelSpec specifying how the table named @table_name is represented
  * in @cnc.
  *
- * Returns: (transfer none) (nullable): a #GdaVconnectionDataModelSpec pointer, of %NULL if there is no 
table named @table_name
+ * Returns: (transfer none) (allow-none): a #GdaVconnectionDataModelSpec pointer, of %NULL if there is no 
table named @table_name
  *
  * Since: 4.2.6
  */
@@ -427,13 +425,14 @@ gda_vconnection_data_model_get (GdaVconnectionDataModel *cnc, const gchar *table
  * either if no table named @table_name exists, or if that table actually exists but no #GdaDataModel
  * has yet been created. For a more general approach, use the gda_vconnection_data_model_get().
  *
- * Returns: (transfer none) (nullable): the #GdaDataModel, or %NULL
+ * Returns: (transfer none) (allow-none): the #GdaDataModel, or %NULL
  */
 GdaDataModel *
 gda_vconnection_data_model_get_model (GdaVconnectionDataModel *cnc, const gchar *table_name)
 {
        GdaVConnectionTableData *td;
        g_return_val_if_fail (GDA_IS_VCONNECTION_DATA_MODEL (cnc), NULL);
+
        if (!table_name || !(*table_name))
                return NULL;
 
@@ -451,15 +450,17 @@ gda_vconnection_data_model_get_model (GdaVconnectionDataModel *cnc, const gchar
  *
  * Find the name of the table associated to @model in @cnc
  *
- * Returns: (transfer none) (nullable): the table name, or %NULL if not found
+ * Returns: (transfer none) (allow-none): the table name, or %NULL if not found
  */
 const gchar *
 gda_vconnection_data_model_get_table_name (GdaVconnectionDataModel *cnc, GdaDataModel *model)
 {
        GdaVConnectionTableData *td;
        g_return_val_if_fail (GDA_IS_VCONNECTION_DATA_MODEL (cnc), NULL);
+
        if (!model)
                return NULL;
+
        g_return_val_if_fail (GDA_IS_DATA_MODEL (model), NULL);
 
        td = _gda_vconnection_get_table_data_by_model (cnc, model);
@@ -488,7 +489,6 @@ gda_vconnection_data_model_foreach (GdaVconnectionDataModel *cnc,
        GSList *copy, *list;
        g_return_if_fail (GDA_IS_VCONNECTION_DATA_MODEL (cnc));
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
-
        if (!func || !priv->table_data_list)
                return;
 
@@ -527,6 +527,7 @@ _gda_vconnection_get_table_data_by_unique_name (GdaVconnectionDataModel *cnc, co
 {
        GSList *list;
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
+
        for (list = priv->table_data_list; list; list = list->next) {
                if (!strcmp (((GdaVConnectionTableData*) list->data)->unique_name, unique_name))
                        return (GdaVConnectionTableData*) list->data;
@@ -539,6 +540,7 @@ _gda_vconnection_get_table_data_by_model (GdaVconnectionDataModel *cnc, GdaDataM
 {
        GSList *list;
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
+
        for (list = priv->table_data_list; list; list = list->next) {
                if (((GdaVConnectionTableData*) list->data)->real_model == model)
                        return (GdaVConnectionTableData*) list->data;
@@ -554,44 +556,29 @@ _gda_vconnection_data_model_table_data_free (GdaVConnectionTableData *td)
        if (td->real_model)
                g_object_unref (td->real_model);
        if (td->columns) {
-               g_list_free_full (td->columns, (GDestroyNotify) g_object_unref);
-    td->columns = NULL;
+               g_list_free_full (td->columns, g_object_unref);
+               td->columns = NULL;
        }
        g_free (td->table_name);
-  td->table_name = NULL;
        g_free (td->unique_name);
-  td->unique_name = NULL;
-       if (td->spec_free_func) {
+       if (td->spec_free_func)
                td->spec_free_func (td->spec);
-    td->spec = NULL;
-  }
        for (i = 0; i < PARAMS_NB; i++) {
-               if (td->modif_params[i]) {
+               if (td->modif_params[i])
                        g_object_unref (td->modif_params[i]);
-      td->modif_params[i] = NULL;
-    }
-               if (td->modif_stmt[i]) {
+               if (td->modif_stmt[i])
                        g_object_unref (td->modif_stmt[i]);
-      td->modif_stmt[i] = NULL;
-    }
        }
 
-       if (td->context.hash) {
+       if (td->context.hash)
                g_hash_table_destroy (td->context.hash);
-    td->context.hash = NULL;
-  }
        g_free (td);
 }
 
-
 static void
 vcontext_free (VContext *context)
 {
-       GObject *obj = g_weak_ref_get (&(context->context_object));
-       if (obj) {
-               g_hash_table_remove (context->vtable->context.hash, obj);
-               g_object_unref (obj);
-       }
+       g_weak_ref_set (&context->context_object, NULL);
        if (context->context_data) {
                g_ptr_array_free (context->context_data, TRUE);
                context->context_data = NULL;
@@ -605,10 +592,10 @@ vcontext_free (VContext *context)
 void
 _gda_vconnection_set_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
 {
-       GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
-       g_mutex_lock (& (priv->lock_context));
        GSList *list;
+       GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
        if (obj) {
+               g_mutex_lock (& (priv->lock_context));
                for (list = priv->table_data_list; list; list = list->next) {
                        GdaVConnectionTableData *td = (GdaVConnectionTableData*) list->data;
                        VContext *vc = NULL;
@@ -623,8 +610,8 @@ _gda_vconnection_set_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
 
                        if (! vc) {
                                vc = g_new0 (VContext, 1);
-                               g_weak_ref_set (&(vc->context_object), obj);
-                               vc->context_data = g_ptr_array_new_full (1, (GDestroyNotify) 
_gda_vconnection_virtual_filtered_data_unref);
+                               g_weak_ref_set (&vc->context_object, obj);
+                               vc->context_data = g_ptr_array_new_with_free_func ((GDestroyNotify) 
_gda_vconnection_virtual_filtered_data_unref);
                                vc->vtable = td;
                                g_hash_table_insert (td->context.hash, obj, vc);
 #ifdef DEBUG_VCONTEXT
@@ -641,14 +628,15 @@ _gda_vconnection_set_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
                         * an exception already occurred */
                        td->context.current_vcontext = NULL;
                }
+               g_mutex_unlock (& (priv->lock_context));
        }
-       g_mutex_unlock (& (priv->lock_context));
 }
 
 void
 _gda_vconnection_change_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
 {
        GSList *list;
+       GObject *old_obj;
        GdaVconnectionDataModelPrivate *priv = gda_vconnection_data_model_get_instance_private (cnc);
 
        for (list = priv->table_data_list; list; list = list->next) {
@@ -661,7 +649,7 @@ _gda_vconnection_change_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
                VContext *ovc, *nvc;
                ovc = td->context.current_vcontext;
                nvc = g_new0 (VContext, 1);
-               g_weak_ref_set (&(nvc->context_object), obj);
+               g_weak_ref_init (&nvc->context_object, obj);
                nvc->vtable = ovc->vtable;
                nvc->context_data = ovc->context_data;
                ovc->context_data = NULL;
@@ -669,6 +657,9 @@ _gda_vconnection_change_working_obj (GdaVconnectionDataModel *cnc, GObject *obj)
 #ifdef DEBUG_VCONTEXT
                g_print ("VCNew %p\n", nvc);
 #endif
-               g_hash_table_remove (td->context.hash, obj);
+               old_obj = g_weak_ref_get (&ovc->context_object);
+               if (old_obj != NULL) {
+                       g_hash_table_remove (td->context.hash, old_obj);
+               }
        }
 }