Remove the data field from MonoVTable to reduce memory usage.

[mono.git] / mono / metadata / object.c

diff --git a/mono/metadata/object.c b/mono/metadata/object.c
index 91c8dd289d7133e002353651e10a84a709e0c3ed..86cc1ce29997fbe92ac6501c378a70b7566f6978 100644 (file)
--- a/mono/metadata/object.c
+++ b/mono/metadata/object.c
@@ -1834,7 +1834,7 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
        MonoClassRuntimeInfo *runtime_info, *old_info;
        MonoClassField *field;
        char *t;
-       int i;
+       int i, vtable_slots;
        int imt_table_bytes = 0;
        guint32 vtable_size, class_size;
        guint32 cindex;
@@ -1902,8 +1902,14 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
                return NULL;
        }
 
+       vtable_slots = class->vtable_size;
+       /* we add an additional vtable slot to store the pointer to static field data only when needed */
+       class_size = mono_class_data_size (class);
+       if (class_size)
+               vtable_slots++;
+
        if (ARCH_USE_IMT) {
-               vtable_size = MONO_SIZEOF_VTABLE + class->vtable_size * sizeof (gpointer);
+               vtable_size = MONO_SIZEOF_VTABLE + vtable_slots * sizeof (gpointer);
                if (class->interface_offsets_count) {
                        imt_table_bytes = sizeof (gpointer) * (MONO_IMT_SIZE);
                        vtable_size += sizeof (gpointer) * (MONO_IMT_SIZE);
@@ -1912,7 +1918,7 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
                }
        } else {
                vtable_size = sizeof (gpointer) * (class->max_interface_id + 1) +
-                       MONO_SIZEOF_VTABLE + class->vtable_size * sizeof (gpointer);
+                       MONO_SIZEOF_VTABLE + vtable_slots * sizeof (gpointer);
        }
 
        mono_stats.used_class_count++;
@@ -1947,7 +1953,8 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
 #endif
                vt->gc_descr = class->gc_descr;
 
-       if ((class_size = mono_class_data_size (class))) {
+       if (class_size) {
+               /* we store the static field pointer at the end of the vtable: vt->vtable [class->vtable_size] */
                if (class->has_static_refs) {
                        gpointer statics_gc_descr;
                        int max_set = 0;
@@ -1957,13 +1964,14 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
                        bitmap = compute_class_bitmap (class, default_bitmap, sizeof (default_bitmap) * 8, 0, &max_set, TRUE);
                        /*g_print ("bitmap 0x%x for %s.%s (size: %d)\n", bitmap [0], class->name_space, class->name, class_size);*/
                        statics_gc_descr = mono_gc_make_descr_from_bitmap (bitmap, max_set + 1);
-                       vt->data = mono_gc_alloc_fixed (class_size, statics_gc_descr);
-                       mono_domain_add_class_static_data (domain, class, vt->data, NULL);
+                       vt->vtable [class->vtable_size] = mono_gc_alloc_fixed (class_size, statics_gc_descr);
+                       mono_domain_add_class_static_data (domain, class, vt->vtable [class->vtable_size], NULL);
                        if (bitmap != default_bitmap)
                                g_free (bitmap);
                } else {
-                       vt->data = mono_domain_alloc0 (domain, class_size);
+                       vt->vtable [class->vtable_size] = mono_domain_alloc0 (domain, class_size);
                }
+               vt->has_static_fields = TRUE;
                mono_stats.class_static_data_size += class_size;
        }
 
@@ -2015,7 +2023,7 @@ mono_class_create_runtime_vtable (MonoDomain *domain, MonoClass *class, gboolean
                        const char *data = mono_field_get_data (field);
 
                        g_assert (!(field->type->attrs & FIELD_ATTRIBUTE_HAS_DEFAULT));
-                       t = (char*)vt->data + field->offset;
+                       t = (char*)mono_vtable_get_static_field_data (vt) + field->offset;
                        /* some fields don't really have rva, they are just zeroed (bss? bug #343083) */
                        if (!data)
                                continue;
@@ -2977,16 +2985,24 @@ mono_field_static_set_value (MonoVTable *vt, MonoClassField *field, void *value)
                mono_domain_unlock (vt->domain);
                dest = mono_get_special_static_data (GPOINTER_TO_UINT (addr));
        } else {
-               dest = (char*)vt->data + field->offset;
+               dest = (char*)mono_vtable_get_static_field_data (vt) + field->offset;
        }
        set_value (field->type, dest, value, FALSE);
 }
 
-/* Used by the debugger */
+/**
+ * mono_vtable_get_static_field_data:
+ *
+ * Internal use function: return a pointer to the memory holding the static fields
+ * for a class or NULL if there are no static fields.
+ * This is exported only for use by the debugger.
+ */
 void *
 mono_vtable_get_static_field_data (MonoVTable *vt)
 {
-       return vt->data;
+       if (!vt->has_static_fields)
+               return NULL;
+       return vt->vtable [vt->klass->vtable_size];
 }
 
 static guint8*
@@ -3004,7 +3020,7 @@ mono_field_get_addr (MonoObject *obj, MonoVTable *vt, MonoClassField *field)
                        mono_domain_unlock (vt->domain);
                        src = mono_get_special_static_data (GPOINTER_TO_UINT (addr));
                } else {
-                       src = (guint8*)vt->data + field->offset;
+                       src = (guint8*)mono_vtable_get_static_field_data (vt) + field->offset;
                }
        } else {
                src = (guint8*)obj + field->offset;
@@ -3260,7 +3276,7 @@ mono_field_static_get_value_for_thread (MonoInternalThread *thread, MonoVTable *
                gpointer addr = g_hash_table_lookup (vt->domain->special_static_fields, field);
                src = mono_get_special_static_data_for_thread (thread, GPOINTER_TO_UINT (addr));
        } else {
-               src = (char*)vt->data + field->offset;
+               src = (char*)mono_vtable_get_static_field_data (vt) + field->offset;
        }
        set_value (field->type, value, src, TRUE);
 }