Add option for strict write barriers

Author: jechter

mono/metadata/boehm-gc.c

@@ -59,6 +59,7 @@ void *pthread_get_stackaddr_np(pthread_t);
 #define MIN_BOEHM_MAX_HEAP_SIZE (MIN_BOEHM_MAX_HEAP_SIZE_IN_MB << 20)
 
 static gboolean gc_initialized = FALSE;
+static gboolean gc_strict_wbarriers = FALSE;
 static mono_mutex_t mono_gc_lock;
 
 typedef void (*GC_push_other_roots_proc)(void);
@@ -247,7 +248,10 @@ mono_gc_base_init (void)
 			#endif					
 				}
 				continue;
-			} else {
+			} else if (g_str_has_prefix (opt, "strict-wbarriers")) {
+				gc_strict_wbarriers = TRUE;
+				continue;
+			}else {
 				/* Could be a parameter for sgen */
 				/*
 				fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
@@ -273,6 +277,24 @@ mono_gc_base_init (void)
 	gc_initialized = TRUE;
 }
 
+void 
+mono_gc_dirty(void **ptr)
+{
+	GC_dirty (ptr);
+}
+
+void 
+mono_gc_dirty_range(void **ptr, size_t size)
+{
+	if (G_UNLIKELY(gc_strict_wbarriers))
+	{
+		for (int i = 0; i < size/sizeof(void*); i++)
+			GC_dirty(ptr + i);
+	}
+	else
+		GC_dirty (ptr);
+}
+
 void
 mono_gc_base_cleanup (void)
 {
@@ -647,7 +669,7 @@ mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
 {
 	/* libgc requires that we use HIDE_POINTER... */
 	*link_addr = (void*)HIDE_POINTER (obj);
-	GC_dirty (link_addr);
+	mono_gc_dirty (link_addr);
 	if (track)
 		GC_REGISTER_LONG_LINK (link_addr, obj);
 	else
@@ -892,57 +914,60 @@ void
 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
 {
 	*(void**)field_ptr = value;
-	GC_dirty (field_ptr);
+	mono_gc_dirty (field_ptr);
 }
 
 void
 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
 {
 	*(void**)slot_ptr = value;
-	GC_dirty (slot_ptr);
+	mono_gc_dirty (slot_ptr);
 }
 
 void
 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
 {
 	mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
-	GC_dirty (dest_ptr);
+	mono_gc_dirty_range (dest_ptr, count * sizeof(gpointer));
 }
 
 void
 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
 {
 	*(void**)ptr = value;
-	GC_dirty (ptr);
+	mono_gc_dirty (ptr);
 }
 
 void
 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
 {
 	mono_atomic_store_ptr ((volatile gpointer *)ptr, value);
-	GC_dirty (ptr);
+	mono_gc_dirty (ptr);
 }
 
 void
 mono_gc_wbarrier_generic_nostore (gpointer ptr)
 {
-	GC_dirty (ptr);
+	mono_gc_dirty (ptr);
 }
 
 void
 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
 {
-	mono_gc_memmove_atomic (dest, src, count * mono_class_value_size (klass, NULL));
-	GC_dirty (dest);
+	size_t size = count * mono_class_value_size (klass, NULL);
+	mono_gc_memmove_atomic (dest, src, size);
+	mono_gc_dirty_range (dest, size);
 }
 
 void
 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
 {
 	/* do not copy the sync state */
-	mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
-			mono_object_class (obj)->instance_size - sizeof (MonoObject));
-	GC_dirty (obj);
+	size_t size = mono_object_class (obj)->instance_size - sizeof (MonoObject);
+	char * dstPtr = (char*)obj + sizeof (MonoObject);
+	mono_gc_memmove_aligned (dstPtr, (char*)src + sizeof (MonoObject),
+			size);
+	mono_gc_dirty_range ((void**)dstPtr, size);
 }
 
 void
@@ -1514,7 +1539,7 @@ void
 mono_gc_wbarrier_range_copy (gpointer _dest, gpointer _src, int size)
 {
 	memcpy (_dest, _src, size);
-	GC_dirty (_dest);
+	mono_gc_dirty_range (_dest, size);
 }
 
 void*
@@ -1875,7 +1900,7 @@ handle_data_grow (HandleData *handles, gboolean track)
 		gpointer *entries;
 		entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * new_size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, NULL, "GC Handle Table (Boehm)");
 		mono_gc_memmove_aligned (entries, handles->entries, sizeof (*handles->entries) * handles->size);
-		GC_dirty (entries);
+		mono_gc_dirty_range (entries, new_size * sizeof (*handles->entries));
 		mono_gc_free_fixed (handles->entries);
 		handles->entries = entries;
 	}
@@ -1908,7 +1933,7 @@ alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
 			mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
 	} else {
 		handles->entries [slot] = obj;
-		GC_dirty (handles->entries + slot);
+		mono_gc_dirty (handles->entries + slot);
 	}
 
 #ifndef DISABLE_PERFCOUNTERS
@@ -2026,7 +2051,7 @@ mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
 			handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
 		} else {
 			handles->entries [slot] = obj;
-			GC_dirty (handles->entries + slot);
+			mono_gc_dirty (handles->entries + slot);
 		}
 	} else {
 		/* print a warning? */
@@ -2105,7 +2130,7 @@ mono_gchandle_free (guint32 gchandle)
 				mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
 		} else {
 			handles->entries [slot] = NULL;
-			GC_dirty (handles->entries + slot);
+			mono_gc_dirty (handles->entries + slot);
 		}
 		vacate_slot (handles, slot);
 	} else {
@@ -2148,7 +2173,7 @@ mono_gchandle_free_domain (MonoDomain *domain)
 				if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
 					vacate_slot (handles, slot);
 					handles->entries [slot] = NULL;
-					GC_dirty (handles->entries + slot);
+					mono_gc_dirty (handles->entries + slot);
 				}
 			}
 		}