X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mono%2Fsgen%2Fsgen-array-list.c;h=2fd54d986d0d6ded4b26dc3efb5203198bd4d3ec;hb=2709ca7625d75e5b3cf8eac8a34b95395bd15c46;hp=f84868e0a6f5f8d8999ce2ffd4e7947884ad9d3a;hpb=b8893efbccd64f92c81082e42b8e480b74881927;p=mono.git

diff --git a/mono/sgen/sgen-array-list.c b/mono/sgen/sgen-array-list.c
index f84868e0a6f..2fd54d986d0 100644
--- a/mono/sgen/sgen-array-list.c
+++ b/mono/sgen/sgen-array-list.c
@@ -1,5 +1,6 @@
-/*
- * sgen-array-list.c: A pointer array list that doesn't require reallocs
+/**
+ * \file
+ * A pointer array list that doesn't require reallocs
  *
  * Copyright (C) 2016 Xamarin Inc
  *
@@ -112,6 +113,32 @@ sgen_array_list_update_next_slot (SgenArrayList *array, guint32 new_index)
 	}
 }
 
+/*
+ * Extension for the array list that allows fast allocation and index based fetching
+ * of long lived memory of various sizes, without the need of realloc. Not thread safe.
+ */
+guint32
+sgen_array_list_alloc_block (SgenArrayList *array, guint32 slots_to_add)
+{
+	guint32 new_index = array->next_slot;
+	guint32 old_capacity = array->capacity;
+
+	/* FIXME Don't allocate arrays that will be skipped */
+	/* There are no empty arrays between next_slot and capacity because we allocate incrementally */
+	while ((old_capacity - new_index) < slots_to_add) {
+		sgen_array_list_grow (array, old_capacity);
+		new_index = old_capacity;
+		old_capacity = array->capacity;
+	}
+
+	SGEN_ASSERT (0, sgen_array_list_index_bucket (new_index) == sgen_array_list_index_bucket (new_index + slots_to_add - 1),
+			"We failed to allocate a continuous block of slots");
+
+	array->next_slot = new_index + slots_to_add;
+	/* The slot address will point to the allocated memory */
+	return new_index;
+}
+
 guint32
 sgen_array_list_add (SgenArrayList *array, gpointer ptr, int data, gboolean increase_size_before_set)
 {
@@ -151,37 +178,56 @@ retry:
 }
 
 /*
- * Removes all NULL pointers from the array. Not thread safe
+ * Does a linear search through the pointer array to find `ptr`.  Returns the index if
+ * found, otherwise (guint32)-1.
  */
-void
-sgen_array_list_remove_nulls (SgenArrayList *array)
+guint32
+sgen_array_list_find (SgenArrayList *array, gpointer ptr)
 {
-	guint32 start = 0;
 	volatile gpointer *slot;
 
 	SGEN_ARRAY_LIST_FOREACH_SLOT (array, slot) {
-		if (*slot)
-			*sgen_array_list_get_slot (array, start++) = *slot;
+		if (*slot == ptr)
+			return __index;
 	} SGEN_ARRAY_LIST_END_FOREACH_SLOT;
+	return (guint32)-1;
+}
 
-	mono_memory_write_barrier ();
-	array->next_slot = start;
+gboolean
+sgen_array_list_default_cas_setter (volatile gpointer *slot, gpointer ptr, int data)
+{
+	if (InterlockedCompareExchangePointer (slot, ptr, NULL) == NULL)
+		return TRUE;
+	return FALSE;
 }
 
-/*
- * Does a linear search through the pointer array to find `ptr`.  Returns the index if
- * found, otherwise (guint32)-1.
- */
-guint32
-sgen_array_list_find (SgenArrayList *array, gpointer ptr)
+gboolean
+sgen_array_list_default_is_slot_set (volatile gpointer *slot)
+{
+	return *slot != NULL;
+}
+
+/* Removes all NULL pointers from the array. Not thread safe */
+void
+sgen_array_list_remove_nulls (SgenArrayList *array)
 {
+	guint32 start = 0;
 	volatile gpointer *slot;
+	gboolean skipped = FALSE;
 
 	SGEN_ARRAY_LIST_FOREACH_SLOT (array, slot) {
-		if (*slot == ptr)
-			return __index;
+		if (*slot) {
+			*sgen_array_list_get_slot (array, start++) = *slot;
+			if (skipped)
+				*slot = NULL;
+		} else {
+			skipped = TRUE;
+		}
 	} SGEN_ARRAY_LIST_END_FOREACH_SLOT;
-	return (guint32)-1;
+
+	mono_memory_write_barrier ();
+	array->next_slot = start;
+	array->slot_hint = start;
 }
 
 #endif