2 * sgen-copy-object.h: This is where objects are copied.
4 * Copyright 2001-2003 Ximian, Inc
5 * Copyright 2003-2010 Novell, Inc.
6 * Copyright (C) 2012 Xamarin Inc
8 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
14 * GCObject* copy_object_no_checks (GCObject *obj, SgenGrayQueue *queue)
16 * which allocates new space for `obj`, copies it there, forwards `obj` to its new location,
17 * and enqueues the copy into `queue`.
19 * To be defined by the includer:
21 * COLLECTOR_SERIAL_ALLOC_FOR_PROMOTION(vt, obj, objsize, has_refs)
23 * Allocates space for promoting object `obj`, with size `objsize`, and initizializes the
24 * vtable with `vt`. `has_refs` indicates whether the object contains references.
26 * collector_pin_object(obj, queue)
28 * Called when no space for `obj` could be allocated. It must pin `obj` and enqueue it into
29 * `queue` for scanning.
32 extern guint64 stat_copy_object_called_nursery;
33 extern guint64 stat_objects_copied_nursery;
35 extern guint64 stat_nursery_copy_object_failed_from_space;
36 extern guint64 stat_nursery_copy_object_failed_forwarded;
37 extern guint64 stat_nursery_copy_object_failed_pinned;
39 extern guint64 stat_slots_allocated_in_vain;
42 * This function can be used even if the vtable of obj is not valid
43 * anymore, which is the case in the parallel collector.
45 static MONO_ALWAYS_INLINE void
46 par_copy_object_no_checks (char *destination, GCVTable vt, void *obj, mword objsize)
48 sgen_client_pre_copy_checks (destination, vt, obj, objsize);
49 binary_protocol_copy (obj, destination, vt, objsize);
51 /* FIXME: assumes object layout */
52 memcpy ((char*)destination + sizeof (mword), (char*)obj + sizeof (mword), objsize - sizeof (mword));
54 /* adjust array->bounds */
55 SGEN_ASSERT (9, sgen_vtable_get_descriptor (vt), "vtable %p has no gc descriptor", vt);
57 sgen_client_update_copied_object (destination, vt, obj, objsize);
61 * Copies an object and enqueues it if a queue is given.
62 * This can return OBJ itself on OOM.
64 static MONO_NEVER_INLINE GCObject *
65 copy_object_no_checks (GCObject *obj, SgenGrayQueue *queue)
67 GCVTable vt = SGEN_LOAD_VTABLE_UNCHECKED (obj);
68 gboolean has_references = SGEN_VTABLE_HAS_REFERENCES (vt);
69 mword objsize = SGEN_ALIGN_UP (sgen_client_par_object_get_size (vt, obj));
70 void *destination = COLLECTOR_SERIAL_ALLOC_FOR_PROMOTION (vt, obj, objsize, has_references);
72 if (G_UNLIKELY (!destination)) {
73 /* FIXME: Is this path ever tested? */
74 collector_pin_object (obj, queue);
75 sgen_set_pinned_from_failed_allocation (objsize);
79 par_copy_object_no_checks ((char *)destination, vt, obj, objsize);
81 /* set the forwarding pointer */
82 SGEN_FORWARD_OBJECT (obj, destination);
85 SGEN_LOG (9, "Enqueuing gray object %p (%s)", destination, sgen_client_vtable_get_name (vt));
86 GRAY_OBJECT_ENQUEUE_SERIAL (queue, (GCObject *)destination, sgen_vtable_get_descriptor (vt));
89 return (GCObject *)destination;
92 #if defined(COPY_OR_MARK_PARALLEL)
93 static MONO_NEVER_INLINE GCObject *
94 copy_object_no_checks_par (GCObject *obj, SgenGrayQueue *queue)
96 mword vtable_word = *(mword*)obj;
97 GCObject *destination;
99 destination = (GCObject*) SGEN_VTABLE_IS_FORWARDED (vtable_word);
102 GCVTable vt = (GCVTable) vtable_word;
103 GCObject *final_destination;
105 * At this point we know vt is not tagged and we shouldn't access the vtable through obj
106 * since it could get copied at any time by another thread.
108 gboolean has_references = SGEN_VTABLE_HAS_REFERENCES (vt);
109 mword objsize = SGEN_ALIGN_UP (sgen_client_par_object_get_size (vt, obj));
110 destination = major_collector.alloc_object_par (vt, objsize, has_references);
112 par_copy_object_no_checks ((char*)destination, vt, obj, objsize);
114 /* FIXME we might need a membar here so other threads see the vtable before we forward */
116 /* set the forwarding pointer */
117 SGEN_FORWARD_OBJECT_PAR (obj, destination, final_destination);
119 if (destination == final_destination) {
120 /* In a racing case, only the worker that allocated the object enqueues it */
121 if (has_references) {
122 SGEN_LOG (9, "Enqueuing gray object %p (%s)", destination, sgen_client_vtable_get_name (vt));
123 GRAY_OBJECT_ENQUEUE_PARALLEL (queue, (GCObject *)destination, sgen_vtable_get_descriptor (vt));
126 destination = final_destination;
134 #undef COLLECTOR_SERIAL_ALLOC_FOR_PROMOTION
135 #undef collector_pin_object
136 #undef COPY_OR_MARK_PARALLEL