[sgen] Scan pinned objects in nursery as part of concurrent mark

[mono.git] / mono / sgen / sgen-pinning.c

diff --git a/mono/sgen/sgen-pinning.c b/mono/sgen/sgen-pinning.c
index fc0ba0bbdf6c6e977ed1b5a9c33205d90fcdd615..85629f436ec46189ebd1aa7d8b30e8efdc9ad8c4 100644 (file)
--- a/mono/sgen/sgen-pinning.c
+++ b/mono/sgen/sgen-pinning.c
@@ -32,15 +32,29 @@
 
 static SgenPointerQueue pin_queue;
 static size_t last_num_pinned = 0;
+/*
+ * While we hold the pin_queue_mutex, all objects in pin_queue_objs will
+ * stay pinned, which means they can't move, therefore they can be scanned.
+ */
+static SgenPointerQueue pin_queue_objs;
+static MonoCoopMutex pin_queue_mutex;
 
 #define PIN_HASH_SIZE 1024
 static void *pin_hash_filter [PIN_HASH_SIZE];
 
+void
+sgen_pinning_init (void)
+{
+       mono_coop_mutex_init (&pin_queue_mutex);
+}
+
 void
 sgen_init_pinning (void)
 {
+       mono_coop_mutex_lock (&pin_queue_mutex);
        memset (pin_hash_filter, 0, sizeof (pin_hash_filter));
        pin_queue.mem_type = INTERNAL_MEM_PIN_QUEUE;
+       sgen_pointer_queue_clear (&pin_queue_objs);
 }
 
 void
@@ -48,6 +62,27 @@ sgen_finish_pinning (void)
 {
        last_num_pinned = pin_queue.next_slot;
        sgen_pointer_queue_clear (&pin_queue);
+       mono_coop_mutex_unlock (&pin_queue_mutex);
+}
+
+void
+sgen_pinning_register_pinned_in_nursery (GCObject *obj)
+{
+       sgen_pointer_queue_add (&pin_queue_objs, obj);
+}
+
+void
+sgen_scan_pin_queue_objects (ScanCopyContext ctx)
+{
+       int i;
+       ScanObjectFunc scan_func = ctx.ops->scan_object;
+
+       mono_coop_mutex_lock (&pin_queue_mutex);
+       for (i = 0; i < pin_queue_objs.next_slot; ++i) {
+               GCObject *obj = (GCObject *)pin_queue_objs.data [i];
+               scan_func (obj, sgen_obj_get_descriptor_safe (obj), ctx.queue);
+       }
+       mono_coop_mutex_unlock (&pin_queue_mutex);
 }
 
 void
@@ -173,7 +208,7 @@ sgen_dump_pin_queue (void)
        int i;
 
        for (i = 0; i < last_num_pinned; ++i) {
-               void *ptr = pin_queue.data [i];
+               GCObject *ptr = (GCObject *)pin_queue.data [i];
                SGEN_LOG (3, "Bastard pinning obj %p (%s), size: %zd", ptr, sgen_client_vtable_get_name (SGEN_LOAD_VTABLE (ptr)), sgen_safe_object_get_size (ptr));
        }
 }
@@ -182,6 +217,7 @@ typedef struct _CementHashEntry CementHashEntry;
 struct _CementHashEntry {
        GCObject *obj;
        unsigned int count;
+       gboolean forced; /* if it should stay cemented after the finishing pause */
 };
 
 static CementHashEntry cement_hash [SGEN_CEMENT_HASH_SIZE];
@@ -197,10 +233,70 @@ sgen_cement_init (gboolean enabled)
 void
 sgen_cement_reset (void)
 {
-       memset (cement_hash, 0, sizeof (cement_hash));
+       int i;
+       for (i = 0; i < SGEN_CEMENT_HASH_SIZE; i++) {
+               if (cement_hash [i].forced) {
+                       cement_hash [i].forced = FALSE;
+               } else {
+                       cement_hash [i].obj = NULL;
+                       cement_hash [i].count = 0;
+               }
+       }
        binary_protocol_cement_reset ();
 }
 
+
+/*
+ * The pin_queue should be full and sorted, without entries from the cemented
+ * objects. We traverse the cement hash and check if each object is pinned in
+ * the pin_queue (the pin_queue contains entries between obj and obj+obj_len)
+ */
+void
+sgen_cement_force_pinned (void)
+{
+       int i;
+
+       if (!cement_enabled)
+               return;
+
+       for (i = 0; i < SGEN_CEMENT_HASH_SIZE; i++) {
+               GCObject *obj = cement_hash [i].obj;
+               size_t index;
+               if (!obj)
+                       continue;
+               if (cement_hash [i].count < SGEN_CEMENT_THRESHOLD)
+                       continue;
+               SGEN_ASSERT (0, !cement_hash [i].forced, "Why do we have a forced cemented object before forcing ?");
+
+               /* Returns the index of the target or of the first element greater than it */
+               index = sgen_pointer_queue_search (&pin_queue, obj);
+               if (index == pin_queue.next_slot)
+                       continue;
+               SGEN_ASSERT (0, pin_queue.data [index] >= (gpointer)obj, "Binary search should return a pointer greater than the search target");
+               if (pin_queue.data [index] < (gpointer)((char*)obj + sgen_safe_object_get_size (obj)))
+                       cement_hash [i].forced = TRUE;
+       }
+}
+
+gboolean
+sgen_cement_is_forced (GCObject *obj)
+{
+       guint hv = sgen_aligned_addr_hash (obj);
+       int i = SGEN_CEMENT_HASH (hv);
+
+       SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Looking up cementing for non-nursery objects makes no sense");
+
+       if (!cement_enabled)
+               return FALSE;
+
+       if (!cement_hash [i].obj)
+               return FALSE;
+       if (cement_hash [i].obj != obj)
+               return FALSE;
+
+       return cement_hash [i].forced;
+}
+
 gboolean
 sgen_cement_lookup (GCObject *obj)
 {