Object ID Ring with tests

runtime/vm/scavenger.cc

Index: runtime/vm/scavenger.cc
diff --git a/runtime/vm/scavenger.cc b/runtime/vm/scavenger.cc
index 8d6e4bf5be189dedb5a462cb1a672fb9afa992e9..a4c9dd46d281e692bc7bfadf32611b4a7d468fd9 100644
--- a/runtime/vm/scavenger.cc
+++ b/runtime/vm/scavenger.cc
@@ -17,6 +17,7 @@
 #include "vm/verifier.h"
 #include "vm/visitor.h"
 #include "vm/weak_table.h"
+#include "vm/object_id_ring.h"
 
 namespace dart {
 
@@ -404,6 +405,14 @@ void Scavenger::IterateStoreBuffers(Isolate* isolate,
 }
 
 
+void Scavenger::IterateObjectIdTable(Isolate* isolate,
+                                     ScavengerVisitor* visitor) {
+  ObjectIdRing* ring = isolate->object_id_ring();
+  ASSERT(ring != NULL);
+  ring->VisitPointers(visitor);
+}
+
+
 void Scavenger::IterateRoots(Isolate* isolate,
                              ScavengerVisitor* visitor,
                              bool visit_prologue_weak_persistent_handles) {
@@ -413,6 +422,7 @@ void Scavenger::IterateRoots(Isolate* isolate,
                                StackFrameIterator::kDontValidateFrames);
   int64_t middle = OS::GetCurrentTimeMicros();
   IterateStoreBuffers(isolate, visitor);
+  IterateObjectIdTable(isolate, visitor);
   int64_t end = OS::GetCurrentTimeMicros();
   heap_->RecordTime(kVisitIsolateRoots, middle - start);
   heap_->RecordTime(kIterateStoreBuffers, end - middle);
@@ -590,6 +600,44 @@ void Scavenger::ProcessWeakTables() {
 }
 
 
+class ObjectIdRingMovePointerVisitor : public ObjectPointerVisitor {
+ public:
+  explicit ObjectIdRingMovePointerVisitor(Isolate* isolate) :
+      ObjectPointerVisitor(isolate) {}
+
+  void Move(RawObject** current) {
+    RawObject* raw_obj = *current;
+    ASSERT(raw_obj->IsHeapObject());
+    if (raw_obj->IsOldObject()) {
+      // Skip old objects.
+      return;
+    }
+    uword raw_addr = RawObject::ToAddr(raw_obj);
+    uword header = *reinterpret_cast<uword*>(raw_addr);
+    if (IsForwarding(header)) {
+      // The object has survived. Update its address in the table.
+      uword new_addr = ForwardedAddr(header);
+      raw_obj = RawObject::FromAddr(new_addr);
+      *current = raw_obj;
+    }
+  }
+
+  void VisitPointers(RawObject** first, RawObject** last) {
+    for (RawObject** current = first; current <= last; current++) {
+      Move(current);
+    }
+  }
+};
+
+
+void Scavenger::ProcessObjectIdTable(Isolate* isolate) {
+  ObjectIdRingMovePointerVisitor visitor(isolate);
+  ObjectIdRing* ring = isolate->object_id_ring();
+  ASSERT(ring != NULL);
+  ring->VisitPointers(&visitor);
+}
+
+
 void Scavenger::VisitObjectPointers(ObjectPointerVisitor* visitor) const {
   uword cur = FirstObjectStart();
   while (cur < top_) {
@@ -642,6 +690,7 @@ void Scavenger::Scavenge(bool invoke_api_callbacks) {
   IterateWeakRoots(isolate, &weak_visitor, invoke_api_callbacks);
   visitor.Finalize();
   ProcessWeakTables();
+  ProcessObjectIdTable(isolate);

[Ivan Posva, 2013/07/11 17:01:42]

It is unclear to me why you need this here and all the machinery associated with
it. You have already processed the object id ring above in IterateRoots.

[Cutch, 2013/07/11 21:31:47]

You are correct.

   int64_t end = OS::GetCurrentTimeMicros();
   heap_->RecordTime(kProcessToSpace, middle - start);
   heap_->RecordTime(kIterateWeaks, end - middle);