Object ID Ring with tests

runtime/vm/scavenger.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scavenger.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
@@ skipping 386 matching lines @@
     }
     delete pending;
     pending = next;
   }
   heap_->RecordData(kStoreBufferEntries, entries);
   // Done iterating through old objects remembered in the store buffers.
   visitor->VisitingOldObject(NULL);
 }
 
 
+void Scavenger::IterateObjectIdTable(Isolate* isolate,
+                                     ScavengerVisitor* visitor) {
+  RawObject** table = heap_->get_object_id_ring_table();
+  const intptr_t table_size = heap_->get_object_id_ring_table_size();
+  if ((table == NULL) || (table_size <= 0)) {
+    return;
+  }
+  visitor->VisitPointers(&table[0], &table[table_size]);
+}
+
+
 void Scavenger::IterateRoots(Isolate* isolate,
                              ScavengerVisitor* visitor,
                              bool visit_prologue_weak_persistent_handles) {
   int64_t start = OS::GetCurrentTimeMicros();
   isolate->VisitObjectPointers(visitor,
                                visit_prologue_weak_persistent_handles,
                                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);
 }
 
 
 bool Scavenger::IsUnreachable(RawObject** p) {
   RawObject* raw_obj = *p;
   if (!raw_obj->IsHeapObject()) {
     return false;
@@ skipping 157 matching lines @@
         }
       }
     }
     // Remove the old table as it has been replaced with the newly allocated
     // table above.
     delete table;
   }
 }
 
 
+void Scavenger::ProcessObjectIdTable() {
+  RawObject** table = heap_->get_object_id_ring_table();

[Ivan Posva, 2013/07/10 01:10:13]

It would be better if we used a pointer visitor here instead of accessing the
internals of the ObjectIdRing directly.

[Cutch, 2013/07/10 17:23:10]

All accesses to the ring table via the scavenger and the marker are now done
using an ObjectPointerVisitor.

+  const intptr_t table_size = heap_->get_object_id_ring_table_size();
+  if ((table == NULL) || (table_size <= 0)) {
+    return;
+  }
+  for (intptr_t i = 0; i < table_size; i++) {
+    RawObject* raw_obj = table[i];
+    ASSERT(raw_obj->IsHeapObject());
+    if (raw_obj->IsOldObject()) {
+      // SKip old objects.
+      continue;
+    }
+    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);
+      table[i] = raw_obj;
+    }
+  }
+}
+
+
 void Scavenger::VisitObjectPointers(ObjectPointerVisitor* visitor) const {
   uword cur = FirstObjectStart();
   while (cur < top_) {
     RawObject* raw_obj = RawObject::FromAddr(cur);
     cur += raw_obj->VisitPointers(visitor);
   }
 }
 
 
 void Scavenger::VisitObjects(ObjectVisitor* visitor) const {
@@ skipping 32 matching lines @@
   Prologue(isolate, invoke_api_callbacks);
   IterateRoots(isolate, &visitor, !invoke_api_callbacks);
   int64_t start = OS::GetCurrentTimeMicros();
   ProcessToSpace(&visitor);
   int64_t middle = OS::GetCurrentTimeMicros();
   IterateWeakReferences(isolate, &visitor);
   ScavengerWeakVisitor weak_visitor(this);
   IterateWeakRoots(isolate, &weak_visitor, invoke_api_callbacks);
   visitor.Finalize();
   ProcessWeakTables();
+  ProcessObjectIdTable();
   int64_t end = OS::GetCurrentTimeMicros();
   heap_->RecordTime(kProcessToSpace, middle - start);
   heap_->RecordTime(kIterateWeaks, end - middle);
   Epilogue(isolate, invoke_api_callbacks);
 
   if (FLAG_verify_after_gc) {
     OS::PrintErr("Verifying after Scavenge...");
     heap_->Verify();
     OS::PrintErr(" done.\n");
   }
 
   // Done scavenging. Reset the marker.
   ASSERT(scavenging_);
   scavenging_ = false;
 }
 
 
 void Scavenger::WriteProtect(bool read_only) {
   space_->Protect(
       read_only ? VirtualMemory::kReadOnly : VirtualMemory::kReadWrite);
 }
 
 
 }  // namespace dart