- Allow to pre-filter before calling the FindObjectVisitor.

runtime/vm/pages.cc

Index: runtime/vm/pages.cc
===================================================================
--- runtime/vm/pages.cc	(revision 31392)
+++ runtime/vm/pages.cc	(working copy)
@@ -82,16 +82,23 @@
 
 
 RawObject* HeapPage::FindObject(FindObjectVisitor* visitor) const {
+  uword filter_addr = visitor->filter_addr();
   uword obj_addr = object_start();
   uword end_addr = object_end();
-  while (obj_addr < end_addr) {
-    RawObject* raw_obj = RawObject::FromAddr(obj_addr);
-    if (raw_obj->FindObject(visitor)) {
-      return raw_obj;  // Found object, return it.
+  if ((filter_addr == 0) ||
+      ((filter_addr >= obj_addr) && (filter_addr < end_addr))) {

[siva, 2013/12/30 22:15:12]

Instead of a filter_addr method in the visitor interface wouldn't it be better
to have a method:

virtual bool VisitRange(uword start_addr, uword end_addr);

which allows the visitor to decide whether this range needs to
be visited or not.

and the code here could be:

if (visitor->VisitRange(obj_addr, end_addr)) {
  ....
  ....
  if (visitor->VisitRange(obj_addr, end_addr) &&
      raw_obj->FindObject(visitor)) {
    return raw_obj;
  }
}

[Ivan Posva, 2013/12/31 00:26:59]

Redone as discussed.

On 2013/12/30 22:15:12, siva wrote:

+    while (obj_addr < end_addr) {
+      RawObject* raw_obj = RawObject::FromAddr(obj_addr);
+      uword next_obj_addr = obj_addr + raw_obj->Size();
+      if (((filter_addr == 0) ||
+           ((filter_addr >= obj_addr) && (filter_addr < end_addr))) &&

[siva, 2013/12/30 22:15:12]

next_obj_addr ?

[Ivan Posva, 2013/12/31 00:26:59]

Done.

+          raw_obj->FindObject(visitor)) {
+        return raw_obj;  // Found object, return it.
+      }
+      obj_addr = next_obj_addr;
     }
-    obj_addr += raw_obj->Size();
+    ASSERT(obj_addr == end_addr);
   }
-  ASSERT(obj_addr == end_addr);
   return Object::null();
 }