- Allow to pre-filter before calling the FindObjectVisitor.

runtime/vm/pages.cc

 // Copyright (c) 2012, 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/pages.h"
 
 #include "platform/assert.h"
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
@@ skipping 64 matching lines @@
   uword end_addr = object_end();
   while (obj_addr < end_addr) {
     RawObject* raw_obj = RawObject::FromAddr(obj_addr);
     obj_addr += raw_obj->VisitPointers(visitor);
   }
   ASSERT(obj_addr == end_addr);
 }
 
 
 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();
 }
 
 
 void HeapPage::WriteProtect(bool read_only) {
   VirtualMemory::Protection prot;
   if (read_only) {
     if (executable_) {
       prot = VirtualMemory::kReadExecute;
     } else {
@@ skipping 517 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result= static_cast<int>((static_cast<double>(gc_time) /
                              static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart