Update comments in the global handles interface.

(I also reordered functions in the .cc file to match the order in the
.h file.)

R=antonm@chromium.org

Review URL: http://codereview.chromium.org/7056068

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8188 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/global-handles.cc b/src/global-handles.cc
index c96dd3cd8f32985c9bd42a7f81dce969a06a9729..87066faeaf64950a8349da385e36cd206b23bea6 100644 (file)
--- a/src/global-handles.cc
+++ b/src/global-handles.cc
@@ -467,17 +467,6 @@ void GlobalHandles::IterateWeakRoots(ObjectVisitor* v) {
 }
 
 
-void GlobalHandles::IterateNewSpaceWeakIndependentRoots(ObjectVisitor* v) {
-  for (int i = 0; i < new_space_nodes_.length(); ++i) {
-    Node* node = new_space_nodes_[i];
-    ASSERT(node->is_in_new_space_list());
-    if (node->is_independent() && node->IsWeakRetainer()) {
-      v->VisitPointer(node->location());
-    }
-  }
-}
-
-
 void GlobalHandles::IterateWeakRoots(WeakReferenceGuest f,
                                      WeakReferenceCallback callback) {
   for (NodeIterator it(this); !it.done(); it.Advance()) {
@@ -497,6 +486,17 @@ void GlobalHandles::IdentifyWeakHandles(WeakSlotCallback f) {
 }
 
 
+void GlobalHandles::IterateNewSpaceStrongAndDependentRoots(ObjectVisitor* v) {
+  for (int i = 0; i < new_space_nodes_.length(); ++i) {
+    Node* node = new_space_nodes_[i];
+    if (node->IsStrongRetainer() ||
+        (node->IsWeakRetainer() && !node->is_independent())) {
+      v->VisitPointer(node->location());
+    }
+  }
+}
+
+
 void GlobalHandles::IdentifyNewSpaceWeakIndependentHandles(
     WeakSlotCallbackWithHeap f) {
   for (int i = 0; i < new_space_nodes_.length(); ++i) {
@@ -510,6 +510,17 @@ void GlobalHandles::IdentifyNewSpaceWeakIndependentHandles(
 }
 
 
+void GlobalHandles::IterateNewSpaceWeakIndependentRoots(ObjectVisitor* v) {
+  for (int i = 0; i < new_space_nodes_.length(); ++i) {
+    Node* node = new_space_nodes_[i];
+    ASSERT(node->is_in_new_space_list());
+    if (node->is_independent() && node->IsWeakRetainer()) {
+      v->VisitPointer(node->location());
+    }
+  }
+}
+
+
 bool GlobalHandles::PostGarbageCollectionProcessing(
     GarbageCollector collector) {
   // Process weak global handle callbacks. This must be done after the
@@ -586,17 +597,6 @@ void GlobalHandles::IterateAllRoots(ObjectVisitor* v) {
 }
 
 
-void GlobalHandles::IterateNewSpaceStrongAndDependentRoots(ObjectVisitor* v) {
-  for (int i = 0; i < new_space_nodes_.length(); ++i) {
-    Node* node = new_space_nodes_[i];
-    if (node->IsStrongRetainer() ||
-        (node->IsWeakRetainer() && !node->is_independent())) {
-      v->VisitPointer(node->location());
-    }
-  }
-}
-
-
 void GlobalHandles::IterateAllRootsWithClassIds(ObjectVisitor* v) {
   for (NodeIterator it(this); !it.done(); it.Advance()) {
     if (it.node()->has_wrapper_class_id() && it.node()->IsRetainer()) {

diff --git a/src/global-handles.h b/src/global-handles.h
index 9f3143f288d4841c03a09c8af16d221a48b64224..153d4dac1a2b1e7617d82359e64bdfbe3d704347 100644 (file)
--- a/src/global-handles.h
+++ b/src/global-handles.h
@@ -162,9 +162,6 @@ class GlobalHandles {
   // Iterates over all strong handles.
   void IterateStrongRoots(ObjectVisitor* v);
 
-  // Iterates over all strong and dependent handles.
-  void IterateNewSpaceStrongAndDependentRoots(ObjectVisitor* v);
-
   // Iterates over all handles.
   void IterateAllRoots(ObjectVisitor* v);
 
@@ -174,9 +171,6 @@ class GlobalHandles {
   // Iterates over all weak roots in heap.
   void IterateWeakRoots(ObjectVisitor* v);
 
-  // Iterates over all weak independent roots in heap.
-  void IterateNewSpaceWeakIndependentRoots(ObjectVisitor* v);
-
   // Iterates over weak roots that are bound to a given callback.
   void IterateWeakRoots(WeakReferenceGuest f,
                         WeakReferenceCallback callback);
@@ -185,10 +179,21 @@ class GlobalHandles {
   // them as pending.
   void IdentifyWeakHandles(WeakSlotCallback f);
 
-  // Find all weak independent handles satisfying the callback predicate, mark
-  // them as pending.
+  // NOTE: Three ...NewSpace... functions below are used during
+  // scavenge collections and iterate over sets of handles that are
+  // guaranteed to contain all handles holding new space objects (but
+  // may also include old space objects).
+
+  // Iterates over strong and dependent handles. See the node above.
+  void IterateNewSpaceStrongAndDependentRoots(ObjectVisitor* v);
+
+  // Finds weak independent handles satisfying the callback predicate
+  // and marks them as pending. See the note above.
   void IdentifyNewSpaceWeakIndependentHandles(WeakSlotCallbackWithHeap f);
 
+  // Iterates over weak independent handles. See the note above.
+  void IterateNewSpaceWeakIndependentRoots(ObjectVisitor* v);
+
   // Add an object group.
   // Should be only used in GC callback function before a collection.
   // All groups are destroyed after a mark-compact collection.