Revision: 12196
Author: [email protected]
Date: Thu Jul 26 01:27:20 2012
Log: Limited the size of transition arrays so they never end up in the
large object space.
Also renamed SizeOf on DescriptorArray to LengthOf for consistency.
Review URL: https://chromiumcodereview.appspot.com/10822011
http://code.google.com/p/v8/source/detail?r=12196
Modified:
/branches/bleeding_edge/src/objects-inl.h
/branches/bleeding_edge/src/objects.cc
/branches/bleeding_edge/src/objects.h
=======================================
--- /branches/bleeding_edge/src/objects-inl.h Thu Jul 19 11:58:23 2012
+++ /branches/bleeding_edge/src/objects-inl.h Thu Jul 26 01:27:20 2012
@@ -3580,6 +3580,14 @@
Map* Map::elements_transition_map() {
return transitions()->elements_transition();
}
+
+
+bool Map::CanHaveMoreTransitions() {
+ if (!HasTransitionArray()) return true;
+ return FixedArray::SizeFor(transitions()->length() +
+ TransitionArray::kTransitionSize)
+ <= Page::kMaxNonCodeHeapObjectSize;
+}
MaybeObject* Map::AddTransition(String* key, Map* target) {
=======================================
--- /branches/bleeding_edge/src/objects.cc Wed Jul 25 08:23:07 2012
+++ /branches/bleeding_edge/src/objects.cc Thu Jul 26 01:27:20 2012
@@ -2120,8 +2120,6 @@
static void RightTrimFixedArray(Heap* heap, FixedArray* elms, int to_trim)
{
ASSERT(elms->map() != HEAP->fixed_cow_array_map());
// For now this trick is only applied to fixed arrays in new and paged
space.
- // In large object space the object's start must coincide with chunk
- // and thus the trick is just not applicable.
ASSERT(!HEAP->lo_space()->Contains(elms));
const int len = elms->length();
@@ -2217,7 +2215,7 @@
}
// If duplicates were detected, trim the descriptor array to the right
size.
- int new_array_size = DescriptorArray::SizeFor(new_number_of_descriptors);
+ int new_array_size =
DescriptorArray::LengthFor(new_number_of_descriptors);
if (new_array_size < result->length()) {
RightTrimFixedArray<FROM_MUTATOR>(
isolate->heap(), *result, result->length() - new_array_size);
@@ -4883,7 +4881,7 @@
result->SetLastAdded(last_added);
}
- if (flag == INSERT_TRANSITION) {
+ if (flag == INSERT_TRANSITION && CanHaveMoreTransitions()) {
TransitionArray* transitions;
MaybeObject* maybe_transitions = AddTransition(name, result);
if (!maybe_transitions->To(&transitions)) return maybe_transitions;
@@ -5843,7 +5841,7 @@
}
// Allocate the array of keys.
MaybeObject* maybe_array =
- heap->AllocateFixedArray(SizeFor(number_of_descriptors));
+ heap->AllocateFixedArray(LengthFor(number_of_descriptors));
if (!maybe_array->To(&result)) return maybe_array;
result->set(kEnumCacheIndex, Smi::FromInt(0));
=======================================
--- /branches/bleeding_edge/src/objects.h Wed Jul 25 08:23:07 2012
+++ /branches/bleeding_edge/src/objects.h Thu Jul 26 01:27:20 2012
@@ -2635,7 +2635,9 @@
// fit in a page).
static const int kMaxNumberOfDescriptors = 1024 + 512;
- static int SizeFor(int number_of_descriptors) {
+ // Returns the fixed array length required to hold number_of_descriptors
+ // descriptors.
+ static int LengthFor(int number_of_descriptors) {
return ToKeyIndex(number_of_descriptors);
}
@@ -4896,6 +4898,11 @@
String* name,
LookupResult* result);
+ // The size of transition arrays are limited so they do not end up in
large
+ // object space. Otherwise ClearNonLiveTransitions would leak memory
while
+ // applying in-place right trimming.
+ inline bool CanHaveMoreTransitions();
+
void SetLastAdded(int index) {
set_bit_field3(LastAddedBits::update(bit_field3(), index));
}
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
