Fix memory leaks in ~Zone and ~Isolate

src/zone.cc

Index: src/zone.cc
diff --git a/src/zone.cc b/src/zone.cc
index 42ce8c5cb7c2d72392c3f80cbbc92f42ac418cf4..2900f4aac0e83da31cbaaab3699f78125aa090fc 100644
--- a/src/zone.cc
+++ b/src/zone.cc
@@ -34,24 +34,6 @@ namespace v8 {
 namespace internal {
 
 
-Zone::Zone()
-    : zone_excess_limit_(256 * MB),
-      segment_bytes_allocated_(0),
-      position_(0),
-      limit_(0),
-      scope_nesting_(0),
-      segment_head_(NULL) {
-}
-unsigned Zone::allocation_size_ = 0;
-
-
-ZoneScope::~ZoneScope() {
-  ASSERT_EQ(Isolate::Current(), isolate_);
-  if (ShouldDeleteOnExit()) isolate_->zone()->DeleteAll();
-  isolate_->zone()->scope_nesting_--;
-}
-
-
 // Segments represent chunks of memory: They have starting address
 // (encoded in the this pointer) and a size in bytes. Segments are
 // chained together forming a LIFO structure with the newest segment
@@ -60,6 +42,11 @@ ZoneScope::~ZoneScope() {
 
 class Segment {
  public:
+  void Initialize(Segment* next, int size) {
+    next_ = next;
+    size_ = size;
+  }
+
   Segment* next() const { return next_; }
   void clear_next() { next_ = NULL; }
 
@@ -77,19 +64,39 @@ class Segment {
 
   Segment* next_;
   int size_;
-
-  friend class Zone;
 };
 
 
+Zone::Zone()
+    : zone_excess_limit_(256 * MB),
+      segment_bytes_allocated_(0),
+      position_(0),
+      limit_(0),
+      scope_nesting_(0),
+      segment_head_(NULL) {
+}
+unsigned Zone::allocation_size_ = 0;
+
+Zone::~Zone() {
+  if (segment_head_ != NULL) {
+    delete segment_head_;

[Vitaly Repeshko, 2011/08/16 17:52:32]

This should use DeleteSegment.

[Jakob Kummerow, 2011/08/17 08:47:30]

Done.
This required putting the code into a separate method, because DeleteSegment()
depends on the isolate's counters being alive, but at the time ~Zone() runs
they're already deleted.

+  }
+}
+
+ZoneScope::~ZoneScope() {
+  ASSERT_EQ(Isolate::Current(), isolate_);
+  if (ShouldDeleteOnExit()) isolate_->zone()->DeleteAll();
+  isolate_->zone()->scope_nesting_--;
+}
+
+
 // Creates a new segment, sets it size, and pushes it to the front
 // of the segment chain. Returns the new segment.
 Segment* Zone::NewSegment(int size) {
   Segment* result = reinterpret_cast<Segment*>(Malloced::New(size));
   adjust_segment_bytes_allocated(size);
   if (result != NULL) {
-    result->next_ = segment_head_;
-    result->size_ = size;
+    result->Initialize(segment_head_, size);
     segment_head_ = result;
   }
   return result;