Optimize functions on a second thread.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 15ac5c31ae944a12a209db2e5206b91a70c01503..3bb89bda91fedee9656f55f50e6e385a807ad9bb 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -1199,6 +1199,7 @@ class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
 
 
 void Heap::Scavenge() {
+  RelocationLock relocation_lock(this);
 #ifdef DEBUG
   if (FLAG_verify_heap) VerifyNonPointerSpacePointers();
 #endif
@@ -6161,6 +6162,8 @@ bool Heap::SetUp(bool create_heap_objects) {
 
   store_buffer()->SetUp();
 
+  if (FLAG_parallel_recompilation) relocation_mutex_ = OS::CreateMutex();
+
   return true;
 }
 
@@ -6246,6 +6249,8 @@ void Heap::TearDown() {
 
   isolate_->memory_allocator()->TearDown();
 
+  if (FLAG_parallel_recompilation) delete relocation_mutex_;

[Yang, 2012/07/19 12:47:30]

I think you can omit checking for the flag since deleting NULL is safe.

[sanjoy, 2012/07/19 15:06:09]

Done.

+
 #ifdef DEBUG
   delete debug_utils_;
   debug_utils_ = NULL;