Optimize functions on a second thread.

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1181 matching lines @@
     }
     return NULL;
   }
 
  private:
   Heap* heap_;
 };
 
 
 void Heap::Scavenge() {
+  RelocationLock relocation_lock(this);
 #ifdef DEBUG
   if (FLAG_verify_heap) VerifyNonPointerSpacePointers();
 #endif
 
   gc_state_ = SCAVENGE;
 
   // Implements Cheney's copying algorithm
   LOG(isolate_, ResourceEvent("scavenge", "begin"));
 
   // Clear descriptor cache.
@@ skipping 4942 matching lines @@
     if (!CreateInitialObjects()) return false;
 
     global_contexts_list_ = undefined_value();
   }
 
   LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity()));
   LOG(isolate_, IntPtrTEvent("heap-available", Available()));
 
   store_buffer()->SetUp();
 
+  if (FLAG_parallel_recompilation) relocation_mutex_ = OS::CreateMutex();
+
   return true;
 }
 
 
 void Heap::SetStackLimits() {
   ASSERT(isolate_ != NULL);
   ASSERT(isolate_ == isolate());
   // On 64 bit machines, pointers are generally out of range of Smis.  We write
   // something that looks like an out of range Smi to the GC.
 
@@ skipping 65 matching lines @@
     lo_space_->TearDown();
     delete lo_space_;
     lo_space_ = NULL;
   }
 
   store_buffer()->TearDown();
   incremental_marking()->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;
 #endif
 }
 
 
 void Heap::Shrink() {
   // Try to shrink all paged spaces.
   PagedSpaces spaces;
@@ skipping 964 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_KIND_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal