Add a new API V8::SetJitCodeEventHandler to push code name and location to users such as profilers.

src/serialize.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 728 matching lines @@
   Object** limit = current + (size >> kPointerSizeLog2);
   if (FLAG_log_snapshot_positions) {
     LOG(isolate_, SnapshotPositionEvent(address, source_->position()));
   }
   ReadChunk(current, limit, space_number, address);
 #ifdef DEBUG
   bool is_codespace = (space == HEAP->code_space()) ||
       ((space == HEAP->lo_space()) && (space_number == kLargeCode));
   ASSERT(HeapObject::FromAddress(address)->IsCode() == is_codespace);
 #endif
+  if (HeapObject::FromAddress(address)->IsCode()) {

[danno, 2012/08/02 11:22:36]

The deserializer is very performance sensitive, by adding this code you are
slowing down the deserialization of all objects, even though it only applies to
Code objects. The "right" way to do this is to walk the code space after
deserialization is done if a hook is installed. If you don't want to do that in
this patch, then please just leave out this case altogether for serialized code
for now.

+    Code* code = Code::cast(HeapObject::FromAddress(address));
+
+    JIT_CODE_EVENT(AddCode(code));
+  }
 }
 
 
 // This macro is always used with a constant argument so it should all fold
 // away to almost nothing in the generated code.  It might be nicer to do this
 // with the ternary operator but there are type issues with that.
 #define ASSIGN_DEST_SPACE(space_number)                                        \
   Space* dest_space;                                                           \
   if (space_number == NEW_SPACE) {                                             \
     dest_space = isolate->heap()->new_space();                                \
@@ skipping 923 matching lines @@
 int Serializer::SpaceAreaSize(int space) {
   if (space == CODE_SPACE) {
     return isolate_->memory_allocator()->CodePageAreaSize();
   } else {
     return Page::kPageSize - Page::kObjectStartOffset;
   }
 }
 
 
 } }  // namespace v8::internal