Run Crankshaft on a separate thread.

src/runtime-profiler.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 126 matching lines @@
     PrintF(" 0x%" V8PRIxPTR, reinterpret_cast<intptr_t>(function->address()));
     PrintF(" for recompilation, reason: %s", reason);
     if (FLAG_type_info_threshold > 0) {
       int typeinfo, total, percentage;
       GetICCounts(function, &typeinfo, &total, &percentage);
       PrintF(", ICs with typeinfo: %d/%d (%d%%)", typeinfo, total, percentage);
     }
     PrintF("]\n");
   }
 
-  // The next call to the function will trigger optimization.
-  function->MarkForLazyRecompilation();
+  if (FLAG_optimize_in_parallel) {
+    function->RecompileInParallel();
+  } else {
+    function->MarkForLazyRecompilation();
+  }
 }
 
 
 void RuntimeProfiler::AttemptOnStackReplacement(JSFunction* function) {
   // See AlwaysFullCompiler (in compiler.cc) comment on why we need
   // Debug::has_break_points().
   ASSERT(function->IsMarkedForLazyRecompilation());
   if (!FLAG_use_osr ||
       isolate_->DebuggerHasBreakPoints() ||
       function->IsBuiltin()) {
@@ skipping 305 matching lines @@
 
 bool RuntimeProfilerRateLimiter::SuspendIfNecessary() {
   if (!RuntimeProfiler::IsSomeIsolateInJS()) {
     return RuntimeProfiler::WaitForSomeIsolateToEnterJS();
   }
   return false;
 }
 
 
 } }  // namespace v8::internal