Allocate optimizing compiler thread only when necessary.

src/isolate.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 1785 matching lines @@
       // FLAG_force_memory_constrained in Isolate::Init; move to here when
       // isolate cleanup is done
       is_memory_constrained_(false),
       has_fatal_error_(false),
       use_crankshaft_(true),
       initialized_from_snapshot_(false),
       cpu_profiler_(NULL),
       heap_profiler_(NULL),
       function_entry_hook_(NULL),
       deferred_handles_head_(NULL),
-      optimizing_compiler_thread_(this),
+      optimizing_compiler_thread_(NULL),
       marking_thread_(NULL),
       sweeper_thread_(NULL),
       stress_deopt_count_(0) {
   id_ = NoBarrier_AtomicIncrement(&isolate_counter_, 1);
   TRACE_ISOLATE(constructor);
 
   memset(isolate_addresses_, 0,
       sizeof(isolate_addresses_[0]) * (kIsolateAddressCount + 1));
 
   heap_.isolate_ = this;
@@ skipping 74 matching lines @@
 
 
 void Isolate::Deinit() {
   if (state_ == INITIALIZED) {
     TRACE_ISOLATE(deinit);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
     debugger()->UnloadDebugger();
 #endif
 
-    if (FLAG_concurrent_recompilation) optimizing_compiler_thread_.Stop();
+    if (FLAG_concurrent_recompilation) {
+      optimizing_compiler_thread_->Stop();
+      delete optimizing_compiler_thread_;
+    }
 
     if (FLAG_sweeper_threads > 0) {
       for (int i = 0; i < FLAG_sweeper_threads; i++) {
         sweeper_thread_[i]->Stop();
         delete sweeper_thread_[i];
       }
       delete[] sweeper_thread_;
     }
 
     if (FLAG_marking_threads > 0) {
@@ skipping 321 matching lines @@
 
   // SetUp the object heap.
   ASSERT(!heap_.HasBeenSetUp());
   if (!heap_.SetUp()) {
     V8::FatalProcessOutOfMemory("heap setup");
     return false;
   }
 
   deoptimizer_data_ = new DeoptimizerData(memory_allocator_);
 
+  if (FLAG_concurrent_recompilation) {
+    optimizing_compiler_thread_ = new OptimizingCompilerThread(this);
+    optimizing_compiler_thread_->Start();
+  }
+
   const bool create_heap_objects = (des == NULL);
   if (create_heap_objects && !heap_.CreateHeapObjects()) {
     V8::FatalProcessOutOfMemory("heap object creation");
     return false;
   }
 
   if (create_heap_objects) {
     // Terminate the cache array with the sentinel so we can iterate.
     PushToPartialSnapshotCache(heap_.undefined_value());
   }
@@ skipping 86 matching lines @@
                                    DONT_TRACK_ALLOCATION_SITE, 0);
     stub.InitializeInterfaceDescriptor(
         this, code_stub_interface_descriptor(CodeStub::FastCloneShallowArray));
     CompareNilICStub::InitializeForIsolate(this);
     ToBooleanStub::InitializeForIsolate(this);
     ArrayConstructorStubBase::InstallDescriptors(this);
     InternalArrayConstructorStubBase::InstallDescriptors(this);
     FastNewClosureStub::InstallDescriptors(this);
   }
 
-  if (FLAG_concurrent_recompilation) optimizing_compiler_thread_.Start();
-
   if (FLAG_marking_threads > 0) {
     marking_thread_ = new MarkingThread*[FLAG_marking_threads];
     for (int i = 0; i < FLAG_marking_threads; i++) {
       marking_thread_[i] = new MarkingThread(this);
       marking_thread_[i]->Start();
     }
   }
 
   if (FLAG_sweeper_threads > 0) {
     sweeper_thread_ = new SweeperThread*[FLAG_sweeper_threads];
@@ skipping 181 matching lines @@
 
 #ifdef DEBUG
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                       \
 const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
 ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
 ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
 } }  // namespace v8::internal