Make number of available threads isolate-dependent and expose it to ResourceConstraints.

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 113 matching lines @@
 #endif
   thread_id_ = ThreadId::Current();
 }
 
 
 v8::TryCatch* ThreadLocalTop::TryCatchHandler() {
   return TRY_CATCH_FROM_ADDRESS(try_catch_handler_address());
 }
 
 
-int SystemThreadManager::NumberOfParallelSystemThreads(
-    ParallelSystemComponent type) {
-  int number_of_threads = Min(CPU::NumberOfProcessorsOnline(), kMaxThreads);
-  ASSERT(number_of_threads > 0);
-  if (number_of_threads ==  1) {
-    return 0;
-  }
-  if (type == PARALLEL_SWEEPING) {
-    return number_of_threads;
-  } else if (type == CONCURRENT_SWEEPING) {
-    return number_of_threads - 1;
-  }
-  return 1;
-}
-
-
 // Create a dummy thread that will wait forever on a semaphore. The only
 // purpose for this thread is to have some stack area to save essential data
 // into for use by a stacks only core dump (aka minidump).
 class PreallocatedMemoryThread: public Thread {
  public:
   char* data() {
     if (data_ready_semaphore_ != NULL) {
       // Initial access is guarded until the data has been published.
       data_ready_semaphore_->Wait();
       delete data_ready_semaphore_;
@@ skipping 1623 matching lines @@
       random_number_generator_(NULL),
       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_(NULL),
       sweeper_thread_(NULL),
+      num_sweeper_threads_(0),
+      max_available_threads_(0),
       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;
   stack_guard_.isolate_ = this;
 
@@ skipping 72 matching lines @@
 
 
 void Isolate::Deinit() {
   if (state_ == INITIALIZED) {
     TRACE_ISOLATE(deinit);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
     debugger()->UnloadDebugger();
 #endif
 
-    if (FLAG_concurrent_recompilation) {
+    if (concurrent_recompilation_enabled()) {
       optimizing_compiler_thread_->Stop();
       delete optimizing_compiler_thread_;
+      optimizing_compiler_thread_ = NULL;
     }
 
-    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_;
+    for (int i = 0; i < num_sweeper_threads_; i++) {
+      sweeper_thread_[i]->Stop();
+      delete sweeper_thread_[i];
+      sweeper_thread_[i] = NULL;
     }
+    delete[] sweeper_thread_;
+    sweeper_thread_ = NULL;
+
 
     if (FLAG_hydrogen_stats) GetHStatistics()->Print();
 
     if (FLAG_print_deopt_stress) {
       PrintF(stdout, "=== Stress deopt counter: %u\n", stress_deopt_count_);
     }
 
     // We must stop the logger before we tear down other components.
     Sampler* sampler = logger_->sampler();
     if (sampler && sampler->IsActive()) sampler->Stop();
@@ skipping 303 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());
   }
 
   InitializeThreadLocal();
 
   bootstrapper_->Initialize(create_heap_objects);
   builtins_.SetUp(this, create_heap_objects);
 
   if (create_heap_objects) heap_.CreateStubsRequiringBuiltins();
 
+  // Set default value if not yet set.
+  // TODO(yangguo): move this to ResourceConstraints::ConfigureDefaults
+  // once ResourceConstraints becomes an argument to the Isolate constructor.
+  if (max_available_threads_ < 1) {
+    // Choose the default between 1 and 4.
+    max_available_threads_ = Max(Min(CPU::NumberOfProcessorsOnline(), 4), 1);
+  }
+
+  num_sweeper_threads_ = SweeperThread::NumberOfThreads(max_available_threads_);
+
+  if (FLAG_trace_hydrogen || FLAG_trace_hydrogen_stubs) {
+    PrintF("Concurrent recompilation has been disabled for tracing.\n");
+  } else if (OptimizingCompilerThread::Enabled(max_available_threads_)) {
+    optimizing_compiler_thread_ = new OptimizingCompilerThread(this);
+    optimizing_compiler_thread_->Start();
+  }
+
+  if (num_sweeper_threads_ > 0) {
+    sweeper_thread_ = new SweeperThread*[num_sweeper_threads_];
+    for (int i = 0; i < num_sweeper_threads_; i++) {
+      sweeper_thread_[i] = new SweeperThread(this);
+      sweeper_thread_[i]->Start();
+    }
+  }
+
   // Only preallocate on the first initialization.
   if (FLAG_preallocate_message_memory && preallocated_message_space_ == NULL) {
     // Start the thread which will set aside some memory.
     PreallocatedMemoryThreadStart();
     preallocated_message_space_ =
         new NoAllocationStringAllocator(
             preallocated_memory_thread_->data(),
             preallocated_memory_thread_->length());
     PreallocatedStorageInit(preallocated_memory_thread_->length() / 4);
   }
@@ skipping 74 matching lines @@
     BinaryOpStub::InitializeForIsolate(this);
     CompareNilICStub::InitializeForIsolate(this);
     ToBooleanStub::InitializeForIsolate(this);
     ArrayConstructorStubBase::InstallDescriptors(this);
     InternalArrayConstructorStubBase::InstallDescriptors(this);
     FastNewClosureStub::InstallDescriptors(this);
     NumberToStringStub::InstallDescriptors(this);
     NewStringAddStub::InstallDescriptors(this);
   }
 
-  if (FLAG_sweeper_threads > 0) {
-    sweeper_thread_ = new SweeperThread*[FLAG_sweeper_threads];
-    for (int i = 0; i < FLAG_sweeper_threads; i++) {
-      sweeper_thread_[i] = new SweeperThread(this);
-      sweeper_thread_[i]->Start();
-    }
-  }
-
   initialized_from_snapshot_ = (des != NULL);
 
   return true;
 }
 
 
 // Initialized lazily to allow early
 // v8::V8::SetAddHistogramSampleFunction calls.
 StatsTable* Isolate::stats_table() {
   if (stats_table_ == NULL) {
@@ skipping 171 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