Minimize malloc heap allocation on process startup.

src/isolate.h

 // Copyright 2011 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 238 matching lines @@
   Address js_entry_sp_;  // the stack pointer of the bottom js entry frame
   Address external_callback_;  // the external callback we're currently in
   StateTag current_vm_state_;
 
   // Generated code scratch locations.
   int32_t formal_count_;
 
   // Call back function to report unsafe JS accesses.
   v8::FailedAccessCheckCallback failed_access_check_callback_;
 
+  // Whether out of memory exceptions should be ignored.
+  bool ignore_out_of_memory_;
+
  private:
   void InitializeInternal();
 
   Address try_catch_handler_address_;
 };
 
 #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS)
 
 #define ISOLATE_PLATFORM_INIT_LIST(V)                                          \
   /* VirtualFrame::SpilledScope state */                                       \
@@ skipping 170 matching lines @@
     Isolate* isolate = reinterpret_cast<Isolate*>(
         Thread::GetExistingThreadLocal(isolate_key_));
     ASSERT(isolate != NULL);
     return isolate;
   }
 
   INLINE(static Isolate* UncheckedCurrent()) {
     return reinterpret_cast<Isolate*>(Thread::GetThreadLocal(isolate_key_));
   }
 
+  // Usually called by Init(), but can be called early e.g. to allow
+  // testing components that require logging but not the whole
+  // isolate.
+  //
+  // Safe to call more than once.
+  void InitializeLoggingAndCounters();
+
   bool Init(Deserializer* des);
 
   bool IsInitialized() { return state_ == INITIALIZED; }
 
   // True if at least one thread Enter'ed this isolate.
   bool IsInUse() { return entry_stack_ != NULL; }
 
   // Destroys the non-default isolates.
   // Sets default isolate into "has_been_disposed" state rather then destroying,
   // for legacy API reasons.
@@ skipping 32 matching lines @@
   static Thread::LocalStorageKey thread_id_key() {
     return thread_id_key_;
   }
 
   // If a client attempts to create a Locker without specifying an isolate,
   // we assume that the client is using legacy behavior. Set up the current
   // thread to be inside the implicit isolate (or fail a check if we have
   // switched to non-legacy behavior).
   static void EnterDefaultIsolate();
 
-  // Debug.
   // Mutex for serializing access to break control structures.
   Mutex* break_access() { return break_access_; }
 
+  // Mutex for serializing access to debugger.
+  Mutex* debugger_access() { return debugger_access_; }
+
   Address get_address_from_id(AddressId id);
 
   // Access to top context (where the current function object was created).
   Context* context() { return thread_local_top_.context_; }
   void set_context(Context* context) {
     ASSERT(context == NULL || context->IsContext());
     thread_local_top_.context_ = context;
   }
   Context** context_address() { return &thread_local_top_.context_; }
 
@@ skipping 139 matching lines @@
   };
 
   void SetCaptureStackTraceForUncaughtExceptions(
       bool capture,
       int frame_limit,
       StackTrace::StackTraceOptions options);
 
   // Tells whether the current context has experienced an out of memory
   // exception.
   bool is_out_of_memory();
+  bool ignore_out_of_memory() {
+    return thread_local_top_.ignore_out_of_memory_;
+  }
+  void set_ignore_out_of_memory(bool value) {
+    thread_local_top_.ignore_out_of_memory_ = value;
+  }
 
   void PrintCurrentStackTrace(FILE* out);
   void PrintStackTrace(FILE* out, char* thread_data);
   void PrintStack(StringStream* accumulator);
   void PrintStack();
   Handle<String> StackTraceString();
   Handle<JSArray> CaptureCurrentStackTrace(
       int frame_limit,
       StackTrace::StackTraceOptions options);
 
@@ skipping 88 matching lines @@
 #undef GLOBAL_ARRAY_ACCESSOR
 
 #define GLOBAL_CONTEXT_FIELD_ACCESSOR(index, type, name)      \
   Handle<type> name() {                                       \
     return Handle<type>(context()->global_context()->name()); \
   }
   GLOBAL_CONTEXT_FIELDS(GLOBAL_CONTEXT_FIELD_ACCESSOR)
 #undef GLOBAL_CONTEXT_FIELD_ACCESSOR
 
   Bootstrapper* bootstrapper() { return bootstrapper_; }
-  Counters* counters() { return counters_; }
+  Counters* counters() {
+    // Call InitializeLoggingAndCounters() if logging is needed before
+    // the isolate is fully initialized.
+    ASSERT(counters_ != NULL);
+    return counters_;
+  }
   CodeRange* code_range() { return code_range_; }
   RuntimeProfiler* runtime_profiler() { return runtime_profiler_; }
   CompilationCache* compilation_cache() { return compilation_cache_; }
-  Logger* logger() { return logger_; }
+  Logger* logger() {
+    // Call InitializeLoggingAndCounters() if logging is needed before
+    // the isolate is fully initialized.
+    ASSERT(logger_ != NULL);
+    return logger_;
+  }
   StackGuard* stack_guard() { return &stack_guard_; }
   Heap* heap() { return &heap_; }
-  StatsTable* stats_table() { return stats_table_; }
+  StatsTable* stats_table();
   StubCache* stub_cache() { return stub_cache_; }
   DeoptimizerData* deoptimizer_data() { return deoptimizer_data_; }
   ThreadLocalTop* thread_local_top() { return &thread_local_top_; }
 
   TranscendentalCache* transcendental_cache() const {
     return transcendental_cache_;
   }
 
   MemoryAllocator* memory_allocator() {
     return memory_allocator_;
@@ skipping 80 matching lines @@
   unibrow::Mapping<unibrow::Ecma262Canonicalize>*
       interp_canonicalize_mapping() {
     return &interp_canonicalize_mapping_;
   }
 
   void* PreallocatedStorageNew(size_t size);
   void PreallocatedStorageDelete(void* p);
   void PreallocatedStorageInit(size_t size);
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
-  Debugger* debugger() { return debugger_; }
-  Debug* debug() { return debug_; }
+  Debugger* debugger() {
+    if (!NoBarrier_Load(&debugger_initialized_)) InitializeDebugger();
+    return debugger_;
+  }
+  Debug* debug() {
+    if (!NoBarrier_Load(&debugger_initialized_)) InitializeDebugger();
+    return debug_;
+  }
 #endif
 
   inline bool DebuggerHasBreakPoints();
 
 #ifdef DEBUG
   HistogramInfo* heap_histograms() { return heap_histograms_; }
 
   JSObject::SpillInformation* js_spill_information() {
     return &js_spill_information_;
   }
@@ skipping 111 matching lines @@
   // This mutex protects highest_thread_id_, thread_data_table_ and
   // default_isolate_.
   static Mutex* process_wide_mutex_;
 
   static Thread::LocalStorageKey per_isolate_thread_data_key_;
   static Thread::LocalStorageKey isolate_key_;
   static Thread::LocalStorageKey thread_id_key_;
   static Isolate* default_isolate_;
   static ThreadDataTable* thread_data_table_;
 
-  bool PreInit();
-
   void Deinit();
 
   static void SetIsolateThreadLocals(Isolate* isolate,
                                      PerIsolateThreadData* data);
 
   enum State {
     UNINITIALIZED,    // Some components may not have been allocated.
-    PREINITIALIZED,   // Components have been allocated but not initialized.
     INITIALIZED       // All components are fully initialized.
   };
 
   State state_;
   EntryStackItem* entry_stack_;
 
   // Allocate and insert PerIsolateThreadData into the ThreadDataTable
   // (regardless of whether such data already exists).
   PerIsolateThreadData* AllocatePerIsolateThreadData(ThreadId thread_id);
 
@@ skipping 23 matching lines @@
   void PrintStackTrace(FILE* out, ThreadLocalTop* thread);
   void MarkCompactPrologue(bool is_compacting,
                            ThreadLocalTop* archived_thread_data);
   void MarkCompactEpilogue(bool is_compacting,
                            ThreadLocalTop* archived_thread_data);
 
   void FillCache();
 
   void PropagatePendingExceptionToExternalTryCatch();
 
+  void InitializeDebugger();
+
   int stack_trace_nesting_level_;
   StringStream* incomplete_message_;
   // The preallocated memory thread singleton.
   PreallocatedMemoryThread* preallocated_memory_thread_;
   Address isolate_addresses_[k_isolate_address_count + 1];  // NOLINT
   NoAllocationStringAllocator* preallocated_message_space_;
 
   Bootstrapper* bootstrapper_;
   RuntimeProfiler* runtime_profiler_;
   CompilationCache* compilation_cache_;
   Counters* counters_;
   CodeRange* code_range_;
   Mutex* break_access_;
+  Atomic32 debugger_initialized_;
+  Mutex* debugger_access_;
   Heap heap_;
   Logger* logger_;
   StackGuard stack_guard_;
   StatsTable* stats_table_;
   StubCache* stub_cache_;
   DeoptimizerData* deoptimizer_data_;
   ThreadLocalTop thread_local_top_;
   bool capture_stack_trace_for_uncaught_exceptions_;
   int stack_trace_for_uncaught_exceptions_frame_limit_;
   StackTrace::StackTraceOptions stack_trace_for_uncaught_exceptions_options_;
@@ skipping 69 matching lines @@
   ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
   friend class ExecutionAccess;
   friend class IsolateInitializer;
   friend class ThreadManager;
   friend class Simulator;
   friend class StackGuard;
   friend class ThreadId;
+  friend class TestMemoryAllocatorScope;
   friend class v8::Isolate;
   friend class v8::Locker;
   friend class v8::Unlocker;
 
   DISALLOW_COPY_AND_ASSIGN(Isolate);
 };
 
 
 // If the GCC version is 4.1.x or 4.2.x an additional field is added to the
 // class as a work around for a bug in the generated code found with these
@@ skipping 143 matching lines @@
 
 // Mark the global context with out of memory.
 inline void Context::mark_out_of_memory() {
   global_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_