Reduce boot-up memory use of V8.

src/platform-macos.cc

 // 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 455 matching lines @@
   return munmap(address, size) == 0;
 }
 
 
 class Thread::PlatformData : public Malloced {
  public:
   PlatformData() : thread_(kNoThread) {}
   pthread_t thread_;  // Thread handle for pthread.
 };
 
+
 Thread::Thread(const Options& options)
     : data_(new PlatformData),
-      stack_size_(options.stack_size) {
-  set_name(options.name);
-}
-
-
-Thread::Thread(const char* name)
-    : data_(new PlatformData),
-      stack_size_(0) {
-  set_name(name);
+      stack_size_(options.stack_size()) {
+  set_name(options.name());
 }
 
 
 Thread::~Thread() {
   delete data_;
 }
 
 
 static void SetThreadName(const char* name) {
   // pthread_setname_np is only available in 10.6 or later, so test
@@ skipping 232 matching lines @@
 
   thread_act_t profiled_thread() { return profiled_thread_; }
 
  private:
   // Note: for profiled_thread_ Mach primitives are used instead of PThread's
   // because the latter doesn't provide thread manipulation primitives required.
   // For details, consult "Mac OS X Internals" book, Section 7.3.
   thread_act_t profiled_thread_;
 };
 
+
 class SamplerThread : public Thread {
  public:
+  static const int kSamplerThreadStackSize = 32 * KB;
+
   explicit SamplerThread(int interval)
-      : Thread("SamplerThread"),
+      : Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
         interval_(interval) {}
 
   static void AddActiveSampler(Sampler* sampler) {
     ScopedLock lock(mutex_);
     SamplerRegistry::AddActiveSampler(sampler);
     if (instance_ == NULL) {
       instance_ = new SamplerThread(sampler->interval());
       instance_->Start();
     } else {
       ASSERT(instance_->interval_ == sampler->interval());
@@ skipping 135 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal