Minimize uses of lazy initialization by adding explicit initialization functions.

src/platform-win32.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 123 matching lines @@
 
 double ceiling(double x) {
   return ceil(x);
 }
 
 
 static Mutex* limit_mutex = NULL;
 
 #if defined(V8_TARGET_ARCH_IA32)
 static OS::MemCopyFunction memcopy_function = NULL;
-static LazyMutex memcopy_function_mutex = LAZY_MUTEX_INITIALIZER;
 // Defined in codegen-ia32.cc.
 OS::MemCopyFunction CreateMemCopyFunction();
 
 // Copy memory area to disjoint memory area.
 void OS::MemCopy(void* dest, const void* src, size_t size) {
-  if (memcopy_function == NULL) {
-    ScopedLock lock(memcopy_function_mutex.Pointer());
-    if (memcopy_function == NULL) {
-      OS::MemCopyFunction temp = CreateMemCopyFunction();
-      MemoryBarrier();
-      memcopy_function = temp;
-    }
-  }
   // Note: here we rely on dependent reads being ordered. This is true
   // on all architectures we currently support.
   (*memcopy_function)(dest, src, size);
 #ifdef DEBUG
   CHECK_EQ(0, memcmp(dest, src, size));
 #endif
 }
 #endif  // V8_TARGET_ARCH_IA32
 
 #ifdef _WIN64
@@ skipping 388 matching lines @@
 
 // Returns a string identifying the current timezone for the
 // timestamp taking into account daylight saving.
 char* Time::LocalTimezone() {
   // Return the standard or DST time zone name based on whether daylight
   // saving is in effect at the given time.
   return InDST() ? dst_tz_name_ : std_tz_name_;
 }
 
 
-void OS::SetUp() {
-  // Seed the random number generator.
-  // Convert the current time to a 64-bit integer first, before converting it
-  // to an unsigned. Going directly can cause an overflow and the seed to be
-  // set to all ones. The seed will be identical for different instances that
-  // call this setup code within the same millisecond.
-  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
-  srand(static_cast<unsigned int>(seed));
-  limit_mutex = CreateMutex();
-}
-
-
 void OS::PostSetUp() {
   // Math functions depend on CPU features therefore they are initialized after
   // CPU.
   MathSetup();
+#if defined(V8_TARGET_ARCH_IA32)
+  memcopy_function = CreateMemCopyFunction();
+#endif
 }
 
 
 // Returns the accumulated user time for thread.
 int OS::GetUserTime(uint32_t* secs,  uint32_t* usecs) {
   FILETIME dummy;
   uint64_t usertime;
 
   // Get the amount of time that the thread has executed in user mode.
   if (!GetThreadTimes(GetCurrentThread(), &dummy, &dummy, &dummy,
@@ skipping 1368 matching lines @@
 
 
 class SamplerThread : public Thread {
  public:
   static const int kSamplerThreadStackSize = 64 * KB;
 
   explicit SamplerThread(int interval)
       : Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
         interval_(interval) {}
 
+  static void SetUp() {
+    if (!mutex_) {
+      mutex_ = OS::CreateMutex();
+    }
+  }
+
   static void AddActiveSampler(Sampler* sampler) {
-    ScopedLock lock(mutex_.Pointer());
+    ScopedLock lock(mutex_);
     SamplerRegistry::AddActiveSampler(sampler);
     if (instance_ == NULL) {
       instance_ = new SamplerThread(sampler->interval());
       instance_->Start();
     } else {
       ASSERT(instance_->interval_ == sampler->interval());
     }
   }
 
   static void RemoveActiveSampler(Sampler* sampler) {
-    ScopedLock lock(mutex_.Pointer());
+    ScopedLock lock(mutex_);
     SamplerRegistry::RemoveActiveSampler(sampler);
     if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
       RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
       delete instance_;
       instance_ = NULL;
     }
   }
 
   // Implement Thread::Run().
   virtual void Run() {
@@ skipping 65 matching lines @@
       sampler->SampleStack(sample);
       sampler->Tick(sample);
     }
     ResumeThread(profiled_thread);
   }
 
   const int interval_;
   RuntimeProfilerRateLimiter rate_limiter_;
 
   // Protects the process wide state below.
-  static LazyMutex mutex_;
+  static Mutex* mutex_;
   static SamplerThread* instance_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SamplerThread);
 };
 
 
-LazyMutex SamplerThread::mutex_ = LAZY_MUTEX_INITIALIZER;
+Mutex* SamplerThread::mutex_ = NULL;
 SamplerThread* SamplerThread::instance_ = NULL;
 
 
+void OS::SetUp() {
+  // Seed the random number generator.
+  // Convert the current time to a 64-bit integer first, before converting it
+  // to an unsigned. Going directly can cause an overflow and the seed to be
+  // set to all ones. The seed will be identical for different instances that
+  // call this setup code within the same millisecond.
+  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
+  srand(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
+  SamplerThread::SetUp();
+}
+
+
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),
       profiling_(false),
       active_(false),
       samples_taken_(0) {
   data_ = new PlatformData;
 }
 
 
@@ skipping 11 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal