Minimize uses of lazy initialization by adding explicit initialization functions.

src/platform-macos.cc

Index: src/platform-macos.cc
diff --git a/src/platform-macos.cc b/src/platform-macos.cc
index dbcd80e9f21222faab02df1aab68f3958f7b27f4..afcd80affff3812b0622e6735c118b2a811e1870 100644
--- a/src/platform-macos.cc
+++ b/src/platform-macos.cc
@@ -94,18 +94,8 @@ double ceiling(double x) {
 static Mutex* limit_mutex = NULL;
 
 
-void OS::SetUp() {
-  // Seed the random number generator. We preserve microsecond resolution.
-  uint64_t seed = Ticks() ^ (getpid() << 16);
-  srandom(static_cast<unsigned int>(seed));
-  limit_mutex = CreateMutex();
-}
-
-
 void OS::PostSetUp() {
-  // Math functions depend on CPU features therefore they are initialized after
-  // CPU.
-  MathSetup();
+  POSIXPostSetUp();
 }
 
 
@@ -753,8 +743,14 @@ class SamplerThread : public Thread {
       : 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());
@@ -765,7 +761,7 @@ class SamplerThread : public Thread {
   }
 
   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_);
@@ -862,7 +858,7 @@ class SamplerThread : public Thread {
   RuntimeProfilerRateLimiter rate_limiter_;
 
   // Protects the process wide state below.
-  static LazyMutex mutex_;
+  static Mutex* mutex_;
   static SamplerThread* instance_;
 
  private:
@@ -872,10 +868,19 @@ class SamplerThread : public Thread {
 #undef REGISTER_FIELD
 
 
-LazyMutex SamplerThread::mutex_ = LAZY_MUTEX_INITIALIZER;
+Mutex* SamplerThread::mutex_ = NULL;
 SamplerThread* SamplerThread::instance_ = NULL;
 
 
+void OS::SetUp() {
+  // Seed the random number generator. We preserve microsecond resolution.
+  uint64_t seed = Ticks() ^ (getpid() << 16);
+  srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
+  SamplerThread::SetUp();
+}

[danno, 2012/04/04 20:47:57]

Can you please move these back to where they use to be in the file? It makes the
diff shorter and the change more compact. Also applies to other platform files.

[Philippe, 2012/04/05 11:30:18]

I had unfortunately to move this function here to make it be declared after the
SamplerThread class which it uses (SamplerThread::SetUp()). We have to move
either OS::SetUp() or SamplerThread.

+
+
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),