Minimize uses of lazy initialization by adding explicit initialization functions.

src/platform-freebsd.cc

Index: src/platform-freebsd.cc
diff --git a/src/platform-freebsd.cc b/src/platform-freebsd.cc
index 6a004ea7fa0fec3ddef51c680538ce01fa8614a6..6b1c987e2ff9ebadd7cb16e9fde4047fa6b26654 100644
--- a/src/platform-freebsd.cc
+++ b/src/platform-freebsd.cc
@@ -80,22 +80,8 @@ double ceiling(double x) {
 static Mutex* limit_mutex = 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());
-  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();
 }
 
 
@@ -730,8 +716,14 @@ class SignalSender : public Thread {
       : Thread(Thread::Options("SignalSender", kSignalSenderStackSize)),
         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) {
       // Install a signal handler.
@@ -751,7 +743,7 @@ class SignalSender : 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_);
@@ -844,7 +836,7 @@ class SignalSender : public Thread {
   RuntimeProfilerRateLimiter rate_limiter_;
 
   // Protects the process wide state below.
-  static LazyMutex mutex_;
+  static Mutex* mutex_;
   static SignalSender* instance_;
   static bool signal_handler_installed_;
   static struct sigaction old_signal_handler_;
@@ -853,12 +845,25 @@ class SignalSender : public Thread {
   DISALLOW_COPY_AND_ASSIGN(SignalSender);
 };
 
-LazyMutex SignalSender::mutex_ = LAZY_MUTEX_INITIALIZER;
+Mutex* SignalSender::mutex_ = NULL;
 SignalSender* SignalSender::instance_ = NULL;
 struct sigaction SignalSender::old_signal_handler_;
 bool SignalSender::signal_handler_installed_ = false;
 
 
+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());
+  srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
+  SignalSender::SetUp();
+}
+
+
 Sampler::Sampler(Isolate* isolate, int interval)
     : isolate_(isolate),
       interval_(interval),