Minimize uses of lazy initialization by adding explicit initialization functions.

src/platform-linux.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 61 matching lines @@
 
 
 double ceiling(double x) {
   return ceil(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();
-
-#ifdef __arm__
-  // When running on ARM hardware check that the EABI used by V8 and
-  // by the C code is the same.
-  bool hard_float = OS::ArmUsingHardFloat();
-  if (hard_float) {
-#if !USE_EABI_HARDFLOAT
-    PrintF("ERROR: Binary compiled with -mfloat-abi=hard but without "
-           "-DUSE_EABI_HARDFLOAT\n");
-    exit(1);
-#endif
-  } else {
-#if USE_EABI_HARDFLOAT
-    PrintF("ERROR: Binary not compiled with -mfloat-abi=hard but with "
-           "-DUSE_EABI_HARDFLOAT\n");
-    exit(1);
-#endif
-  }
-#endif
+void OS::PostSetUp() {
+  POSIXPostSetUp();
 }
 
 
-void OS::PostSetUp() {
-  // Math functions depend on CPU features therefore they are initialized after
-  // CPU.
-  MathSetup();
-}
-
-
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
   return 0;  // Linux runs on anything.
 }
 
 
 #ifdef __arm__
 static bool CPUInfoContainsString(const char * search_string) {
   const char* file_name = "/proc/cpuinfo";
   // This is written as a straight shot one pass parser
   // and not using STL string and ifstream because,
@@ skipping 951 matching lines @@
     FULL_INTERVAL
   };
 
   static const int kSignalSenderStackSize = 64 * KB;
 
   explicit SignalSender(int interval)
       : Thread(Thread::Options("SignalSender", kSignalSenderStackSize)),
         vm_tgid_(getpid()),
         interval_(interval) {}
 
+  static void SetUp() {
+    if (!mutex_) {
+      mutex_ = OS::CreateMutex();
+    }
+  }
+
   static void InstallSignalHandler() {
     struct sigaction sa;
     sa.sa_sigaction = ProfilerSignalHandler;
     sigemptyset(&sa.sa_mask);
     sa.sa_flags = SA_RESTART | SA_SIGINFO;
     signal_handler_installed_ =
         (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
   }
 
   static void RestoreSignalHandler() {
     if (signal_handler_installed_) {
       sigaction(SIGPROF, &old_signal_handler_, 0);
       signal_handler_installed_ = false;
     }
   }
 
   static void AddActiveSampler(Sampler* sampler) {
-    ScopedLock lock(mutex_.Pointer());
+    ScopedLock lock(mutex_);
     SamplerRegistry::AddActiveSampler(sampler);
     if (instance_ == NULL) {
       // Start a thread that will send SIGPROF signal to VM threads,
       // when CPU profiling will be enabled.
       instance_ = new SignalSender(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;
       RestoreSignalHandler();
     }
   }
 
   // Implement Thread::Run().
@@ skipping 82 matching lines @@
 #endif  // DEBUG
     USE(result);
 #endif  // ANDROID
   }
 
   const int vm_tgid_;
   const int interval_;
   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_;
 
  private:
   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. We preserve microsecond resolution.
+  uint64_t seed = Ticks() ^ (getpid() << 16);
+  srandom(static_cast<unsigned int>(seed));
+  limit_mutex = CreateMutex();
+
+#ifdef __arm__
+  // When running on ARM hardware check that the EABI used by V8 and
+  // by the C code is the same.
+  bool hard_float = OS::ArmUsingHardFloat();
+  if (hard_float) {
+#if !USE_EABI_HARDFLOAT
+    PrintF("ERROR: Binary compiled with -mfloat-abi=hard but without "
+           "-DUSE_EABI_HARDFLOAT\n");
+    exit(1);
+#endif
+  } else {
+#if USE_EABI_HARDFLOAT
+    PrintF("ERROR: Binary not compiled with -mfloat-abi=hard but with "
+           "-DUSE_EABI_HARDFLOAT\n");
+    exit(1);
+#endif
+  }
+#endif
+  SignalSender::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());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal