Rollback of r11015, r11014, r11011, r11010 in trunk branch.

src/platform-posix.cc

Index: src/platform-posix.cc
diff --git a/src/platform-posix.cc b/src/platform-posix.cc
index a729b662605ad1377395cf7f0fb9668d3863ce48..4b1edfe06a8895ae53d46c1ff5c08bd5419f86d8 100644
--- a/src/platform-posix.cc
+++ b/src/platform-posix.cc
@@ -127,15 +127,17 @@ double modulo(double x, double y) {
 }
 
 
+static Mutex* math_function_mutex = OS::CreateMutex();
+
 #define UNARY_MATH_FUNCTION(name, generator)             \
 static UnaryMathFunction fast_##name##_function = NULL;  \
-V8_DECLARE_ONCE(fast_##name##_init_once);                \
-void init_fast_##name##_function() {                     \
-  fast_##name##_function = generator;                    \
-}                                                        \
 double fast_##name(double x) {                           \
-  CallOnce(&fast_##name##_init_once,                     \
-           &init_fast_##name##_function);                \
+  if (fast_##name##_function == NULL) {                  \
+    ScopedLock lock(math_function_mutex);                \
+    UnaryMathFunction temp = generator;                  \
+    MemoryBarrier();                                     \
+    fast_##name##_function = temp;                       \
+  }                                                      \
   return (*fast_##name##_function)(x);                   \
 }
 
@@ -305,14 +307,14 @@ int OS::VSNPrintF(Vector<char> str,
 
 #if defined(V8_TARGET_ARCH_IA32)
 static OS::MemCopyFunction memcopy_function = NULL;
-static LazyMutex memcopy_function_mutex = LAZY_MUTEX_INITIALIZER;
+static Mutex* memcopy_function_mutex = OS::CreateMutex();
 // 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());
+    ScopedLock lock(memcopy_function_mutex);
     if (memcopy_function == NULL) {
       OS::MemCopyFunction temp = CreateMemCopyFunction();
       MemoryBarrier();